From djk@tobit.co.uk Sun Dec 01 09:42:41 1996 Received: from dirku.tobit.co.uk (dirku.demon.co.uk [158.152.30.189]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id JAA18869 for ; Sun, 1 Dec 1996 09:42:35 -0600 (CST) Received: from localhost (djk@localhost) by dirku.tobit.co.uk (8.7.4/8.7.3) with SMTP id PAA11985 for ; Sun, 1 Dec 1996 15:42:30 GMT Date: Sun, 1 Dec 1996 15:42:30 +0000 (GMT) From: Dirk-Jan Koopman Reply-To: djk@tobit.co.uk To: ss@tapr.org Subject: SS on 2m In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi, I shall be pointing out to our 'authorities' that you now have your STA, hopefully this will mean that we will get ours RSN... In the meantime, perhaps some thought might go into a use for SS on 2m. As you may know there is a prize for the first 2way comms between the US and Europe (or it might just be GB, can't remember exactly). It seems to me (as a non-dxer) that the lazy way to establish paths is to get computers to sit there on a 'channel' and squirt 'packets' at each other. What would be the processing gain available for a 50 or 100 bps signal spread to 2Mhz (we don't have 4Mhz on 2m)? Would I be right in thinking this is > 40db? One could easily avoid the EME section. If it were demonstrated to work, I wonder how long it would be before the EME boys would be demanding SS STAs, after all 40db would make their link budgets look like local vhf comms. Who needs satellites? (well man-made ones anyway?) An idea might be each station sends a packet (a tuple of callsign and locator) at specified times (under GPS control?) and if heard it is immediately returned with the tuple of the receiving station and if that is heard then it is returned again with a flag at the end (eg K) for the three way handshake. Stick a couple of kilowatts on for a bit extra umph into a very long yagi (there is lose talk of 100 ele aerials) and ... Any views? Shall I start building? Whadayasay? -- Dirk-Jan Koopman Tel/Fax: +44 1362 696076 Mobile: +44 973 333806 Computer Consultant Email: djk@tobit.co.uk or G1TLH@GB7TLH.#35.GBR.EU "The typewriting machine, when played with expression, is no more annoying than the piano when played by a sister or near relation." --Oscar Wilde From wa4dsy@wa4dsy.radio.org Sun Dec 01 12:49:34 1996 Received: from wa4mei.radio.org (wa4mei.radio.org [206.28.192.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id MAA26598 for ; Sun, 1 Dec 1996 12:49:32 -0600 (CST) Received: by wa4mei.radio.org (/\==/\ Smail3.1.28.1 #28.8) id ; Sun, 1 Dec 96 13:49 EST Message-Id: From: "Dale Heatherington" To: "ss@tapr.org" Date: Sun, 01 Dec 96 13:49:23 Reply-To: "Dale Heatherington" Priority: Normal X-Mailer: Dale Heatherington's Registered PMMail 1.53 For OS/2 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Subject: Re: [SS:583] SS on 2m On Sun, 1 Dec 1996 09:46:22 -0600 (CST), Dirk-Jan Koopman wrote: >What would be the processing gain available for a 50 or 100 bps signal >spread to 2Mhz (we don't have 4Mhz on 2m)? Would I be right in thinking >this is > 40db? One could easily avoid the EME section. If it were >demonstrated to work, I wonder how long it would be before the EME boys >would be demanding SS STAs, after all 40db would make their link budgets >look like local vhf comms. Who needs satellites? (well man-made ones >anyway?) Thats 40 db over what it would be if the information part of the signal was 2 mhz wide. There is no real power gain in sending 100 baud PSK with 1 watt vs spreading it over 2 mhz with one watt. Path loss is the same. -------------------------------------------------- Dale Heatherington, WA4DSY e-mail - wa4dsy@wa4dsy.radio.org e-mail - daheath@ibm.net (in case the first one doesn't work) Web page - http://www.wa4dsy.radio.org This message brought to you by OS/2 Warp v4 From davek@komacke.com Sun Dec 01 13:59:49 1996 Received: from sydney.komacke.com (sjx-ca25-21.ix.netcom.com [204.30.65.213]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id NAA29362 for ; Sun, 1 Dec 1996 13:59:45 -0600 (CST) Received: from musty.kobie.komacke.com (musty.kobie.komacke.com [192.168.2.2]) by sydney.komacke.com (8.7.4/8.7.3) with SMTP id LAA01230 for ; Sun, 1 Dec 1996 11:59:39 -0800 Message-Id: <3.0.32.19961201115918.0069bc74@sydney> X-Header1: Finger for my PGP key X-Sender: davepost@sydney X-Mailer: Windows Eudora Pro Version 3.0 (32) Date: Sun, 01 Dec 1996 11:59:41 -0800 To: ss@tapr.org From: Dave Koberstein Subject: Re: [SS:584] Re: SS on 2m Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" At 12:51 PM 12/1/96 -0600, you wrote: >On Sun, 1 Dec 1996 09:46:22 -0600 (CST), Dirk-Jan Koopman wrote: > -- (snip) -- >>this is > 40db? One could easily avoid the EME section. If it were >>demonstrated to work, I wonder how long it would be before the EME boys >>would be demanding SS STAs, after all 40db would make their link budgets >>look like local vhf comms. Who needs satellites? (well man-made ones >>anyway?) > >Thats 40 db over what it would be if the information part of the signal >was 2 mhz wide. There is no real power gain in sending 100 baud >PSK with 1 watt vs spreading it over 2 mhz with one watt. Path loss is the same. > -------------------- End of Original ---------------------------------- Processing gain doesn't help with your signal-to-thermal-noise ratio. That's a subtle point that many people miss and is probably worth explaining. Think of the de-spreading of a DSSS signal on receive as doing two things: 1) takes the energy of the spread signal of interest and pulls it back into the original narrow bandwidth 2) takes everything else (that's not correlated with the spreading code) and spreads it out evenly across the original spreading bandwidth Given point #2, if you have a strong narrow band interfering signal in the middle of your band of interest, the despreading will spread that interfering signal across the original band. This gives you "processing gain" with respect to that interfering signal over what you would have had if you didn't use DSSS in the first place. Interestingly, DSSS actually reduces your S/N slightly in the case where that interfering signal would not have been on top of your narrow band signal, had you not used DSSS. Using DSSS, the interferer is "spread" in the receiver by the despreading function and you actually get energy in your IF that you wouldn't have had otherwise. However, if your interfering signal is just thermal noise, atmospheric noise, or even another DSSS signal that is spread completely across your band of interest, the despreading will just "respread" that interfering signal across the same bandwidth. This gives you no advantage compared to sending your signal unspread in the first place. In the EME example, the background noise is there whether it's respread or not. If you have a S/N of 10 dB without DSSS, you'll still have a S/N of 10 dB after going through the spreading/despreading functions of DSSS. Hope that made sense. Davek ____________________________________________________________ Dave Koberstein work: davek@proxim.com / http://www.proxim.com keep in touch: davek@komacke.com / http://www.komacke.com ham internet: n9dk@n9dk.ampr.org [44.4.12.172] (ax.25/PBBS: n9dk@w6yx.#nocal.ca.usa.noam) From lfry@mindspring.com Sun Dec 01 17:31:46 1996 Received: from mule1.mindspring.com (mule1.mindspring.com [204.180.128.167]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id RAA09381 for ; Sun, 1 Dec 1996 17:31:44 -0600 (CST) Received: from glory (user-168-121-136-107.dialup.mindspring.com [168.121.136.107]) by mule1.mindspring.com (8.8.2/8.7.3) with SMTP id XAA51244 for ; Sun, 1 Dec 1996 23:31:41 GMT Message-Id: <2.2.32.19961201233211.00313390@mindspring.com> X-Sender: lfry@mindspring.com X-Mailer: Windows Eudora Pro Version 2.2 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sun, 01 Dec 1996 18:32:11 -0500 To: ss@tapr.org From: "Lee W. Fry" Subject: Re: [SS:582] Re: SS below 70cm? At 10:37 PM 11/30/96 -0600, George wrote [about SINCGARS]: > >How frequently does it hop and how far? Don't know. Found an interesting reference to the front end design at http://www2.nova-eng.com/nova/sincgars.html. A general description of the radio is at http://www.polaris.net/~gdls/sincgar.htm. http://www.monmouth.army.mil/cecom/lrc/comm/tradio/sincloap/mode.html has a reference to a mode switch for a FH net master mode which electronically maintains all net radios within the plus or minus 4 second window required for frequency hopping communications. Anybody have any ideas about how to recognize that a FHSS or DSSS system is sharing spectrum with you? There is a picture from a spectrum analyzer at http://www.lxe.com/radio.htm showing 900MHz showing DSSS and FHSS on the same display. If we were going to look for the presence of uncooperating (uncooperating meaning we don't know for sure they are there or what frequencies they are on) military emitters on 2M, 220, or 440 how would we go about it? I don't suppose that SS is called low probability of detection for nothing. Lee W. Fry AA0JP lfry@mindspring.com See my Part 15 Spread Spectrum Device Compendium at: http://www.mindspring.com/~lfry/part15.htm From dclark@pobox.com Sun Dec 01 17:48:57 1996 Received: from alpha.cc.oberlin.edu (alpha.cc.oberlin.edu [132.162.1.245]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id RAA10579 for ; Sun, 1 Dec 1996 17:48:55 -0600 (CST) Received: from rn1645.resnet.oberlin.edu by OBERLIN.EDU (PMDF V5.0-7 #16946) id <01ICI86Q40SW00L1FE@OBERLIN.EDU> for ss@tapr.org; Sun, 01 Dec 1996 18:48:51 -0400 (EDT) Date: Sun, 01 Dec 1996 18:50:03 -0500 (EST) From: Daniel JB Clark Subject: $200 SS X-Sender: dclark@rn1645.resnet.oberlin.edu To: ss@tapr.org Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII Content-transfer-encoding: 7BIT I just read this via usenet: You should be aware there was just a group buy off one of the TAPR SIG groups (SS@tapr.org). A 2megabit SS transciever for $200. I reilize this deal is probably long over, but I'd be interested in the manufacturer and model number of this equipment. Thanks and 73. -- ============================================================================ Daniel JB Clark | dclark@pobox.com | sdc8711@oberlin.edu ============================================================================ "cow" on Free Internet | lifetime email aliases | Internet Service Provider: Chess Server: telnet | http://pobox.com/pobox/| Oberlin College ResNet fics.onenet.net 5000 | finger @pobox.com | http://www.oberlin.edu ============================================================================ From buaas@wireless.net Sun Dec 01 23:23:12 1996 Received: from wireless.net (wireless.net [198.253.254.1]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id XAA25934 for ; Sun, 1 Dec 1996 23:23:09 -0600 (CST) Received: (from buaas@localhost) by wireless.net (8.8.2/8.6.12) id VAA19889 for ss@tapr.org; Sun, 1 Dec 1996 21:23:34 -0800 (PST) Date: Sun, 1 Dec 1996 21:23:34 -0800 (PST) From: "Robert A. Buaas" Message-Id: <199612020523.VAA19889@wireless.net> To: ss@tapr.org Subject: Re: $200 SS Daniel-- The $200 SS was a group buy I organized of AT&T (now Lucent) (in the Netherlands) WaveLAN 915 MHz ISA cards. Limited stock, one-time buy. Drivers available for various OS's (DOS, Windoz, UNIX). See http://wavelan.com for more info, or email me directly. best regards/bob K6KGS From djk@tobit.co.uk Mon Dec 02 06:10:04 1996 Received: from dirku.tobit.co.uk (dirku.demon.co.uk [158.152.30.189]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id GAA15658 for ; Mon, 2 Dec 1996 06:10:01 -0600 (CST) Received: from localhost (djk@localhost) by dirku.tobit.co.uk (8.7.4/8.7.3) with SMTP id MAA03013 for ; Mon, 2 Dec 1996 12:09:34 GMT Date: Mon, 2 Dec 1996 12:09:33 +0000 (GMT) From: Dirk-Jan Koopman Reply-To: djk@tobit.co.uk To: ss@tapr.org Subject: some questions Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi, Further to my recent post (thanks for the info - back to coherent CW -sigh), I have some more questions:- 1. What is the performance of a DSSS system such as is now commercially available in the presence of doppler shift @ 2.4 GHZ (only thing available here in GB). What I am wondering about is things carrying such devices at closing and leaving speeds at maybe upto 400mph. Please assume the aerial is at the worst possible place i.e. next to the line of travel. 2. Using 10-50mW (only) is it really possible to have a number of units transmitting at once with different spreading codes centred on the same freq in close proximity (say small nos of feet apart) (@ speeds of no more than a few fps :-). 3. What is the average delay thru a typical system? Dirk -- Dirk-Jan Koopman Tel/Fax: +44 1362 696076 Mobile: +44 973 333806 Computer Consultant Email: djk@tobit.co.uk or G1TLH@GB7TLH.#35.GBR.EU "The typewriting machine, when played with expression, is no more annoying than the piano when played by a sister or near relation." --Oscar Wilde From Robert.Glassey@nmp.nokia.com Mon Dec 02 06:26:56 1996 Received: from noknic.nokia.com (noknic.nokia.com [131.228.6.10]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id GAA16170 for ; Mon, 2 Dec 1996 06:26:53 -0600 (CST) From: Robert.Glassey@nmp.nokia.com Received: from samail01.nmp.nokia.com (samail01.nmp.nokia.com [131.228.240.6]) by noknic.nokia.com (8.6.9/8.6.9) with ESMTP id OAA11325 for ; Mon, 2 Dec 1996 14:26:20 +0200 Received: from by samail01.nmp.nokia.com with SMTP (1.37.109.20/16.2) id AA225639486; Mon, 2 Dec 1996 14:24:46 +0200 X-Openmail-Hops: 2 Date: Mon, 2 Dec 96 12:22:44 +0000 Message-Id: In-Reply-To: <"v03007817aec60aa9dd7e(a)(091)129.120.111.42(093)*"@MHS> Subject: [SS:578] Re: SS below 70cm? Sender: Robert.Glassey@nmp.nokia.com To: ss@tapr.org > A lot of the designs that people have shown me for doing SS work under > Part 97 use existing RF modules on 900, 2.4, and 5 gigs. It still > comes down to fact that amateurs can do digital a lot easier than RF. > When RF modules are available for the 3 part 15 bands, certainly > amateurs are going to try to use them. One reason the 2-meter > repeater explosion happened -- the availability of inexpensive > landmobile radios for repeaters. We are going to need to start using > some of the new RF technology that is being made available now to > design amateur radios that can be used with wideband digital > modulations for 6,2,and 220 if we really want to make sure we are > operating on our amateur bands. Lets get out of the 2m mentality, that's old and already spoken for technology, the 2.4 and 5 GHz folks are on the right track. It does baffle me a bit that people would actually want to promote SS on bands below 70cm, or even 70cm itself. There are many technical problems relating to interference resistance and band sharing. These bands are already heavilly used (depending upon your definition of use, educational, simplicity, installed equipment, etc, not just user bits per Hz), there is no readilly avaliable equipment, there is very little bandwidth, and there is the obvious political agro from those who already use the band, and exploit the low noise floor for DX and EME, or the simplicity of FM for cheap, power efficent hand helds, or what ever. RF at 23cm and up to 4GHz is pretty easy if you have a reasonable PCB and SMD components. IC's and modules are widely avaliable and cheap for these frequencies. High gains and directionality are possible from small yagi's and cheap dishes. One of the most compelling reasons for going for microwave bands is the old argument "use them or loose them". They are already under threat from local loop service providers and will soon be under threat from ISP WAN's. Once these bands were technological wastelands, allocated to amateurs because nobody else wanted them, to see if amateurs could find a use for them. Well, we haven't, but commercial interests have. The only way we can justify retaining the 100's of MHZ we have available up there is to use make use of the same technology the comercial folks are using. The only use capable of justifying the allocation of these bands is high speed data networks, ie SS WANs with at least 128kbps access and point to point links in the 2-10 Mbps range. This is the only way to competitively fill the bandwidth. There can be no doubt that the demand for such an amateur service exists and will grow dramatically in the next few years. This is the future of amateur radio, and it will never fit on 70cm or below, so why step on someone else's toes? It would be a sad day for amateur radio if we were to loose these bands and this oppertunity because of infighting over bands that cannot support our future anyway, just because supposed 'radio' enthusiests are afraid of the Giga word! The SS comunity claims to be (and should be) pushing the frontiers of technology, so why on earth restrict yourself to ancient VHF RF technology and then take the heat for not being compatible with the old technology you are using! Microwave is EASIER! The technology exists, modules exist, high gain antennas are cheap and small, and you don't need to worry about the interference caused by uncontrolled high power narrow band transmissions or worry about the interference you may cause them. SS relies on a well controlled short link network structure to be efficent, and needs a wide bandwidth if competitive data rates are to be achieved with frequency reuse and interference rejection. One high power narrow band user in your simple DSSS pass band can cause you to loose the capacity of many SS stations, and many narrow band stations makes hopping, chanalizing, notching etc a technical dificulity that could be almost completely ovoided by using microwave frequencies, while still leaving heaps of spectrum clear for narrow band users. Hi gain antennas allow much lower power (simpler PA's), and much greater rejection of interference from other SS stations and non-amateur interferers, as well as multipath all of which reduces capacity and throughput speed. One single SS link at a distance may well be below the noise floor, but any half decent SS WAN with a hundred users (maybe thousands if the SS network can really prove itself to be competitive with the ISP's), that makes full use of the available spectrum MUST be above the noise floor, if it's not then capacity is being wasted, and we could loose the spectrum, or at least have to share it with the ISP's, and that will really restrict amateur advancements. Exclusive amateur SS allocations in the microwave bands is the only way amateur SS can really achieve its massive potential. If technically inclined internet users could access the net via radio from home, and have a chance to play with (and learn about) the equipemnt and get cheap, independent access, then amateur radio would become the IN thing again, and TAPR can promote this! Few serious comminucations oriented technical people are interested in the pathetic early 80's technology we have today. 900Mhz is a good start, but you should be looking to go up, and expand, rather than go lower and face restrictions and concern from all quarters. Make a good systemn that people will want to use that does nobody out of their other interests and SS will be a winner, make enemies and SS will loose through lack of support and loss of essential bandwidth, and so will amateur radio. Rob From Robert.Glassey@nmp.nokia.com Mon Dec 02 07:38:06 1996 Received: from noknic.nokia.com (noknic.nokia.com [131.228.6.10]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id HAA18473 for ; Mon, 2 Dec 1996 07:38:04 -0600 (CST) From: Robert.Glassey@nmp.nokia.com Received: from samail01.nmp.nokia.com (samail01.nmp.nokia.com [131.228.240.6]) by noknic.nokia.com (8.6.9/8.6.9) with ESMTP id PAA27927 for ; Mon, 2 Dec 1996 15:36:48 +0200 Received: from by samail01.nmp.nokia.com with SMTP (1.37.109.20/16.2) id AA294953708; Mon, 2 Dec 1996 15:35:08 +0200 X-Openmail-Hops: 2 Date: Mon, 2 Dec 96 13:08:10 +0000 Message-Id: In-Reply-To: Subject: [SS:583] SS on 2m Sender: Robert.Glassey@nmp.nokia.com To: ss@tapr.org > What would be the processing gain available for a 50 or 100 bps signal > spread to 2Mhz (we don't have 4Mhz on 2m)? Would I be right in > thinking this is > 40db? One could easily avoid the EME section. If it > were demonstrated to work, I wonder how long it would be before the > EME boys would be demanding SS STAs, after all 40db would make their > link budgets look like local vhf comms. Who needs satellites? (well > man-made ones anyway?) Err, the 40dB processing 'gain' is more of an interference rejection of 40dB. The gain does take a signal in the noise floor and make it 40dB above the noise, but it is a complimentary process that assumes that you have already spread your signal out, and thereby loosing 40dB. Overall gain=0. Using SS will not gain you 40dB of overall system performance, but will allow 40dB rejection of the sum total of all other stations in the spreading bandwidth, including multipath. (note that a 1 Watt 2m handheld say 1km away, would be 30dB stronger than a 100mW SS transmitter 10kM away, and anyone serious about networking would want at least 100 times more than 100bps (loosing 20dB) SS networks on 2m would be very challanging and ultimatly very complex for the poor performance they would offer, then there's the politics...) SS gives you frequency diversity as well, but I'm not sure if that would help on a VHF path over the atlantic. SS will allow you use much slower data rates than you would be able to do with a single carrier, since channel variations are less critical. This is where you would gain, if you could send say one bit every 10 seconds you would have a true gain of 30dB over a 100bps system. The problems then becomes long term variations, the troppo or whatever might only be present for a few seconds at a time, so your full packet would need to be over in that time, limiting the gain to be had here. Then there's sync problems of a SS sequence if a packet is only a few seconds long with a high processing 'gain'. Interference wise, if you keep away from built up areas, have a good F/B ratio, and pointed your antenna out to sea, nobody would probably notice. Rob From dewayne@warpspeed.com Mon Dec 02 09:17:27 1996 Received: from warpspeed.com (WA8DZP@odo.warpspeed.com [204.118.182.20]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id JAA23126 for ; Mon, 2 Dec 1996 09:17:24 -0600 (CST) Received: from [204.118.182.22] by warpspeed.com with ESMTP (Apple Internet Mail Server 2.0a8); Mon, 2 Dec 1996 07:17:19 -0800 Message-Id: In-Reply-To: <2.2.32.19961126215508.008ce3b4@wdl1.wdl.lmco.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 2 Dec 1996 07:17:15 -0800 To: ss@tapr.org From: Dewayne Hendricks Subject: Re: [SS:555] Where are the experimenters? At 3:58 PM -0600 11/26/96, Lee W. Fry wrote: >In the two weeks since the TAPR STA was granted, there has barely been a >peep out of this list. The current participating station list has about 25 >names on it and only a hand full have even posted here before: Greg, >Dewayne, Steve B. and Steve S. and Jeff. Where are the others and what are >they doing? > One reason that you're not hearing anything is that most STA activity has moved over to the new SS-STA list. There has been lots of discussion there as compared to this list of late. >Questions: > >I suspect the FW and WL code on the list indicates FreeWave and WaveLan >based projects. True? > True! >Is there a commercial 5 watt amp that the FW crowd is looking at? > I have been using a 5 watt unit from FreeWave. It costs about $650. You can find out more about it at their website: . I have gotten good results with it, but find that for most links that I have had to put up, 1 watt does just fine. At the $650 price point, I doubt that most hams would consider the FW unit. >Can anybody with 1 watt systems report sucesses with > 6dbi (non-stock) >antennas? What antennas? > I have been having good success with a number of different antennas. You can find more info on what I've been doing with Part 15 stuff at: . -- Dewayne -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dewayne Hendricks, WA8DZP ! AOL: HENDRICKS Warp Speed Imagineering ! Internet: dewayne@warpspeed.com 43730 Vista Del Mar ! Packet Radio: WA8DZP @ K3MC.#NOCAL.CA.USA.NOAM Fremont, CA 94539-3204 ! WWW: Fax: (510) 770-9854 ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From njf@lissos.tsinet.gr Mon Dec 02 09:24:12 1996 Received: from lissos (lissos.tsinet.gr [143.233.180.3]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id JAA23695 for ; Mon, 2 Dec 1996 09:24:02 -0600 (CST) Received: from lissos by lissos (SMI-8.6/SMI-SVR4) id RAA11730; Mon, 2 Dec 1996 17:25:10 -0200 Sender: njf@tsinet.gr Message-ID: <32A32D14.50FF@lissos.tsinet.gr> Date: Mon, 02 Dec 1996 17:25:08 -0200 From: "NIKOS J. FARSARIS" Organization: TELECOMMUNICATION SYSTEMS INSTITUTE X-Mailer: Mozilla 3.0 (X11; I; SunOS 5.4 sun4m) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: [SS:589] some questions References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Dirk-Jan Koopman wrote: > 2. Using 10-50mW (only) is it really possible to have a number of units > transmitting at once with different spreading codes centred on the same > freq in close proximity (say small nos of feet apart) (@ speeds of no more > than a few fps :-). Dear Dirk-Jan, Would you explain me this question again ?? (Ithink I have the answer as regards the ""different spreading codes centred on the same freq in close proximity "") but may be a Spatial Diversity (multistatic) is a sollution! -- NIKOS J. FARSARIS, Dipl. Elec. Eng., Ph.D. Candidate A.U.TH. RADAR / RF Research,TELECOMMUNICATION SYSTEMS INSTITUTE OF CRETE (T.S.I.) 37 Iroon Polytechneiou Ave,73133 CHANIA CRETE GREECE Tel: 30-821-28457/28423 Fax: 28459 E-mail: njf@tsinet.gr, njf@ee.auth.gr From Kreblon@ccwf.cc.utexas.edu Mon Dec 02 11:12:43 1996 Received: from piglet.cc.utexas.edu (root@piglet.cc.utexas.edu [128.83.42.61]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id LAA29114 for ; Mon, 2 Dec 1996 11:12:42 -0600 (CST) Received: from cc.utexas.edu.utexas.edu (kreblon.botany.utexas.edu [128.83.173.24]) by piglet.cc.utexas.edu (8.7.6/8.7.3/piglet.mc-1.4) with SMTP id LAA27389 for ; Mon, 2 Dec 1996 11:12:38 -0600 (CST) Date: Mon, 2 Dec 1996 11:12:38 -0600 (CST) Message-Id: <199612021712.LAA27389@piglet.cc.utexas.edu> X-Sender: kreblon@ccwf.cc.utexas.edu X-Mailer: Windows Eudora Version 1.4.4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: Kreblon@ccwf.cc.utexas.edu (Bob Nagy) Subject: Unsubscribe Could you un-subscribe me from this list? Thanks Bob Nagy *************************************************************** Bob Nagy-AA5PB- Chief Engineer KVRX 91.7 / KVR TV9 Nagy's "Down Home" Page- http://bluebonnet.pai.utexas.edu/Facstaff/stfpages/bnagy/ Daily word: " Osszi levelek" -Autumn Leaves- in Hungarian *************************************************************** From glenne@hpsadr2.sr.hp.com Mon Dec 02 11:39:38 1996 Received: from palrel1.hp.com (palrel1.hp.com [15.253.72.10]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id LAA00460 for ; Mon, 2 Dec 1996 11:39:35 -0600 (CST) Received: from srmail.sr.hp.com (srmail.sr.hp.com [15.4.45.14]) by palrel1.hp.com with ESMTP (8.7.5/8.7.3) id JAA20588 for ; Mon, 2 Dec 1996 09:39:31 -0800 (PST) Received: from hpsadr2.sr.hp.com (n6gn.sr.hp.com) by srmail.sr.hp.com with ESMTP (1.37.109.16/15.5+ECS 3.3) id AA079928370; Mon, 2 Dec 1996 09:39:30 -0800 Received: by hpsadr2.sr.hp.com (1.37.109.16/15.5+ECS 3.3) id AA115068369; Mon, 2 Dec 1996 09:39:29 -0800 From: Glenn Elmore Message-Id: <199612021739.AA115068369@hpsadr2.sr.hp.com> Subject: Re: [SS:579] Re: SS below 70cm? To: ss@tapr.org Date: Mon, 2 Dec 1996 09:39:28 -0800 (PST) In-Reply-To: <11441@wb9mjn.ampr.org> from "ss@tapr.org" at Nov 30, 96 10:32:55 am X-Mailer: ELM [version 2.4 PL21] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Don wrote: > On 6 meter EME, I ve only heard of one person who had accomplished this, > and he was using the resources of a government funded research group. He had > a large field of fixed yagis, and when the moon came across the boresite of > the array, he did EME for grins. > Consequently, 6 meter EME intereferance is really a non-issue. Let alone the > channel 2 problem. > Actually, a number of amateurs were successful. Among the first, if not the first, was Lou Ancieaux, wb6nmt, later of Lunar Electronics fame. He used a rhombic located at the Naval Receiver Facility near Sonoma, California but it was "homebrew" and I don't believe there was any real funding by the government except for space to put it and maybe a little help getting poles placed to support it. I remember hearing not only echos but terrestrial backscatter from w0eye (I think) in Colorado as he and wb6nmt tried with one or two other stations to make EME QSO. This must have been ~1970. w7fn was also active and I'm pretty sure there were several others. 50 MHz amateur EME has been achieved by several amateurs. I'd say it's not been a major use of the band though. > 2 meter and 70 cm interferance could be a problem. These are the two most > used EME bands. 70 cm is a very good band for eme. > > 900 Mhz is a non-issue too. The ham SS would just be a small addition to > the existing commercial licensed, and unlicensed activity. Of which the li- > censed activity has priority over ham radio in this band. > > 2.4 Ghz is an issue. This is the best space communications band available > to Hams. But, due to terrain absorbtion, and antenna directivity, it should > be workable. The moon is rarely on the horizon. And an upward pointed EME > array will really do a wamy on any 1 watt DSSS signals. FHSS can be programmed > to avoid the EME spectrum altogether. From my experience, 70 cm and 23 cm are excellent bands for EME, particularly the latter. 2.4 has been relatively unused for the mode, largely I think due to the difficulty and expense of generating a lot of narrowband transmit power. w6yfk was on for many years with a "near commercial" installation and wa6exv was working at a locked microwave_oven/rain_gutter_for_waveguide arrangement and there have been a few stalwarts operating in the EME contests but by and large the band has gone unused in comparison with other amateur bands for EME. > I guess the best advice for EME's is to do it "right". That is, design an- > tennas primarily for off boresite rejection of signals. SS is not the only > terrestrial noise source, anyway. Blowing up about SS, is stupid, when there > is so much other noise out there. Especially from power poles, cars and con- > sumer computing/entertainment devices, and compact florescent lighting, and > power factor controllers, and and and... and as you say, for all of the higher bands where the system temperature stands a chance of being lower than 290 K, just pointing a significant part of the beam at terra firma is a bad idea both due to signal loss and thermal noise increase. It is pretty standard practice to measure noise temperature (noise figure) of an EME station by comparing the noise floors when pointed at cold sky (a known radio-quiet region of the heavens) and local dirt. From the measured delta it is easy to compute Tsys and it gives one a pretty good overall station performance number something which is very desirable when you can't hear echos and don't know why. "Doing it right" is a win for both SS and EME, probably more so for EME due to the extremely low link margins that even the best amateur moonbounce stations run. It seems to me that in general, there is a lot more discussion of potential interference issues that people can *imagine* might be problems WRT amateur SS and narrowband uses than there is experience with the reality of the situation. I haven't yet put any of my DSSS stuff for L3TNC on the air at more than the bench level; no testing over real paths that is, but our existing FSK 904 MHz digital radios *have* been coexisting with a variety of radios and services in 902-928 for ~5 years now. At 230 kbps their occupied bandwidth is a little more than half a megahertz. They are wide enough and some of our link margins low enough that we are potential "targets" for problems from Part 15 and military uses of the same spectrum. In addition, these radios don't operate well at very low C/N ratios. In spite of locating this hardware in and near the edge of a city of 1/8 million during these last years and in spite of the presence of a large variety of signals from SS sources; consumer, commercial etc, we have had very few problems with sharing the spectrum with SS or any other users in this busy band. I say this in part to refute other statements to the contrary attributed to me on other distribution lists. This success we have seen is due to antenna directivity along with the restricted power of Part 15 users but most of all due to the tremendous incremental path losses associated with the non-LOS paths that exist to almost all potential interferers. The incremental losses accrued for almost all paths between low-level sites far exceed the processing gains and even the antenna directivity losses that might also be available to reduce the interference problem. For the most part we could all be running non-spread on the same channel( a variety of widths actually) and things would work as well. There have been two exceptions to this; Part 15 devices which are *very* close, colocated or within a few tens or a hundred feet of our radios and Navy ship-to-air radar with its 270 megawatt ERP. To the best of my knowledge, our transmissions have not interfered with *any* other users. So, while I understand the concern at the thought of potential loss of use by EME operators (I used to be one and have a stack of QSLs to prove it for both 432 MHz and 1296 MHz) I think the severity of the "problem" is generally overestimated. If all users were located on hilltops and LOS to each other, the situation could be somewhat different. (As we put OCARs on the band we have to be careful about "fixing" the paths among users too well). As has already been stated, no amount of processing gain will ever be enough to allow mindless addition of SS users to a band. Some scenario can always be envisioned in which there would be problems. However, the realities of signal propagation at UHF and microwave over paths between typical amateur sites are such that, I believe, any problems can be solved by amateurs willing to cooperate. Whether we still have such willingness to get along is another question entirely. Glenn Elmore n6gn amateur IP: glenn@SantaRosa.ampr.org Internet: glenne@sr.hp.com |--------------- N6GN's Higher Speed Packet WWW Page -------------------| | | | http://www.tapr.org/~n6gn/index.html | | | |-----------------------------------------------------------------------| From Robert.Glassey@nmp.nokia.com Mon Dec 02 14:17:35 1996 Received: from noknic.nokia.com (noknic.nokia.com [131.228.6.10]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA07185 for ; Mon, 2 Dec 1996 14:17:33 -0600 (CST) From: Robert.Glassey@nmp.nokia.com Received: from samail01.nmp.nokia.com (samail01.nmp.nokia.com [131.228.240.6]) by noknic.nokia.com (8.6.9/8.6.9) with ESMTP id WAA25146 for ; Mon, 2 Dec 1996 22:15:50 +0200 Received: from by samail01.nmp.nokia.com with SMTP (1.37.109.20/16.2) id AA246147649; Mon, 2 Dec 1996 22:14:09 +0200 X-Openmail-Hops: 2 Date: Mon, 2 Dec 96 20:12:24 +0000 Message-Id: In-Reply-To: <199612021739.AA115068369@hpsadr2.sr.hp.com> Subject: [SS:595] Re: SS below 70cm? Sender: Robert.Glassey@nmp.nokia.com To: ss@tapr.org Glenn wrote: > It seems to me that in general, there is a lot more discussion of > potential interference issues that people can *imagine* might be > problems WRT amateur SS and narrowband uses than there is experience > with the reality of the situation. I agree. A lot of the potential problems can be ovoided by good design, using appropriate frequencies, powers, antennas etc, ovoiding for example the narrow 1296 segment of 23cm, and of course by mutual cooperation in the few cases of interference that may still happen. Most of the defensive reaction to SS seem to be based on the *appearence* of some SS activists to have total disregard for other users, blindly claiming that there can't possibly be a problem, and take no precautions against interference in their system designs. To gain support for SS it must be made clear that the SS comunity takes interference seriously, makes every effort to reduce it to a level where other users will not be effected, and will listen to concerns about possible interference. Too much pro-SS rhetoric is based on extrapolation of examples of well designed systems operating under quite different circumstances, claiming that if the other systems don't have problems neither will we, without even considering the problems while the systems they quote are usually carefully designed to ovoid such problems. > This success we have seen is due to antenna directivity along with the > restricted power of Part 15 users but most of all due to the > tremendous incremental path losses associated with the non-LOS paths > that exist to almost all potential interferers. The incremental > losses accrued for almost all paths between low-level sites far exceed > the processing gains and even the antenna directivity losses that > might also be available to reduce the interference problem. For the > most part we could all be running non-spread on the same channel( a > variety of widths actually) and things would work as well. Sounds like one of many strong argument for microwave SS rather than VHF SS. > So, while I understand the concern at the thought of potential loss > of use by EME operators (I used to be one and have a stack of QSLs to > prove it for both 432 MHz and 1296 MHz) I think the severity of the > "problem" is generally overestimated. If all users were located on > hilltops and LOS to each other, the situation could be somewhat > different. (As we put OCARs on the band we have to be careful about > "fixing" the paths among users too well). > As has already been stated, no amount of processing gain will ever be > enough to allow mindless addition of SS users to a band. Some > scenario can always be envisioned in which there would be problems. > However, the realities of signal propagation at UHF and microwave over > paths between typical amateur sites are such that, I believe, any > problems can be solved by amateurs willing to cooperate. Whether we > still have such willingness to get along is another question entirely. I agree here too. I think microwave SS is a real winner, and is the future of amateur radio. We don't want to tarnish the SS comunity by mindlessly applying SS where it does not belong, or even where it doesn't work best. Our efforts should be focused on the future, creating a viable amateur SS WAN and high speed links, away from established technologies, in a new frontier where the is room to grow! Lets show the rest of the amateur community that we are prepeared to cooperate, and respect their use of the bands. Rob From buaas@wireless.net Mon Dec 02 16:47:00 1996 Received: from wireless.net (wireless.net [198.253.254.1]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id QAA14934 for ; Mon, 2 Dec 1996 16:46:56 -0600 (CST) Received: (from buaas@localhost) by wireless.net (8.8.2/8.6.12) id OAA21279 for ss@tapr.org; Mon, 2 Dec 1996 14:47:37 -0800 (PST) Date: Mon, 2 Dec 1996 14:47:37 -0800 (PST) From: "Robert A. Buaas" Message-Id: <199612022247.OAA21279@wireless.net> To: ss@tapr.org Subject: Re: [SS:590] SS below 70cm? In [SS:590] Re: SS below 70cm?" Robert.Glassey@nmp.nokia.com writes: >It does baffle me a bit that people would actually want to promote SS on >bands below 70cm, or even 70cm itself. There are many technical problems >relating to interference resistance and band sharing. These bands are >already heavilly used (depending upon your definition of use, >educational, simplicity, installed equipment, etc, not just user bits >per Hz), there is no readilly avaliable equipment, there is very little >bandwidth, and there is the obvious political agro from those who >already use the band, and exploit the low noise floor for DX and EME, or >the simplicity of FM for cheap, power efficent hand helds, or what ever. Rob-- When was the last time you looked at your spectrum analyzer of 6m, 2m, 220, 450? What were the counts of simultaneous signals per MHz, minimum, average, maximum, on a per-second basis? What numbers do you get if you look at the frequencies used for "Trunked" services, one of the simplist versions of slow Frequency Hopping SS? The utilization density for SS is significantly higher. You don't have any interference until you get denial-of-service, when you run out of channels. It's worth noting that it takes complexity to get higher utilization at equivalent levels of performance. SS systems are inherently complex, and that is one of the reasons why SS has not been much pursued in Amateur contexts. The idea of "find an unused frequency(s) and use it (them)" is exactly what FHSS accomplishes, as I demonstrated some time ago in one of my STA experiments, much to the shock/chagrin of the local frequency-coordinators. HOWEVER, doing this required significantly greater system complexity than is the current state-of-the-art used by the current band occupants. Therein lies the rub. Other services are now eyeing our allocations, seeing their sparce use, and are perfectly willing to apply whatever capital investment is required to use them efficiently/completely. We amateurs are not without the same resources and ingenuity; what we lack, currently, is motivation. We somehow think that the current "the bands are heavily used" argument will continue to hold up. Soon, it won't. What then? SS has the potential to give us the vehicle to save our bands from commercial piracy, and that, to me, is a very compelling reason for encouraging its use at VHF. Perhaps more immediately, it gives us the means to break the logjam of "no more frequencies available" and do it automatically as part of the frequency hopping pattern development. Add to that it's potential for advances in weak-signal work, it doesn't take much to convince the objective observer. SS is an idea, not a particular realization. Like Ham Radio generally, different uses result in varied realizations. So long as good engineering practice and design criteria contemplate the minimization of interference, satisfactory results can be had by all. Isn't that the spirit of cooperation we're talking about? best regards/bob K6KGS From fred@tekdata.com Mon Dec 02 17:49:58 1996 Received: from tekdata.com (vh2-029.wwa.com [205.243.70.94]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id RAA18129 for ; Mon, 2 Dec 1996 17:49:33 -0600 (CST) Received: (from fred@localhost) by tekdata.com (8.6.12/8.6.12) id RAA22790; Mon, 2 Dec 1996 17:46:34 -0600 Date: Mon, 2 Dec 1996 17:46:34 -0600 (CST) From: "Fred M. Spinner" To: ss@tapr.org cc: ss@tapr.org Subject: Re: [SS:597] Re: SS below 70cm? In-Reply-To: <199612022247.OAA21279@wireless.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Mon, 2 Dec 1996, Robert A. Buaas wrote: > In [SS:590] Re: SS below 70cm?" Robert.Glassey@nmp.nokia.com writes: > > >It does baffle me a bit that people would actually want to promote SS on > >bands below 70cm, or even 70cm itself. There are many technical problems > > When was the last time you looked at your spectrum analyzer of 6m, 2m, > 220, 450? What were the counts of simultaneous signals per MHz, > minimum, average, maximum, on a per-second basis? What numbers do you > get if you look at the frequencies used for "Trunked" services, one of > the simplist versions of slow Frequency Hopping SS? The utilization > density for SS is significantly higher. You don't have any interference Lets also get down to the truth. I live in the Chicago area and recently bought a "Ten-Tec" 2m to 6m transverter kit. I wanted to align the receiver with an on-air signal before finishing the kit. Do you know why I couldn't? There were no on-air signals on 6m! For like a week! I finished the unit, and keyed up the one active repeater on 6m and used the "Kerchunks" to align the receiver. Then I tried to make a contact through the repeater when I was done with the unit, and couldn't get anyone back to me. Yes, Chicago has a channel 2, but trust me 70cm and above isn't much better. Even on 2m in Chicago, except for "prime-time" there is only maybe 2-3 QSOs going on at once over the whole band. We have to face the fact that SS is going to infringe on a group of hams that believe that have rights to spectrum that they, frankly, don't use. People tend to fear what they don't understand! Ham radio is almost cooked anyway. You are right that SS and digital modes are going to be the last hope of the hobby. Fred M. Spinner, KA9VAW fred@tekdata.com, ka9vaw@amsat.org From bm@lynx.ve3jf.ampr.org Mon Dec 02 19:56:36 1996 Received: from lynx.ve3jf.ampr.org (lynx.ve3jf.ampr.org [44.135.96.100]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id TAA24489 for ; Mon, 2 Dec 1996 19:56:30 -0600 (CST) Received: (from bm@localhost) by lynx.ve3jf.ampr.org (8.6.12/8.6.12) id BAA00631 for ss@tapr.org; Tue, 3 Dec 1996 01:55:56 GMT From: Barry McLarnon VE3JF Message-Id: <199612030155.BAA00631@lynx.ve3jf.ampr.org> Subject: Re: [SS:585] Re: SS on 2m To: ss@tapr.org Date: Tue, 3 Dec 1996 01:55:56 +0000 (GMT) In-Reply-To: <3.0.32.19961201115918.0069bc74@sydney> from "Dave Koberstein" at Dec 1, 96 02:03:19 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Dave Koberstein said: > Interestingly, DSSS actually reduces your S/N slightly in the case where > that interfering signal would not have been on top of your narrow band > signal, had you not used DSSS. Using DSSS, the interferer is "spread" in > the receiver by the despreading function and you actually get energy in > your IF that you wouldn't have had otherwise. Good point. If you have any strong local 2m activity (and who doesn't?), then your noise floor will be significantly worse with DSSS than with narrowband signalling. > However, if your interfering signal is just thermal noise, atmospheric > noise, or even another DSSS signal that is spread completely across your > band of interest, the despreading will just "respread" that interfering > signal across the same bandwidth. This gives you no advantage compared to > sending your signal unspread in the first place. The potential advantage of SS in EME is mitigation of libration fading. If you don't have much local 2m activity, it would probably be worthwhile to try it. Barry -- Barry McLarnon VE3JF/VA3TCP | Internet: bm@hydra.carleton.ca Ottawa Amateur Radio Club | AMPRnet: bm@lynx.ve3jf.ampr.org Packet Working Group | Web: http://hydra.carleton.ca From srbible@gnatnet.net Mon Dec 02 20:11:06 1996 Received: from rupe.gnatnet.net (root@rupe.gnatnet.net [206.30.198.8]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id UAA25124 for ; Mon, 2 Dec 1996 20:11:04 -0600 (CST) Received: from avatar.gnatnet.net (dialup119.gnatnet.net [206.30.198.219]) by rupe.gnatnet.net (8.6.13/8.6.12) with SMTP id WAA30373 for ; Mon, 2 Dec 1996 22:11:46 -0500 Message-Id: <1.5.4.32.19961203021104.006cab14@gnatnet.net> X-Sender: srbible@gnatnet.net X-Mailer: Windows Eudora Light Version 1.5.4 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 02 Dec 1996 21:11:04 -0500 To: ss@tapr.org From: "Steven R. Bible" Subject: Re: [SS:590] Re: SS below 70cm? At 06:33 AM 12/2/96 -0600, you wrote: [snip] >It does baffle me a bit that people would actually want to promote SS on >bands below 70cm, or even 70cm itself. There are many technical problems [snip] Hmmmm... I have always been interested in the HF propagation experiments the Navy did in the Artic. I would really like to be able to do SS in the HF bands to measure propagation delays between stations and different parts of the world. We could have SS beacon stations transmitting and we would know more about the atmospheric effects than by just simply saying "I hear it." [snip] >The SS comunity claims to be (and should be) pushing the frontiers of >technology, so why on earth restrict yourself to ancient VHF RF >technology and then take the heat for not being compatible with the old >technology you are using! [snip] Since when did pushing technology become a function of frequency? - Steve, N7HPR (n7hpr@tapr.org) From Robert.Glassey@nmp.nokia.com Tue Dec 03 05:59:02 1996 Received: from noknic.nokia.com (noknic.nokia.com [131.228.6.10]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id FAA24883 for ; Tue, 3 Dec 1996 05:59:00 -0600 (CST) From: Robert.Glassey@nmp.nokia.com Received: from samail01.nmp.nokia.com (samail01.nmp.nokia.com [131.228.240.6]) by noknic.nokia.com (8.6.9/8.6.9) with ESMTP id NAA01252 for ; Tue, 3 Dec 1996 13:56:27 +0200 Received: from by samail01.nmp.nokia.com with SMTP (1.37.109.20/16.2) id AA100454084; Tue, 3 Dec 1996 13:54:45 +0200 X-Openmail-Hops: 2 Date: Tue, 3 Dec 96 11:50:59 +0000 Message-Id: In-Reply-To: <199612030155.BAA00631@lynx.ve3jf.ampr.org> Subject: [SS:599] Re: SS on 2m Sender: Robert.Glassey@nmp.nokia.com To: ss@tapr.org Barry McLarnon VE3JF/VA3TCP wrote: > Good point. If you have any strong local 2m activity (and who > doesn't?), then your noise floor will be significantly worse with DSSS > than with narrowband signalling. Exactly! This has the collary that you must therefore transmit higher SS power, which will have a much greater interference potential to the other users of the band. Directional antennas will help, but are much better at higher frequencies, where other activity is less and use much lower power with higher path losses, and usually in a small section of the band leaving 10's of MHz free for SS use, and expand into. Notching/hopping schemes will also help but this gets pretty complicated unless you restrict you bandwidth to ovoid repeater/simplex FM frequencies, plus EME/DX/SAT frequencies (what's left?). You don't need to worry about this at 23cm and above. Rob From Robert.Glassey@nmp.nokia.com Tue Dec 03 07:38:08 1996 Received: from noknic.nokia.com (noknic.nokia.com [131.228.6.10]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id HAA28340 for ; Tue, 3 Dec 1996 07:38:03 -0600 (CST) From: Robert.Glassey@nmp.nokia.com Received: from samail01.nmp.nokia.com (samail01.nmp.nokia.com [131.228.240.6]) by noknic.nokia.com (8.6.9/8.6.9) with ESMTP id PAA23942 for ; Tue, 3 Dec 1996 15:37:27 +0200 Received: from by samail01.nmp.nokia.com with SMTP (1.37.109.20/16.2) id AA186170149; Tue, 3 Dec 1996 15:35:49 +0200 X-Openmail-Hops: 2 Date: Tue, 3 Dec 96 13:28:11 +0000 Message-Id: In-Reply-To: <199612022247.OAA21279@wireless.net> Subject: [SS:597] Re: SS below 70cm? Sender: Robert.Glassey@nmp.nokia.com To: ss@tapr.org >> relating to interference resistance and band sharing. These bands are >> already heavilly used (depending upon your definition of use, >> educational, simplicity, installed equipment, etc, not just user bits >> per Hz), there is no readilly avaliable equipment, there is very > Rob-- > > When was the last time you looked at your spectrum analyzer of 6m, 2m, > 220, 450? What were the counts of simultaneous signals per MHz, > minimum, average, maximum, on a per-second basis? What numbers do you > get if you look at the frequencies used for "Trunked" services, one of > the simplist versions of slow Frequency Hopping SS? The utilization > density for SS is significantly higher. You don't have any I know what you are saying, but like I said it depends upon you definition of use. On HF for example if you dont have a beam, and listen on a frequency, hear nothing and them transmit, you may well get a reply telling you the frequency is in use. Of course if SS was the only mode in use you could fit a lot more stations on the same band, but is that the only valid use for the band? SS gets more users on a band though reusing frequencies. You cannot allow anyone to transitt higher power (since 1 station with 100 times the power (say 10W instead of 100mW) is the same as 100 low power stations in a DSSS system). Also if the SS system is actually makeing use of the its capacity then the noise floor MUST be raised by an amount equivilent to the processing gain, that also excludes DX. So if DX is to be considered a valid use of amateur radio for any of the numeous reasons, then we must accept the it will USE a lot more capacity than SS even though it may actually only be on for a small amount of the time, and may never show up on a spec-an. This is a different use to commercial trunked systems, and it uses more resources, but should be exclude it because of that? But its not just DX, FM takes a lot of bandwidth, when a trunked digital system would be much more spectraly efficent. But we are amateurs, one reason for using simple FM is that beginners can easilly build a FM transceiver from a few chips and transistors, where we could never build a full trucked digital transceiver. We sacrifice spectrum utility for simplicity of equipment, because we are amateurs, and simplicity is an essential ingrediant in home brew and self training. This is a valid use of amateur resources, using them for the purpose they were allocated. My first receiver was a crystal set! and my first home brew HF transceiver was DSB, because it was simple. I didn't start by trying to build a multiband, multimode, digitally controlled, synthersised rig, and even now only make things that complex at work, and use the Giga word. We should not get carried away trying to get the most users per Hz, that is a commercial approach, and provides very little for the radio experimenter and beginners. Many valid uses of amateur radio will be spectrally inefficent, and wont show up on a spec-an, but that makes them no less important. To argue against these modes is to argue against the whole concept of amateur radio! SS networks is one area where spectral efficency is both possible and desireable, so lets go for it! But you wont get it if you have to share with uncontrolled narrow band technology on VHF. > The idea of "find an unused frequency(s) and use it > (them)" is exactly what FHSS accomplishes, as I demonstrated some time > ago in one of my STA experiments This assumes of course you can hear the EME/DX that another operator has build a massive antenna system to receive. > HOWEVER, doing this required significantly > greater system complexity than is the current state-of-the-art used > by the current band occupants. Exactly, if you keep away from these guys all together you dont need such complexity, and can focus your efforts on getting performance out of your system. > Therein lies the rub. Other services > are now eyeing our allocations, seeing their sparce use, and are > perfectly willing to apply whatever capital investment is required > to use them efficiently/completely. We amateurs are not without the > same resources and ingenuity; what we lack, currently, is motivation. > We somehow think that the current "the bands are heavily used" > argument will continue to hold up. Soon, it won't. What then? Like I say it depends upon your definition of use, when I tune over the HF band I am often impressed at how well utilised the amateur bands are compared to the commercial bands. The amateur bands are often as packed as the short wave broadcast bands, and use a more efficent modulation system as well! When I tune over the land mobile and aeronaughtical bands on VHF-UHF I find a similar situation, the ham bands are often better utilised than the commercial bands, expect for a few spot frequencies, and the cellular bands around 900MHz. How about UHF TV, there's a few hundred wasted MHz (counting only the empty channels :-), or is it? The military also have 100's of MHz here that also appears empty - except when an exersize is going on, but is it? The amateur allocations that are under real threat are the microwave bands. The only reason commercial interests target amateur bands is that they see us as easy pickings (perhaps because of our infighting), not as free bandwidth. > SS has the potential to give us the vehicle to save our bands > from commercial piracy, and that, to me, is a very compelling > reason for encouraging its use at VHF. Perhaps more immediately, > it gives us the means to break the logjam of "no more frequencies > available" and do it automatically as part of the frequency hopping > pattern development. Add to that it's potential for advances in > weak-signal work, it doesn't take much to convince the objective > observer. You cant argue that there are no more frequencies, while at the same time say there is no activity! FM isn't that inefficent! Channel searching can be added to amateur FM systems, but doesn't need to be, since the operators already do it 'QSY'. If you want more activity you need more users, not channel changeing. By discouraging existing users (with political agro) and using 'below the noise' SS systems you are warmly inviting commercial piracy. And if SS activity is enough to justify a amateur allocation, the noise floor, (or chance of repeatedly hopping onto a frequency that someone you cant hear is using with more sensitive equipment) must become significant. You can't claim SS is efficent if it doesn't interfere, and I don't believe SS efficency is worth causeing the other users interference. There is of course a small amount of (inefficent) experimental activity that can be tollerated, but this can never become a viable SS WAN with competitive data rates and user/HZ efficency, not without stepping on a lot of toes, and even then the system wouldn't come close to a microwave system for performance and simplicity, which you would loose by not using microwave bands. I see no reason to cause any agrovation, justified or otherwise, by using SS on VHF, when microwave is so much easier, and has much greater potential to expand. SS needs support to be successfull, you dont get that by standing on everyone's toes. Rob From dewayne@warpspeed.com Tue Dec 03 10:29:28 1996 Received: from warpspeed.com (WA8DZP@odo.warpspeed.com [204.118.182.20]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id KAA05128; Tue, 3 Dec 1996 10:29:22 -0600 (CST) Received: from [204.118.182.22] by warpspeed.com with ESMTP (Apple Internet Mail Server 2.0a8); Tue, 3 Dec 1996 08:29:15 -0800 Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Tue, 3 Dec 1996 08:29:13 -0800 To: ss@tapr.org, fccreg@tapr.org, netsig@tapr.org From: Dewayne Hendricks Subject: W5YI Report on TAPR SS STA The latest edition of the "W5YI Report", Vol. 18, Issue 23 has a special report on the TAPR SS STA and Lyle Johnson's keynote talk at this year's ARRL/TAPR DCC. Check it out!! More info on the "W5YI Report " can be found at: . -- Dewayne -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dewayne Hendricks, WA8DZP ! AOL: HENDRICKS Warp Speed Imagineering ! Internet: dewayne@warpspeed.com 43730 Vista Del Mar ! Packet Radio: WA8DZP @ K3MC.#NOCAL.CA.USA.NOAM Fremont, CA 94539-3204 ! WWW: Fax: (510) 770-9854 ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From rwtaylor@m5.sprynet.com Tue Dec 03 11:48:20 1996 Received: from m5.sprynet.com (m5.sprynet.com [165.121.2.92]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id LAA08611 for ; Tue, 3 Dec 1996 11:48:17 -0600 (CST) Received: from SPRY01 (dd66-221.compuserve.com [199.174.207.221]) by m5.sprynet.com (8.6.12/8.6.12) with SMTP id JAA18828 for ; Tue, 3 Dec 1996 09:48:12 -0800 Message-Id: <199612031748.JAA18828@m5.sprynet.com> Comments: Authenticated sender is From: "rwtaylor" To: ss@tapr.org Date: Wed, 4 Dec 1996 00:12:32 +0000 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Subject: unsubscribe Reply-to: rwtaylor@sprynet.com Return-receipt-to: rwtaylor@sprynet.com Priority: normal X-mailer: Pegasus Mail for Windows (v2.42a) could you temporarily unsubscribe me from this list thanks Robert Taylor KL7ENY/HS0CZG RT From strohs@halcyon.com Wed Dec 04 10:49:34 1996 Received: from mail1.halcyon.com (mail1.halcyon.com [206.63.63.40]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id KAA13420 for ; Wed, 4 Dec 1996 10:49:31 -0600 (CST) Received: from coho.halcyon.com by mail1.halcyon.com (5.65v3.2/1.1.10.5/10Nov96-0444PM) id AA19525; Wed, 4 Dec 1996 08:48:36 -0800 Date: Wed, 4 Dec 1996 08:49:24 -0800 (PST) From: Steve Stroh To: ss@tapr.org Subject: Re: [SS:602] Re: SS below 70cm? In-Reply-To: Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Tue, 3 Dec 1996 Robert.Glassey@nmp.nokia.com wrote: > But its not just DX, FM takes a lot of bandwidth, when a trunked digital > system would be much more spectraly efficent. But we are amateurs, one > reason for using simple FM is that beginners can easilly build a FM > transceiver from a few chips and transistors, where we could never build > a full trucked digital transceiver. I'd classify that as an assumption on your part rather than a "truth". >From what little I know of trunked systems, it would be relatively easy to build a functional trunked radio. All that is required is to listen to a dedicated control channel (simple receiver for 220 perhaps) in addtion to the primary receiver, and transmit a small amount of data to the trunking controller to reserve a channel. A small unit simpler than a TNC could handle this, and a slightly more complex unit on each repeater. > We sacrifice spectrum utility for > simplicity of equipment, because we are amateurs, and simplicity is an > essential ingrediant in home brew and self training. My perception is that we sacrifice spectrum utility because each group wants "their own" ego box repeater on the air, and if you're not a member of that group, you're discuraged in subtle or overt ways from using that repeater. Being excluded, YOU want to build your OWN ego box repeater so you can talk too. In the early days of repeaters, there were enough frequencies available that this wasn't a problem. In the 1990's, in most metro areas all the frequencies are spoken for (note I didn't say In Use). There's now incentive to share repeater systems between user groups, but no real interest because the pattern has been set over the last 25 years that each group has a separate repeater on its own frequency. All it would take is one talented group in one metro area and a small number of repeaters. Steve N8GNJ -- Steve Stroh Woodinville, Washington, USA strohs@halcyon.com From Robert.Glassey@nmp.nokia.com Wed Dec 04 13:32:50 1996 Received: from noknic.nokia.com (noknic.nokia.com [131.228.6.10]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id NAA20940 for ; Wed, 4 Dec 1996 13:32:48 -0600 (CST) From: Robert.Glassey@nmp.nokia.com Received: from samail01.nmp.nokia.com (samail01.nmp.nokia.com [131.228.240.6]) by noknic.nokia.com (8.6.9/8.6.9) with ESMTP id VAA06334 for ; Wed, 4 Dec 1996 21:32:15 +0200 Received: from by samail01.nmp.nokia.com with SMTP (1.37.109.20/16.2) id AA020647834; Wed, 4 Dec 1996 21:30:34 +0200 X-Openmail-Hops: 2 Date: Wed, 4 Dec 96 19:29:18 +0000 Message-Id: Subject: [SS:605] Re: SS below 70cm? Sender: Robert.Glassey@nmp.nokia.com To: ss@tapr.org >> system would be much more spectraly efficent. But we are amateurs, >> one reason for using simple FM is that beginners can easilly build a >> FM transceiver from a few chips and transistors, where we could never >> build a full trucked digital transceiver. > > I'd classify that as an assumption on your part rather than a "truth". > From what little I know of trunked systems, it would be relatively > easy to build a functional trunked radio. All that is required is to OK yes, it wouldn't be too dificult for me or perhaps you to make such a system, after all I do it for a living, but I haven't got the time or inclination to do it in my spare time. I perfer to do smaller scale projects that focus on perhaps one single technical aspect, which I have the time and interest to do. Similary a beginner might actually attempt a simple FM transceiver, where they wouldn't dream of trying it if they had to make a full systhisised trunked radio with microprocessor control and digital modulation and demodulation, just to get on air. They'ed just buy one. That would mean the death of home construction, and any experiance amateurs might gain in doing it. Then who would be left to build a SS unit? Ham radio should not be an exclusive club where only experianced engineers can get a licence, it's about learning, and a beginner gets the most immediate results if he can attach a crystal to a frequency multiplier chip, add a variactor across the crystal, and built a small PA with say 1/2 a watt output, and get on air! Or convert a land mobile rig in his spare time because even if he was an experiance engineer he doesn't want to build a transceiver from scratch, but wants something to play around with, try new techniques etc. The posibilities are limitless, and that's the way it should be. We should not make something as complex as a truncked radio minimum entry level, as the home brewers simplist choice. That would spell the end of home brew, since its easier to just buy the equipment, and you wouldn't be able to use anything you could reasonably build in your spare time, unless it was a major project. This is not to say that there shouldn't be high tech stuff, after all those with more experiance will want to do more complicated things. What I'm saying is that the simpler stuff is just as valid use of amateur radio as is the complex stuff, and should not be excluded by a few people with greater expriance, who perhaps see the whole band as their personal property and resent the existance of lower tech users. That's getting too eliteist for me. Lo tech, inefficent modes, or weak signal work can be just as valid a use of the ham bands, in accordance with the purpose amateur bands are allocated. They are not second class users. Yes, we cant get too carried away supporting outdate modes, but at the same time we dont want to set the entry level too high. As technology progresses, the newer modes will become as easy as the older modes so you might as well go for the new modes. I never built a CW transceiver, since a DSB transceiver way not much more complex and much more usefull. (since I'm not a big CW user). Then I didn't do SSB because I could get away with DSB. Efficency is a good argument for getting the maximum speed and number of users out of a SS network, but can never be used as an argument the claim moral superiority over other valid uses of the amateur spectrum. You respect them and they'll respect you, they might even join you! > My perception is that we sacrifice spectrum utility because each group > wants "their own" ego box repeater on the air, and if you're not a > member of that group, you're discuraged in subtle or overt ways from > using that repeater. This is unfortunate, I gather it happened here in England too, but thankfully most have grown out of that sort of behaviour. In New Zealand, my original QTH, repeater contruction was often coordinated on a national level, and roaming activity was encouraged, and several repeaters were built specifically for the purpose of repeater DX! One I was involved in could often make contacts over 1000km on 2m, and used two seperate phased array antennas for diversity with microprocessor control. Today a national system of 70cm repeaters links the entire country, with some sections of the link now going digital (and trunked) over a 700kbps link. The beginner can still access it with his 'crystal set' though. I once cobbled together a 70cm transciever out of spare test equipment and modules and made a contact over 1000km using the link. Thats no major task, but its fun to do! 73's, Rob From fred@tekdata.com Wed Dec 04 14:38:31 1996 Received: from tekdata.com (vh2-054.wwa.com [205.243.70.119]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA24134 for ; Wed, 4 Dec 1996 14:38:16 -0600 (CST) Received: (from fred@localhost) by tekdata.com (8.6.12/8.6.12) id OAA26381; Wed, 4 Dec 1996 14:38:01 -0600 Date: Wed, 4 Dec 1996 14:38:00 -0600 (CST) From: "Fred M. Spinner" To: ss@tapr.org Subject: Re: [SS:606] Re: SS below 70cm? In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Wed, 4 Dec 1996 Robert.Glassey@nmp.nokia.com wrote: > > OK yes, it wouldn't be too dificult for me or perhaps you to make such a > system, after all I do it for a living, but I haven't got the time or > inclination to do it in my spare time. I perfer to do smaller scale > projects that focus on perhaps one single technical aspect, which I have > the time and interest to do. > > Ham radio should not be an exclusive club where only experianced > engineers can get a licence, it's about learning, and a beginner gets > the most immediate results if he can attach a crystal to a frequency > multiplier chip, add a variactor across the crystal, and built a small > PA with say 1/2 a watt output, and get on air! > This is not to say that there shouldn't be high tech stuff, after all > those with more experiance will want to do more complicated things. What > I'm saying is that the simpler stuff is just as valid use of amateur > radio as is the complex stuff, and should not be excluded by a few > people with greater expriance, who perhaps see the whole band as their > personal property and resent the existance of lower tech users. That's > getting too eliteist for me. > > Lo tech, inefficent modes, or weak signal work can be just as valid a > use of the ham bands, in accordance with the purpose amateur bands are > allocated. They are not second class users. (No, actually under all proposals now, the SS users are second-class under the "lo-tech") I am kinda getting a kick out of this line of thought because I don't think any engineer would ever mind someone using a simple mode like FM to learn. We done it ourselves in the past! I don't know how this got "read-in" to the debate. Actually, the engineers in the hobby tend not to be of the "frequency coordinator" type who like to restrict what we can do IMHO. IMHO, the hams under FCC rule are Americans. We are supposed to be a capitalistic and free society. When it comes right down to it, ham radio is a method of allowing self-education. The reason we have ham bands is that an individual in this country should have some access to spectrum. The "public-safety" and "trained operator" excuses are fine too, but I think really we've survived because we should have from a ethical standpoint. Freedom of speech is another little reason for having ham radio too.. (A company would have lost our bands due to underuse years ago!) Having said that, I think we should TRY co-existing SS and narrowband modes, and see if we have a problem before we assume we do! -- The more activity, learning, etc. the better! It's amazing to me how afraid hams have become to new ideas and progress. For once I think the ARRL has gone in the right direction. I'm disappointed in AMSAT. If our technically knowledgable hams fight others like that we are sunk- we should know that we can work together and capitalize upon innovation. Or we can stagnate into non-existance. P.S. AMSAT going against PANSAT really made AMSAT look foolish, IMHO. Fred M. Spinner, KA9VAW fred@tekdata.com, ka9vaw@amsat.org From rlanier@su102s.ess.harris.com Wed Dec 04 16:33:33 1996 Received: from ess.harris.com (su15a.ess.harris.com [130.41.1.251]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id QAA29950 for ; Wed, 4 Dec 1996 16:33:31 -0600 (CST) Received: from losalamos.ess.harris.com (su102s.ess.harris.com [130.41.13.101]) by ess.harris.com (8.8.3/8.8.3) with SMTP id RAA23373 for ; Wed, 4 Dec 1996 17:33:28 -0500 (EST) Received: from Paris.GASD102designcenter by losalamos.ess.harris.com (4.1/SMI-4.1) id AA02881; Wed, 4 Dec 96 17:33:27 EST Received: by Paris.GASD102designcenter (SMI-8.6/SMI-SVR4) id RAA29726; Wed, 4 Dec 1996 17:33:25 -0500 Date: Wed, 4 Dec 1996 17:33:25 -0500 From: rlanier@su102s.ess.harris.com (Tony Lanier) Message-Id: <199612042233.RAA29726@Paris.GASD102designcenter> To: ss@tapr.org Subject: Re: [SS:607] Re: SS below 70cm? X-Sun-Charset: US-ASCII Fred M. Spinner, KA9VAW wrote: > Having said that, I think we should TRY co-existing SS and narrowband > modes, and see if we have a problem before we assume we do! > -- The more activity, learning, etc. the better! I said the same thing 6 months ago! Some of us KNOW SS has some strong points and several have demonstrated it. Why are we back to argueing about it? SS will never progress at this rate; that is why I am proceeding with SS WITHOUT getting into a discussion about!!! > It's amazing to me how afraid hams have become to new ideas and progress. Sickening is the word that comes to my mind ... > P.S. AMSAT going against PANSAT really made AMSAT look foolish, IMHO. I didn't hear about this. What reason did AMSAT give for not supporting PANSAT? 73s de Tony, KE4ATO From wd5ivd@tapr.org Wed Dec 04 18:25:02 1996 Received: from [128.83.251.35] (slip-53-3.ots.utexas.edu [128.83.251.35]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id SAA04685 for ; Wed, 4 Dec 1996 18:25:00 -0600 (CST) Message-Id: In-Reply-To: <199612042233.RAA29726@Paris.GASD102designcenter> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Wed, 4 Dec 1996 17:59:58 -0600 To: ss@tapr.org From: "Greg Jones, WD5IVD" Subject: Re: [SS:608] Re: SS below 70cm? >I didn't hear about this. What reason did AMSAT give for not supporting >PANSAT? > >73s de Tony, KE4ATO A good question for AMSAT-BB sometime. It wasn't really an issue of not supporting PANSAT, but some other issues. You should read the reply comments that AMSAT files on RM-8737 if you havn't. All the comments and reply comments we could get on-line are on http://www.tapr.org/ss Cheers - Greg ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd ----- From clh10@po.cwru.edu Wed Dec 04 19:06:06 1996 Received: from celeste.INS.CWRU.Edu (root@celeste.INS.CWRU.Edu [129.22.8.214]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id TAA06569 for ; Wed, 4 Dec 1996 19:06:03 -0600 (CST) Received: from [129.22.249.174] (wormwood.STUDENT.CWRU.Edu [129.22.249.174]) by celeste.INS.CWRU.Edu with SMTP (8.7.6+cwru/CWRU-3.0) id UAA10148; Wed, 4 Dec 1996 20:06:02 -0500 (EST) (from clh10@po.cwru.edu for ) Date: Wed, 4 Dec 1996 20:06:02 -0500 (EST) X-Sender: clh10@pop.cwru.edu Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: clh10@po.cwru.edu (clh10@po.cwru.edu) Subject: Interest in a Senior Project Greetings, I am an electrical engineering major at Case Western Reserve University in Cleveland OH, finishing my senior year. As part of our graduation requirement, we must complete two senior projects. The first one I have finished, and was based on the simulation of the forward-link code division multiple access transmission signals according to IS-95. While it was an excellent way to learn about the theory behind CDMA, and Spread Spectrum as a whole, the simulation was done solely in programming. Next semester, when I continue my second senior project on the area of Spread Spectrum communications, I would like to work on a problem that involves hardware rather than computer simulation. However, since my department is not particularly strong in the area of communications, I am looking outside of the university for ideas on what particular task in SSC would be suitable. If you have any tasks that you would feel are suitable for this purpose, I'd like to hear about them. In addition, there is at least one other student who is interested in pursuing a senior project in this area as well. Thank you, Cory L. Hojka N9RBA (technician w/ code) Cory L. Hojka Beta Nu of Theta Chi Fraternity Case Western Reserve University Cleveland, OH Two dogs crow in the bark. Their hunger, their tummies rub. Cries the cat of the soul, Yip Yip. Such are the things way are. From edsadow@ids.net Wed Dec 04 20:45:40 1996 Received: from pobox.ids.net (pobox.ids.net [155.212.1.122]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id UAA10939 for ; Wed, 4 Dec 1996 20:45:39 -0600 (CST) Received: from pslip053d.egr-ri.ids.net (pslip053d.egr-ri.ids.net [155.212.93.53]) by pobox.ids.net (8.8.3/8.8.3) with SMTP id VAA04045 for ; Wed, 4 Dec 1996 21:45:26 -0500 (EST) Date: Wed, 4 Dec 1996 21:45:26 -0500 (EST) Message-Id: <1.5.4.16.19961204214640.1c27266c@mail.ids.net> X-Sender: edsadow@mail.ids.net X-Mailer: Windows Eudora Light Version 1.5.4 (16) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: Edward Sadowski Subject: Re: [SS:608] Re: SS below 70cm? At 04:33 PM 12/4/96 -0600, you wrote: >Fred M. Spinner, KA9VAW wrote: >> Having said that, I think we should TRY co-existing SS and narrowband >> modes, and see if we have a problem before we assume we do! >> -- The more activity, learning, etc. the better! > >I said the same thing 6 months ago! Some of us KNOW SS has some strong >points and several have demonstrated it. Why are we back to argueing about it? >SS will never progress at this rate; that is why I am proceeding with SS WITHOUT >getting into a discussion about!!! > >> It's amazing to me how afraid hams have become to new ideas and progress. > >Sickening is the word that comes to my mind ... > You guys are on the cutting edge! Don't forget, there are lots of hams out there who DON'T own a computer or do ax.25 or any of the simple stuff we take for granted and old hat! Those guys are AFRAID of THESE things!!! Just remember, explorers and trail blazers always have been, are, and always will be in the avant garde minority. The rest are content in being sheep. Although I don't have the knowledge or expertise of you fellows, I can appreciate and applaude your pioneering work. 73, Ed, W1BF >> P.S. AMSAT going against PANSAT really made AMSAT look foolish, IMHO. > >I didn't hear about this. What reason did AMSAT give for not supporting PANSAT? > >73s de Tony, KE4ATO > > From zsolt@direct.ca Wed Dec 04 21:45:13 1996 Received: from orb.direct.ca (root@orb.direct.ca [199.60.229.5]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id VAA13767 for ; Wed, 4 Dec 1996 21:45:11 -0600 (CST) Received: from boxer.direct.ca ([204.174.244.30]) by orb.direct.ca with SMTP id <34100-5268>; Wed, 4 Dec 1996 19:44:59 -0800 Date: Wed, 4 Dec 1996 20:45:11 -0800 (PST) From: George Cserenyi To: Tony Lanier cc: ss@tapr.org Subject: Re: [SS:608] Re: SS below 70cm? In-Reply-To: <199612042233.RAA29726@Paris.GASD102designcenter> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Yes, yes, yes! On Wed, 4 Dec 1996, Tony Lanier wrote: > Fred M. Spinner, KA9VAW wrote: > > Having said that, I think we should TRY co-existing SS and narrowband > > modes, and see if we have a problem before we assume we do! > > -- The more activity, learning, etc. the better! > > I said the same thing 6 months ago! Some of us KNOW SS has some strong > points and several have demonstrated it. Why are we back to argueing about it? > SS will never progress at this rate; that is why I am proceeding with SS WITHOUT > getting into a discussion about!!! > I'd like to do the same, am long on time but short on cash az being a retired hard/soft-ware engineer. Where sould I start? Ho much will it cost to get a test setup going? George ve7ciz > > It's amazing to me how afraid hams have become to new ideas and progress. > > Sickening is the word that comes to my mind ... > > > P.S. AMSAT going against PANSAT really made AMSAT look foolish, IMHO. > > I didn't hear about this. What reason did AMSAT give for not supporting PANSAT? > > 73s de Tony, KE4ATO > > > From Robert.Glassey@nmp.nokia.com Thu Dec 05 06:15:18 1996 Received: from noknic.nokia.com (noknic.nokia.com [131.228.6.10]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id GAA08230 for ; Thu, 5 Dec 1996 06:15:15 -0600 (CST) From: Robert.Glassey@nmp.nokia.com Received: from samail01.nmp.nokia.com (samail01.nmp.nokia.com [131.228.240.6]) by noknic.nokia.com (8.6.9/8.6.9) with ESMTP id OAA24288 for ; Thu, 5 Dec 1996 14:12:30 +0200 Received: from by samail01.nmp.nokia.com with SMTP (1.37.109.20/16.2) id AA105797842; Thu, 5 Dec 1996 14:10:42 +0200 X-Openmail-Hops: 2 Date: Thu, 5 Dec 96 12:09:05 +0000 Message-Id: Subject: Re: SS below 70cm? Sender: Robert.Glassey@nmp.nokia.com To: ss@tapr.org > I am kinda getting a kick out of this line of thought because I don't > think any engineer would ever mind someone using a simple mode like > FM to learn. We done it ourselves in the past! I don't know how this > got "read-in" to the debate. Sorry, I'm flying off on a tangent here. The point was that spectral efficency isn't the only parameter to consider when allocating spectrum, especially for amateur radio. That fact that 2m is often under used compared to a trunked system or a SS system is almost irrelivent, since that is not what it is allocated for, although it my be an argument to reduce the size of the band. Getting more users on the band would help reduce this posibility, but there are other bands, that are of considerably more value to us if we want to create a decent SS WAN, which has even lower utility (like practically nill) and is (or soon will be) under direct pressure from commercial interests who want to use it for the same purpose. Commercial interests could take the microwaves bands almost without resistance, when there is a large base of users on 2m. Putting SS on 2m is not a very good way of saving the band, if it needs saving at all. There is already a lot of people who will fight for 2m. You only create in-fighting and discourage utilisation of the band by non-SS users. This only works against us! If you want to fill a band, go for the ones that are of most value to SS. I'm sure SS will work on a small experimental scale on 2m if enough attention is paid to ovoiding narrow band signals (mostly because of their effect of SS performance), but 2m can never support a decent WAN, and the agro and technical dificulities of operating SS on a band occupied by high power low tech users seem to make the whole exersize pointless. Please, don't underestimate the objections many have to SS, we are not all afraid and ignorant, and we do not unilaterally oppose SS either. I greatly SUPPORT the principle of SS and its application to amateur data netorks which desprately needs to be brough into the 21st century. I have been involved in the design and construction of 'amateur' (ISM) and commercial SS transcievers for several years now (all above 800MHz), and have a great interest in SS theory particularly as it applies to high performance digital networks, and have studied it at post graduate level in conjunction with phD projects and 900MHz multipath propagation studies. I'm interested in creating a high performance amateur SS WAN, and see no need to go anywhere near frequencies justifiably used by other amateurs to do it. I see no need to even take the risk of causing interference, and believe any well utilised SS system MUST operate above the noise floor if it is to be efficent, which is what we want. I see no need for either narrow band users OR SS users to compromise on this issue. There is room enough for everyone, provided we dont let the microwave bands be lost to comercial interests. We have been given almost ideal frequencies for SS networks yet some people want to throw them away and fight other amateurs for spectrum that is much less than ideal anyway! This is what baffels me! Rob Not frightened of either SS or the Giga word! From bad@uhf.wireless.net Thu Dec 05 09:38:14 1996 Received: from uhf.wdc.net (uhf.wdc.net [198.147.74.44]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id JAA16963 for ; Thu, 5 Dec 1996 09:38:09 -0600 (CST) Received: (from bad@localhost) by uhf.wdc.net (8.8.3/8.6.12) id KAA19501; Thu, 5 Dec 1996 10:40:17 -0500 (EST) Date: Thu, 5 Dec 1996 10:40:16 -0500 (EST) From: Bernie Doehner To: clh10@po.cwru.edu cc: ss@tapr.org Subject: Re: [SS:610] Interest in a Senior Project In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi Cory: We built a 98 MHz. low power (1 dBm) DSSS radio (BPSK) for our senior project. My partner (N3FLA) and I actualy saw it working... The sad part is that we got kicked out of the lab we were in into another lab and he didn't watch power supply voltages when he hooked up and ended up applying +20V to TTL circuitry. We still got an A in the project, based on our report and what the TA saw, but it would have been nice to be able to show it off to the advisor, but there wasn't enough time to rebuild at this point. (We were majorly behind, because it took 7 weeks to etch the circuit boards for the RF decks!!!!! We needed to be babysat by a TA while etching (acid etching), and most of the time it came out either under or over etched - I hope you make out better!) Question: How extensive does your project have to be? How much of a "research" component do you have to put into it? Besides losing a lot of time with the etching, our advisor forced us to do a lot of reading in Dixon and other SS texts, further taking away from design and building time. I guess my message is, you can design and build a simple NE602/NE605/MMIC based DSSS system in 6 months with plenty of time to waste. However, if I had to do it again, I'd go for a FHSS system on 6 meters. Around here (central Massachusetts), I'd be surprised if spectral utilization ever got beyond 1%! In my opinion 6 meters would be the ideal band for a FHSS system (easy to build antennas and circuits, no need to be above tree lines, no need to watch feedline loss - all the "nuisances" of working with UHF/microwave go away). 73 Bernie From wd5ivd@tapr.org Thu Dec 05 10:31:52 1996 Received: from [208.134.134.42] ([208.134.134.42]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id KAA18805 for ; Thu, 5 Dec 1996 10:31:51 -0600 (CST) Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Thu, 5 Dec 1996 10:29:35 -0600 To: " Spread Spectrum " From: "Greg Jones, WD5IVD" Subject: Horz Omnis There has been some discussion regarding horz slot antennas for the 900Mhz stuff plus the other bands to help communications, since most users on are shared bands are running vertical. Bob Morgan, WB5AOH, (on the list) has been looking at building one but I was wondering if someone has designs for one or can point to reference that discuss constrution and theory. Cheers - Greg ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd ----- From wd5ivd@tapr.org Thu Dec 05 10:41:03 1996 Received: from [208.134.134.42] ([208.134.134.42]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id KAA19243 for ; Thu, 5 Dec 1996 10:41:02 -0600 (CST) Message-Id: In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Thu, 5 Dec 1996 10:41:25 -0600 To: ss@tapr.org From: "Greg Jones, WD5IVD" Subject: Re: [SS:613] Re: SS below 70cm? Two short comments. >I'm interested in creating a high performance amateur SS WAN, and see no >need to go anywhere near frequencies justifiably used by other amateurs >to do it. I see no need to even take the risk of causing interference, >and believe any well utilised SS system MUST operate above the noise >floor if it is to be efficent, which is what we want. I see no need for >either narrow band users OR SS users to compromise on this issue. There >is room enough for everyone, provided we dont let the microwave bands be >lost to comercial interests. Looking forward to reading about your designs and implementations. >We have been given almost ideal frequencies for SS networks yet some >people want to throw them away and fight other amateurs for spectrum >that is much less than ideal anyway! > >This is what baffels me! Why would it baffel you ? It doesn't me. Amateur Radio is about doing what you want to do to expand your operating knowledge, education, or interest. You believe and will develop stuff for the higher bands -- great! There will be others that will want to operate someplace else. No problem. That is the great thing about amateur radio. Now -- back to discussing more technical issues. Instead of is it proper and all that, let's talk about designs folks. Like how can someone design some RF to interface with the code Phil Karn has been working for someone to test with. Phil is on the list, maybe he can discuss what he has been working on since the ARRL and TAPR Digital Communications Conference and hopefully we can locate some folks on this list that can do a project. How could system be developed for 219. How are we going to get on 5Gigs and higher with reproducable systems and systems that can both be maintained and handled in large numbers for both users and networks. Also, I would be interested ion hearing comments about how to implement some interface to the DSP code that Frank Perkins posted the other day. Nothing keeping us from taking that code on a faster DSP or what Phil has running on a PC and cranking out testing systems with a RF interface. Cheers - Greg ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd ----- From dcole@on-ramp.ior.com Thu Dec 05 10:48:08 1996 Received: from on-ramp.ior.com (on-ramp.ior.com [199.79.239.11]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id KAA19540 for ; Thu, 5 Dec 1996 10:48:06 -0600 (CST) Received: from pm2-21.ior.com(really [204.212.119.21]) by on-ramp.ior.com via sendmail with smtp id for ; Thu, 5 Dec 96 08:47:19 -0800 (PST) (/\##/\ Smail3.1.30.16 #30.4 built 17-mar-96) Message-ID: <32A6FC18.6CDC@on-ramp.ior.com> Date: Thu, 05 Dec 1996 08:45:12 -0800 From: doug cole Organization: spokane county communications X-Mailer: Mozilla 3.0 (Win16; I) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: [SS:606] Re: SS below 70cm? References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit just a tiny reality check as far as use of spectrum is concerned, it seems to me that avionics still to this day use AM for their modulo-format now why aren't we screaming for the FAA to madate FHSS for the air industry ? :) just a small reality check that's all de N7BFS Doug Cole ps: couldn't agree more with your arguement Robert :) Robert.Glassey@nmp.nokia.com wrote: > > >> system would be much more spectraly efficent. But we are amateurs, > >> one reason for using simple FM is that beginners can easilly build a > >> FM transceiver from a few chips and transistors, where we could never > >> build a full trucked digital transceiver. > > > > I'd classify that as an assumption on your part rather than a "truth". > > > From what little I know of trunked systems, it would be relatively > > easy to build a functional trunked radio. All that is required is to > > OK yes, it wouldn't be too dificult for me or perhaps you to make such a > system, after all I do it for a living, but I haven't got the time or > inclination to do it in my spare time. I perfer to do smaller scale > projects that focus on perhaps one single technical aspect, which I have > the time and interest to do. Similary a beginner might actually attempt > a simple FM transceiver, where they wouldn't dream of trying it if they > had to make a full systhisised trunked radio with microprocessor control > and digital modulation and demodulation, just to get on air. They'ed > just buy one. That would mean the death of home construction, and any > experiance amateurs might gain in doing it. Then who would be left to > build a SS unit? > > Ham radio should not be an exclusive club where only experianced > engineers can get a licence, it's about learning, and a beginner gets > the most immediate results if he can attach a crystal to a frequency > multiplier chip, add a variactor across the crystal, and built a small > PA with say 1/2 a watt output, and get on air! Or convert a land mobile > rig in his spare time because even if he was an experiance engineer he > doesn't want to build a transceiver from scratch, but wants something to > play around with, try new techniques etc. The posibilities are > limitless, and that's the way it should be. We should not make something > as complex as a truncked radio minimum entry level, as the home brewers > simplist choice. That would spell the end of home brew, since its easier > to just buy the equipment, and you wouldn't be able to use anything you > could reasonably build in your spare time, unless it was a major > project. > > This is not to say that there shouldn't be high tech stuff, after all > those with more experiance will want to do more complicated things. What > I'm saying is that the simpler stuff is just as valid use of amateur > radio as is the complex stuff, and should not be excluded by a few > people with greater expriance, who perhaps see the whole band as their > personal property and resent the existance of lower tech users. That's > getting too eliteist for me. > > Lo tech, inefficent modes, or weak signal work can be just as valid a > use of the ham bands, in accordance with the purpose amateur bands are > allocated. They are not second class users. > > Yes, we cant get too carried away supporting outdate modes, but at the > same time we dont want to set the entry level too high. As technology > progresses, the newer modes will become as easy as the older modes so > you might as well go for the new modes. I never built a CW transceiver, > since a DSB transceiver way not much more complex and much more usefull. > (since I'm not a big CW user). Then I didn't do SSB because I could get > away with DSB. > > Efficency is a good argument for getting the maximum speed and number of > users out of a SS network, but can never be used as an argument the > claim moral superiority over other valid uses of the amateur spectrum. > You respect them and they'll respect you, they might even join you! > > > My perception is that we sacrifice spectrum utility because each group > > wants "their own" ego box repeater on the air, and if you're not a > > member of that group, you're discuraged in subtle or overt ways from > > using that repeater. > > This is unfortunate, I gather it happened here in England too, but > thankfully most have grown out of that sort of behaviour. In New > Zealand, my original QTH, repeater contruction was often coordinated on > a national level, and roaming activity was encouraged, and several > repeaters were built specifically for the purpose of repeater DX! One I > was involved in could often make contacts over 1000km on 2m, and used > two seperate phased array antennas for diversity with microprocessor > control. Today a national system of 70cm repeaters links the entire > country, with some sections of the link now going digital (and trunked) > over a 700kbps link. The beginner can still access it with his 'crystal > set' though. I once cobbled together a 70cm transciever out of spare > test equipment and modules and made a contact over 1000km using the > link. Thats no major task, but its fun to do! > > 73's, > > Rob From glenne@hpsadr2.sr.hp.com Thu Dec 05 12:26:53 1996 Received: from palrel1.hp.com (palrel1.hp.com [15.253.72.10]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id MAA24752 for ; Thu, 5 Dec 1996 12:26:52 -0600 (CST) Received: from srmail.sr.hp.com (srmail.sr.hp.com [15.4.45.14]) by palrel1.hp.com with ESMTP (8.7.5/8.7.3) id KAA29526 for ; Thu, 5 Dec 1996 10:26:51 -0800 (PST) Received: from hpsadr2.sr.hp.com (n6gn.sr.hp.com) by srmail.sr.hp.com with ESMTP (1.37.109.16/15.5+ECS 3.3) id AA071190410; Thu, 5 Dec 1996 10:26:51 -0800 Received: by hpsadr2.sr.hp.com (1.37.109.16/15.5+ECS 3.3) id AA136670408; Thu, 5 Dec 1996 10:26:48 -0800 From: Glenn Elmore Message-Id: <199612051826.AA136670408@hpsadr2.sr.hp.com> Subject: Re: [SS:615] Horz Omnis To: ss@tapr.org (Greg Jones, WD5IVD) Date: Thu, 5 Dec 1996 10:26:47 -0800 (PST) In-Reply-To: from "Greg Jones, WD5IVD" at Dec 5, 96 10:33:58 am X-Mailer: ELM [version 2.4 PL21] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Greg wrote: > There has been some discussion regarding horz slot antennas for the 900Mhz > stuff plus the other bands to help communications, since most users on are > shared bands are running vertical. > > Bob Morgan, WB5AOH, (on the list) has been looking at building one but I > was wondering if someone has designs for one or can point to reference that > discuss constrution and theory. Steven Bell, kb7trz presented a paper and now has a web page (which I don't seem to have a bookmark for) regarding design and construction of waveguide slot antennas. Guide gets a bit large at 900 MHz but is probably not out of the question. Appropriate rain gutter stock might even work. He also has a mathcad 6.0 program for designing such antennas given the guide dimensions. I do have a copy of that here locally. He recently posted this information on the sbms microwave reflector. Glenn n6gn From cestey@millcomm.com Thu Dec 05 17:09:09 1996 Received: from mill2.millcomm.com (root@Mill2.MillComm.COM [199.170.133.2]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id RAA06344 for ; Thu, 5 Dec 1996 17:09:08 -0600 (CST) Received: from honrbc2.resd.honeywell.com by mill2.millcomm.com with smtp (Smail3.1.29.1 #2) id m0vVmvW-000MbcC; Thu, 5 Dec 96 17:09 CST Message-Id: X-Sender: cestey@millcomm.com X-Mailer: Windows Eudora Version 1.4.4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Thu, 05 Dec 1996 17:10:39 -0600 To: ss@tapr.org From: cestey@millcomm.com (Carl Estey) Subject: Re: [SS:615] Horz Omnis Greg, WD5IVD, wrote: [snip] >Bob Morgan, WB5AOH, (on the list) has been looking at building one but I >was wondering if someone has designs for one or can point to reference that >discuss constrution and theory. What are the power restrictions under the STA in the 900-Mhz band? Has anyone done anything with homebrewing PAs? How critical is the switching time of some of the hybrid devices available? This might be a cheap way out instead of the six hundred buck commercial amp I heard about? How good are the receivers (sensitivity) on the Beta Test group units? 73 Carl Carl Estey, Amateur Radio Station WA0CQG 10021 Drew Ave. S., Bloomington, MN 55431-2727 (612) 835-0056/ 0067 E-Mail: cestey@millcomm.com or wa0cqg@wa0cqg-uhf.ampr.org Digital Frequency Coordinator - Metropolitan Minneapolis/St. Paul area From wd5ivd@tapr.org Thu Dec 05 21:49:22 1996 Received: from [208.134.134.42] ([208.134.134.42]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id VAA17165 for ; Thu, 5 Dec 1996 21:49:20 -0600 (CST) Message-Id: In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Thu, 5 Dec 1996 21:46:07 -0600 To: ss@tapr.org From: "Greg Jones, WD5IVD" Subject: Re: [SS:619] Re: Horz Omnis >Greg, WD5IVD, wrote: > >[snip] > >>Bob Morgan, WB5AOH, (on the list) has been looking at building one but I >>was wondering if someone has designs for one or can point to reference that >>discuss constrution and theory. > >What are the power restrictions under the STA in the 900-Mhz band? Has >anyone done anything with homebrewing PAs? How critical is the switching >time of some of the hybrid devices available? This might be a cheap way out >instead of the six hundred buck commercial amp I heard about? How good are >the receivers (sensitivity) on the Beta Test group units? Current power rules apply for SS on 900Mhz. Those rules were not wavied. http://www.tapr.org/ss/rules.html see section 97.311(g) What was waived can be found in: http://www.tapr.org/ss/tapr_ss_sta.html I'll let some others comment on the amp issues. Cheers - Greg ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd ----- From karn@qualcomm.com Thu Dec 05 22:16:17 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id WAA18508 for ; Thu, 5 Dec 1996 22:16:15 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id UAA20094; Thu, 5 Dec 1996 20:15:10 -0800 (PST) Date: Thu, 5 Dec 1996 20:15:10 -0800 (PST) From: Phil Karn Message-Id: <199612060415.UAA20094@servo.qualcomm.com> To: clh10@po.cwru.edu (clh10@po.cwru.edu) CC: ss@tapr.org In-reply-to: (clh10@po.cwru.edu) Subject: Re: [SS:610] Interest in a Senior Project In my opinion, one of the most useful hardware projects in this area would be a general purpose digital software radio. That is, a radio in which as much of the back end as possible is replaced by software and/or dedicated DSP hardware. This is now a common industry technique, including IS-95 CDMA equipment. Phil From karn@qualcomm.com Thu Dec 05 23:21:26 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id XAA22481 for ; Thu, 5 Dec 1996 23:21:25 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id VAA20245; Thu, 5 Dec 1996 21:20:53 -0800 (PST) Date: Thu, 5 Dec 1996 21:20:53 -0800 (PST) From: Phil Karn Message-Id: <199612060520.VAA20245@servo.qualcomm.com> To: ss@tapr.org In-reply-to: (Robert.Glassey@nmp.nokia.com) Subject: Re: [SS:613] Re: SS below 70cm? Rob, I actually agree with much that you say. 2m is probably not the place for a large-scale SS packet radio computer network that could perhaps be better built on 1.2 or 2.4 GHz. Yet SS can support much more than packet radio as it is traditionally understood in the amateur service. In particular, systems like IS-95 CDMA can be directly adapted to provide FM-repeater-like land mobile voice services with much greater spectral efficiency. Isn't this something of the *most* potential interest on our most congested FM bands, e.g., 2m? It's easy to say that spectral efficiency is "unimportant" in the amateur service if a) you don't believe that threats to amateur spectrum are real and b) you're one of the lucky few who got a dedicated 2m repeater pair in a major metropolitan area before the allocations ran out 20+ years ago. If you'll pardon my language, this strikes me as a classic "f*** you Jack, I'm all right" attitude. I have said this before: de-facto practice notwithstanding, no one owns any particular frequency in the amateur service. Having been there first doesn't make any difference. All frequencies are open to all hams licensed to operate on them, and all hams must cooperate in using them most effectively. It says as much in Part 97 and on the bottom of the form 610 you sign for your US ham ticket. On the weak signal side, my goal is not to blanket the 2m weak signal band with indiscriminate strong SS signals, but to enable the use of forward error correction to enhance the DX operations that already go on there. The problem is that the same bandwidth limits that preclude the SS operations that may not make sense in the DX bands also work to preclude the potentially advantageous use of forward error correction. That's because FEC must either increase bandwidth or reduce throughput in order to work its greatest power gains. Particularly if you're interested in digital voice, which has certain minimum data rate requirements, there is no easy way to apply FEC without running into the existing bandwidth limits. Phil From jeff@mich.com Fri Dec 06 02:23:09 1996 Received: from server1.mich.com (server1.mich.com [198.108.16.2]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id CAA07202 for ; Fri, 6 Dec 1996 02:23:08 -0600 (CST) Received: from gw-aerodata.mich.com (gw-aerodata.mich.com [198.108.16.240]) by server1.mich.com (8.7.6/8.7.3) with SMTP id DAA13892; Fri, 6 Dec 1996 03:23:25 -0500 Message-Id: <2.2.32.19961206082353.006f9098@mich.com> X-Sender: jeff@mich.com X-Mailer: Windows Eudora Pro Version 2.2 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Fri, 06 Dec 1996 03:23:53 -0500 To: ss@tapr.org From: Jeff King Subject: Re: [SS:619] Re: Horz Omnis Cc: cestey@millcomm.com Correct me if I get anything wrong Greg. At 05:15 PM 12/5/96 -0600, Carl Estey wrote: >What are the power restrictions under the STA in the 900-Mhz band? I believe its 100watts output. >Has >anyone done anything with homebrewing PAs? How critical is the switching >time of some of the hybrid devices available? You mean the cell phone bricks? I'd say you'd want 200us or less switching time. >This might be a cheap way out >instead of the six hundred buck commercial amp I heard about? How good are >the receivers (sensitivity) on the Beta Test group units? Sensitivity is -110db on the reciever. Bandwidth of the hopped signal is about 200khz. I believe there are 115 or so 'channels' it can hop to across 902-928mhz. -Jeff From Robert.Glassey@nmp.nokia.com Fri Dec 06 06:18:32 1996 Received: from noknic.nokia.com (noknic.nokia.com [131.228.6.10]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id GAA14638 for ; Fri, 6 Dec 1996 06:18:30 -0600 (CST) From: Robert.Glassey@nmp.nokia.com Received: from samail01.nmp.nokia.com (samail01.nmp.nokia.com [131.228.240.6]) by noknic.nokia.com (8.6.9/8.6.9) with ESMTP id OAA16635 for ; Fri, 6 Dec 1996 14:17:46 +0200 Received: from by samail01.nmp.nokia.com with SMTP (1.37.109.20/16.2) id AA029024555; Fri, 6 Dec 1996 14:15:55 +0200 X-Openmail-Hops: 2 Date: Fri, 6 Dec 96 12:14:22 +0000 Message-Id: In-Reply-To: <"v0300780caecca90354e4(a)(091)208.134.134.42(093)*"@MHS> Subject: [SS:616] Re: SS below 70cm? Sender: Robert.Glassey@nmp.nokia.com To: ss@tapr.org Greg wrote: > Looking forward to reading about your designs and implementations. Most of the phD stuff was theoretical relating to multipath and propagation, but there were two SS systems I was involved in (not related to work): The most unusual was adding DSSS to standard FM. Here the chip clock was derived from the the carrier frequency using a prescaler, and at the receiver an early-late corrolator was used to control a VCO which the RX DSSS sequence was derived from. Also the demodulated FM could be taken from the VCO control line! I wasn't directly involved in the construction of this, but it was an interesting project to be associated with. The other was a more conventional DSSS system, which was more construction than theory. The heart of the RX was a synchronous oscilator which locked the chip rate to the demodulated data rate. When it was out of lock the sync oscilator wandered untill corrolation was hit, then the despread data edges locked the sync oscilator. This was a spare time project with a few guys at work, and we had the main baseband and IF parts of it going on the bench but I left the company before we got it onto RF, we intended to use the 900MHz ISM band. We looked at several types of syncing architectures but the syncronous oscilator was the easiest for a first hack. Of course it was far from an optimum system. I've also played around a bit with the Cylink 900MHz SS boxes a while back, and more recently have taken an interest in IS-95. > >We have been given almost ideal frequencies for SS networks yet some > >people want to throw them away and fight other amateurs for spectrum > >that is much less than ideal anyway! > > > >This is what baffels me! > It doesn't me. Amateur Radio is about doing what you want to do to > expand your operating knowledge, education, or interest. > You believe and will develop stuff for the higher bands -- great! > There will be others that will want to operate someplace else. > No problem. That is the great thing about amateur radio. Yeah, OK, you have a point, it just seems like wasted effort that causes a lot of unnessesary agro, when you could be gaining support and retaining valuable bands. Cheers, Rob From Robert.Glassey@nmp.nokia.com Fri Dec 06 06:18:52 1996 Received: from noknic.nokia.com (noknic.nokia.com [131.228.6.10]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id GAA14655 for ; Fri, 6 Dec 1996 06:18:50 -0600 (CST) From: Robert.Glassey@nmp.nokia.com Received: from samail01.nmp.nokia.com (samail01.nmp.nokia.com [131.228.240.6]) by noknic.nokia.com (8.6.9/8.6.9) with ESMTP id OAA16787 for ; Fri, 6 Dec 1996 14:18:17 +0200 Received: from by samail01.nmp.nokia.com with SMTP (1.37.109.20/16.2) id AA029154590; Fri, 6 Dec 1996 14:16:30 +0200 X-Openmail-Hops: 2 Date: Fri, 6 Dec 96 12:15:04 +0000 Message-Id: Subject: Re: SS below 70cm? Sender: Robert.Glassey@nmp.nokia.com To: ss@tapr.org Phil wrote: > I actually agree with much that you say. 2m is probably not the place > for a large-scale SS packet radio computer network that could perhaps > be better built on 1.2 or 2.4 GHz. Thanks. Yip, I reckon this is definatly the way to go for a data network, I reckon this is an area of massive potential for ham radio. > Yet SS can support much more than packet radio as it is traditionally > understood in the amateur service. In particular, systems like IS-95 > CDMA can be directly adapted to provide FM-repeater-like land mobile > voice services with much greater spectral efficiency. Isn't this > something of the *most* potential interest on our most congested FM > bands, e.g., 2m? > allocations ran out 20+ years ago. If you'll pardon my language, this > strikes me as a classic "f*** you Jack, I'm all right" attitude. OK I see your point here, the situation is obviously a little different there compared to what I have experianced. It doesn't seem very good if you have all the repeater channels in an area allocated and only enough activity to justify a few. In this situation it would be nice to retire some of the existing repeaters on 2m and 70cm in due course and replace them with a IS-95 type system, while still leaving a reasonable base of FM repeaters, and not touching parts of the band where a high noise floor would be a potential problem (even if it isn't in 99% of real cases). We would need to get commercial support (eventually) from the big 3 (or someone else) to produce IS-95 handhelds etc. It still seams easier to do this on higher bands, and leave 2m repeaters to die a natural death in the face of competition. I agree this monopoly of allocated frequency for a dozen unnessesary repeaters is not very good, and your quote sounds like it is appropriate! > On the weak signal side, my goal is not to blanket the 2m weak signal > band with indiscriminate strong SS signals, but to enable the use of > forward error correction to enhance the DX operations that already go > on there. The problem is that the same bandwidth limits that preclude > the SS operations that may not make sense in the DX bands also work to > preclude the potentially advantageous use of forward error > correction. How wide? of course with DX you want to put as much power into the air as possible, to go that last mile. This would be the whole point of using FEC on a DX link, it wouldn't be used to allow reduced TX power, but rather to make better use of the power you already have. So how wide? Would it be possible (regulations permitting) to allocate a small segment say 100kHz wide to SS-DX? Chanalised into say 25kHz channels to allow different TX and RX from nearby sites. Perhaps it would be better to allocate these channels as far from each other as possible, squeezed in where they might fit. It a coordinated proposal as submitted to the FCC/frequceny coordinators could the regulations and allocations be changed to allow this? Perhaps specific proposals might have better success than generally asking for allocations that would allow anyone "to blanket the 2m weak signal band with indiscriminate strong SS signals" wheather the intended to or not. > That's because FEC must either increase bandwidth or > reduce throughput in order to work its greatest power > gains. One thing I like about SS and FEC is that your extra FEC data only costs you processing gain, but gives a lot more in return. It seems possible to apply FEC as the last step in the despeading to acheive much better Eb/No performance. Its like the FEC comes for free with SS. Cheers, Rob From wb9mjn@wb9mjn.ampr.org Fri Dec 06 08:36:59 1996 Received: from wb9mjn.ampr.org (wb9mjn.ampr.org [44.72.98.19]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id IAA19516 for ; Fri, 6 Dec 1996 08:36:49 -0600 (CST) From: wb9mjn@wb9mjn.ampr.org Date: Fri, 06 Dec 96 08:20:15 UTC Message-Id: <11579@wb9mjn.ampr.org> To: ss@tapr.org Subject: Re: [SS:615] Horz Omnis In-Reply-To: your message of Thu Dec 05 10:33:58 1996 Hi Greg, Glen, others ? Horizontal polarisation gives me the willies, hi. I remember when we used the same logic, that all the other inband activity was vertical, on our first 220/9600 baud link. Turns out, we opened up a whole new can of worms. By exposing the RF to 20 dB stronger TV noise, some distance away in the spectrum, we ended up with a Image response problem instead. Has anybody checked the first IF freq, and LO injection side? To see what TV stations would be at Image frequencies? And, of course, there is radar up higher, FAA radar. Which is usually horizontally polarised as well. Its just above a Ghz, typically. Our Manhattan, IL site sees the southern FAA terminal control area radar for Ohare Airport, hi! Back in 1986, We went back vertical, and had no more problems. BTW, I have completed a 915 Mhz prototype microstrip patch antenna with good results. Email me for more details. This antenna can be used vertical or horizontally polarized. Simply by tipping it sideways, hi. Its a single patch. Which is the electrical dual to a 2 slot array, only unidirectional. 73, Don. Mailbox : WB9MJN @ N9HSI.IL.USA.NA AMPRNet : wb9mjn@wb9mjn.ampr.org[44.72.98.19] Internet: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu From glenne@hpsadr2.sr.hp.com Fri Dec 06 10:00:31 1996 Received: from palrel1.hp.com (palrel1.hp.com [15.253.72.10]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id KAA22221 for ; Fri, 6 Dec 1996 10:00:29 -0600 (CST) Received: from srmail.sr.hp.com (srmail.sr.hp.com [15.4.45.14]) by palrel1.hp.com with ESMTP (8.7.5/8.7.3) id IAA11322 for ; Fri, 6 Dec 1996 08:00:27 -0800 (PST) Received: from hpsadr2.sr.hp.com (n6gn.sr.hp.com) by srmail.sr.hp.com with ESMTP (1.37.109.16/15.5+ECS 3.3) id AA140158026; Fri, 6 Dec 1996 08:00:27 -0800 Received: by hpsadr2.sr.hp.com (1.37.109.16/15.5+ECS 3.3) id AA205118025; Fri, 6 Dec 1996 08:00:25 -0800 From: Glenn Elmore Message-Id: <199612061600.AA205118025@hpsadr2.sr.hp.com> Subject: Re: [SS:621] Re: Interest in a Senior Project To: ss@tapr.org (Phil Karn) Date: Fri, 6 Dec 1996 08:00:24 -0800 (PST) In-Reply-To: <199612060415.UAA20094@servo.qualcomm.com> from "Phil Karn" at Dec 5, 96 10:21:48 pm X-Mailer: ELM [version 2.4 PL21] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Phil > In my opinion, one of the most useful hardware projects in this area > would be a general purpose digital software radio. That is, a radio in > which as much of the back end as possible is replaced by software > and/or dedicated DSP hardware. This is now a common industry > technique, including IS-95 CDMA equipment. this is just about exactly the charter I have placed on L3TNCRF, further described on my web pages. However, getting time to get it into distributable form is difficult for me. Glenn n6gn amateur IP: glenn@SantaRosa.ampr.org Internet: glenne@sr.hp.com |--------------- N6GN's Higher Speed Packet WWW Page -------------------| | | | http://www.tapr.org/~n6gn/index.html | | | |-----------------------------------------------------------------------| From glenne@hpsadr2.sr.hp.com Fri Dec 06 10:11:48 1996 Received: from palrel1.hp.com (palrel1.hp.com [15.253.72.10]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id KAA22740 for ; Fri, 6 Dec 1996 10:11:47 -0600 (CST) Received: from srmail.sr.hp.com (srmail.sr.hp.com [15.4.45.14]) by palrel1.hp.com with ESMTP (8.7.5/8.7.3) id IAA12292 for ; Fri, 6 Dec 1996 08:11:46 -0800 (PST) Received: from hpsadr2.sr.hp.com (n6gn.sr.hp.com) by srmail.sr.hp.com with ESMTP (1.37.109.16/15.5+ECS 3.3) id AA141288705; Fri, 6 Dec 1996 08:11:45 -0800 Received: by hpsadr2.sr.hp.com (1.37.109.16/15.5+ECS 3.3) id AA236908704; Fri, 6 Dec 1996 08:11:44 -0800 From: Glenn Elmore Message-Id: <199612061611.AA236908704@hpsadr2.sr.hp.com> Subject: Re: [SS:623] Re: Horz Omnis To: ss@tapr.org (Jeff King) Date: Fri, 6 Dec 1996 08:11:44 -0800 (PST) In-Reply-To: <2.2.32.19961206082353.006f9098@mich.com> from "Jeff King" at Dec 6, 96 02:27:47 am X-Mailer: ELM [version 2.4 PL21] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit > >Has > >anyone done anything with homebrewing PAs? How critical is the switching > >time of some of the hybrid devices available? > > You mean the cell phone bricks? I'd say you'd want 200us or less switching > time. > > >This might be a cheap way out > >instead of the six hundred buck commercial amp I heard about? How good are > >the receivers (sensitivity) on the Beta Test group units? The Mitsubisha/Toshibi/Matsushita driver/PA/T-R modules I used in the 230 kbps 904 MHz FSK radios were quite inexpensive. Up to the output stage they are linear with the two last devices biased class C but these can be rebiased for linear operation, as I've already done for OCAR use. The entire power train and T-R switch can turn around in under 10 us using only 3 terminal regulators as bias switches. However, I don't understand why adding 10-20 dB of transmit power gain is a useful endeavor compared to the alternatives. If 1 watt isn't enough for your link, either the path or something in the hardware is extremely bad. On the receive side, 3 dB noise figure is really about all that is necessary for a terrestrial link. The antenna temperature is at about that level and improvements beyond this level in the receive preamp are not particularly rewarded. Additional gain *is* likely to increase distortion products in downstream stages; mixers and IF amplifiers. All in all, I don't think that additional gain on either transmit or receive is normally a very good place to first look to start improving the system. Glenn n6gn From glenne@hpsadr2.sr.hp.com Fri Dec 06 10:27:21 1996 Received: from palrel1.hp.com (palrel1.hp.com [15.253.72.10]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id KAA23348 for ; Fri, 6 Dec 1996 10:27:19 -0600 (CST) Received: from srmail.sr.hp.com (srmail.sr.hp.com [15.4.45.14]) by palrel1.hp.com with ESMTP (8.7.5/8.7.3) id IAB13758 for ; Fri, 6 Dec 1996 08:27:18 -0800 (PST) Received: from hpsadr2.sr.hp.com (n6gn.sr.hp.com) by srmail.sr.hp.com with ESMTP (1.37.109.16/15.5+ECS 3.3) id AA144359637; Fri, 6 Dec 1996 08:27:18 -0800 Received: by hpsadr2.sr.hp.com (1.37.109.16/15.5+ECS 3.3) id AA261889637; Fri, 6 Dec 1996 08:27:17 -0800 From: Glenn Elmore Message-Id: <199612061627.AA261889637@hpsadr2.sr.hp.com> Subject: Re: [SS:626] Re: Horz Omnis To: ss@tapr.org Date: Fri, 6 Dec 1996 08:27:16 -0800 (PST) In-Reply-To: <11579@wb9mjn.ampr.org> from "ss@tapr.org" at Dec 6, 96 08:38:34 am X-Mailer: ELM [version 2.4 PL21] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit >From Don: > > Horizontal polarisation gives me the willies, hi. I remember when we > used the same logic, that all the other inband activity was vertical, on our > first 220/9600 baud link. Turns out, we opened up a whole new can of worms. > By exposing the RF to 20 dB stronger TV noise, some distance away in the > spectrum, we ended up with a Image response problem instead. > I've run both polarizations over the years on most of the vhf-microwave bands, in different circumstances. We used polarization diversity briefly to try and reduce some ISM QRM at 900 MHz. In general, any improvements due to picking a specific polarizaion around here have been fairly small to unnoticable. There is some theoretical basis for preferring or rejecting horizontal polarization under certain conditions. In situations where potential interferers are LOS and the polarization of their signals has not yet been corrupted by diffraction and scattering (perhaps as in your TV example) running orthogonal to them can be useful. However, around here, it hasn't generally proved to be all that useful. If the radio systems have poor out-of-band rejection or poor large signal perfomance those problems should probably be corrected at somewhere besides the antenna anyway. If the signals are in-band, antenna directivity is often more useful than relying on polarization isolation to reduce the interferring signals. In addition, many antennas which have a given polarization in the main beam exhibit significant orthogonal polarizations off the sides or back. Glenn n6gn From fred@tekdata.com Fri Dec 06 11:01:13 1996 Received: from tekdata.com (vh1-012.wwa.com [205.243.70.13]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id LAA24894 for ; Fri, 6 Dec 1996 11:01:05 -0600 (CST) Received: (from fred@localhost) by tekdata.com (8.6.12/8.6.12) id KAA00802; Fri, 6 Dec 1996 10:04:23 -0600 Date: Fri, 6 Dec 1996 10:04:23 -0600 (CST) From: "Fred M. Spinner" To: ss@tapr.org Subject: Re: [SS:622] Re: SS below 70cm? In-Reply-To: <199612060520.VAA20245@servo.qualcomm.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Actually, from an engineering standpoint, I kinda think FHSS is the way to go on 6m, 2m, & 220.. but I think it would be nice for it to be legal to do DSSS also. On FHSS, just use unused or underused NB channels... Oh DSSS-- 52 MHz is a very do-able range for even TTL parts. I would suspect it could be a good IF for DSSS rigs that eventually are transverted to microwave, but there is a bit of an advantage to be allowed to try it out before knocking it up to microwave... Also remember some of us are "flatlanders" and there is often a terrain issue with microwave. I don't think my neighbors would like more than one dish on top of my house! VHF and UHF have the advantage of traveling reasonably through trees, etc... I see use for both microwaves and VHF/UHF with SS.. I do agree that utilization of the Microwave bands is more vital to ham radio than SS is at all. But that's a Apple to Orange comparison! Fred M. Spinner, KA9VAW fred@tekdata.com, ka9vaw@amsat.org From jeff@mich.com Fri Dec 06 13:00:34 1996 Received: from server1.mich.com (server1.mich.com [198.108.16.2]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id NAA00455 for ; Fri, 6 Dec 1996 13:00:32 -0600 (CST) Received: from gw-aerodata.mich.com (gw-aerodata.mich.com [198.108.16.240]) by server1.mich.com (8.7.6/8.7.3) with SMTP id OAA09504; Fri, 6 Dec 1996 14:01:24 -0500 Message-Id: <2.2.32.19961206190112.006ca7d0@mich.com> X-Sender: jeff@mich.com X-Mailer: Windows Eudora Pro Version 2.2 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Fri, 06 Dec 1996 14:01:12 -0500 To: ss@tapr.org, ss@tapr.org From: Jeff King Subject: Re: [SS:628] Re: Horz Omnis At 10:12 AM 12/6/96 -0600, Glenn Elmore wrote: >The Mitsubisha/Toshibi/Matsushita driver/PA/T-R modules I used in the >230 kbps 904 MHz FSK radios were quite inexpensive. Up to the output >stage they are linear with the two last devices biased class C but these >can be rebiased for linear operation, as I've already done for OCAR use. >The entire power train and T-R switch can turn around in under 10 us >using only 3 terminal regulators as bias switches. They have a web site and/or distributor? Interested in those. > >However, I don't understand why adding 10-20 dB of transmit power gain >is a useful endeavor compared to the alternatives. If 1 watt isn't >enough for your link, either the path or something in the hardware is >extremely bad. Yes, true. But putting the amplifier/pre-amp at the antenna allows you to use less expensive coax. This often can pay for the additional price of the amp (9913 vs. LMR-600). Also, 10-20db is often the difference between a good path and a unusable path. Remember that foilage loss at 900mhz is considerablly more then at 2 metres. Getting antennas at "line of sight" at 900mhz is harder then 2 metres because the 900mhz antennas can't "see" through trees as well as 2 metres. Also, many of us don't live in areas that have easy line of sight paths and/or that are heavily wooded (like Michigan :-(. -Jeff wb8wka From wpns@world.std.com Fri Dec 06 13:19:54 1996 Received: from europe.std.com (europe.std.com [199.172.62.20]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id NAA01443 for ; Fri, 6 Dec 1996 13:19:52 -0600 (CST) Received: from world.std.com by europe.std.com (8.7.5/BZS-8-1.0) id OAA28825; Fri, 6 Dec 1996 14:19:50 -0500 (EST) Received: by world.std.com (5.65c/Spike-2.0) id AA15496; Fri, 6 Dec 1996 14:19:42 -0500 From: wpns@world.std.com (William Smith) Message-Id: <199612061919.AA15496@world.std.com> Subject: Syncronizing SS systems? To: ss@tapr.org Date: Fri, 6 Dec 1996 14:19:42 -0500 (EST) In-Reply-To: from "Robert.Glassey@nmp.nokia.com" at Dec 6, 96 06:23:33 am X-Mailer: ELM [version 2.4 PL25] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Robert.Glassey@nmp.nokia.com sez: >The most unusual was adding DSSS to standard FM. Here the chip clock was >construction than theory. The heart of the RX was a synchronous >oscilator which locked the chip rate to the demodulated data rate. When >it was out of lock the sync oscilator wandered untill corrolation was >hit, then the despread data edges locked the sync oscilator. This was a >several types of syncing architectures but the syncronous oscilator was >the easiest for a first hack. Of course it was far from an optimum How _do_ you syncronize SS systems, how long does it take to 'lock', and how long are you unlocked if something goes wrong? >I've also played around a bit with the Cylink 900MHz SS boxes a while >back, and more recently have taken an interest in IS-95. What's IS-95? -- Willie Smith wpns@world.std.com N1JBJ@amsat.org #define NII Information SuperCollider From bad@uhf.wireless.net Fri Dec 06 14:21:51 1996 Received: from uhf.wdc.net (uhf.wdc.net [198.147.74.44]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id OAA04025 for ; Fri, 6 Dec 1996 14:21:47 -0600 (CST) Received: (from bad@localhost) by uhf.wdc.net (8.8.3/8.6.12) id PAA02234; Fri, 6 Dec 1996 15:22:31 -0500 (EST) Date: Fri, 6 Dec 1996 15:22:29 -0500 (EST) From: Bernie Doehner To: ss@tapr.org Subject: good reference books for Barker codes. Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi: Is there a good reference book for Barker Codes that you might be able to recommend? Bernie From glenne@hpsadr2.sr.hp.com Fri Dec 06 14:48:16 1996 Received: from palrel1.hp.com (palrel1.hp.com [15.253.72.10]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id OAA05321 for ; Fri, 6 Dec 1996 14:48:15 -0600 (CST) Received: from srmail.sr.hp.com (srmail.sr.hp.com [15.4.45.14]) by palrel1.hp.com with ESMTP (8.7.5/8.7.3) id MAA08550 for ; Fri, 6 Dec 1996 12:48:14 -0800 (PST) Received: from hpsadr2.sr.hp.com (n6gn.sr.hp.com) by srmail.sr.hp.com with ESMTP (1.37.109.16/15.5+ECS 3.3) id AA183015292; Fri, 6 Dec 1996 12:48:13 -0800 Received: by hpsadr2.sr.hp.com (1.37.109.16/15.5+ECS 3.3) id AA226405291; Fri, 6 Dec 1996 12:48:11 -0800 From: Glenn Elmore Message-Id: <199612062048.AA226405291@hpsadr2.sr.hp.com> Subject: Re: [SS:631] Re: Horz Omnis To: ss@tapr.org (Jeff King) Date: Fri, 6 Dec 1996 12:48:11 -0800 (PST) In-Reply-To: <2.2.32.19961206190112.006ca7d0@mich.com> from "Jeff King" at Dec 6, 96 01:02:01 pm X-Mailer: ELM [version 2.4 PL21] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit k Jeff wb8wka wrote: > (I wrote) > >The Mitsubisha/Toshibi/Matsushita driver/PA/T-R modules I used in the > >230 kbps 904 MHz FSK radios were quite inexpensive. Up to the output > >stage they are linear with the two last devices biased class C but these > >can be rebiased for linear operation, as I've already done for OCAR use. > >The entire power train and T-R switch can turn around in under 10 us > >using only 3 terminal regulators as bias switches. > > They have a web site and/or distributor? Interested in those. RF Parts seems to have a pretty good supply of modules; drivers and PAs and a limited supply of PIN T/R switches. Mitsubishi has been promising to get stateside warehousing of these parts but I haven't heard for sure that they have succeeded. > Yes, true. But putting the amplifier/pre-amp at the antenna allows > you to use less expensive coax. This often can pay for the additional > price of the amp (9913 vs. LMR-600). Also, 10-20db is often the difference > between a good path and a unusable path. Remember that foilage loss at > 900mhz is considerablly more then at 2 metres. Getting antennas at > "line of sight" at 900mhz is harder then 2 metres because the 900mhz > antennas can't "see" through trees as well as 2 metres. Also, many of > us don't live in areas that have easy line of sight paths and/or that > are heavily wooded (like Michigan :-(. It's true that line loss can be important, and with 2 dB of system degradation per db of line loss it holds even more importance than straight transmit power or receive noise floor alone since it applys to both transmit and receive. I've made many measurements of path loss of amateur links at 2M through 3cm and I've been operating in, around and through trees at 900 MHz for ~7 years, 24 hours/day. However, I still hold that adding excessive transmit power or receive gain is normally not addressing the "big ticket items". Please see: http://www.tapr.org/~n6gn/dcc/problem.html for my response and support for this view. Glenn n6gn From chbrain@dircon.co.uk Fri Dec 06 15:49:22 1996 Received: from felix.dircon.co.uk (felix.dircon.co.uk [193.128.224.10]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id PAA08042 for ; Fri, 6 Dec 1996 15:49:18 -0600 (CST) Received: by felix.dircon.co.uk id AA11294 (5.67b/IDA-1.5 for ); Fri, 6 Dec 1996 21:41:14 GMT Received: from gw2-118.pool.dircon.co.uk(194.112.35.118) by amnesiac via smap (V1.3) id sma011283; Fri Dec 6 21:40:53 1996 Message-Id: <1.5.4.32.19961206213545.0066b234@popmail.dircon.co.uk> X-Sender: chbrain@popmail.dircon.co.uk X-Mailer: Windows Eudora Light Version 1.5.4 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Fri, 06 Dec 1996 21:35:45 +0000 To: ss@tapr.org From: Charles Brain Subject: Re: [SS:633] good reference books for Barker codes. At 14:23 06/12/96 -0600, you wrote: >Hi: > >Is there a good reference book for Barker Codes that you might be able to >recommend? > >Bernie > > > > Try the back of the ARRL SS Sourcebook. Regards Charles G4GUO From rlanier@su102s.ess.harris.com Fri Dec 06 16:18:12 1996 Received: from ess.harris.com (su15a.ess.harris.com [130.41.1.251]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id QAA09379 for ; Fri, 6 Dec 1996 16:18:10 -0600 (CST) Received: from losalamos.ess.harris.com (su102s.ess.harris.com [130.41.13.101]) by ess.harris.com (8.8.3/8.8.3) with SMTP id RAA18941 for ; Fri, 6 Dec 1996 17:18:06 -0500 (EST) Received: from Paris.GASD102designcenter by losalamos.ess.harris.com (4.1/SMI-4.1) id AA08553; Fri, 6 Dec 96 17:18:06 EST Received: by Paris.GASD102designcenter (SMI-8.6/SMI-SVR4) id RAA12017; Fri, 6 Dec 1996 17:18:04 -0500 Date: Fri, 6 Dec 1996 17:18:04 -0500 From: rlanier@su102s.ess.harris.com (Tony Lanier) Message-Id: <199612062218.RAA12017@Paris.GASD102designcenter> To: ss@tapr.org Subject: Re: [SS:617] Re: SS below 70cm? X-Sun-Charset: US-ASCII > just a tiny reality check as far as use of spectrum is concerned, it > seems to me that avionics still to this day use AM for their > modulo-format now why aren't we screaming for the FAA to madate FHSS for > the air industry ? :) > just a small reality check that's all > de N7BFS Doug Cole How is this a reality check? From clh10@po.cwru.edu Fri Dec 06 16:55:18 1996 Received: from cornelius.INS.CWRU.Edu (root@cornelius.INS.CWRU.Edu [129.22.8.216]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id QAA11118 for ; Fri, 6 Dec 1996 16:55:17 -0600 (CST) Received: from [129.22.249.174] (wormwood.STUDENT.CWRU.Edu [129.22.249.174]) by cornelius.INS.CWRU.Edu with SMTP (8.7.6+cwru/CWRU-3.0) id RAA25137; Fri, 6 Dec 1996 17:55:16 -0500 (EST) (from clh10@po.cwru.edu for ) Date: Fri, 6 Dec 1996 17:55:16 -0500 (EST) X-Sender: clh10@pop.cwru.edu Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: clh10@po.cwru.edu (clh10@po.cwru.edu) Subject: Re: [SS:632] Syncronizing SS systems? >What's IS-95? IS-95 is the commercial CDMA system used for Cellular communications. For more information, you might try the following web page. http://www.cdg.org/a_ross/CAI.html Cory L. Hojka Beta Nu of Theta Chi Fraternity Case Western Reserve University Cleveland, OH From bad@uhf.wireless.net Fri Dec 06 17:16:35 1996 Received: from uhf.wdc.net (uhf.wdc.net [198.147.74.44]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id RAA11994 for ; Fri, 6 Dec 1996 17:16:31 -0600 (CST) Received: (from bad@localhost) by uhf.wdc.net (8.8.3/8.6.12) id SAA00615; Fri, 6 Dec 1996 18:16:58 -0500 (EST) Date: Fri, 6 Dec 1996 18:16:56 -0500 (EST) From: Bernie Doehner To: ss@tapr.org Subject: Re: [SS:635] Re: good reference books for Barker codes. In-Reply-To: <1.5.4.32.19961206213545.0066b234@popmail.dircon.co.uk> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII > Try the back of the ARRL SS Sourcebook. > > Regards Charles G4GUO > Hi Charles: Are you serious? I at one point almost bought the sourcebook but people advised against it because they said it was too superficial. Maybe that statement doesn't apply to Coding. I'll try to find it around here. Bernie From karn@qualcomm.com Fri Dec 06 18:26:09 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id SAA15757 for ; Fri, 6 Dec 1996 18:26:07 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id QAA22299; Fri, 6 Dec 1996 16:25:36 -0800 (PST) Date: Fri, 6 Dec 1996 16:25:36 -0800 (PST) From: Phil Karn Message-Id: <199612070025.QAA22299@servo.qualcomm.com> To: ss@tapr.org In-reply-to: (Robert.Glassey@nmp.nokia.com) Subject: Re: [SS:624] Re: SS below 70cm? Robert, Have any of the SS systems you worked on used FEC? I'm surprised that so many commercial systems do not (including apparently the Cylink boxes). As Viterbi has said very well, FEC is absolutely free in a spread system and there is no reason (other than laziness) not to do it. And it can make a dramatic difference in performance and QRM potential. Phil From karn@qualcomm.com Fri Dec 06 18:40:17 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id SAA16409 for ; Fri, 6 Dec 1996 18:40:15 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id QAA22352; Fri, 6 Dec 1996 16:39:44 -0800 (PST) Date: Fri, 6 Dec 1996 16:39:44 -0800 (PST) From: Phil Karn Message-Id: <199612070039.QAA22352@servo.qualcomm.com> To: ss@tapr.org In-reply-to: <199612061611.AA236908704@hpsadr2.sr.hp.com> (message from Glenn Elmore on Fri, 6 Dec 1996 10:12:53 -0600 (CST)) Subject: Re: [SS:628] Re: Horz Omnis >All in all, I don't think that additional gain on either transmit or >receive is normally a very good place to first look to start improving >the system. I heartily agree. If anything, we need the ability to *reduce* gain on the transmit side to whatever is actually required... Phil From karn@qualcomm.com Fri Dec 06 18:52:17 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id SAA17010 for ; Fri, 6 Dec 1996 18:52:16 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id QAA22368; Fri, 6 Dec 1996 16:51:44 -0800 (PST) Date: Fri, 6 Dec 1996 16:51:44 -0800 (PST) From: Phil Karn Message-Id: <199612070051.QAA22368@servo.qualcomm.com> To: ss@tapr.org In-reply-to: (fred@tekdata.com) Subject: Re: [SS:630] Re: SS below 70cm? >Actually, from an engineering standpoint, I kinda think FHSS is the way to >go on 6m, 2m, & 220.. but I think it would be nice for it to be legal >to do DSSS also. >On FHSS, just use unused or underused NB channels... I agree, FHSS is almost certainly the way to go on these bands from an engineering standpoint. With burst-error-resistant coding, it can resist a few narrowband jammers much better than direct sequence. DS, on the other hand, can generally achieve better Eb/N0 performance against gaussian noise (because it's easier to demodulate coherently) which makes it the method of choice on more controlled-access channels, like cellular telephony. Phil From ssampson@oklahoma.net Fri Dec 06 19:38:02 1996 Received: from dns.okc (dns.oklahoma.net [208.2.112.2]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id TAA19958 for ; Fri, 6 Dec 1996 19:38:00 -0600 (CST) Received: from disco.okc.oklahoma.net by dns.okc (SMI-8.6/SMI-SVR4) id TAA25350; Fri, 6 Dec 1996 19:41:58 -0600 Message-Id: <199612070141.TAA25350@dns.okc> From: "Steve Sampson" To: Subject: Re: [SS:636] Re: SS below 70cm? Date: Fri, 6 Dec 1996 19:35:36 -0600 X-MSMail-Priority: Normal X-Priority: 3 X-Mailer: Microsoft Internet Mail 4.70.1155 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit > > just a tiny reality check as far as use of spectrum is concerned, it > > seems to me that avionics still to this day use AM for their > > modulo-format now why aren't we screaming for the FAA to madate FHSS for > > the air industry ? :) > > just a small reality check that's all > > How is this a reality check? I don't understand the reality-check reference either, unless you mean we are as backwards as aviation :-) Having flown for 14 years I find the whole aviation system an even bigger joke than Ham radio. But it is crippled by a staggering bureaucracy. One thing I was glad for, was the fact that we had our own radar and could basically exit the air route system and participate in the air space system. One thing the Soviet and American military agreed upon, was that the FAA was an impediment, and we did the cold war wherever we damn well pleased :-) I watched the Mode-S system wither on the vine, because the FAA cannot interface to it with its tube based computers. But basically it is a digital link on the IFF/SIF frequency. The idea being that voice communications was really an impediment to commercial aviation. The TCAS (Threat Collision and Avoidance) system was projected to operate in a Mode-S environment, but now competes with bandwidth for the old IFF/SIF system. The reason this is bad, is that any airplane is being hit by hundreds of other airplanes as well as the ground sites. The ground sites with Mode-S would have cut their transmissions by 75% thus freeing up the bandwidth. You know how an IFF/SIF system finds the azimuth of a target? They spray through the air a continuous stream of interrogations, and then when they start getting replies, they remember the start reply and then when the replies stop, they remember the last reply. The azimuth then is the end minus the start divided by two. It works, is not very accurate, and is very wasteful of bandwdth. I think the "new" FAA being released into the commercial arena is probably going to be the most exciting industry to be in. Wait ten years, and we will see 118 - 136 MHz being released to the public. It will be worthless for aviation, as 2 meters is for Ham radio. Steve From karn@qualcomm.com Fri Dec 06 20:57:10 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id UAA24342 for ; Fri, 6 Dec 1996 20:57:09 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id SAA22765; Fri, 6 Dec 1996 18:56:38 -0800 (PST) Date: Fri, 6 Dec 1996 18:56:38 -0800 (PST) From: Phil Karn Message-Id: <199612070256.SAA22765@servo.qualcomm.com> To: ss@tapr.org In-reply-to: <199612061919.AA15496@world.std.com> (wpns@world.std.com) Subject: Re: [SS:632] Syncronizing SS systems? >How _do_ you syncronize SS systems, how long does it take to 'lock', >and how long are you unlocked if something goes wrong? In a DS system (which I know best), the usual method is to just search through the whole spreading sequence looking for a correlation peak to jump out of the noise. The speed at which you can search is a function of the Ec/N0 (like Eb/N0, but per chip) -- the stronger the signal, the faster you can search while remaining likely to detect the signal. How long it takes depends on the length of the sequence and the search rate; on average you have to search half the sequence space. In both IS-95 and GPS there is a relatively short code that's used primarily to aid acquisition: 32768 chips for IS-95, 1023 chips for GPS. Other, longer sequences can be used in combination once initial synchronization has been achieved. In the IS-95 case, it typically takes just a few seconds to acquire synchronization, about the same time it takes a conventional AMPS/FM phone to acquire and lock onto a paging channel. >What's IS-95? TIA Interim Standard 95. It describes the CDMA digital cellular air interface that we (Qualcomm) developed. See my web page for more details: and --Phil From wb9mjn@wb9mjn.ampr.org Fri Dec 06 22:18:17 1996 Received: from wb9mjn.ampr.org (wb9mjn.ampr.org [44.72.98.19]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id WAA27722 for ; Fri, 6 Dec 1996 22:17:58 -0600 (CST) From: wb9mjn@wb9mjn.ampr.org Date: Fri, 06 Dec 96 22:13:06 UTC Message-Id: <11609@wb9mjn.ampr.org> To: ss@tapr.org Subject: Re: [SS:629] Re: Horz Omnis In-Reply-To: your message of Fri Dec 06 10:34:06 1996 <199612061627.AA261889637@hpsadr2.sr.hp.com> Hi Glenn, On 220/9600 and Channel 11 TV problem. We were a few miles , sky scraper top to sky scrapper top from the Channel 11 transmitter antenna. TV antennas are usually omni, so they would be expected to have similar orthogonal polarisation performance in all the azimuthal directions. The same for 2 way style colinears. So, in this case, polarisation isolation was used. 73, Don. Mailbox : WB9MJN @ N9HSI.IL.USA.NA AMPRNet : wb9mjn@wb9mjn.ampr.org[44.72.98.19] Internet: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu From chbrain@dircon.co.uk Sat Dec 07 03:06:01 1996 Received: from felix.dircon.co.uk (felix.dircon.co.uk [193.128.224.10]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id DAA14978 for ; Sat, 7 Dec 1996 03:05:57 -0600 (CST) Received: by felix.dircon.co.uk id AA02708 (5.67b/IDA-1.5 for ); Sat, 7 Dec 1996 08:56:22 GMT Received: from gw2-142.pool.dircon.co.uk(194.112.35.142) by amnesiac via smap (V1.3) id sma002690; Sat Dec 7 08:56:04 1996 Message-Id: <1.5.4.32.19961207085052.00664884@popmail.dircon.co.uk> X-Sender: chbrain@popmail.dircon.co.uk X-Mailer: Windows Eudora Light Version 1.5.4 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sat, 07 Dec 1996 08:50:52 +0000 To: ss@tapr.org From: Charles Brain Subject: Re: [SS:638] Re: good reference books for Barker codes. At 17:23 06/12/96 -0600, you wrote: >> Try the back of the ARRL SS Sourcebook. >> >> Regards Charles G4GUO >> > >Hi Charles: > >Are you serious? I at one point almost bought the sourcebook but >people advised against it because they said it was too superficial. >Maybe that statement doesn't apply to Coding. I'll try to find it around >here. > >Bernie > > > Yes, one of the appendicies describes in about 2 pages Barker codes. I must admit it is about the only useful part of it. Regards Charles From Robert.Glassey@nmp.nokia.com Sat Dec 07 07:09:42 1996 Received: from noknic.nokia.com (noknic.nokia.com [131.228.6.10]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id HAA20832 for ; Sat, 7 Dec 1996 07:09:40 -0600 (CST) From: Robert.Glassey@nmp.nokia.com Received: from samail01.nmp.nokia.com (samail01.nmp.nokia.com [131.228.240.6]) by noknic.nokia.com (8.6.9/8.6.9) with ESMTP id PAA02607 for ; Sat, 7 Dec 1996 15:08:37 +0200 Received: from by samail01.nmp.nokia.com with SMTP (1.37.109.20/16.2) id AA032384008; Sat, 7 Dec 1996 15:06:48 +0200 X-Openmail-Hops: 2 Date: Sat, 7 Dec 96 13:05:04 +0000 Message-Id: In-Reply-To: <199612070025.QAA22299@servo.qualcomm.com> Subject: [SS:639] Re: SS below 70cm? Sender: Robert.Glassey@nmp.nokia.com To: ss@tapr.org Phil Wrote: > Robert, > > Have any of the SS systems you worked on used FEC? I'm surprised that > so many commercial systems do not (including apparently the Cylink > boxes). > As Viterbi has said very well, FEC is absolutely free in a spread > system and there is no reason (other than laziness) not to do it. And > it can make a dramatic difference in performance and QRM potential. Nope, both the SS systems I was involved with were pretty basic demonstrators. I don't know about the Cylink boxes. But I agree FEC is well worth it for SS. When we come to making an amateur SS WAN it should definatly be part of the standard. Cheers, Rob From dcole@on-ramp.ior.com Sat Dec 07 15:05:38 1996 Received: from on-ramp.ior.com (on-ramp.ior.com [199.79.239.11]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id PAA06259 for ; Sat, 7 Dec 1996 15:05:36 -0600 (CST) Received: from pm2-18.ior.com(really [204.212.119.18]) by on-ramp.ior.com via sendmail with smtp id for ; Sat, 7 Dec 96 13:05:32 -0800 (PST) (/\##/\ Smail3.1.30.16 #30.4 built 17-mar-96) Message-ID: <32A9DBB5.56B3@on-ramp.ior.com> Date: Sat, 07 Dec 1996 13:03:49 -0800 From: doug cole Organization: spokane county communications X-Mailer: Mozilla 3.0 (Win16; I) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: [SS:632] Syncronizing SS systems? References: <199612061919.AA15496@world.std.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Please to whomever answers willie and any other questions about spread spectrum please answer it through the sig , otherwise people like me who don't know what IS-95 and all the other jargon that you engineers are using won't be assimilated by us ignorants..... I am very anxious to learn more about spread spectrum and put it to use but need info in the form of email from the sig and also from any publications that may be able to help me to learn. thanks for all the talk so far to everyone who has submitted their opinions I for one really do appreciate the interactions that I have been reading on this sig ! 73's doug cole N7BFS From dcole@on-ramp.ior.com Sat Dec 07 15:14:07 1996 Received: from on-ramp.ior.com (on-ramp.ior.com [199.79.239.11]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id PAA06459 for ; Sat, 7 Dec 1996 15:14:06 -0600 (CST) Received: from pm2-18.ior.com(really [204.212.119.18]) by on-ramp.ior.com via sendmail with smtp id for ; Sat, 7 Dec 96 13:14:03 -0800 (PST) (/\##/\ Smail3.1.30.16 #30.4 built 17-mar-96) Message-ID: <32A9DDB7.61EA@on-ramp.ior.com> Date: Sat, 07 Dec 1996 13:12:23 -0800 From: doug cole Organization: spokane county communications X-Mailer: Mozilla 3.0 (Win16; I) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: [SS:634] Re: Horz Omnis References: <199612062048.AA226405291@hpsadr2.sr.hp.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hello Glen I was wondering about your reference of "the big ticket items" and being a lowly experimenter without an engineering degree or any thing and just doing it on weekends I am not sure what those big ticket items are.... Could you point me in the right directions as far as books that might help me learn more about spread spectrum or high speed data communications ( as that is what I am actually interested in ) for amateur radio. I have just decided to dive into this part of the hobby but need some info to start on and any help you can give would be most appreciated :) 73's Doug Cole de N7BFS From fields@svpal.org Sat Dec 07 16:03:55 1996 Received: from svpal.svpal.org (fields@svpal.svpal.org [204.118.32.56]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id QAA08932 for ; Sat, 7 Dec 1996 16:03:54 -0600 (CST) Received: (from fields@localhost) by svpal.svpal.org (8.7.5/8.7.3) id OAA15277; Sat, 7 Dec 1996 14:03:31 -0800 (PST) Date: Sat, 7 Dec 1996 14:03:30 -0800 (PST) From: Carol Fields Subject: FEC To: ss@tapr.org In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII There was the implication that FEC (forward Error Correction) was almost free in SS in previous messages. What type of FEC code would you recommend and why? Would you think a hardware or software FEC is better for SS? Is there a feeling that this is better than just resending a packet? FIELDS@SVPAL.ORG Home email account of Julian and Carol Fields. On Sat, 7 Dec 1996 Robert.Glassey@nmp.nokia.com wrote: > But I agree FEC is well worth it for SS. When we come to making an > amateur SS WAN it should definatly be part of the standard. From Sjolin@aol.com Sat Dec 07 17:23:10 1996 Received: from emout20.mail.aol.com (emout20.mx.aol.com [198.81.11.46]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id RAA12334 for ; Sat, 7 Dec 1996 17:23:09 -0600 (CST) From: Sjolin@aol.com Received: by emout20.mail.aol.com (8.6.12/8.6.12) id SAA11518 for ss@tapr.org; Sat, 7 Dec 1996 18:22:39 -0500 Date: Sat, 7 Dec 1996 18:22:39 -0500 Message-ID: <961207182238_1487841560@emout20.mail.aol.com> To: ss@tapr.org Subject: Re: [SS:647] Re: Syncronizing SS systems? In a message dated 96-12-07 16:49:41 EST, you write: << am very anxious to learn more about spread spectrum and put it to use but need info in the form of email from the sig and also from any publications that may be able to help me to learn. >> Check TAPR website. I believe it is www. tapr.org. They have an excellent write ups by NK6K and others. 73 de Dave, N0IT From clh10@po.cwru.edu Sat Dec 07 18:16:06 1996 Received: from arthur.INS.CWRU.Edu (root@arthur.INS.CWRU.Edu [129.22.8.215]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id SAA14136 for ; Sat, 7 Dec 1996 18:16:02 -0600 (CST) Received: from [129.22.249.174] (wormwood.STUDENT.CWRU.Edu [129.22.249.174]) by arthur.INS.CWRU.Edu with SMTP (8.7.6+cwru/CWRU-3.0) id TAA11718; Sat, 7 Dec 1996 19:16:01 -0500 (EST) (from clh10@po.cwru.edu for ) Date: Sat, 7 Dec 1996 19:16:01 -0500 (EST) X-Sender: clh10@pop.cwru.edu Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: clh10@po.cwru.edu (clh10@po.cwru.edu) Subject: Re: [SS:649] FEC >There was the implication that FEC (forward Error >Correction) was almost free in SS in previous messages. >What type of FEC code would you recommend and why? >Would you think a hardware or software FEC >is better for SS? >Is there a feeling that this is better than >just resending a packet? As an example, IS-95 uses the combination of Convolutional Encoding along with Block Interleaving. Convolutional encoding in IS-95 gives two bits for every bit put into the Convolutional Encoder (This defines the convolutional encoder as being of rate 1/2. If it were three bits for every input bit, the rate would be 1/3). These two bits represent transitions from one data state to another. Since there are only certain valid transtions from one state to another, a wrong transition can be possibly detected and corrected. The other technique is interleaving. Data is entered row by row into an array of I rows and J columns, it is then taken out by column. (This method is known as Block Interleaving.) The reverse of this process is done at the receiver.The importance of interleaving is that it spreads the effect of noise over an entire packet. So if noise is at the beginning of the block of data, it would affect x1, x1+j, x2+j, etc. Rather than x1, x2, x3. So, with Convolutional Encoding and Block Interleaving, the effect on our transmission of data in IS-95 is to increase the data rate from 9.6 kbps to 19.2 kbps (affect of CE) and impose a delay of IJ (affect of having to fill the matrix in BI). Not much of a price to pay for enhanced error correction. If you are not afraid of theory, Viterbi's CDMA: Principles of Spread Spectrum Communications is a good book for an overview of CDMA techniques. Cory L. Hojka Beta Nu of Theta Chi Fraternity Case Western Reserve University Cleveland, OH From karn@qualcomm.com Sat Dec 07 19:02:58 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id TAA15993 for ; Sat, 7 Dec 1996 19:02:56 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id RAA07646; Sat, 7 Dec 1996 17:02:23 -0800 (PST) Date: Sat, 7 Dec 1996 17:02:23 -0800 (PST) From: Phil Karn Message-Id: <199612080102.RAA07646@servo.qualcomm.com> To: ss@tapr.org In-reply-to: <1.5.4.32.19961207085052.00664884@popmail.dircon.co.uk> (message from Charles Brain on Sat, 7 Dec 1996 03:09:35 -0600 (CST)) Subject: Re: [SS:645] Re: good reference books for Barker codes. A good reference book I recommend is Multiple Access Communications: Foundations for Emerging Technologies It's an IEEE reprint collection edited by Norman Abramson. ISBN 0-87942-292-0. It leads off with the classic Costas paper Poisson, Shannon and the Radio Amateur. The book contains a whole section on spread spectrum CDMA. It also includes Barker's original 1953 paper and a followup by Golomb and Scholtz in 1965 that generalized Barker sequences. Phil From karn@qualcomm.com Sat Dec 07 20:28:32 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id UAA19220 for ; Sat, 7 Dec 1996 20:28:30 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id SAA07785; Sat, 7 Dec 1996 18:27:55 -0800 (PST) Date: Sat, 7 Dec 1996 18:27:55 -0800 (PST) From: Phil Karn Message-Id: <199612080227.SAA07785@servo.qualcomm.com> To: ss@tapr.org In-reply-to: (message from Carol Fields on Sat, 7 Dec 1996 16:06:11 -0600 (CST)) Subject: Re: [SS:649] FEC >There was the implication that FEC (forward Error >Correction) was almost free in SS in previous messages. >What type of FEC code would you recommend and why? >Would you think a hardware or software FEC >is better for SS? >Is there a feeling that this is better than >just resending a packet? Yes, FEC is "free" in a spread spectrum system in the sense that SS always performs better with FEC than without it given the same bandwidth and RF power. Andrew Viterbi has written an excellent article on this exact point; it appeared in IEEE Communications Magazine for May 1979 and is included in the Abramson collection I mentioned earlier. The best kind of FEC depends on the kind of SS. For direct sequence, convolutional coding is probably the best. Interleaving will help deal with pulsed interference and fading. Other codes could be layered on top of the basic convolutional code, such as a Reed-Solomon code or a simple block CRC with retransmission. We use the latter for packet data over IS-95. For frequency hopping, the requirements change somewhat, particularly in the presence of a few scattered narrowband jammers: the code must have excellent performance against the burst of errors that occur when the hopper lands on a narrowband interferer. A suitably interleaved convolutional code can again work here, though direct use of Reed-Solomon coding is also possible because of its inherent resistance to burst errors without interleaving. Also, frequency hopped systems often use higher order (non-binary) signalling alphabets such as M-ary FSK, and these are a simple match to the Reed-Solomon codes which are also non-binary. E.g., a 256-ary FSK system is a nice match to a (255,x) RS code over GF(256) since each FSK "tone" maps directly to one 8-bit RS symbol. There is no question that low-level FEC is much more powerful than just resending a packet. This is not to say that retransmission has no place in the system; as I mentioned above, it's part of the CDMA packet data system that I developed at Qualcomm. It's just that while retransmission is good at taking a low error rate and reducing it essentially to zero, FEC is much better at taking a high error rate and reducing it to a low (but not zero) level. The two together thus make a very natural combination. Phil From srbible@gnatnet.net Sun Dec 08 19:22:51 1996 Received: from rupe.gnatnet.net (root@rupe.gnatnet.net [206.30.198.8]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id TAA11284 for ; Sun, 8 Dec 1996 19:22:49 -0600 (CST) Received: from avatar.gnatnet.net (dialup13.gnatnet.net [206.30.198.113]) by rupe.gnatnet.net (8.6.13/8.6.12) with SMTP id VAA05661 for ; Sun, 8 Dec 1996 21:23:30 -0500 Message-Id: <1.5.4.32.19961209012246.00696ea8@gnatnet.net> X-Sender: srbible@gnatnet.net X-Mailer: Windows Eudora Light Version 1.5.4 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sun, 08 Dec 1996 20:22:46 -0500 To: ss@tapr.org From: "Steven R. Bible" Subject: Re: [SS:650] Re: Syncronizing SS systems? At 05:25 PM 12/7/96 -0600, you wrote: >In a message dated 96-12-07 16:49:41 EST, you write: > ><< am very anxious to learn more about spread spectrum and put it to use > but need info in the form of email from the sig and also from any > publications that may be able to help me to learn. >> > >Check TAPR website. I believe it is www. tapr.org. They have an excellent >write ups by NK6K and others. Actually, It was I (N7HPR) as guest columnest for NK6K. The piece "Spread Spectrum -- It's not just for breackfast anymore!" is posted at: http://www.tapr.org/ss/qexss.html It average >200 hits a week. Quite a surprise considering its humble beginnings. One of these days I hope to update it. Other Amateur Spread Spectrum information is available at: http://www.tapr.org/ss/ 73, - Steve, N7HPR (n7hpr@tapr.org) From strohs@halcyon.com Mon Dec 09 01:11:46 1996 Received: from mail1.halcyon.com (mail1.halcyon.com [206.63.63.40]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id BAA00529 for ; Mon, 9 Dec 1996 01:11:44 -0600 (CST) Received: from coho.halcyon.com by mail1.halcyon.com (5.65v3.2/1.1.10.5/10Nov96-0444PM) id AA15762; Sun, 8 Dec 1996 21:15:49 -0800 Date: Sun, 8 Dec 1996 21:18:26 -0800 (PST) From: Steve Stroh To: TAPR Spread Spectrum SIG Mailing List Subject: Wireless Networking built into PC's Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII I picked up a new magazine at the newsstand- "boot", subtitled "For the PC Fanatic", the December 1996 issue. It's mostly about bleeding-edge PC-based gaming, but it has a lot of energy and fun, and some surprisingly good technical content. For more info check out http://www.bootnet.com. In an interview with Rod Schrock, Compaq's vice president in charge of the Presario line of home PC's, the following quote caught my eye: boot: What is the single most important technology on the horizon? Schrock: I'd have to say the technology with the most appeal is something that hasn't been talked about too much yet, and that's the in-home network. Our strategy is to design into our PCs, by 1998, in-home wireless networking. That will let you bring all that media-rich content in over the Net, or however, and distribute it throughout the home. It will enable the digital home. We won't have a bunch of isolated boxes anymore. Obligatory SS content: Such a system would almost have to be SS. That quote hit me between the eyes like a 2x4. A criticism I've had of PC companies for a long time is why didn't a vendor like Intel, Dell, Compaq, etc. just have the courage to put an Ethernet adapter on the motherboard on every one of their PC's. It seems to me that it would be even simpler to put a simple wireless tranceiver onboard, and run it almost completely in software from the excess processing power on the Pentium/Pro/MMX processor (which should, by this point, be labelled "The KA9Q approach"). All sorts of things that could have Compaq-compatible wireless comms added to them: thermostats, sprinklers, lighting circuits, weather stations, music systems, intercoms, major appliances, the possibilities are endless. I have no doubt that Compaq can pull it off. Compaq was one of the first PC makers to make a commitment to the home PC market not because it was profitable but because it was hard- it's a challenge to stay ahead of the consumer market and the mindset that requires infuses the rest of the company with a sense of urgency and drive to be cost competitive. I agree with them- on reflection it makes SO much sense to do things around a home wirelessly rather than drilling holes and cabling ad infinitum. Putting the PC in the center of the home control system is a leap forward also- couple the wireless networking possibilities with speech recognition made possible with the MMX. Steve N8GNJ -- Steve Stroh Woodinville, Washington, USA strohs@halcyon.com From Sjolin@aol.com Mon Dec 09 01:35:53 1996 Received: from emout06.mail.aol.com (emout06.mx.aol.com [198.81.11.97]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id BAA02558 for ; Mon, 9 Dec 1996 01:35:51 -0600 (CST) From: Sjolin@aol.com Received: by emout06.mail.aol.com (8.6.12/8.6.12) id BAA24941 for ss@tapr.org; Mon, 9 Dec 1996 01:21:28 -0500 Date: Mon, 9 Dec 1996 01:21:28 -0500 Message-ID: <961209012127_1786192643@emout06.mail.aol.com> To: ss@tapr.org Subject: Re: [SS:654] Re: Syncronizing SS systems? In a message dated 96-12-08 20:58:02 EST, you write: << Actually, It was I (N7HPR) as guest columnest for NK6K. The piece "Spread Spectrum -- It's not just for breackfast anymore!" is posted at: http://www.tapr.org/ss/qexss.html It average >200 hits a week. Quite a surprise considering its humble beginnings. >> Sorry about that Steve. Great article! Even I understood most of it. 73 de Dave, N0IT From glenne@hpsadr2.sr.hp.com Mon Dec 09 08:39:17 1996 Received: from palrel1.hp.com (palrel1.hp.com [15.253.72.10]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id IAA16028 for ; Mon, 9 Dec 1996 08:39:15 -0600 (CST) Received: from srmail.sr.hp.com (srmail.sr.hp.com [15.4.45.14]) by palrel1.hp.com with ESMTP (8.7.5/8.7.3) id GAA05564 for ; Mon, 9 Dec 1996 06:39:14 -0800 (PST) Received: from hpsadr2.sr.hp.com (n6gn.sr.hp.com) by srmail.sr.hp.com with ESMTP (1.37.109.16/15.5+ECS 3.3) id AA156902353; Mon, 9 Dec 1996 06:39:14 -0800 Received: by hpsadr2.sr.hp.com (1.37.109.16/15.5+ECS 3.3) id AA216372352; Mon, 9 Dec 1996 06:39:12 -0800 From: Glenn Elmore Message-Id: <199612091439.AA216372352@hpsadr2.sr.hp.com> Subject: Re: [SS:648] Re: Horz Omnis To: ss@tapr.org (doug cole) Date: Mon, 9 Dec 1996 06:39:12 -0800 (PST) In-Reply-To: <32A9DDB7.61EA@on-ramp.ior.com> from "doug cole" at Dec 7, 96 03:20:47 pm X-Mailer: ELM [version 2.4 PL21] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit > > Hello Glen I was wondering about your reference of "the big ticket > items" > and being a lowly experimenter without an engineering degree or any > thing and just doing it on weekends I am not sure what those big ticket > items are.... > Could you point me in the right directions as far as books that might > help me learn more about spread spectrum or high speed data > communications ( as that is what I am actually interested in ) for > amateur radio. > > I have just decided to dive into this part of the hobby but need some > info to start on and any help you can give would be most appreciated :) Doug, Hi Doug, don't be put off by the apparantly foreign language that gets used here at times and by all means, jump in as you are interested. I don't know that I can give you a particularly good bibliography of SS, I think that there are now a at least a few texts with considerable detail and others with a lot of introductory material. You might start with the ARRL book and a listen to the introductory session at the most recent DCC. It's audio is available on the TAPR pages I think. Others on this list may have further suggestions. To (hopefully) clear up ambiguity in my previous "big ticket item" reference, please start with http://www.tapr.org/~n6gn/index.html and see if that helps. The "What's the Problem" section is taken in part from an attempt I made at the most recent conference to uncover some of these issues. 73 Glenn Elmore n6gn amateur IP: glenn@SantaRosa.ampr.org Internet: glenne@sr.hp.com From glenne@hpsadr2.sr.hp.com Mon Dec 09 09:14:35 1996 Received: from palrel1.hp.com (palrel1.hp.com [15.253.72.10]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id JAA17269 for ; Mon, 9 Dec 1996 09:14:34 -0600 (CST) Received: from srmail.sr.hp.com (srmail.sr.hp.com [15.4.45.14]) by palrel1.hp.com with ESMTP (8.7.5/8.7.3) id HAA08441 for ; Mon, 9 Dec 1996 07:14:33 -0800 (PST) Received: from hpsadr2.sr.hp.com (n6gn.sr.hp.com) by srmail.sr.hp.com with ESMTP (1.37.109.16/15.5+ECS 3.3) id AA159494472; Mon, 9 Dec 1996 07:14:32 -0800 Received: by hpsadr2.sr.hp.com (1.37.109.16/15.5+ECS 3.3) id AA258374471; Mon, 9 Dec 1996 07:14:31 -0800 From: Glenn Elmore Message-Id: <199612091514.AA258374471@hpsadr2.sr.hp.com> Subject: Re: [SS:618] Re: Horz Omnis (fwd) To: ss@tapr.org Date: Mon, 9 Dec 1996 07:14:31 -0800 (PST) X-Mailer: ELM [version 2.4 PL21] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit I found the URL to the slot antenna information which Steven Bell, kb7trz presented. http://192.82.208.21/employees/byee_engr/slot_ant.html The MathCad program should be there as well. Glenn n6gn From john@images.demon.co.uk Mon Dec 09 14:31:25 1996 Received: from relay-7.mail.demon.net (relay-7.mail.demon.net [194.217.242.9]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA06004 for ; Mon, 9 Dec 1996 14:31:24 -0600 (CST) Received: from images.demon.co.uk ([158.152.23.206]) by relay-6.mail.demon.net id aa617259; 9 Dec 96 20:28 GMT Received: from images (john@localhost [127.0.0.1]) by images.demon.co.uk (8.6.12/v3.2) with SMTP id UAA00397; Mon, 9 Dec 1996 20:28:41 GMT Sender: john@images.demon.co.uk Message-ID: <32AC7679.7FFF9747@images.demon.co.uk> Date: Mon, 09 Dec 1996 20:28:41 +0000 From: John Melton X-Mailer: Mozilla 3.0 (X11; I; Linux 1.3.32 i586) MIME-Version: 1.0 To: ss@tapr.org Subject: Java Web Site Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hi, I am setting up a Web Site with information on the use of Java in Ham Radio. If you are doing any development using Java for Ham radio, let me know and I will put the information on my the web site. Thanks, John Melton, g0orx/n6lyt john@images.demon.co.uk From zsolt@direct.ca Mon Dec 09 14:39:43 1996 Received: from aphex.direct.ca (root@aphex.direct.ca [199.60.229.6]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id OAA06454 for ; Mon, 9 Dec 1996 14:39:41 -0600 (CST) Received: from boxer.direct.ca (van-pm-0224.direct.ca [204.174.243.54]) by aphex.direct.ca (8.8.3/8.8.0) with SMTP id MAA14232; Mon, 9 Dec 1996 12:39:34 -0800 (PST) Date: Mon, 9 Dec 1996 13:40:10 -0800 (PST) From: George Cserenyi To: Steve Stroh cc: ss@tapr.org Subject: Re: [SS:655] Wireless Networking built into PC's In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Mon, 9 Dec 1996, Steve Stroh wrote: > > I picked up a new magazine at the newsstand- "boot", subtitled "For the PC > Fanatic", the December 1996 issue. It's mostly about bleeding-edge > PC-based gaming, but it has a lot of energy and fun, and some surprisingly > good technical content. For more info check out http://www.bootnet.com. [...] > That quote hit me between the eyes like a 2x4. A criticism I've had of PC > companies for a long time is why didn't a vendor like Intel, Dell, Compaq, ^^^^^^^^^^ > etc. just have the courage to put an Ethernet adapter on the motherboard > on every one of their PC's. [...] The answer is very sipmple, an Ethernet adapter costs money. If it costs $5 extra per board, on a 100k run they save half a million dollars, a sum to to be sneezed at.... George [...] > -- > Steve Stroh Woodinville, Washington, USA strohs@halcyon.com > From ssampson@claven.tinker.af.mil Mon Dec 09 15:44:12 1996 Received: from othello.tinker.af.mil (othello.tinker.af.mil [137.240.231.43]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id PAA09792 for ; Mon, 9 Dec 1996 15:44:06 -0600 (CST) Received: from localhost by othello.tinker.af.mil (AIX 4.1/UCB 5.64/4.03) id AA13512; Mon, 9 Dec 1996 15:40:49 -0600 Sender: ssampson@othello.tinker.af.mil Message-Id: <32AC8761.41C6@eds.tinker.af.mil> Date: Mon, 09 Dec 1996 15:40:49 -0600 From: Steve Sampson X-Mailer: Mozilla 2.02 (X11; I; AIX 1) Mime-Version: 1.0 To: ss@tapr.org Subject: Re: [SS:658] Re: Horz Omnis References: <199612091514.AA258374471@hpsadr2.sr.hp.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Glenn Elmore wrote: > > I found the URL to the slot antenna information which Steven Bell, kb7trz presented. > > http://192.82.208.21/employees/byee_engr/slot_ant.html > > The MathCad program should be there as well. > > Glenn n6gn This looks like the antenna I bought from the San Diego Microwave group. They had a bunch made up for 10 GHz to be used for beacons. Both the ARRL and RSGB books show the antenna's to be horizontal polarization and omnidirectional. I believe the RSGB book shows a flange on the bottom. I don't know what the effect of it missing has, as the San Diego one does not have that feature. The antenna came with a waveguide mount and an end cap, but unassembled, for about $40 bucks as I recall, with the waveguide mount driving the cost. That price should scale down nicely with just an SMA or other coaxial connector. Steve From RLANIER@mailb.harris.com Mon Dec 09 15:45:33 1996 Received: from sol.corp.Harris.COM (sol.corp.harris.com [137.237.25.4]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id PAA09859 for ; Mon, 9 Dec 1996 15:45:29 -0600 (CST) Received: from mailb.harris.com by sol.corp.Harris.COM (8.6.12/Kurts Special version 2.0) id QAA26905; Mon, 9 Dec 1996 16:45:24 -0500 Received: from ccMail by mailb.harris.com (IMA Internet Exchange 1.04b) id 2ac87ee0; Mon, 9 Dec 96 16:43:10 -0500 Mime-Version: 1.0 Date: Mon, 9 Dec 1996 16:30:52 -0500 Message-ID: <2ac87ee0@mailb.harris.com> From: RLANIER@mailb.harris.com (RLANIER) Subject: Re: [SS:653] Re: FEC To: ss@tapr.org Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Description: cc:Mail note part >>There was the implication that FEC (forward Error >>Correction) was almost free in SS in previous messages. >>What type of FEC code would you recommend and why? >>Would you think a hardware or software FEC >>is better for SS? >>Is there a feeling that this is better than >>just resending a packet? >Yes, FEC is "free" in a spread spectrum system in the sense that SS always >performs better with FEC than without it given the same bandwidth and RF >power. Andrew Viterbi has written an excellent article on this exact point; >Phil I still don't understand how SS is "free" in a SS system. FEC still has to be implemented into the system, either using hardware or software or both. How is that free? Do you mean that certain properties of FEC are "built-in" into a SS system? Tony From clh10@po.cwru.edu Mon Dec 09 20:08:28 1996 Received: from celeste.INS.CWRU.Edu (root@celeste.INS.CWRU.Edu [129.22.8.214]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id UAA24439 for ; Mon, 9 Dec 1996 20:08:25 -0600 (CST) Received: from [129.22.249.174] (wormwood.STUDENT.CWRU.Edu [129.22.249.174]) by celeste.INS.CWRU.Edu with SMTP (8.7.6+cwru/CWRU-3.0) id VAA12433; Mon, 9 Dec 1996 21:08:18 -0500 (EST) (from clh10@po.cwru.edu for ) Date: Mon, 9 Dec 1996 21:08:18 -0500 (EST) X-Sender: clh10@pop.cwru.edu Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: clh10@po.cwru.edu (clh10@po.cwru.edu) Subject: Re: [SS:662] Re: FEC > I still don't understand how SS is "free" in a SS system. FEC still > has to be implemented into the system, either using hardware or > software or both. How is that free? > > Do you mean that certain properties of FEC are "built-in" into a SS > system? > > Tony > > Hmmm... Well besides the fact that SS provides a very good signal to noise ratio in the right conditions, there is extra hardware required to implement the FEC. However, the answer as whether it is "free" is perhaps misphrased. Perhaps it would be better to aks what advantages does SS offer for the implementation of FEC. The following is an excerpt from CDMA: Principles of Spread Spectrum Communications by Viterbi. Coding and Interleaving By its very nature, direct sequence spread spectrum CDMA provides a considerably higher dimensionality than needed to transmit information by any single user. This is reflected by the high processing gain, or bandwidth-to-data rate, W/R. ..., we demonstrate how this excess dimensionality or redundancy can be exploited to improve performance, without compromising the other advantages of the high processing gain. In other words, we can add in Convolutional Encoding and Interleaving without having to accept a lower gain. Cory L. Hojka Beta Nu of Theta Chi Fraternity Case Western Reserve University Cleveland, OH From rdcole@mindspring.com Mon Dec 09 20:15:07 1996 Received: from mule0.mindspring.com (mule0.mindspring.com [204.180.128.166]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id UAA24588 for ; Mon, 9 Dec 1996 20:15:06 -0600 (CST) Received: from ron (ip198.ft.worth3.tx.interramp.com [38.27.17.198]) by mule0.mindspring.com (8.8.2/8.7.3) with SMTP id CAA175432 for ; Tue, 10 Dec 1996 02:15:03 GMT Message-Id: <1.5.4.32.19961210021528.0066d7e4@pop.mindspring.com> X-Sender: rdcole@pop.mindspring.com X-Mailer: Windows Eudora Light Version 1.5.4 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 09 Dec 1996 20:15:28 -0600 To: ss@tapr.org From: Ron Cole Subject: Re: [SS:655] Wireless Networking built into PC's At 01:18 AM 12/9/96 -0600, you wrote: > >Obligatory SS content: Such a system would almost have to be SS. > >That quote hit me between the eyes like a 2x4. A criticism I've had of PC >companies for a long time is why didn't a vendor like Intel, Dell, Compaq, >etc. just have the courage to put an Ethernet adapter on the motherboard >on every one of their PC's. It seems to me that it would be even simpler >to put a simple wireless tranceiver onboard, and run it almost completely >in software from the excess processing power on the Pentium/Pro/MMX >processor (which should, by this point, be labelled "The KA9Q approach"). > >Steve N8GNJ If you take a look at Compaq's business line like the Desk Pro and Up they all come with 10-BaseT NIC built onto the motherboard. Some of their latest Laptops have High Speed IRD interfaces built in, and the docking stations have a 10-BaseT NIC. I would not be suprised to see either built-in or as an option a 900 Mhz DSSS NIC from Compaq soon. They seem to be commited to Networking. Now I just need to stir up some interest in 900 Mhz Amateur Networking here in the DFW Metroplex. I know of a couple of users on the band, NBFM ATV, and a couple of FM Repeaters. I wonder how a FreeWave DRG-115 would operate on a tower site overlooking the City ? Ron Cole N5HYY Ron Cole ---------------------------------------+------------------------------------ ------- rdcole@mindspring.com | N5HYH | ---------------------------------------+------------------------------------ ------- From clh10@po.cwru.edu Mon Dec 09 20:23:33 1996 Received: from celeste.INS.CWRU.Edu (root@celeste.INS.CWRU.Edu [129.22.8.214]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id UAA25062 for ; Mon, 9 Dec 1996 20:23:32 -0600 (CST) Received: from [129.22.249.174] (wormwood.STUDENT.CWRU.Edu [129.22.249.174]) by celeste.INS.CWRU.Edu with SMTP (8.7.6+cwru/CWRU-3.0) id VAA15626; Mon, 9 Dec 1996 21:23:30 -0500 (EST) (from clh10@po.cwru.edu for ) Date: Mon, 9 Dec 1996 21:23:30 -0500 (EST) X-Sender: clh10@pop.cwru.edu Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: clh10@po.cwru.edu (clh10@po.cwru.edu) Subject: Re: [SS:655] Wireless Networking built into PC's >Schrock: I'd have to say the technology with the most appeal is something >that hasn't been talked about too much yet, and that's the in-home >network. Our strategy is to design into our PCs, by 1998, in-home >wireless networking. That will let you bring all that media-rich content >in over the Net, or however, and distribute it throughout the home. It >will enable the digital home. We won't have a bunch of isolated boxes >anymore. > >Obligatory SS content: Such a system would almost have to be SS. > >That quote hit me between the eyes like a 2x4. A criticism I've had of PC >companies for a long time is why didn't a vendor like Intel, Dell, Compaq, >etc. just have the courage to put an Ethernet adapter on the motherboard >on every one of their PC's. It seems to me that it would be even simpler >to put a simple wireless tranceiver onboard, and run it almost completely >in software from the excess processing power on the Pentium/Pro/MMX >processor (which should, by this point, be labelled "The KA9Q approach"). Being a mac user, I will certainly agree that it is nice to have a computer that came with built-in ethernet. However, the issue that is really being addressed is a wireless network standard for local computer networks. While I can't remember off hand where I read about, I know several computer companies, including Apple, are trying to convince the FCC to open up a certain part of the bandwdith for such a purpose. I haven't heard much about it in a while though. I also don't think they were asking for it to be SS either. For the most part, a single computer in a home would not necessarily need a SS system for wireless networking. They could just use something similar to the packet radio that amateurs use today. The point at which one might want to use SS technology is if there were a lot of computers trying to communicate, such as an office. But then, one can just wire up the office for much higher bandwidth at a significantly lower cost than using SS. (Ethernet reliably gives me a speed of about 70 kilobytes/s, while the highest cellular standard that I can think of, off hand, runs at 14.4 kilobits/s max). Cory L. Hojka Beta Nu of Theta Chi Fraternity Case Western Reserve University Cleveland, OH From xbrucex@popmail.mcs.net Mon Dec 09 21:59:34 1996 Received: from Kitten.mcs.com (Kitten.mcs.com [192.160.127.90]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id VAA29979 for ; Mon, 9 Dec 1996 21:59:23 -0600 (CST) Received: from xbrucex (xbrucex.pr.mcs.net [205.164.12.165]) by Kitten.mcs.com (8.8.2/8.8.2) with SMTP id VAA00445 for ; Mon, 9 Dec 1996 21:59:15 -0600 (CST) Message-Id: <199612100359.VAA00445@Kitten.mcs.com> X-Sender: xbrucex@popmail.mcs.net X-Mailer: Windows Eudora Light Version 1.5.2 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 09 Dec 1996 21:57:18 -0600 To: ss@tapr.org From: xbrucex Subject: Re: [SS:665] Re: Wireless Networking built into PC's Guys - You need to take a look at some of the current SS PCMCIA cards. I'm seeing many cards that provide 1-2Mbs and some of the new ones are starting to claim 4Mbs for the next evolution. Most opperate in the 2.4 ISM band, but there is some noise about going to 5.7Ghz ISM. Also, the SS computer proposal you are talking about is called NII-Supernet (European) and Appel et-al were proposing a US version. GL Bruce k9bc At 20:30 12/9/96 -0600, you wrote: > >>Schrock: I'd have to say the technology with the most appeal is something >>that hasn't been talked about too much yet, and that's the in-home >>network. Our strategy is to design into our PCs, by 1998, in-home >>wireless networking. That will let you bring all that media-rich content >>in over the Net, or however, and distribute it throughout the home. It >>will enable the digital home. We won't have a bunch of isolated boxes >>anymore. >> >>Obligatory SS content: Such a system would almost have to be SS. >> >>That quote hit me between the eyes like a 2x4. A criticism I've had of PC >>companies for a long time is why didn't a vendor like Intel, Dell, Compaq, >>etc. just have the courage to put an Ethernet adapter on the motherboard >>on every one of their PC's. It seems to me that it would be even simpler >>to put a simple wireless tranceiver onboard, and run it almost completely >>in software from the excess processing power on the Pentium/Pro/MMX >>processor (which should, by this point, be labelled "The KA9Q approach"). >Being a mac user, I will certainly agree that it is nice to have a computer >that came with built-in ethernet. However, the issue that is really being >addressed is a wireless network standard for local computer networks. While >I can't remember off hand where I read about, I know several computer >companies, including Apple, are trying to convince the FCC to open up >a certain part of the bandwdith for such a purpose. I haven't heard much >about it in a while though. I also don't think they were asking for it to >be SS either. For the most part, a single computer in a home would not >necessarily need a SS system for wireless networking. They could just >use something similar to the packet radio that amateurs use today. The point at >which one might want to use SS technology is if there were a lot of computers >trying to communicate, such as an office. But then, one can just wire up >the office for much higher bandwidth at a significantly lower cost than >using SS. (Ethernet reliably gives me a speed of about 70 kilobytes/s, >while the >highest cellular standard that I can think of, off hand, runs at 14.4 >kilobits/s max). > >Cory L. Hojka >Beta Nu of Theta Chi Fraternity >Case Western Reserve University >Cleveland, OH > > > > From karn@laptop.ka9q.ampr.org Mon Dec 09 22:27:05 1996 Received: from laptop.ka9q.ampr.org (root@ietf-attendee40.mtg.ietf.org [205.180.222.140]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id WAA01476 for ; Mon, 9 Dec 1996 22:27:03 -0600 (CST) Received: by laptop.ka9q.ampr.org id m0vXDRV-000MFdC (Debian Smail-3.2 1996-Jul-4 #2); Mon, 9 Dec 1996 13:40:53 -0800 (PST) Message-Id: Date: Mon, 9 Dec 1996 13:40:53 -0800 (PST) From: Phil Karn To: ss@tapr.org In-reply-to: (message from Steve Stroh on Mon, 9 Dec 1996 01:18:27 -0600 (CST)) Subject: Re: [SS:655] Wireless Networking built into PC's Some spread-spectrum-based home networks already exist, but the one I'm most familiar with runs over power wiring: CEbus, aka TIA IS-60. The data rate is only 10 kbps, so it's not fast enough to be interesting for anything beyond turning lights on and off and perhaps programming your VCR. For high speed intra-home networking we already have a pretty good technology: 10 base T ethernet. The supplies are cheap, and the installation isn't that bad if you just upgrade your existing phone and CATV wall outlets as I did. Phil From ddennis@metronet.com Mon Dec 09 23:05:08 1996 Received: from metronet.com (root@mail.metronet.com [192.245.137.6]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id XAA03239 for ; Mon, 9 Dec 1996 23:04:58 -0600 (CST) Received: from dal53.metronet.com by metronet.com with SMTP id AA00461 (5.67a/IDA1.5hp for ); Mon, 9 Dec 1996 23:05:37 -0600 Received: by dal53.metronet.com with Microsoft Mail id <01BBE625.4D97E800@dal53.metronet.com>; Mon, 9 Dec 1996 23:04:17 -0600 Message-Id: <01BBE625.4D97E800@dal53.metronet.com> From: David Dennis To: "'ss@tapr.org'" Subject: 900MHz AMPs Date: Mon, 9 Dec 1996 23:03:41 -0600 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable >Bob Morgan, WB5AOH, (on the list) has been looking at building one but = I >was wondering if someone has designs for one or can point to reference = that >discuss constrution and theory. > >What are the power restrictions under the STA in the 900-Mhz band? Has >anyone done anything with homebrewing PAs? How critical is the = switching >time of some of the hybrid devices available? This might be a cheap = way out >instead of the six hundred buck commercial amp I heard about? How good = are >the receivers (sensitivity) on the Beta Test group units? From my experience of 900MHz ATV there are plenty of "Brick" amps = available for 900MHz. These are mostly for cellular apps and trunking = radios. I have no idea if they would meet the switching requirements = but it would certainly be a lot less than $600.00 for an amp that would = put out +43dBm or 20Watts. From karn@laptop.ka9q.ampr.org Tue Dec 10 00:09:27 1996 Received: from laptop.ka9q.ampr.org (root@ietf-attendee40.mtg.ietf.org [205.180.222.140]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id AAA10675 for ; Tue, 10 Dec 1996 00:09:22 -0600 (CST) Received: by laptop.ka9q.ampr.org id m0vXLNY-000MDOC (Debian Smail-3.2 1996-Jul-4 #2); Mon, 9 Dec 1996 22:09:20 -0800 (PST) Message-Id: Date: Mon, 9 Dec 1996 22:09:20 -0800 (PST) From: Phil Karn To: ss@tapr.org In-reply-to: <2ac87ee0@mailb.harris.com> (RLANIER@mailb.harris.com) Subject: Re: [SS:662] Re: FEC Tony, When I said "free", I meant in terms of RF power, bandwidth and performance. Adding FEC to a SS system operating in a given bandwidth will always reduce its RF power requirements over an uncoded SS system in the same bandwidth. You can think of coding as just being a more clever way to spread -- if you're going to spread, you might as well spread cleverly. I certainly didn't mean to imply that FEC is "free" in the sense that no hardware or software is needed to support it. Phil From dhoyer@ccm.frontiercorp.com Tue Dec 10 10:14:39 1996 Received: from node1.frontiernet.net (node1.frontiernet.net [205.232.174.11]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id KAA03080 for ; Tue, 10 Dec 1996 10:14:37 -0600 (CST) Received: from ccm.frontiercorp.com (ccm.frontiercorp.com [204.168.13.16]) by node1.frontiernet.net (8.8.2/8.8.2) with SMTP id KAA45072 for ; Tue, 10 Dec 1996 10:50:53 -0500 Received: from ccMail by ccm.frontiercorp.com (SMTPLINK V2.11 PreRelease 4) id AA850243998; Tue, 10 Dec 96 09:47:55 EST Date: Tue, 10 Dec 96 09:47:55 EST From: "Dan Hoyer" Message-Id: <9611108502.AA850243998@ccm.frontiercorp.com> To: ss@tapr.org Subject: Re: [SS:667] Re: Wireless Networking built into PC's Hi all, As a networking engineer who deals with LANs and WANs all day long, I can tell you that I would much rather have a wireless home network for my PCs than have a wired ethernet. If I have my laptop home from the office, I don't want to plug into the wall to talk to my computers at home. With the wireless you can cut the in-home umbilical cord. That much said, Phil has a point that right now 10BaseT is cheap to wire a house with. I'm in the process of installing an in-home wiring plant for voice, data, video, IR, and audio. (and it better not interfere with my amateur radio operation, or I'll rip it ALL OUT!!!!!!) Hopefully the study and enhancement of radio and specifically SS radio technologies will eventually bring around an inexpensive high-speed radio LAN for the home. An added bonus would be to be able to talk to a CEBus system at the same time! :-) Thanks to everyone for all the great information! I just joined this group a couple of days ago, and I'm learning all kinds of stuff! Dan KA9VMI ______________________________ Reply Separator _________________________________ Subject: [SS:667] Re: Wireless Networking built into PC's Author: ss@tapr.org at INTERNET Date: 12/10/96 12:26 AM Some spread-spectrum-based home networks already exist, but the one I'm most familiar with runs over power wiring: CEbus, aka TIA IS-60. The data rate is only 10 kbps, so it's not fast enough to be interesting for anything beyond turning lights on and off and perhaps programming your VCR. For high speed intra-home networking we already have a pretty good technology: 10 base T ethernet. The supplies are cheap, and the installation isn't that bad if you just upgrade your existing phone and CATV wall outlets as I did. Phil From morganb@inetport.com Tue Dec 10 16:53:05 1996 Received: from admin.inetport.com (inetport.com [206.64.12.2]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id QAA20614; Tue, 10 Dec 1996 16:53:01 -0600 (CST) Received: from mail.inetport.com (pm0_90.inetport.com [206.64.12.90]) by admin.inetport.com (8.7.5/8.7.3) with SMTP id QAA14995; Tue, 10 Dec 1996 16:54:54 -0600 (CST) Date: Tue, 10 Dec 1996 16:54:54 -0600 (CST) Message-Id: <199612102254.QAA14995@admin.inetport.com> X-Sender: morganb@inetport.com X-Mailer: Windows Eudora Version 1.4.4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: morganb@inetport.com (Robert B. Morgan) Subject: Re: 900MHz AMPs Cc: ss-sta@tapr.org > >>Bob Morgan, WB5AOH, (on the list) has been looking at building one but = >I > From my experience of 900MHz ATV there are plenty of "Brick" amps = >available for 900MHz. These are mostly for cellular apps and trunking = >radios. I have no idea if they would meet the switching requirements = >but it would certainly be a lot less than $600.00 for an amp that would = >put out +43dBm or 20Watts. I looked in the Newark catalog and a few others, and some Motorola power modules caught my attention. They are: MHW806A3, MHW812A3, MHW912, MHW914, MHW915, and MHW932. Newark (cat 113) listed the prices as follows: -812A3 = $52.92 (class C) -912 = $71.74 rest were class AB -914 = $77.42 -915 = $62.92 -932 = $102.77 Down East MWave listed the -806A3 at $5, and the -932 at $100. They also had some devices of other manufacturers that I wasn't familiar with. Motorola listed a price for only the -812A3, of $41.60 ea, or $35.90 in quantities over 250. The online service said that the other devices weren't priced in the book. I am not sure if that means they aren't on the market, or if they just aren't in the book online. ( see www.Design-NET.com for Motorola datasheets and pricing). I am still waiting on Motorola Fax to send me the sheet on the -806, but sort of suspect it might be obsolete. The last two digits indicates the output power capability in Watts, for instance the MHW932 is a 32 watt device, and is intended for eurpoean digital GSM service in 20 W radios. All of the devices had a nominal 12V power supply rating, and had enough gain to operate off of our 400 mW radios, and in fact most of them will require attenuation on the input. Some of the devices are speced to not include all the band we are using, for instance the MHW-9xx GSM stuff shows 890-915 MHz. Potential problem if it doesn't have some extra bandwidth. The Class C amp is pretty much fixed gain. The others are variable power devices, either by reducing drive, or in the case of the -912 and -914 by means of a DC variable bias from 1 to 3 volts impressed on the RF input pin. I think we will have to do some research to determine if we can live with class C, or if we need to run linear. Another consideration is a need for variable power control. There are probably quite a few other devices out there that we could use. These just happened to be handy and stood out when I looked at the catalogs I have, so I punched up Motorola and got some datasheets over the internet/faxback service they have. The above mentioned power modules, for those not familiar with them, are the active portion of an RF amplifier, with some matching and some bypassing built into them. They need to be mounted on a heatsink and one side of them have a row of pins to solder to a PC board which has some stripline sections to couple RF into and out of the device, and to supply various control and bias voltages, and any required switching crcuitry like receiver bypass/preamp. Mainly what I am saying is that they aren't a complete standalone device ready to insert into a coax between a radio and an antenna, but are a major component of such a device. They are attractive because they already have most of the troublesome RF matching circuitry built in. 73 de Bob WB5AOH Robert Morgan Austin Texas morganb@admin.inetport.com From karn@laptop.ka9q.ampr.org Tue Dec 10 17:03:10 1996 Received: from laptop.ka9q.ampr.org (root@ietf-attendee40.mtg.ietf.org [205.180.222.140]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id RAA21181 for ; Tue, 10 Dec 1996 17:03:08 -0600 (CST) Received: by laptop.ka9q.ampr.org id m0vXa5m-000MDyC (Debian Smail-3.2 1996-Jul-4 #2); Tue, 10 Dec 1996 13:51:58 -0800 (PST) Message-Id: Date: Tue, 10 Dec 1996 13:51:58 -0800 (PST) From: Phil Karn To: ss@tapr.org In-reply-to: <9611108502.AA850243998@ccm.frontiercorp.com> (dhoyer@ccm.frontiercorp.com) Subject: Re: [SS:670] Re: Wireless Networking built into PC's Well, yes. I too would like to be able to lie on the couch in front of the TV with my laptop on my lap and not have a cable running to the wall. Though a wireless modem doesn't solve the problem of bringing power to my laptop to keep the battery from going flat, and if you have one cord going to the wall you might as well have two... Cost is likely to be a major factor. Even if the wireless stuff is fast enough to be useful as a true LAN (which immediately excludes much, though not all of the existing Part 15 market), it is unlikely to be as cheap as 10Base-T equipment. Even PCMCIA cards, which are historically all overpriced, are down to about $110 for an Ethernet card at the local computer superstore. I think it'll be a while before fast wireless PCMCIA network cards are down to this level. Phil From clh10@po.cwru.edu Tue Dec 10 20:07:42 1996 Received: from cornelius.INS.CWRU.Edu (root@cornelius.INS.CWRU.Edu [129.22.8.216]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id UAA00869 for ; Tue, 10 Dec 1996 20:07:39 -0600 (CST) Received: from [129.22.249.174] (wormwood.STUDENT.CWRU.Edu [129.22.249.174]) by cornelius.INS.CWRU.Edu with SMTP (8.7.6+cwru/CWRU-3.0) id VAA01597; Tue, 10 Dec 1996 21:07:38 -0500 (EST) (from clh10@po.cwru.edu for ) Date: Tue, 10 Dec 1996 21:07:38 -0500 (EST) X-Sender: clh10@pop.cwru.edu Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: clh10@po.cwru.edu (clh10@po.cwru.edu) Subject: Re: [SS:672] Re: Wireless Networking built into PC's This will probably be my last post on this subject, since it is starting to stray out of the area of SS, but another type of networking that is commercial available is Infrared. Several printers, laptops, PDA's, and calculators use it already. It does have its limitations, but the cost of putting into a product is cheap, making it an easy way to provide networking without significantly adding to the price of the product. Cory L. Hojka Beta Nu of Theta Chi Fraternity Case Western Reserve University Cleveland, OH From ddennis@metronet.com Tue Dec 10 22:18:05 1996 Received: from metronet.com (root@mail.metronet.com [192.245.137.6]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id WAA05585 for ; Tue, 10 Dec 1996 22:18:00 -0600 (CST) Received: from dal169.metronet.com by metronet.com with SMTP id AA13640 (5.67a/IDA1.5hp for ); Tue, 10 Dec 1996 22:18:51 -0600 Received: by dal169.metronet.com with Microsoft Mail id <01BBE6E7.EBAF7900@dal169.metronet.com>; Tue, 10 Dec 1996 22:17:24 -0600 Message-Id: <01BBE6E7.EBAF7900@dal169.metronet.com> From: David Dennis To: "'ss@tapr.org'" Subject: RE: 671] Re: 900MHz AMPs Date: Tue, 10 Dec 1996 22:15:44 -0600 Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="---- =_NextPart_000_01BBE6E7.EBB71A20" ------ =_NextPart_000_01BBE6E7.EBB71A20 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable ---------- From: Robert B. Morgan[SMTP:morganb@inetport.com] Sent: Tue, December 10, 1996 10:55 AM To: ss@tapr.org Subject: [SS:671] Re: 900MHz AMPs I looked in the Newark catalog and a few others, and some Motorola power modules caught my attention. They are: MHW806A3, MHW812A3, MHW912, MHW914, MHW915, and MHW932. Newark (cat 113) listed the prices as follows: -812A3 =3D $52.92 (class C) -912 =3D $71.74 rest were class AB -914 =3D $77.42 -915 =3D $62.92 -932 =3D $102.77 Down East MWave listed the -806A3 at $5, and the -932 at $100. They = also had some devices of other manufacturers that I wasn't familiar with. Motorola listed a price for only the -812A3, of $41.60 ea, or $35.90 in quantities over 250. The online service said that the other devices weren't priced in the book. I am not sure if that means they aren't on the market, or if they just aren't in the book online. ( see www.Design-NET.com for Motorola datasheets and pricing). I am still waiting on Motorola Fax to send me the sheet on the -806, but sort of suspect it might be obsolete. The last two digits indicates the output power capability in Watts, for instance the MHW932 is a 32 watt device, and is intended for eurpoean digital GSM service in 20 W radios. All of the devices had a nominal 12V power supply rating, and had enough gain to operate off of our 400 mW radios, and in fact most of them will require attenuation on the input. Some of the devices are speced to not include all the band we are using, for instance the MHW-9xx GSM stuff shows 890-915 MHz. Potential problem if it doesn't have some extra bandwidth. The Class C amp is pretty much fixed gain. The others are variable power devices, either by reducing drive, or in the case of the -912 and -914 by means of a DC variable bias from 1 to 3 volts impressed on the RF input pin. I think we will have to do some research to determine if we can live with class C, or if we need to run linear. Another consideration is a need for variable power control. There are probably quite a few other devices out there that we could use. These just happened to be handy and stood out when I looked at the catalogs I have, so I punched up Motorola and got some datasheets over the internet/faxback service they have. The above mentioned power modules, for those not familiar with them, are the active portion of an RF amplifier, with some matching and some bypassing built into them. They need to be mounted on a heatsink and one side of them have a row of pins to solder to a PC board which has some stripline sections to couple RF into and out of the device, and to supply various control and bias voltages, and any required switching crcuitry like receiver bypass/preamp. Mainly what I am saying is that they aren't a complete standalone device ready to insert into a coax between a radio and an antenna, but are a major component of such a device. They are attractive because they already have most of the troublesome RF matching circuitry built in. 73 de Bob WB5AOH Robert Morgan Austin Texas morganb@admin.inetport.com I've used some of these devices on ATV, right at 915MHz. (The top end of = the spec.) I've looked around here but I can't find my old Xmitter but = I think I was last using the -806A. This worked well. If someone can = design the stripline I can turn a drawing into artwork for a board. Do we have an answer to the question, will these switch fast enough? 73's Dave D. 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Thu, 12 Dec 1996 11:00:46 -0600 (CST) Received: from vindemiatrix.tdb.uu.se (62yFw6EirqNmrn+sE47UTK55kG5DZSsF@vindemiatrix [130.238.137.211]) by sabik.tdb.uu.se (8.8.4/8.8.4/STUD_1.1) with ESMTP id SAA12251 for ; Thu, 12 Dec 1996 18:00:44 +0100 (MET) From: Paer Ant Received: (from t93ant@localhost) by vindemiatrix.tdb.uu.se (8.8.3/8.8.3/STUD_NULL_1.1) id SAA05655 for ss@tapr.org; Thu, 12 Dec 1996 18:00:41 +0100 (MET) Message-Id: <199612121700.SAA05655@vindemiatrix.tdb.uu.se> Subject: unsubscribe To: ss@tapr.org Date: Thu, 12 Dec 1996 18:00:39 +0100 (MET) X-Mailer: ELM [version 2.4ME+ PL27 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit From c1f@juno.com Thu Dec 12 15:26:33 1996 Received: from x3.boston.juno.com (x3.boston.juno.com [205.231.100.22]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id PAA19239 for ; Thu, 12 Dec 1996 15:26:31 -0600 (CST) From: c1f@juno.com Received: (from c1f@juno.com) by x3.boston.juno.com (queuemail) id QkH16744; Thu, 12 Dec 1996 16:25:26 EST To: ss@tapr.org Date: Thu, 12 Dec 1996 15:16:27 PST Subject: Re: Interest in a Senior Project Message-ID: <19961212.162354.6878.10.C1F@juno.com> References: X-Mailer: Juno 1.00 X-Juno-Line-Breaks: 0-1,3-8 Hello Bernie 6M FHSS sounds interesting , any ready made units available, or kits or is it all from scratch.... Stan, WA1ECF Cape Cod... From c1f@juno.com Thu Dec 12 15:26:36 1996 Received: from x3.boston.juno.com (x3.boston.juno.com [205.231.100.22]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id PAA19255 for ; Thu, 12 Dec 1996 15:26:34 -0600 (CST) From: c1f@juno.com Received: (from c1f@juno.com) by x3.boston.juno.com (queuemail) id QkJ16744; Thu, 12 Dec 1996 16:25:26 EST To: ss@tapr.org Date: Thu, 12 Dec 1996 15:36:12 PST Subject: Re: Horz Omnis Message-ID: <19961212.162354.6878.12.C1F@juno.com> References: <11579@wb9mjn.ampr.org> X-Mailer: Juno 1.00 X-Juno-Line-Breaks: 0-1,3-7 Hello Don I am interested in a 900 Mhz antenna for a horizontally polarized omnidirectional beacon, Can you send me information on yours... Stan, WA1ECF From kleber@magiclink.com.br Thu Dec 12 16:44:54 1996 Received: from ruby.magiclink.com.br ([200.254.29.1]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id QAA22520 for ; Thu, 12 Dec 1996 16:44:52 -0600 (CST) Received: from mach (slip19 [200.254.29.88]) by ruby.magiclink.com.br (8.8.3/8.6.11) with SMTP id UAA28940 for ; Thu, 12 Dec 1996 20:51:02 -0200 Message-ID: <32B08B87.7F66@magiclink.com.br> Date: Thu, 12 Dec 1996 20:47:35 -0200 From: Kleber Almeida Reply-To: kleber@magiclink.com.br Organization: Arrow Sistemas X-Mailer: Mozilla 3.01 (Win95; I) MIME-Version: 1.0 To: ss@tapr.org Subject: aim antennas... Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Where i abtain iformation (sites) about equipment and method for aim antennas in ISM band and SHF mainly in metropolitan area with many edifications ? From pcport@redestb.es Thu Dec 12 17:04:04 1996 Received: from mx0.redestb.es (mail-redestb.redestb.es [194.179.106.5]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id RAA26525 for ; Thu, 12 Dec 1996 17:04:01 -0600 (CST) Received: from [194.179.106.232] by mx0.redestb.es (post.office MTA v2.0 0813 ID# 0-12342) with SMTP id AAA263 for ; Fri, 13 Dec 1996 00:04:20 +0100 Message-ID: <30CE1803.3FF1@redestb.es> Date: Wed, 13 Dec 1995 01:02:11 +0100 From: "Miguel Angel Portillo" X-Mailer: Mozilla 2.02 [es] (Win16; I) MIME-Version: 1.0 To: ss@tapr.org Subject: unsubscribe From morganb@inetport.com Fri Dec 13 03:22:39 1996 Received: from admin.inetport.com (inetport.com [206.64.12.2]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id DAA29590; Fri, 13 Dec 1996 03:22:37 -0600 (CST) Received: from mail.inetport.com (pm0_85.inetport.com [206.64.12.85]) by admin.inetport.com (8.7.5/8.7.3) with SMTP id DAA09353; Fri, 13 Dec 1996 03:24:54 -0600 (CST) Date: Fri, 13 Dec 1996 03:24:54 -0600 (CST) Message-Id: <199612130924.DAA09353@admin.inetport.com> X-Sender: morganb@inetport.com (Unverified) X-Mailer: Windows Eudora Version 1.4.4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss-sta@tapr.org From: morganb@inetport.com (Robert B. Morgan) Subject: This will make you smile Cc: ss@tapr.org Today (or yesterday evening if you prefer) Dec 12 1996, from about 2030 to about 0230 the next morning, I surfed the web at high speed over the ham radio. (I am sending this to both SS reflectors, this is for operations under the STA). Greg set his system up on his ISDN line, and had his freewave radio on the other end (of course), and after a little bit of server configuration, and a tweak or two on this end, I was surfing the web, at speeds I wasn't accustomed to on my 14.4 kb landline modem. One of the first things I happen to find on TAPR's server was the text of Lyle Johnson's speech at the recent DCC, and scanning through it, one paragraph in particular jumped out at me. Lyle was referring to the SS beta test, and thought something ought to take place in early 1997. That is apparently on track, with the radio order looking like that will be the delivery date (from what I hear anyhow), but here it is the middle of Dec 96, and I am up and running. And Lyle said something about why we have Pentiums and hotshot landline modems, but still run 1200b packet on the air (well I run 9600 most of the time myself but that's another story). Well I smashed that barrier all to smithereens today at high speed, and it was fun. And VERY satisfying. Greg said to turn the usual landline SLIP/PPP compression off before going on the air, apparently he isn't set up for that as yet. So I am running 38400b to a radio modem with an on-the-air modem speed of some 173Kb, to a server/router on an ISDN line with only him and me for users, and I am seeing average file transfer rates as displayed by Netscape of from 1800 to over 2400 bytes/sec (not bits/sec mind you). When I am on my 14400b landline modem, I guess running compressed, to my ISP down the road, I almost never see anything over 1300 bytes/sec average rate, and of course some of the slow sites back down to half that. Then I would stop and think about what I was doing here for the first time. Look at the ll modem, it is off line. The file transfers are humming right along. For the first time, I can talk on the telephone while I am surfing the net. Never could do that before. Then I look over my shoulder at the serial cable running over to the SS radio, and the other end of that is a cable that goes to the antenna, and then it just disappears into space. At least for a block away to Greg's place, where his unit is doing the same. I look down at the oscilloscope that I have connected to the feedline wattmeter, and during the thick of the file transfer, there are some intermittent TX pulses about every 20 or so milliseconds (I am only seeing my acks, I wonder what Greg's radio dutycycle is). There is still a lot of empty time on that channel, at least what I can judge from this end. I guess this qualifies as real QRP operation too, just 400 mW, and a low duty cycle at that. This little unit might make a dandy unit on a solar powered remote site too. After I got tired of playing with TAPR's site, I turned to chasing some things on the web. I actually had a useful and productive session. I had been looking for some solar flare data, and I found it for the first time and downloaded about a megabyte of that, and all together, I probably pulled down somewhere I would estimate around 3 to 4 megabytes of all sorts of stuff, and may have set some sort of a personal ftp transfer record. As far as I could tell, things were working without a hitch, very smooth, no surprises. That 1200b radio barrier we have let hang around all too long is just about to get swept away I think. While it has its uses, this has a lot of potential. And it is for real, right now today. As far as the antenna project is concerned, I didn't get too terribly much more done on it today, but it is tuned reasonably close as far as the feedpoint is concerned, and around 1.5:1 SWR. But now that little 6 element beam has transferred several megabytes of data. 73 de Bob WB5AOH Robert Morgan Austin Texas morganb@admin.inetport.com From dallen@cei.net Fri Dec 13 09:13:52 1996 Received: from mail.cei.net (root@mail.cei.net [204.117.117.29]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id JAA10704 for ; Fri, 13 Dec 1996 09:13:49 -0600 (CST) Received: from home (zorak.cei.net [204.180.109.7]) by mail.cei.net (8.7.5/8.6.9) with SMTP id JAA05033 for ; Fri, 13 Dec 1996 09:13:47 -0600 Message-Id: <1.5.4.32.19961213151438.0069f164@cei.net> X-Sender: dallen@cei.net X-Mailer: Windows Eudora Light Version 1.5.4 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Fri, 13 Dec 1996 09:14:38 -0600 To: ss@tapr.org From: Allen Finne Subject: hello I have just joined the the list and wanted to say a quick hello to everyone on the list. Allen -kb5sqk- From rlanier@su102s.ess.harris.com Fri Dec 13 10:07:04 1996 Received: from ess.harris.com (su15a.ess.harris.com [130.41.1.251]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id KAA13478 for ; Fri, 13 Dec 1996 10:07:02 -0600 (CST) Received: from losalamos.ess.harris.com (su102s.ess.harris.com [130.41.13.101]) by ess.harris.com (8.8.4/8.8.4) with SMTP id LAA11918 for ; Fri, 13 Dec 1996 11:06:57 -0500 (EST) Received: from Paris.GASD102designcenter by losalamos.ess.harris.com (4.1/SMI-4.1) id AA05297; Fri, 13 Dec 96 11:06:56 EST Received: by Paris.GASD102designcenter (SMI-8.6/SMI-SVR4) id LAA03591; Fri, 13 Dec 1996 11:06:55 -0500 Date: Fri, 13 Dec 1996 11:06:55 -0500 From: rlanier@su102s.ess.harris.com (Tony Lanier) Message-Id: <199612131606.LAA03591@Paris.GASD102designcenter> To: ss@tapr.org Subject: Re: [SS:680] This will make you smile X-Sun-Charset: US-ASCII > From ss@tapr.org Fri Dec 13 05:41:24 1996 > Date: Fri, 13 Dec 1996 03:24:44 -0600 (CST) > Originator: ss@tapr.org > From: morganb@inetport.com (Robert B. Morgan) > To: ss@tapr.org > Subject: [SS:680] This will make you smile > X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas > X-Comment: Tucson Amateur Packet Radio Spread Spectrum > > Today (or yesterday evening if you prefer) Dec 12 1996, from about 2030 > to about 0230 the next morning, I surfed the web at high speed over > the ham radio. (I am sending this to both SS reflectors, this is for > operations under the STA). > > Greg set his system up on his ISDN line, and had his freewave radio > on the other end (of course), and after a little bit of server > configuration, and a tweak or two on this end, I was surfing the > web, at speeds I wasn't accustomed to on my 14.4 kb landline modem. > > Greg said to turn the usual landline SLIP/PPP compression off before > going on the air, apparently he isn't set up for that as yet. So I > am running 38400b to a radio modem with an on-the-air modem speed of > some 173Kb, to a server/router on an ISDN line with only him and me > for users, and I am seeing average file transfer rates as displayed > by Netscape of from 1800 to over 2400 bytes/sec (not bits/sec mind you). > When I am on my 14400b landline modem, I guess running compressed, > to my ISP down the road, I almost never see anything over 1300 bytes/sec > average rate, and of course some of the slow sites back down to half that. It seems to me, Bob, that you and Greg have found a way to entice Generation-X to amateur radio. It is a very frustrating situation to surf the net at 28800 at home, but have a direct ISDN connection at work. Maybe your method will jump over the speed hurdle that exists until landline modems (and phone lines) increase in speed. This is a good area where we amateurs can push the envelope in new technologies. > I look down at the oscilloscope that > I have connected to the feedline wattmeter, and during the thick of > the file transfer, there are some intermittent TX pulses about every > 20 or so milliseconds (I am only seeing my acks, I wonder what Greg's > radio dutycycle is). There is still a lot of empty time on that channel, > at least what I can judge from this end. I guess this qualifies as > real QRP operation too, just 400 mW, and a low duty cycle at that. > This little unit might make a dandy unit on a solar powered remote site > too. I would be curious if any QRPers were having a "chat" nearby when you were on the air. This would make a good test bed: download files from the net while at the same time have a QRP session with Greg and see if you get any interference. > > That 1200b radio barrier we have let hang around all too long is just > about to get swept away I think. While it has its uses, this has > a lot of potential. And it is for real, right now today. It would be nice if we could develop a high-speed modem (> 1meg/sec) and implement that in the next amateur satellite (Phase 4 ??), running SS of course. > > 73 de Bob WB5AOH > Robert Morgan > Austin Texas > morganb@admin.inetport.com 73s de Tony KE4ATO tony@spacey.net From rlanier@su102s.ess.harris.com Fri Dec 13 13:03:34 1996 Received: from ess.harris.com (su15a.ess.harris.com [130.41.1.251]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id NAA23287 for ; Fri, 13 Dec 1996 13:03:32 -0600 (CST) Received: from losalamos.ess.harris.com (su102s.ess.harris.com [130.41.13.101]) by ess.harris.com (8.8.4/8.8.4) with SMTP id OAA14088 for ; Fri, 13 Dec 1996 14:03:26 -0500 (EST) Received: from Paris.GASD102designcenter by losalamos.ess.harris.com (4.1/SMI-4.1) id AA09157; Fri, 13 Dec 96 14:03:25 EST Received: by Paris.GASD102designcenter (SMI-8.6/SMI-SVR4) id OAA03698; Fri, 13 Dec 1996 14:03:25 -0500 Date: Fri, 13 Dec 1996 14:03:25 -0500 From: rlanier@su102s.ess.harris.com (Tony Lanier) Message-Id: <199612131903.OAA03698@Paris.GASD102designcenter> To: ss@tapr.org Subject: Re: [SS:681] hello X-Sun-Charset: US-ASCII > I have just joined the the list and wanted to say a quick hello to > everyone on the list. > > Allen > > -kb5sqk- > Hello Allen From ve6bsf@valis.worldgate.com Fri Dec 13 17:03:09 1996 Received: from valis.worldgate.com (root@valis.worldgate.com [198.161.84.2]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id RAA07648; Fri, 13 Dec 1996 17:03:00 -0600 (CST) From: ve6bsf@valis.worldgate.com Received: from ve6bsf-6 (ve6bsf.worldgate.com [207.167.14.65]) by valis.worldgate.com (8.6.12/8.6.12) with SMTP id QAA20977; Fri, 13 Dec 1996 16:02:57 -0700 Message-Id: <199612132302.QAA20977@valis.worldgate.com> Comments: Authenticated sender is To: ss@tapr.org Date: Fri, 13 Dec 1996 16:03:49 +0000 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Subject: unsubscrible CC: hfsig@tapr.org Priority: normal X-mailer: Pegasus Mail for Windows (v2.33) From migarcia@csiam1.mxl.uabc.mx Fri Dec 13 18:40:55 1996 Received: from csiam1.mxl.uabc.mx (csiam1.mxl.uabc.mx [148.231.51.11]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id SAA13045 for ; Fri, 13 Dec 1996 18:40:53 -0600 (CST) Received: from [148.231.73.32] by csiam1.mxl.uabc.mx with SMTP (1.38.193.5/16.2) id AA19583; Fri, 13 Dec 1996 16:41:11 -0800 Message-Id: <32B1F934.2C5C@csiam1.mxl.uabc.mx> Date: Fri, 13 Dec 1996 16:47:48 -0800 From: Miguel Angel Garcia Estrello X-Mailer: Mozilla 2.0 (Win95; I; 16bit) Mime-Version: 1.0 To: ss@tapr.org Subject: unsubscribe From RICHARDS@dilbert.lbl.gov Fri Dec 13 21:37:44 1996 Received: from dilbert.lbl.gov (dilbert.lbl.gov [131.243.65.37]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id VAA21151 for ; Fri, 13 Dec 1996 21:37:42 -0600 (CST) From: RICHARDS@dilbert.lbl.gov Date: Fri, 13 Dec 1996 19:38:27 -0800 (PST) To: ss@tapr.org Message-Id: <961213193827.19b@dilbert.lbl.gov> Subject: SS Audio transmissions in Antarctica I am a physicist at UC Berkeley, and I work on an experiment at the South Pole. We are building a giant neutrino detector using the ice as a target for high-energy neutrinos from space. We need to understand as much as possible about the ice sheet (which is 2.8 km thick at the pole) in order to design the best detector at the best depth. I wish to monitor ice movement using a capacitive microphone placed in a pressure housing at 2 km depth. I would like to relay the acoustic signals to the surface via a SS radio link built on a 50-200 MHz radio platform. Antarctica is not under FCC juristic- tion, so we can operate at frequencies not available to Amateur radio people in the states. I wish to know the following: 1) Will the SS receiver ASICs currently available work in the 50-200 MHz band? 2) Should one convert audio into 8 bit digital data (for example) then mix this data stream with a PRBS at some chipping frequency (say 10 MHz) to acheive a SS signal? The ice is actually quite transparent to radio waves at these frequencies. I wish to use SS to avoid the problem of interference from equipment that operates at pole 4 months out of the year, and also to prevent the generation of RFI which would compromise the performance of the neutrino detector. I understand that these are basic questions that may not be of general interest. Perhaps any interested and knowledgable people could contact me directly? Best, Austin Dr. Austin Richards Dept. of Physics UC Berkeley richards@dilbert.lbl.gov From c1f@juno.com Sat Dec 14 07:07:10 1996 Received: from x3.boston.juno.com (x3.boston.juno.com [205.231.100.22]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id HAA18697 for ; Sat, 14 Dec 1996 07:07:09 -0600 (CST) From: c1f@juno.com Received: (from c1f@juno.com) by x3.boston.juno.com (queuemail) id IRN26708; Sat, 14 Dec 1996 08:06:49 EST To: ss@tapr.org Date: Fri, 13 Dec 1996 18:23:55 PST Subject: Re: [SS:681] hello Message-ID: <19961214.080545.10182.0.C1F@juno.com> References: <1.5.4.32.19961213151438.0069f164@cei.net> X-Mailer: Juno 1.00 X-Juno-Line-Breaks: 0-3 Hello Allen, Welcome to the reflector.... Stan, WA1ECF From bstrick@dallas.net Sat Dec 14 09:03:23 1996 Received: from dns.plano.net (dns.plano.net [204.215.60.2]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id JAA22848 for ; Sat, 14 Dec 1996 09:03:21 -0600 (CST) Received: from nt-35 (aux171.plano.net) by dns.plano.net (5.x/SMI-SVR4) id AA00355; Sat, 14 Dec 1996 09:03:03 -0600 Message-Id: <2.2.32.19961214145555.002f7ad8@plano.net> X-Sender: bstrick@plano.net X-Mailer: Windows Eudora Pro Version 2.2 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sat, 14 Dec 1996 08:55:55 -0600 To: ss@tapr.org From: Bob Stricklin Subject: Re: [SS:686] SS Audio transmissions in Antarctica A few questions? 1. How do you plan to power the telemetry package? Batteries? 2. What is the expected operating temperature down 2 km and on the surface when you go to install the package? 3. Do you have any data on the expected attenuation of rf from 50-200 MHz when passing through ice? This data would be helpful in calculating the power requirements. 4. Do you plan on transmitting from the bottom only? My experience tells me this group will enjoy hearing about a real application and a scientific experiment. At 09:38 PM 12/13/96 -0600, you wrote: > > I am a physicist at UC Berkeley, and I work on an experiment at the >South Pole. We are building a giant neutrino detector using the ice as a >target for high-energy neutrinos from space. We need to understand as much >as possible about the ice sheet (which is 2.8 km thick at the pole) in order >to design the best detector at the best depth. I wish to monitor ice movement >using a capacitive microphone placed in a pressure housing at 2 km depth. >I would like to relay the acoustic signals to the surface via a SS radio link >built on a 50-200 MHz radio platform. Antarctica is not under FCC juristic- >tion, so we can operate at frequencies not available to Amateur radio people >in the states. I wish to know the following: > >1) Will the SS receiver ASICs currently available work in the 50-200 MHz band? >2) Should one convert audio into 8 bit digital data (for example) then >mix this data stream with a PRBS at some chipping frequency (say 10 MHz) to >acheive a SS signal? > > > The ice is actually quite transparent to radio waves at these frequencies. I wish to use SS to avoid the problem of interference from equipment that >operates at pole 4 months out of the year, and also to prevent the generation >of RFI which would compromise the performance of the neutrino detector. > > I understand that these are basic questions that may not be of general >interest. Perhaps any interested and knowledgable people could contact me >directly? > > Best, Austin > > Dr. Austin Richards > Dept. of Physics > UC Berkeley > > richards@dilbert.lbl.gov > > Bob Stricklin, N5BRG bstrick@dallas.net AKA: bstrick@plano.net bstrick@tenet.edu Dallas, Texas From bstrick@dallas.net Sat Dec 14 11:07:13 1996 Received: from dns.plano.net (dns.plano.net [204.215.60.2]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id LAA29492 for ; Sat, 14 Dec 1996 11:07:11 -0600 (CST) Received: from nt-35 (aux134.plano.net) by dns.plano.net (5.x/SMI-SVR4) id AA03213; Sat, 14 Dec 1996 11:06:55 -0600 Message-Id: <2.2.32.19961214165950.002fe84c@plano.net> X-Sender: bstrick@plano.net X-Mailer: Windows Eudora Pro Version 2.2 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sat, 14 Dec 1996 10:59:50 -0600 To: ss@tapr.org From: Bob Stricklin Subject: Re: [SS:686] SS Audio transmissions in Antarctica At 09:38 PM 12/13/96 -0600, you wrote: >1) Will the SS receiver ASICs currently available work in the 50-200 MHz band? Most of the chip sets on the market today are being used at 900 MHz or 2.4 GHz. However it would be possible to build a transverter to operate in the range of 50-200 MHz. >2) Should one convert audio into 8 bit digital data (for example) then >mix this data stream with a PRBS at some chipping frequency (say 10 MHz) to >acheive a SS signal? This would work. Will 8 bits give you enough resolution? You can probably use more than 8 bits without adding much complexity. If you are only going to monitor audio levels you may be able to build a simple system using an off the shelf digital phone with a directional antenna (if you can be sure of its pointing direction when installed) and a small amplifier. I really think a key will be operating power needed to support the package and operating temperature. Bob Stricklin, N5BRG bstrick@dallas.net AKA: bstrick@plano.net bstrick@tenet.edu Dallas, Texas From ka5wgl@airmail.net Sun Dec 15 02:24:05 1996 Received: from mail.airmail.net (mail.airmail.net [206.66.12.40]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id CAA09342 for ; Sun, 15 Dec 1996 02:24:04 -0600 (CST) Received: from AlanWilson from [206.66.7.100] by mail.airmail.net (/\##/\ Smail3.1.30.16 #30.135) with esmtp id ; Sat, 14 Dec 96 23:25:27 -0600 (CST) Message-Id: From: "Alan K. Wilson, M.D." To: Subject: Re: [SS:664] Re: Wireless Networking built into PC's Date: Sat, 14 Dec 1996 23:18:23 -0600 X-MSMail-Priority: Normal X-Priority: 3 X-Mailer: Microsoft Internet Mail 4.70.1155 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Hi, Ron. Where is all the activity in the Metroplex area. I live in Corsicana and am interested in getting started in interconnecting packet to the Internet. I know that some people have already started, so I guess that I just need a contact person. Thanks and 73 Alan, KA5WGL ---------- > From: Ron Cole > To: ss@tapr.org > Subject: [SS:664] Re: Wireless Networking built into PC's > Date: Monday, December 09, 1996 8:20 PM > > At 01:18 AM 12/9/96 -0600, you wrote: > > > >Obligatory SS content: Such a system would almost have to be SS. > > > >That quote hit me between the eyes like a 2x4. A criticism I've had of PC > >companies for a long time is why didn't a vendor like Intel, Dell, Compaq, > >etc. just have the courage to put an Ethernet adapter on the motherboard > >on every one of their PC's. It seems to me that it would be even simpler > >to put a simple wireless tranceiver onboard, and run it almost completely > >in software from the excess processing power on the Pentium/Pro/MMX > >processor (which should, by this point, be labelled "The KA9Q approach"). > > > >Steve N8GNJ > > If you take a look at Compaq's business line like the Desk Pro and Up they > all come with 10-BaseT NIC built onto the motherboard. Some of their > latest Laptops have High Speed IRD interfaces built in, and the docking > stations have a 10-BaseT NIC. > > I would not be suprised to see either built-in or as an option a 900 Mhz > DSSS NIC from Compaq soon. They seem to be commited to Networking. > > Now I just need to stir up some interest in 900 Mhz Amateur Networking here > in the DFW Metroplex. I know of a couple of users on the band, NBFM ATV, > and a couple of FM Repeaters. > > I wonder how a FreeWave DRG-115 would operate on a tower site overlooking > the City ? > > Ron Cole > N5HYY > Ron Cole > ---------------------------------------+------------------------------------ > ------- > rdcole@mindspring.com | > N5HYH | > ---------------------------------------+------------------------------------ > ------- > From rlanier@su102s.ess.harris.com Mon Dec 16 07:55:34 1996 Received: from ess.harris.com (su15a.ess.harris.com [130.41.1.251]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id HAA18630 for ; Mon, 16 Dec 1996 07:55:32 -0600 (CST) Received: from losalamos.ess.harris.com (su102s.ess.harris.com [130.41.13.101]) by ess.harris.com (8.8.4/8.8.4) with SMTP id IAA10221 for ; Mon, 16 Dec 1996 08:55:30 -0500 (EST) Received: from Paris.GASD102designcenter by losalamos.ess.harris.com (4.1/SMI-4.1) id AA20936; Mon, 16 Dec 96 08:55:30 EST Received: by Paris.GASD102designcenter (SMI-8.6/SMI-SVR4) id IAA07630; Mon, 16 Dec 1996 08:55:25 -0500 Date: Mon, 16 Dec 1996 08:55:25 -0500 From: rlanier@su102s.ess.harris.com (Tony Lanier) Message-Id: <199612161355.IAA07630@Paris.GASD102designcenter> To: ss@tapr.org Subject: Re: [SS:688] Re: SS Audio transmissions in Antarctica X-Sun-Charset: US-ASCII > > My experience tells me this group will enjoy hearing about a real > application and a scientific experiment. > > > At 09:38 PM 12/13/96 -0600, you wrote: > > > > I am a physicist at UC Berkeley, and I work on an experiment at the > >South Pole. We are building a giant neutrino detector using the ice as a > >target for high-energy neutrinos from space. We need to understand as much > >as possible about the ice sheet (which is 2.8 km thick at the pole) in order > >to design the best detector at the best depth. I wish to monitor ice movement > >using a capacitive microphone placed in a pressure housing at 2 km depth. > >I would like to relay the acoustic signals to the surface via a SS radio link > >built on a 50-200 MHz radio platform. Antarctica is not under FCC juristic- > >tion, so we can operate at frequencies not available to Amateur radio people You are correct that there are people on this reflector that would be very interested to know about this experiment. Finding other uses for SS other than Amateur Radio is refreshing. 73 de Tony KE4ATO From memo@kim.fcfm.buap.mx Mon Dec 16 22:25:49 1996 Received: from kim.fcfm.buap.mx (memo@kim.fcfm.buap.mx [148.228.125.6]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id WAA29255 for ; Mon, 16 Dec 1996 22:25:47 -0600 (CST) Received: (from memo@localhost) by kim.fcfm.buap.mx (8.6.12/8.6.9) id EAA15201 for ss@tapr.org; Tue, 17 Dec 1996 04:31:35 -0600 Date: Tue, 17 Dec 1996 04:31:35 -0600 From: Guillermo Castillo Nunez Message-Id: <199612171031.EAA15201@kim.fcfm.buap.mx> To: ss@tapr.org Subject: Motorola Mitrek? Hello all. Once I heard from some that old Motorola Mitrek tranceiver, can be get in south california. I would like to know if some knows whewre to ask for them or buy them. or someboby can to sell me ?, I need two or tree working ! Please let me know. Sincerely Memo. xe1ff@amsat.org or memo@kim.fcfm.buap.mx From dcole@on-ramp.ior.com Tue Dec 17 20:40:06 1996 Received: from on-ramp.ior.com (on-ramp.ior.com [199.79.239.11]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id UAA12555 for ; Tue, 17 Dec 1996 20:40:04 -0600 (CST) Received: from pm2-08.ior.com(really [204.212.119.2]) by on-ramp.ior.com via sendmail with smtp id for ; Tue, 17 Dec 96 18:40:02 -0800 (PST) (/\##/\ Smail3.1.30.16 #30.4 built 17-mar-96) Message-ID: <32B75952.5D91@on-ramp.ior.com> Date: Tue, 17 Dec 1996 18:39:14 -0800 From: doug cole Organization: spokane county communications X-Mailer: Mozilla 3.0 (Win16; I) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: [SS:692] Motorola Mitrek? References: <199612171031.EAA15201@kim.fcfm.buap.mx> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hello Guillermo : I have purchased uhf mitreks from a company in billings montana called CW-Wolfe Communications, their address is 1113 central ave. billings montana, usa 59102. Phone # is 1-406-252-9617. Ask for Bud Wolfe as he is the owner and an amateur radio operator and tell him you are a ham and ask if he has any more uhf mitreks and tell him that they are for amateur use and he should give you a better price than commercial buyers :) good luck 73's doug cole de N7BFS ps: if you need help modifying these for full duplex let me know as I have done many of them and am most familiar with them... From clearbrook_technical@linux.clrtech.com Tue Dec 17 22:33:23 1996 Received: from linux.clrtech.com. (excel55.jumppoint.com [204.191.232.180]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id WAA17703 for ; Tue, 17 Dec 1996 22:33:21 -0600 (CST) Received: from fk-win.mtn.clrtech.com (fk-win.mtn.clrtech.com [172.17.100.103]) by linux.clrtech.com. (8.6.9/8.6.9) with SMTP id VAA00511 for ; Tue, 17 Dec 1996 21:44:50 -0800 Date: Tue, 17 Dec 1996 21:44:50 -0800 Message-Id: <199612180544.VAA00511@linux.clrtech.com.> X-Sender: clearbrook_technical@linux.clrtech.com (Unverified) X-Mailer: Windows Eudora Light Version 1.5.2 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: Clearbrook Technical Subject: linux wavelan drivers Hi, i picked up some of the WaveLan boards on the original buy, and have a link running over about a 10km distance, using linux boxes as routers at both ends, performance has been very good, moving zipped files using the WS_FTP client it shows a consistent 1.4MBits xfer rate! Question: someone a while back mentioned a linux driver that was available or being worked on, that had hooks for monitoring the RF on these cards, does anyone have any info on these drivers...? It would be nice to be able to see what the links are doing in real time..... cheers fred kehler (ve7ipb) clearbrook technical services ltd 604 850 3010 From emcastro@pobox.com Wed Dec 18 06:51:15 1996 Received: from virtual-net.com.br (virtual-net.com.br [200.246.123.10]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id GAA10079 for ; Wed, 18 Dec 1996 06:51:08 -0600 (CST) Received: from [200.246.123.124] by virtual-net.com.br; (5.65v3.2/1.1.8.2/12Jun96-1054AM) id AA12854; Wed, 18 Dec 1996 10:57:58 -0200 Received: by TBASP01 with Microsoft Mail id <01BBED1E.4AE0F840@TBASP01>; Wed, 18 Dec 1996 20:01:44 -0300 Message-Id: <01BBED1E.4AE0F840@TBASP01> From: "Eric M. de Castro" To: "'ss@tapr.org'" Subject: unsubscribe Date: Wed, 18 Dec 1996 09:51:14 -0300 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit From wb9mjn@wb9mjn.ampr.org Wed Dec 18 09:46:34 1996 Received: from wb9mjn.ampr.org (wb9mjn.ampr.org [44.72.98.19]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id JAA18009 for ; Wed, 18 Dec 1996 09:43:12 -0600 (CST) From: wb9mjn@wb9mjn.ampr.org Date: Wed, 18 Dec 96 09:07:15 UTC Message-Id: <11700@wb9mjn.ampr.org> To: ss@tapr.org Subject: LAN Implimentations / Antenna Options... Hi, There is an oportunity to move the LAN architecture ideas forward with the 915 Radios, and various antenna types. Comments have been made that Omni antenna at central hub is a way to do this. This follows the traditional 145.01 Ham Radio technigue. Commercial wireless systems commonly use sectorized hub technigues. This greatly increases capacity, within the wireless range (area) of the hub. Hams are going to want to do CUSEEME, amoung other things. One CUSEEME op- eration in a Omni hub'd system, maxes that capacity. With a sectorized hub, the other spokes of the hub still have capacity. Or, in other words, we have as many CUSEEME QSO s possible, as the number of spokes. I m not sure of the channel access technigue used by the Freewave Radios, can anybody enlighten me? If its CSMA, this would be another reason to sectorise a hub. Within each sector, of a high hub, the users will have a much greater chance to hear each other. Versus, trying to hear users on the other side of the hill. Microstrip patch antennas typically have F/B ratios in excess of 20 dB. When placed on buildings, antenna seperations of 10 meters are possible. This re- presents a 60 dB isolation. At 30 dBm power level, the RF from one radio, colocated at a site would be at -30 dBm out of the antenna on the other side of the building. This is a practical possibility. We could run two , or more radios at a single high site, without desense, on seperate hopping codes. There are also multipath advantages. Reflections off other structures on the building, are made negligable, while the antenna provides a wide beam width of coverage. I ve been told that the hopping rate of the Freewave radios is 10 ms. 10 ms represents a propagation distance of 1800 miles. Multipath protection, from reflections in excess of 1800 miles additional path distance would then be available from these radios. Needless to say, in a terrestrial enviorment, this is akin to no multipath protection at all from this FHSS. The WWW.BALTZER.NL/WIRELESSCD Web page points out measurements, that pre- dict, that indoor antennas, even with sufficient signal level, will not work at the data rates of the Freewave radio, when talking to a site a distance away, outside the building. 20 us delay spreads were measured for this situation. This puts the point of dimishing performance at a data rate of 10 kb/s (1/5 of 1/20us). The Freewave radio use a raw data rate of 173 KB/s i believe. Outdoor antennas in an suburban/urban enviorment are reported to have measured delay spreads of 2 us, worse case. This makes the point of diminishing performance 100 KB. 173 KB would probably work in most circum- stances, but every now and then, it wont, based on this information. A Microstrip patch antenna, operated in a window will have similar per- formance to an outdoor antenna. Without the reliability problems outdoor antennas represent. A microstrip patch antenna would be an ideal user antenna for a 915 Freewave radio LAN. I ve made a prototype Microstrip Patch antenna for 915. The dimensions are 12 by 9 by 2 inches thick. It has 6 dBd gain, but when oriented for horizontal polarisation, the antennas may be butted together along the 12 inch side, and stacked for additional gain. Indoors, this may be done with double faced foam tape! 2 patches would have aproximately 9 dBd gain. 4 patches, 12 dBd gain. And so on. One may obtain one antenna, and if they need more gain, add antennas afterward. 73, Don. Mailbox : WB9MJN @ N9HSI.IL.USA.NA AMPRNet : wb9mjn@wb9mjn.ampr.org[44.72.98.19] Internet: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu From fred@tekdata.com Wed Dec 18 11:35:28 1996 Received: from tekdata.com (pool10-012.wwa.com [206.222.42.13]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id LAA25539 for ; Wed, 18 Dec 1996 11:35:22 -0600 (CST) Received: (from fred@localhost) by tekdata.com (8.6.12/8.6.12) id LAA04229; Wed, 18 Dec 1996 11:36:52 -0600 Date: Wed, 18 Dec 1996 11:36:52 -0600 (CST) From: "Fred M. Spinner" To: ss@tapr.org Subject: Article I saw... Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII I'm here at work stealing some time from the ol' corporate empire.. I noticed in one of the free mags I got there is a "Buyer's Guide" for wireless LANS.. page 120 12/15/96. They have a web page at www.networkcomputing.com. Since most of the units listed are SS at 902-928 or 2.4 GHz I thought this might be of interest to the group. Fred M. Spinner, KA9VAW From kd4kao@juno.com Wed Dec 18 13:07:16 1996 Received: from x1.boston.juno.com (x1.boston.juno.com [205.231.100.21]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id NAA01170 for ; Wed, 18 Dec 1996 13:07:11 -0600 (CST) Received: (from kd4kao@juno.com) by x1.boston.juno.com (queuemail) id OZA18495; Wed, 18 Dec 1996 14:06:39 EST To: ss@tapr.org Subject: [SS:695] unsubscribe Message-ID: <19961218.151336.4783.0.KD4KAO@juno.com> References: <01BBED1E.4AE0F840@tbasp01> X-Mailer: Juno 1.15 X-Juno-Line-Breaks: 0 From: kd4kao@juno.com (Harley w Patrick) Date: Wed, 18 Dec 1996 14:06:39 EST Please take me off this mailing list. From ssampson@claven.tinker.af.mil Wed Dec 18 14:25:22 1996 Received: from othello.tinker.af.mil (othello.tinker.af.mil [137.240.231.43]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA05306 for ; Wed, 18 Dec 1996 14:25:08 -0600 (CST) Received: from localhost by othello.tinker.af.mil (AIX 4.1/UCB 5.64/4.03) id AA10226; Wed, 18 Dec 1996 14:21:16 -0600 Sender: ssampson@othello.tinker.af.mil Message-Id: <32B8523C.1CFB@eds.tinker.af.mil> Date: Wed, 18 Dec 1996 14:21:16 -0600 From: Steve Sampson Organization: TRW Space & Electronics X-Mailer: Mozilla 2.02 (X11; I; AIX 1) Mime-Version: 1.0 To: ss@tapr.org Subject: Re: [SS:698] unsubscribe References: <19961218.151336.4783.0.KD4KAO@juno.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Harley w Patrick wrote: > > Please take me off this mailing list. You can do that yourself. In case you forgot, go to: http://www.tapr.org and follow the SIG tree till you get to unsubscribe. Merry Christmas, Steve From taylord@ecn.purdue.edu Wed Dec 18 15:36:29 1996 Received: from atom.ecn.purdue.edu (root@atom.ecn.purdue.edu [128.46.132.94]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id PAA09707 for ; Wed, 18 Dec 1996 15:36:26 -0600 (CST) Received: from [128.46.169.162] (instru1.ecn.purdue.edu [128.46.169.162]) by atom.ecn.purdue.edu (8.8.4/3.8.2moyman) with ESMTP id QAA04354; Wed, 18 Dec 1996 16:36:21 -0500 (EST) Date: Wed, 18 Dec 1996 16:36:21 -0500 (EST) X-Sender: taylord@128.46.169.94 Message-Id: In-Reply-To: <199612180544.VAA00511@linux.clrtech.com.> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: David G Taylor Subject: Re: [SS:694] linux wavelan drivers >Hi, i picked up some of the WaveLan boards on the original buy, and have a >link running over about a 10km distance, using linux boxes as routers at >both ends, performance has been very good, moving zipped files using the >WS_FTP client it shows a consistent 1.4MBits xfer rate! > >Question: someone a while back mentioned a linux driver that was available >or being worked on, that had hooks for monitoring the RF on these cards, >does anyone have any info on these drivers...? It would be nice to be able >to see what the links are doing in real time..... >cheers >fred kehler (ve7ipb) >clearbrook technical services ltd 604 850 3010 Would you share the details of the RF amplifier and antennas you are using ? I have 4 bds from the buy which I've been using intrabuilding. I now want to set up a 6 mile link, and a 1 mile link, both going into a hub. The distant ends are in line with each other, so a directional antenna at the hub may work. Suggestions appreciated ! 73 David de KB9KNS (Am cordless; will travel.) --taylord@ecn.purdue.edu From kd4kao@juno.com Wed Dec 18 16:41:37 1996 Received: from x1.boston.juno.com (x1.boston.juno.com [205.231.100.21]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id QAA13092 for ; Wed, 18 Dec 1996 16:41:35 -0600 (CST) Received: (from kd4kao@juno.com) by x1.boston.juno.com (queuemail) id RiX18495; Wed, 18 Dec 1996 17:38:47 EST To: ss@tapr.org Subject: Re: unsubscribe Message-ID: <19961218.184613.4783.3.KD4KAO@juno.com> References: <32B8523C.1CFB@eds.tinker.af.mil> X-Mailer: Juno 1.15 X-Juno-Line-Breaks: 1-4,6-21 From: kd4kao@juno.com (Harley w Patrick) Date: Wed, 18 Dec 1996 17:38:47 EST I never added myself to this list and do not have internet access. So if the sysop of this mailing will PLEASE remove me, I would appreciate it. Patrick On Wed, 18 Dec 1996 14:29:49 -0600 (CST) Steve Sampson writes: >Harley w Patrick wrote: >> >> Please take me off this mailing list. > >You can do that yourself. In case you forgot, go to: > >http://www.tapr.org > >and follow the SIG tree till you get to unsubscribe. > >Merry Christmas, > >Steve > > From bad@uhf.wireless.net Wed Dec 18 16:51:53 1996 Received: from uhf.wdc.net (uhf.wdc.net [198.147.74.44]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id QAA13993 for ; Wed, 18 Dec 1996 16:51:50 -0600 (CST) Received: from localhost (bad@localhost) by uhf.wdc.net (8.8.4/8.6.12) with SMTP id RAA03204 for ; Wed, 18 Dec 1996 17:53:39 -0500 (EST) Date: Wed, 18 Dec 1996 17:53:38 -0500 (EST) From: Bernie Doehner To: ss@tapr.org Subject: Re: [SS:700] Re: linux wavelan drivers In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi Fred/David: Didn't catch the start of this thread.... > >Hi, i picked up some of the WaveLan boards on the original buy, and have a > >link running over about a 10km distance, using linux boxes as routers at > >both ends, performance has been very good, moving zipped files using the > >WS_FTP client it shows a consistent 1.4MBits xfer rate! Nice! > >Question: someone a while back mentioned a linux driver that was available > >or being worked on, that had hooks for monitoring the RF on these cards, > >does anyone have any info on these drivers...? It would be nice to be able > >to see what the links are doing in real time..... > >cheers > >fred kehler (ve7ipb) > >clearbrook technical services ltd 604 850 3010 The only thing I know about is waveinfo. And I thought waveinfo only works on the PCMCIA Wavelan cards (which I use at home). > Would you share the details of the RF amplifier and antennas you are using ? > I have 4 bds from the buy which I've been using intrabuilding. I now want > to set up a 6 mile link, and a 1 mile link, both going into a hub. The > distant ends are in > line with each other, so a directional antenna at the hub may work. > Suggestions appreciated ! Yes. I'd love hear about this too! 73 Bernie nu1s From clearbrook_technical@mindlink.bc.ca Wed Dec 18 17:02:49 1996 Received: from linux.clrtech.com. (excel54.jumppoint.com [204.191.232.179]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id RAA14342 for ; Wed, 18 Dec 1996 17:02:45 -0600 (CST) Received: from fk-shop.clrtech.com (fk-shop.clrtech.com [172.17.20.101]) by linux.clrtech.com. (8.6.9/8.6.9) with SMTP id QAA00888 for ; Wed, 18 Dec 1996 16:14:28 -0800 Date: Wed, 18 Dec 1996 16:14:28 -0800 Message-Id: <199612190014.QAA00888@linux.clrtech.com.> X-Sender: clearbrook_technical@linux.clrtech.com X-Mailer: Windows Eudora Light Version 1.5.2 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: Fred Kehler Subject: Re: [SS:700] Re: linux wavelan drivers >To: ss@tapr.org >From: Fred Kehler >Subject: Re: [SS:700] Re: linux wavelan drivers > >Sure, I'm using nothing :-), at least in the way of amplifiers. I have a 10km line of sight path with the antennas up about 15ft at the ends and a valley floor in between, so should be minimal fresnel losses, on each end i am using an 11 element loop yagi that i ordered from Down East Microwave, with a gain spec of 12.5dbi. feedline is about 30ft- 1/2" heliax at my home end. The other end is at my place of work and i had a long run from the antenna made up of 20ft RG8 and about 30ft of RG58 going directly to the WaveLan cards, I hacked the patch antenna cables off and made adapter cables to go to BNC ends, as i had trouble finding suitable patch cables to go from the cards to my bigger connectors..... >anyway the link has survived the most snow we have had here (Pacific Northwest), even with snow on the antennas it keeps chugging along, i tried inserting another 50ft of RG58 as an attenuator, this seemed to bring the path budget right to the edge as performance dropped right off. I tried doing a link running with an inverter and a yagi strapped to the back of my truck, (about a 5ft piece of wood) i had no trouble establishing contact at 13km and also 19km -all line of sight, i didn't do any actual test of thruput but the connection 'felt' solid. I was surprised with the results i got and intend to follow up with a more experiments when the weather improves :-) >right now i am using the link to surf the net from my home to place of work > >If you have line of sight i would be tempted to try the link with just a couple of good antennas before investing in RF amps... >good luck > >> >>Would you share the details of the RF amplifier and antennas you are using ? >>I have 4 bds from the buy which I've been using intrabuilding. I now want >>to set up a 6 mile link, and a 1 mile link, both going into a hub. The >>distant ends are in >>line with each other, so a directional antenna at the hub may work. >>Suggestions appreciated ! >> >>73 David de KB9KNS >> >> >>(Am cordless; will travel.) --taylord@ecn.purdue.edu >> >> >> >> >> > cheers Fred Kehler Clearbrook Technical Services Ltd voice 604 850-3010 From clearbrook_technical@mindlink.net Wed Dec 18 17:04:04 1996 Received: from linux.clrtech.com. (excel54.jumppoint.com [204.191.232.179]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id RAA14341 for ; Wed, 18 Dec 1996 17:02:45 -0600 (CST) Received: from fk-shop.clrtech.com (fk-shop.clrtech.com [172.17.20.101]) by linux.clrtech.com. (8.6.9/8.6.9) with SMTP id QAA00886 for ; Wed, 18 Dec 1996 16:14:27 -0800 Date: Wed, 18 Dec 1996 16:14:27 -0800 Message-Id: <199612190014.QAA00886@linux.clrtech.com.> X-Sender: clearbrook_technical@linux.clrtech.com X-Mailer: Windows Eudora Light Version 1.5.2 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: Fred Kehler Subject: Re: [SS:700] Re: linux wavelan drivers Sure, I'm using nothing :-), at least in the way of amplifiers. I have a 10km line of sight path with the antennas up about 15ft at the ends and a valley floor in between, so should be minimal fresnel losses, on each end i am using an 11 element loop yagi that i ordered from Down East Microwave, with a gain spec of 12.5dbi. feedline is about 30ft- 1/2" heliax at my home end. The other end is at my place of work and i had a long run from the antenna made up of 20ft RG8 and about 30ft of RG58 going directly to the WaveLan cards, I hacked the patch antenna cables off and made adapter cables to go to BNC ends, as i had trouble finding suitable patch cables to go from the cards to my bigger connectors..... anyway the link has survived the most snow we have had here (Pacific Northwest), even with snow on the antennas it keeps chugging along, i tried inserting another 50ft of RG58 as an attenuator, this seemed to bring the path budget right to the edge as performance dropped right off. I tried doing a link running with an inverter and a yagi strapped to the back of my truck, (about a 5ft piece of wood) i had no trouble establishing contact at 13km and also 19km -all line of sight, i didn't do any actual test of thruput but the connection 'felt' solid. I was surprised with the results i got and intend to follow up with a more experiments when the weather improves :-) right now i am using the link to surf the net from my home to place of work If you have line of sight i would be tempted to try the link with just a couple of good antennas before investing in RF amps... good luck > >Would you share the details of the RF amplifier and antennas you are using ? >I have 4 bds from the buy which I've been using intrabuilding. I now want >to set up a 6 mile link, and a 1 mile link, both going into a hub. The >distant ends are in >line with each other, so a directional antenna at the hub may work. >Suggestions appreciated ! > >73 David de KB9KNS > > >(Am cordless; will travel.) --taylord@ecn.purdue.edu > > > > > cheers Fred Kehler Clearbrook Technical Services Ltd voice 604 850-3010 From wb9mjn@wb9mjn.ampr.org Thu Dec 19 00:07:30 1996 Received: from wb9mjn.ampr.org (wb9mjn.ampr.org [44.72.98.19]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id AAA08756 for ; Thu, 19 Dec 1996 00:06:46 -0600 (CST) From: wb9mjn@wb9mjn.ampr.org Date: Wed, 18 Dec 96 21:46:56 UTC Message-Id: <11732@wb9mjn.ampr.org> To: ss@tapr.org Subject: Re: [SS:704] Re: linux wavelan drivers In-Reply-To: your message of Wed Dec 18 17:14:08 1996 <199612190014.QAA00886@linux.clrtech.com.> Hi Fred Kehler, I m currious what ISM band the Wavelan cards you are using are on. I be- lieve there are 915, and 2.4 Ghz versions of those, right? 73, Don. Mailbox : WB9MJN @ N9HSI.IL.USA.NA AMPRNet : wb9mjn@wb9mjn.ampr.org[44.72.98.19] Internet: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu From clearbrook_technical@mindlink.bc.ca Thu Dec 19 10:44:00 1996 Received: from linux.clrtech.com. (excel18.jumppoint.com [204.191.232.143]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id KAA08017 for ; Thu, 19 Dec 1996 10:43:57 -0600 (CST) Received: from fk-shop.clrtech.com (fk-shop.clrtech.com [172.17.20.101]) by linux.clrtech.com. (8.6.9/8.6.9) with SMTP id JAA01163 for ; Thu, 19 Dec 1996 09:55:54 -0800 Date: Thu, 19 Dec 1996 09:55:54 -0800 Message-Id: <199612191755.JAA01163@linux.clrtech.com.> X-Sender: clearbrook_technical@linux.clrtech.com X-Mailer: Windows Eudora Light Version 1.5.2 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: Fred Kehler Subject: Re: [SS:705] Re: linux wavelan drivers At 12:16 AM 19/12/96 -0600, you wrote: > > Hi Fred Kehler, > > I m currious what ISM band the Wavelan cards you are using are on. I be- >lieve there are 915, and 2.4 Ghz versions of those, right? > Hi Don, these are the 915mhz version, I have not had any experience with the 2.4Ghz versions. >73, Don. > >Mailbox : WB9MJN @ N9HSI.IL.USA.NA >AMPRNet : wb9mjn@wb9mjn.ampr.org[44.72.98.19] >Internet: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu > > > > Fred Kehler Clearbrook Technical Services Ltd. clearbrook_technical@mindlink.bc.ca. From elpidio@aloha.net Thu Dec 19 23:31:07 1996 Received: from haleakala.aloha.net (root@haleakala.aloha.net [204.94.112.33]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id XAA03528 for ; Thu, 19 Dec 1996 23:31:05 -0600 (CST) Received: from hookomo.aloha.net (kauai-97.u.aloha.net [207.12.7.97]) by haleakala.aloha.net (8.7.5/8.6.9) with ESMTP id TAA22495 for ; Thu, 19 Dec 1996 19:31:03 -1000 (HST) Message-Id: <199612200531.TAA22495@haleakala.aloha.net> From: "Elpidio B. Cardenas" To: Subject: unsubscribe Date: Thu, 19 Dec 1996 19:16:22 -1000 X-MSMail-Priority: Normal X-Priority: 3 X-Mailer: Microsoft Internet Mail 4.70.1155 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit From wd5ivd@tapr.org Sun Dec 22 02:39:43 1996 Received: from [208.134.134.42] ([208.134.134.42]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id CAA01002; Sun, 22 Dec 1996 02:39:19 -0600 (CST) Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sun, 22 Dec 1996 02:44:22 -0600 To: "TAPR-BB list mailing", " Spread Spectrum ", "TAPR Spread Sprctrum" From: "Greg Jones, WD5IVD" Subject: TAPR SS STA Application Available TAPR SS STA Application On-Line TAPR requested a Special Temporary Authority ('STA') to conduct an experimental program to test spread spectrum emissions over amateur radio facilities on April 10, 1996. On November 6, 1996, the Federal Communications Commission Wireless Telecommunications Bureau granted the TAPR request for an STA. TAPR is making an application for participation in the STA available for any member of TAPR to use. The URL is: http://www.tapr.org/ss/tapr_sta.html Please note that all areas of the application must be filled out. These will be reviewed by the STA holders and a committee within TAPR. The more detail you can provide in the general answer areas the better. The STA holders reserve the right to add individuals to or remove individuals from the STA at anytime. The application will be used in order to determine eligibility in the STA as well as provide information to the database and final report of the STA. Responsibilities of STA stations: * Stations will be required to maintain the highest standards in operational practices. * Stations will be required to submit a report before the end of the STA that will be used in the final report. * Stations must have a dependable Internet e-mail service so that information and discussion regarding the STA can be held. * Stations must hold at least a Technician Class license * Stations must be aware that any transmissions conducted pursuant to the requested STA will be secondary in nature, and must cease immediately in the event of harmful interference. * Participants must be a current member of TAPR. For more information on TAPR check http://www.tapr.org For more information on TAPR SS information check http://www.tapr.org/ss ------------------------------------------------------------------------ Tucson Amateur Packet Radio 8987-309 E Tanque Verde Rd #337 * Tucson, Az * 85749-9399 * 817-383-0000 ------------------------------------------------------------------------ e-mail: TAPR@TAPR.ORG ftp: ftp.tapr.org web: http://www.tapr.org ------------------------------------------------------------------------ From wd5ivd@tapr.org Sun Dec 22 03:33:43 1996 Received: from [208.134.134.42] ([208.134.134.42]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id DAA02689; Sun, 22 Dec 1996 03:33:40 -0600 (CST) Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Date: Sun, 22 Dec 1996 03:39:41 -0600 To: "TAPR-BB list mailing", " Spread Spectrum ", "TAPR Spread Sprctrum" From: "Greg Jones, WD5IVD" Subject: TAPR Group Purchases on Freewave radios TAPR Group Purchases on Freewave radios URL: http://www.tapr.org/ss TAPR has worked an agreement with FreeWave Technologies, Inc. of Boulder, CO to make there 902-928Mhz 115Kbps radio available to the amateur radio community. This is an exciting deal and TAPR hopes to be make other High-Speed SS radios available to amateur radio operators in the future. TAPR will be taking orders in batches of 50+ units and will try to make a buy at the end of each month, until such time as members no longer require radios. These units will be useful under the current TAPR SS STA (http://www.tapr.org/ss/tapr_sta.html). These radios can be used under part 15 rules after the TAPR SS STA expires or the amateur rules do not change significantly enough for their use under Part 97 in the future. Profits made from these group buys will be used to fund future TAPR projects and to pay past and future TAPR regulatory efforts. Technical Specifications: * Freewave DGR-115 spread spectrum transceivers * Frequency hopping spread spectrum * Uncompressed data rates of 115.2 KBaud (serial) 173kbaud on radio * Distances of 20 miles or more * 1 Watt output power * Bandpass Filter * All transceivers are assigned a unique electronic serial number * -40=9F C to +60=9F C temp range See http://www.tapr.org/ss/freewave.html for full details and price. ------------------------------------------------------------------------ Tucson Amateur Packet Radio 8987-309 E Tanque Verde Rd #337 * Tucson, Az * 85749-9399 * 817-383-0000 ------------------------------------------------------------------------ e-mail: TAPR@TAPR.ORG ftp: ftp.tapr.org web: http://www.tapr.org ------------------------------------------------------------------------ From john@images.demon.co.uk Mon Dec 23 03:39:30 1996 Received: from relay-1.mail.demon.net (relay-1.mail.demon.net [158.152.1.140]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id DAA11626; Mon, 23 Dec 1996 03:39:26 -0600 (CST) Received: from images.demon.co.uk ([(null)]) by relay-1.mail.demon.net id aa22003; 23 Dec 96 9:36 GMT Received: from images (john@localhost [127.0.0.1]) by images.demon.co.uk (8.6.12/v3.2) with SMTP id JAA00574; Mon, 23 Dec 1996 09:33:01 GMT Sender: john@images.demon.co.uk Message-ID: <32BE51CD.185B584D@images.demon.co.uk> Date: Mon, 23 Dec 1996 09:33:01 +0000 From: John Melton X-Mailer: Mozilla 3.0 (X11; I; Linux 1.3.32 i586) MIME-Version: 1.0 To: ss@tapr.org CC: dsp93@tapr.org, dsp@tapr.org Subject: Java Web SIte Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hi, I have started a Web site dedicated to Java and Ham Radio. http://www.images.demon.co.uk/java.html If you know of any more development, let me know and I will add a link. Merry Christmas and Happy New Year to all. John Melton, g0orx/n6lyt From rwilmer@intermind.net Mon Dec 23 12:50:58 1996 Received: from intermind.net (root@terminus.intermind.net [199.3.230.2]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id MAA04470 for ; Mon, 23 Dec 1996 12:50:57 -0600 (CST) Received: from terminus.intermind.net (ppp37.intermind.net [199.3.230.137]) by intermind.net (8.7.5/8.7.3) with SMTP id KAA11365 for ; Mon, 23 Dec 1996 10:46:14 -0800 (PST) Message-Id: <2.2.32.19961223184906.007005f0@intermind.net> X-Sender: rwilmer@intermind.net X-Mailer: Windows Eudora Pro Version 2.2 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 23 Dec 1996 10:49:06 -0800 To: ss@tapr.org From: roy wilmer Subject: Re: [SS:692] Motorola Mitrek? At 10:31 PM 12/16/96 -0600, you wrote: >Hello all. >Once I heard from some that old Motorola Mitrek tranceiver, can be get in >south california. I would like to know if some knows whewre to ask for them >or buy them. or someboby can to sell me ?, I need two or tree working ! >Please let me know. > >Sincerely Memo. > > xe1ff@amsat.org > or > memo@kim.fcfm.buap.mx > > I have had good luck with LML in calif 909-820-1319 fax at 909-820-1885 email at HRH6@aol.com very slow reply they will tune for your freq. Roy wilmer K7YWF From zeus@myth.demon.co.uk Tue Dec 24 14:44:36 1996 Received: from myth.demon.co.uk (myth.demon.co.uk [158.152.20.217]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA18840 for ; Tue, 24 Dec 1996 14:44:33 -0600 (CST) Date: Tue, 24 Dec 1996 20:32:45 GMT From: zeus@myth.demon.co.uk (Mike Cowgill) Reply-To: zeus@myth.demon.co.uk Message-Id: <31835@myth.demon.co.uk> To: ss@tapr.org Subject: UoSat "Merlion" SS Payload X-no-archive: yes X-Mailer: PCElm 1.10 beta 3 Lines: 26 According to this month's Amsat-UK journal (Oscar news) a Spread Spectrum payload will floy on the UoSat-12 Merlion satellite. The article says: "The frequency agile digital S-band downlink is intended for high speed data transfew and will be employed to perform a variety of communication experiments. It is capable of low rate spread spectrum communications and has Viterbi coding options to investigate its performance in the highly dynamic environment of Low Earth Orbit. The downlink will also be used to perform link characterisation at those frequancies. The modulation scheme is NRZ-L/BPSK at 256k, 512k and 1Mbps with square root raised cosine shaping. This data can be processed via various scramblers and encoders. Data is scrambled using a standard V.35 scrambler, or via a programmable 32-bit universal scrambler. A 1/2 rate Viterbi encoder (k=7, G1=171, G2=133) is also included, and a spread spectrum mode permits experimentation with lower data rates for smaller ground stations whilst keeping the chip rate at 1Mbps. The downlink power will be 7W." Sounds good to me! Mike. P.S. The references are: A.da-Silva-Cunel@ee.surrey.ac.uk /www.ee.surrey.ac.uk/CSER/UOSAT From bruce@satscan.com Tue Dec 24 16:02:30 1996 Received: from satscan.com (root@satscan.com [205.199.65.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id QAA22497 for ; Tue, 24 Dec 1996 16:02:26 -0600 (CST) From: bruce@satscan.com Received: from 205.199.65.1 (boris.satscan.com [205.199.65.4]) by satscan.com (8.6.9/8.6.9) with SMTP id OAA07132 for ; Tue, 24 Dec 1996 14:05:25 -0800 Date: Tue, 24 Dec 1996 14:05:25 -0800 Message-Id: <199612242205.OAA07132@satscan.com> X-Sender: bruce@satscan.com X-Mailer: Windows Eudora Version 1.4.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org Subject: Re: [SS:712] UoSat "Merlion" SS Payload > >According to this month's Amsat-UK journal (Oscar news) a Spread Spectrum >payload will floy on the UoSat-12 Merlion satellite. The article says: > >"The frequency agile digital S-band downlink is intended for high speed data >transfew and will be employed to perform a variety of communication >experiments. It is capable of low rate spread spectrum communications and has >Viterbi coding options to investigate its performance in the highly dynamic >environment of Low Earth Orbit. The downlink will also be used to perform >link characterisation at those frequancies. The modulation scheme is >NRZ-L/BPSK at 256k, 512k and 1Mbps with square root raised cosine shaping. >This data can be processed via various scramblers and encoders. Data is >scrambled using a standard V.35 scrambler, or via a programmable 32-bit >universal scrambler. A 1/2 rate Viterbi encoder (k=7, G1=171, G2=133) is also >included, and a spread spectrum mode permits experimentation with lower data >rates for smaller ground stations whilst keeping the chip rate at 1Mbps. The >downlink power will be 7W." > >Sounds good to me! Sounds good for Ham radio? Yes but, sounds better for the "Little LEO'S" that want those ham bands for their own use/profit. Are we (Ham Radio) just doing their research for them? For free to... For the hams it sounds like it will be alot of fun hooking up to that satellite at those data rates.... Bruce Weber, KF7PJ, Satscan Corporation / Cascade Technology PO Box 1109, Sultan WA 98294-1109 (360)-793-3433 FAX: 793-0359 From n3jly@erols.com Thu Dec 26 22:55:49 1996 Received: from smtp2.erols.com (root@smtp2.erols.com [205.252.116.102]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id WAA15845 for ; Thu, 26 Dec 1996 22:55:46 -0600 (CST) Received: from LOCALNAME (col-as4s34.erols.com [206.161.75.226]) by smtp2.erols.com (8.7.5/8.7.3) with SMTP id XAA18093 for ; Thu, 26 Dec 1996 23:55:43 -0500 (EST) Date: Thu, 26 Dec 1996 23:55:43 -0500 (EST) Message-Id: <199612270455.XAA18093@smtp2.erols.com> X-Sender: n3jly@pop.erols.com X-Mailer: Windows Eudora Light Version 1.5.2 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: Tony McConnell Subject: ss the 115Kb radio sounds neat, but i've got a couple of questions... How much support do you think these things will eventually get? How much support would we need to make it a 'viable mode'? Is there anyone else in Baltimore/Washington interesed in experimenting? If everyone turns away from this model/mode will there be some warning? (if i'm going to own a white elephant i want a pair to breed) I'm willing to support the project, i've alalready got an antenna and hardline all picked outok i'm game... i'll try the new radio. should i apply for the sta first or should i order the radio? Tony McConnell N3JLI n3jli is my call, the isp sett the account up verbally over the phone and i haven't taken the time to straighten it out. email n3jly@erols.com From wd5ivd@tapr.org Fri Dec 27 18:36:57 1996 Received: from [129.120.111.42] (knezek2.coe.unt.edu [129.120.111.42]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id SAA15795 for ; Fri, 27 Dec 1996 18:36:52 -0600 (CST) Message-Id: In-Reply-To: <199612270455.XAA18093@smtp2.erols.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Fri, 27 Dec 1996 18:40:49 -0600 To: ss@tapr.org From: "Greg Jones, WD5IVD" Subject: Re: [SS:714] ss >the 115Kb radio sounds neat, but i've got a couple of questions... > > How much support do you think these things will eventually get? A lot. 65 radios were purchased in order to generate the expert 'answer' group and to generate the necessary docs to support subsequent users. As of the announcement, the TAPR office already has another 25 ordered (less than week since the announcement) and I expect that we will be ordering around 100+ radios each month to support various projects. Just a matter of getting the word out and some infrastrcuture started for testing and playing. > How much support would we need to make it a 'viable mode'? What is your defintion of a 'viable mode' ? I find that you need at least 2 radios if you are going to be doing something and no one else is around. 1 radio I think would fit your definiotn of non-viable. :-) The two I am using as I write this e-mail make it very viable as we work towards establishing a network system to support 10 others STA holders in the Denton area by the first of February. > Is there anyone else in Baltimore/Washington interesed in >experimenting? Not that I know of now. Time to be the first. > If everyone turns away from this model/mode will there be some >warning? I don't see support for the radio dropping. If the rules are not written in such a way as to allow us to use them under Part 97 after the STA and RM-8737 process is complete, then personally I will use them under Part 15 like everyone else does already. Freewave is probably selling 1000's of these things a week/month. The few hundred that amateurs will eventually have will not be significant to the commercial usage of them. But you should be aware that the Freewave pruchase is a first in a series, I hope, that gets more SS radios into the amateur service. There are people already using WaveLan and I hope that in the long term TAPR or some other amateur will be able produce some radio that does what amateur radio needs, not just a commercial version convertered or operated under Part 97. > (if i'm going to own a white elephant i want a pair to breed) I don't see these as a white elephant, but as with any technology things are going to change. Just depends on how long you want your invesment to last. There are still people using there TNC-1 units. Are those white elephants ? If they are, people are still getting good use out of them. How long will the Freewave radios be good for. As long as you have a communications need for them. I am sure we will be looking at new or better radios, but maybe at a higher price in the next 24 months. The question you have to ask with any technology.....do you want to get in now and have the most time to understand the play with the technology or get in later. I am happy right now with the money I paid for the units. If I throw them away in 6 months, I'll still be happy. Although I think the use will be for 2-3 years inetad of 6 months. > I'm willing to support the project, i've alalready got an antenna and > hardline all picked outok i'm game... i'll try the new radio. Sounds like you are set. Just need a radio and then something to push bits. > should i apply for the sta first or should i order the radio? You should do both. Cheers - Greg, WD5IVD ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd ----- From arutz@shfmicro.com Fri Dec 27 20:44:24 1996 Received: from alice.adsnet.com (adsnet.com [206.158.2.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id UAA23472 for ; Fri, 27 Dec 1996 20:44:20 -0600 (CST) Received: from pool-001-105.adsnet.com (pool-001-105.adsnet.com [208.4.86.105]) by alice.adsnet.com (8.6.5/8.6.6) with SMTP id UAA10067 for ; Fri, 27 Dec 1996 20:47:23 -0600 Date: Fri, 27 Dec 1996 20:47:23 -0600 Message-Id: <199612280247.UAA10067@alice.adsnet.com> X-Sender: arutz@mail.adsnet.com X-Mailer: Windows Eudora Version 1.4.4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: arutz@shfmicro.com (alan rutz) Subject: Re: [SS:715] Re: ss This is news to me! If someone is still using TAPR-1's, and wants another, how about giving me a call? Unless the upgrade we were promised is soon coming, I kind of want to get rid of this albatross....de alan >> (if i'm going to own a white elephant i want a pair to breed) > >I don't see these as a white elephant, There are still people using there TNC-1 units. Are those white >elephants ? If they are, people are still getting good use out of them. From wd5ivd@tapr.org Fri Dec 27 21:52:43 1996 Received: from [129.120.111.42] (knezek2.coe.unt.edu [129.120.111.42]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id VAA28280 for ; Fri, 27 Dec 1996 21:52:39 -0600 (CST) Message-Id: In-Reply-To: <199612280247.UAA10067@alice.adsnet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Fri, 27 Dec 1996 21:43:21 -0600 To: ss@tapr.org From: "Greg Jones, WD5IVD" Subject: Re: [SS:716] Re: ss Lots of people use TNC-1 with the KISS EPROMs installed. I have one in the corner doing KISS as I type this message. Does a good job. There was an upgrade to the TNC-1 to make it into a TNC-2 years and years ago. Maybe you are talking about some other upgrade long before I was involved. Cheers - Greg >This is news to me! If someone is still using TAPR-1's, and wants another, >how about giving me a call? Unless the upgrade we were promised is soon >coming, I kind of want to get rid of this albatross....de alan > >>> (if i'm going to own a white elephant i want a pair to breed) >> >>I don't see these as a white elephant, There are still people using there >TNC-1 units. Are those white >>elephants ? If they are, people are still getting good use out of them. ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd ----- From jmorriso@bogomips.com Sat Dec 28 00:25:48 1996 Received: from orange.ConcordPacific.Com (root@orange.ConcordPacific.com [204.239.26.10]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id AAA10313 for ; Sat, 28 Dec 1996 00:25:46 -0600 (CST) Received: from bogomips.com (root@bogomips.com [206.108.196.1]) by orange.ConcordPacific.Com (8.6.12/8.6.12) with SMTP id WAA10824 for ; Fri, 27 Dec 1996 22:26:48 -0800 Received: by bogomips.com (Linux Smail3.1.29.1 #3) id m0vdsFq-000TtBC; Fri, 27 Dec 96 22:28 PST Message-Id: From: jmorriso@bogomips.com (John Paul Morrison) Subject: Re: [SS:717] SS digest 197 To: ss@tapr.org Date: Fri, 27 Dec 1996 22:28:21 -0800 (PST) In-Reply-To: <199612280516.XAA02457@tapr.org> from "ss@tapr.org" at Dec 27, 96 11:16:42 pm X-Bogomips: 33.55 Content-Type: text > Date: Fri, 27 Dec 1996 18:40:49 -0600 > From: "Greg Jones, WD5IVD" > To: ss@tapr.org > Subject: Re: ss > Message-ID: > > > that gets more SS radios into the amateur service. There are people > already using WaveLan and I hope that in the long term TAPR or some other > amateur will be able produce some radio that does what amateur radio needs, > not just a commercial version convertered or operated under Part 97. What is the advantage of this 115kbps SS radio, when the WaveLAN does 2Mbps, and costs about the same (US$ 400)? The WaveLan also has DOS, Linux, and NT drivers. The 900MHz WaveLan has 7dBm less power though. --------------------------------------------------------------------------- BogoMIPS Research Labs -- bogosity research & simulation -- VE7JPM -- jmorriso@bogomips.com ve7jpm@ve7jpm.ampr.org jmorriso@ve7ubc.ampr.org --------------------------------------------------------------------------- From jeff@mich.com Sat Dec 28 02:05:19 1996 Received: from server1.mich.com (server1.mich.com [198.108.16.2]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id CAA16861 for ; Sat, 28 Dec 1996 02:05:18 -0600 (CST) Received: from gw-aerodata.mich.com (gw-aerodata.mich.com [198.108.16.240]) by server1.mich.com (8.8.4/8.8.4) with SMTP id DAA17412 for ; Sat, 28 Dec 1996 03:07:20 -0500 Message-Id: <2.2.32.19961228080539.0068f318@mich.com> X-Sender: jeff@mich.com X-Mailer: Windows Eudora Pro Version 2.2 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sat, 28 Dec 1996 03:05:39 -0500 To: ss@tapr.org From: Jeff King Subject: Re: [SS:718] Re: SS digest 197 At 12:26 AM 12/28/96 -0600, John Paul Morrison wrote: > >What is the advantage of this 115kbps SS radio, when the WaveLAN does >2Mbps, and costs about the same (US$ 400)? The WaveLan also has DOS, >Linux, and NT drivers. The 900MHz WaveLan has 7dBm less power though. > RX sensitivity of the WaveLan is around -78db. The FreeWave is -110db. Coupled with the higher power of the FreeWave, that gives it about a 29db system gain advantage over the Wavelan. Also, the FreeWave is a frequency hopper and as such, is more resistant to inband interference then the Wavelan which is a low process gain direct sequence radio (I think its around 10-11db process gain). Each has there place. I will agree, the drivers for the Wavelan make it quite attractive. -Jeff WB8WKA From jeff@mich.com Sat Dec 28 02:59:10 1996 Received: from server1.mich.com (server1.mich.com [198.108.16.2]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id CAA18681 for ; Sat, 28 Dec 1996 02:59:08 -0600 (CST) Received: from gw-aerodata.mich.com (gw-aerodata.mich.com [198.108.16.240]) by server1.mich.com (8.8.4/8.8.4) with SMTP id EAA19715; Sat, 28 Dec 1996 04:01:14 -0500 Message-Id: <2.2.32.19961228085930.006cdfec@mich.com> X-Sender: jeff@mich.com X-Mailer: Windows Eudora Pro Version 2.2 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sat, 28 Dec 1996 03:59:30 -0500 To: ss@tapr.org, ss@tapr.org From: Jeff King Subject: Re: [SS:719] Re: SS digest 197 At 02:12 AM 12/28/96 -0600, Jeff King wrote: >RX sensitivity of the WaveLan is around -78db. The FreeWave is -110db. >Coupled with the higher power of the FreeWave, that gives it about a >29db system gain advantage over the Wavelan. Hmmm....must be tired.... that should read a ' 39db system gain advantage over the Wavelan.' -Jeff WB8WKA Regards, ------------------------------------ | Jeff King Aero Data Systems | | jeff@mich.com P.O. Box 9325 | | (810)471-1787 Livonia, MI 48151 | |F(810)471-0279 United States | ------------------------------------ From ssampson@n5owk.ampr.org Sat Dec 28 04:00:03 1996 Received: from dns.okc (dns.oklahoma.net [208.2.112.2]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id EAA20966 for ; Sat, 28 Dec 1996 04:00:01 -0600 (CST) Received: from ssampson.okc.oklahoma.net by dns.okc (SMI-8.6/SMI-SVR4) id EAA21962; Sat, 28 Dec 1996 04:04:12 -0600 Message-ID: <32C4EED0.7430@n5owk.ampr.org> Date: Sat, 28 Dec 1996 03:56:32 -0600 From: Steve Sampson Organization: Amateur Radio Station N5OWK X-Mailer: Mozilla 3.01Gold (Win95; I) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: [SS:718] Re: SS digest 197 References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit John Paul Morrison wrote: > > What is the advantage of this 115kbps SS radio, when the WaveLAN does > 2Mbps, and costs about the same (US$ 400)? The WaveLan also has DOS, > Linux, and NT drivers. The 900MHz WaveLan has 7dBm less power though. I had the impression that the WaveLAN was more for internal use, or a beam-to-beam between buildings, rather than long range. I think many of us will find the 900 MHz spectrum to be quite a cesspool of devices. Let's see, Rabbit TV systems, portable phones, vehicle locators, etc, etc. What's the chances of a DS system running 2 Mbps in that environment? Heck, can you even run 115 kbps, for that matter? The driver question is a good point. I suspect Freewave has no drivers, but I may be wrong. I haven't checked their Web page yet. I do know that Win95 expects to see a dialup modem in dialup networking, so I guess most people will use Linux (a SLIP or PPP port should work fine) or one of the NOS's. Steve From jeff@mich.com Sat Dec 28 11:31:19 1996 Received: from server1.mich.com (server1.mich.com [198.108.16.2]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id LAA08967 for ; Sat, 28 Dec 1996 11:31:18 -0600 (CST) Received: from gw-aerodata.mich.com (gw-aerodata.mich.com [198.108.16.240]) by server1.mich.com (8.8.4/8.8.4) with SMTP id MAA12557; Sat, 28 Dec 1996 12:33:24 -0500 Message-Id: <2.2.32.19961228173131.006ba84c@mich.com> X-Sender: jeff@mich.com X-Mailer: Windows Eudora Pro Version 2.2 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sat, 28 Dec 1996 12:31:31 -0500 To: ss@tapr.org, ss@tapr.org From: Jeff King Subject: Re: [SS:721] Re: SS digest 197 At 04:06 AM 12/28/96 -0600, Steve Sampson wrote: >I had the impression that the WaveLAN was more for internal use, or a >beam-to-beam between buildings, rather than long range. I think many of >us will find the 900 MHz spectrum to be quite a cesspool of devices. >Let's see, Rabbit TV systems, portable phones, vehicle locators, etc, >etc. >What's the chances of a DS system running 2 Mbps in that environment? Long range in a metropolitian area, its a risk. I know of a 12 mile LOS link using WaveLAN's that is flakey, I belive, for the very reasons you cite. >Heck, can you even run 115 kbps, for that matter? Talking to you via a 2 mile FreeWave link right now. Its not line of sight (heavy trees, buildings). I have a Uniden 900mhz spread spectrum phone that I use all the time in close proximity to the FreeWaves and it doesn't seem to affect it (I do hear some popping on the phone however at the edges of the phones range). The FreeWaves were also tried on the above mentioned 12 mile LOS link and were quite solid. > >The driver question is a good point. I suspect Freewave has no drivers, >but I may be wrong. I haven't checked their Web page yet. I do know >that Win95 expects to see a dialup modem in dialup networking, so I >guess >most people will use Linux (a SLIP or PPP port should work fine) or one >of the NOS's. > >Steve I'm using Trumpet Winsock 3.0 on my FreeWave with Win95. The other end is using PPP on Linux. Trumpet can be configured to run PPP over a null modem cable which is what the FreeWave looks like to it. I am planning on going to some flavor of nos/linux configured as a router as I want to hang more machines off the Freewave then just this one. -Jeff WB8WKA From zsolt@direct.ca Sat Dec 28 12:03:49 1996 Received: from aphex.direct.ca (root@aphex.direct.ca [199.60.229.6]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id MAA10360 for ; Sat, 28 Dec 1996 12:03:48 -0600 (CST) Received: from boxer.direct.ca (van-pm-0509.direct.ca [204.174.243.129]) by aphex.direct.ca (8.8.3/8.8.0) with SMTP id KAA19630 for ; Sat, 28 Dec 1996 10:03:41 -0800 (PST) Date: Sat, 28 Dec 1996 11:13:29 -0800 (PST) From: George Cserenyi To: ss@tapr.org Subject: Re: [SS:722] Re: SS digest 197 In-Reply-To: <2.2.32.19961228173131.006ba84c@mich.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Sat, 28 Dec 1996, Jeff King wrote: > At 04:06 AM 12/28/96 -0600, Steve Sampson wrote: > > >I had the impression that the WaveLAN was more for internal use, or a > >beam-to-beam between buildings, rather than long range. I think many of > >us will find the 900 MHz spectrum to be quite a cesspool of devices. > >Let's see, Rabbit TV systems, portable phones, vehicle locators, etc, > >etc. > >What's the chances of a DS system running 2 Mbps in that environment? > > Long range in a metropolitian area, its a risk. I know of a 12 mile LOS > link using WaveLAN's that is flakey, I belive, for the very reasons > you cite. > > >Heck, can you even run 115 kbps, for that matter? > > Talking to you via a 2 mile FreeWave link right now. Its not line of > sight (heavy trees, buildings). I have a Uniden 900mhz spread spectrum phone > that I use all the time in close proximity to the FreeWaves and it How hard would it be to adapt one of these phones to carry data xmissions as well/instead of voice? What speed could we hope for and how much does a pair of these Uniden 900mhz spread spectrum phones cost? George > doesn't seem to affect it (I do hear some popping on the phone however > at the edges of the phones range). The FreeWaves were also tried on the > above mentioned 12 mile LOS link and were quite solid. > > > > >The driver question is a good point. I suspect Freewave has no drivers, > >but I may be wrong. I haven't checked their Web page yet. I do know > >that Win95 expects to see a dialup modem in dialup networking, so I > >guess > >most people will use Linux (a SLIP or PPP port should work fine) or one > >of the NOS's. > > > >Steve > > I'm using Trumpet Winsock 3.0 on my FreeWave with Win95. The other end is > using PPP on Linux. Trumpet can be configured to run PPP over a null modem > cable which is what the FreeWave looks like to it. I am planning on going > to some flavor of nos/linux configured as a router as I want to hang more > machines off the Freewave then just this one. > > -Jeff WB8WKA > > From wd5ivd@tapr.org Sat Dec 28 12:51:38 1996 Received: from [129.120.111.42] (knezek2.coe.unt.edu [129.120.111.42]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id MAA12923 for ; Sat, 28 Dec 1996 12:51:34 -0600 (CST) Message-Id: In-Reply-To: <2.2.32.19961228173131.006ba84c@mich.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sat, 28 Dec 1996 12:57:38 -0600 To: ss@tapr.org From: "Greg Jones, WD5IVD" Subject: Re: [SS:722] Re: SS digest 197 >At 04:06 AM 12/28/96 -0600, Steve Sampson wrote: > >>I had the impression that the WaveLAN was more for internal use, or a >>beam-to-beam between buildings, rather than long range. I think many of >>us will find the 900 MHz spectrum to be quite a cesspool of devices. >>Let's see, Rabbit TV systems, portable phones, vehicle locators, etc, >>etc. >>What's the chances of a DS system running 2 Mbps in that environment? There seems to be a urban myth about the 'cesspool of devices' on 900Mhz. While there is a lot of Part 15 and other devices on 900Mhz, it all depends on what you operate. While some modes might be effected by existing users on the band, I think we will find that most SS systems that seem to have problems operating are due to radio issues (i.e. poor bandpass filters, not a good path, bad feedline selection, etc) than any loss of communications due to other operations interfering with the signal. Based on what I hear people talking about and seeing myself, 9913 coax and worse don't cut it for 900Mhz and up. Having the beams not pointed at each other don't work very well. Having the beam mounted on the horz antenna (which I have seen an amateur do :-) don't work. I know Glenn can tell stories about the importance of good RF path design. >From the operations I have been doing the last several weeks, I had more problems with the pagers just above the top end of the band running 1000-2000 watts at each node then I had with anything in band. The two cordless phones here at the house neither interfer or get interferred with by the radio. Yes, if I stick the cordless phone right next to the unit I can hear the cracks, but that is more front end desense then anything. Also, my several other Part 15 devices work just fine with the radio transferring lots of data. The pager issue was easily corrected by changing to horz polarization (dropping the signals 20-30db) and adding a bandpass to the one radio that didn't have a bandpass (one of the units here is a pre-production unit that was mfg before they added bandpass filters to all the radios). Now I am getting 5 miles non-line of sight path with one end using a beam and the other end -- which is sitting here now -- running off the snub antenna. I can drive around town and get a good 5 mile radius around the 3 story building hosting the radio connected to the Internet. If I take a beam with me and stop every so often and point the beam back at the hub site I can get easily 10+ miles. The hub site is not a very good located site. That is with the hub site at 1 watt and the other unit I have at 400mw. Based on what Jeff and Dewayne have been doing with the radios, that can easily make the 20+ miles with decent antennas, detail to feedline and filters, and watching where you try to shot a path. I am really looking forward to getting one of Bob Morgans Horz Omnis up when we has some prototypes to play with. Cheers - Greg ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd ----- From buaas@wireless.net Sat Dec 28 13:14:51 1996 Received: from wireless.net (wireless.net [198.253.254.1]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id NAA13999 for ; Sat, 28 Dec 1996 13:14:48 -0600 (CST) Received: (from buaas@localhost) by wireless.net (8.7.6/8.6.12) id LAA02879 for ss@tapr.org; Sat, 28 Dec 1996 11:15:17 -0800 (PST) Date: Sat, 28 Dec 1996 11:15:17 -0800 (PST) From: "Robert A. Buaas" Message-Id: <199612281915.LAA02879@wireless.net> To: ss@tapr.org Subject: Re: [SS:719]... In [SS:719], Jeff King wrote: >RX sensitivity of the WaveLan is around -78db. The FreeWave is -110db. >Coupled with the higher power of the FreeWave, that gives it about a >29db system gain advantage over the Wavelan. Also, the FreeWave is a >frequency >hopper and as such, is more resistant to inband interference then >the Wavelan which is a low process gain direct sequence radio (I >think its around 10-11db process gain). >-Jeff WB8WKA A comment (for clarification): The WaveLAN system uses DQPSK modulation and a 11-bit Barker code to spread a 2Mbps signal across 22MHz of spectrum. Conventional wisdom says that the spreading gain is 10 log 11, a value just larger than 10dB (the required minimum under Part 15). I have less information about the FreeWave, but I do know that it's FM signal is normally hopping around over 100+ hopping channels. Assuming that the channels don't overlap (another Part 15 assumption) and that the number of channels is exactly 100, the process gain is 10 log 100 or 20 dB. Since the number is slightly larger, perhaps the gain is nearer 21 dB. It's worth noting also, there there is roughly an order of magnitude difference in datarate ratio between the two systems--one order of magnitude is usually considered 10 dB (taken as a pwer ratio). A question: Normally, receiver sensitivities are measured in dBm at corresponding BER. In the numbers cited, do we have any information that tells us that the BER's are equivalent, so that we are comparing apples with apples? If the numbers are representative of equivalent BER's (a large IF), then the 32 dB difference is really 22 dB in merit (when one considers the datarate ratio). I suspect the number is nearer 10 dB, but it sure would be nice to know for sure. Very best Holiday Wishes to all on the list. /bob K6KGS From rdcole@mindspring.com Sat Dec 28 19:28:30 1996 Received: from mule1.mindspring.com (mule1.mindspring.com [204.180.128.167]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id TAA03488 for ; Sat, 28 Dec 1996 19:28:29 -0600 (CST) Received: from ron (ip38.fort-worth3.tx.pub-ip.psi.net [38.27.17.38]) by mule1.mindspring.com (8.8.2/8.7.3) with SMTP id BAA38832 for ; Sun, 29 Dec 1996 01:28:26 GMT Message-Id: <199612290128.BAA38832@mule1.mindspring.com> Comments: Authenticated sender is From: "Ron Cole" To: ss@tapr.org Date: Sat, 28 Dec 1996 19:28:56 +0000 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Subject: Freewave Radio Operation Reply-to: rdcole@mindspring.com X-Confirm-Reading-To: rdcole@mindspring.com X-pmrqc: 1 Return-receipt-to: rdcole@mindspring.com Priority: normal X-mailer: Pegasus Mail for Win32 (v2.42a) Well I have a few questions about the Freewave Radios. 1) Since these are Part 15 Radios, What changes are being made that cause them to have to be operated under part 97, and thus the restrictions that imposes? 2) Does the Hopping allow the radios to be placed back to back on seperate antennas to form a Link or Repeater ? 3) Any body running Voice over these radios ? Like using one of the lossy data compressions available for PC or MAC. Ron Cole N5HYH From lfry@mindspring.com Sun Dec 29 06:33:35 1996 Received: from mule1.mindspring.com (mule1.mindspring.com [204.180.128.167]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id GAA16287 for ; Sun, 29 Dec 1996 06:33:33 -0600 (CST) Received: from glory (user-168-121-136-107.dialup.mindspring.com [168.121.136.107]) by mule1.mindspring.com (8.8.2/8.8.4) with SMTP id MAA12620; Sun, 29 Dec 1996 12:33:30 GMT Message-Id: <2.2.32.19961229123419.0039c7a0@mindspring.com> X-Sender: lfry@mindspring.com X-Mailer: Windows Eudora Pro Version 2.2 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sun, 29 Dec 1996 07:34:19 -0500 To: ss@tapr.org From: "Lee W. Fry" Subject: Re: [SS:723] Cordless 900 MHz Conversion Cc: George Cserenyi At 12:07 PM 12/28/96 -0600, George Cserenyi wrote: >How hard would it be to adapt one of these phones to carry data xmissions >as well/instead of voice? What speed could we hope for and how much does >a pair of these Uniden 900mhz spread spectrum phones cost? You might be able to adapt a so-called digital SS phone that internally uses a separate codec chip to digitize the audio for transmission. Some manufacturers even suggest using their chip sets in a data-only mode. Alfa's 9001 cordless phone chip - see http://ns1.2win.com/alfa/wireless.html can be run at 64 kbps full duplex or 160 kbps half duplex in data mode. I have recently seen refurbished digital SS phone sets (brand unspecified) advertised at US$50 each. Lee W. Fry AA0JP lfry@mindspring.com See my Part 15 Spread Spectrum Device Compendium at: http://www.mindspring.com/~lfry/part15.htm From wb9mjn@wb9mjn.ampr.org Sun Dec 29 11:45:04 1996 Received: from wb9mjn.ampr.org (wb9mjn.ampr.org [44.72.98.19]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id LAA28974 for ; Sun, 29 Dec 1996 11:44:44 -0600 (CST) From: wb9mjn@wb9mjn.ampr.org Date: Sun, 29 Dec 96 11:41:33 UTC Message-Id: <11805@wb9mjn.ampr.org> To: ss@tapr.org Subject: Re: [SS:726] Freewave Radio Operation In-Reply-To: your message of Sat Dec 28 19:34:03 1996 <199612290128.BAA38832@mule1.mindspring.com> Hi Ron, On the idea of multiple radios, at a single site. No radios can operate with the Receiver front end overloaded. The signal out of these radios is 30 dBm. Few receivers, can operate with a 30 dBm signal. Antenna isolations is possible tho. I make a patch antenna, with is unidirectional, with in excess of 20 dB F/B ratio. Altho I have not verifyed this, with an additional 10 to 20 dB of spacing isolation, 50 to 60 dB of isolation between radios at a site could be obtained. And there is good probability that the freewave radios will be able to operate with a -20 to -30 dBm interfering signal level, on a different hopping code! Sounds like a good experiment!!  From zsolt@direct.ca Sun Dec 29 11:52:17 1996 Received: from orb.direct.ca (root@orb.direct.ca [199.60.229.5]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id LAA29322 for ; Sun, 29 Dec 1996 11:52:15 -0600 (CST) Received: from boxer.direct.ca (van-pm-0129.direct.ca [204.174.243.29]) by orb.direct.ca (8.8.3/8.8.0) with SMTP id JAA18615; Sun, 29 Dec 1996 09:52:07 -0800 (PST) Date: Sun, 29 Dec 1996 11:02:28 -0800 (PST) From: George Cserenyi To: "Lee W. Fry" cc: ss@tapr.org Subject: Re: [SS:723] Cordless 900 MHz Conversion In-Reply-To: <2.2.32.19961229123419.0039c7a0@mindspring.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Mni thanks Lee, gud news, indeed. On Sun, 29 Dec 1996, Lee W. Fry wrote: > At 12:07 PM 12/28/96 -0600, George Cserenyi wrote: > > >How hard would it be to adapt one of these phones to carry data xmissions > >as well/instead of voice? What speed could we hope for and how much does > >a pair of these Uniden 900mhz spread spectrum phones cost? > > You might be able to adapt a so-called digital SS phone that internally uses > a separate codec chip to digitize the audio for transmission. > > Some manufacturers even suggest using their chip sets in a data-only mode. > Alfa's 9001 cordless phone chip - see > http://ns1.2win.com/alfa/wireless.html can be run at 64 kbps full duplex or > 160 kbps half duplex in data mode. > > I have recently seen refurbished digital SS phone sets (brand unspecified) > advertised at US$50 each. > > Lee W. Fry AA0JP > lfry@mindspring.com > See my Part 15 Spread Spectrum Device Compendium at: > http://www.mindspring.com/~lfry/part15.htm > > From ssampson@oklahoma.net Sun Dec 29 12:10:26 1996 Received: from dns.okc (dns.oklahoma.net [208.2.112.2]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id MAA29742 for ; Sun, 29 Dec 1996 12:10:25 -0600 (CST) Received: from ssampson.okc.oklahoma.net by dns.okc (SMI-8.6/SMI-SVR4) id MAA00684; Sun, 29 Dec 1996 12:14:36 -0600 Message-ID: <32C6B330.2FA7@oklahoma.net> Date: Sun, 29 Dec 1996 12:06:40 -0600 From: Steve Sampson Organization: Amateur Radio Station N5OWK X-Mailer: Mozilla 3.01Gold (Win95; I) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: [SS:726] Freewave Radio Operation References: <199612290128.BAA38832@mule1.mindspring.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Ron Cole wrote: > > Well I have a few questions about the Freewave Radios. > > 1) Since these are Part 15 Radios, What changes are being made that > cause them to have to be operated under part 97, and thus the > restrictions that imposes? I can envision the need for some sites to require more power than allowed under Part 15 rules. The only people that can use more power is the Government and users operating under the TAPR STA. While on first blush, there seems to be no advantage in operating under Part 97, it is only because the current devices are designed for limited bands. Let's say the STA is a success, and the FCC writes the rules for all bands above 10 MHz to be authorized SS modes. In this case, the experiance gained now, using commercial equipment, can be easily designed for future Ham equipment. I think the first HF band to be converted to SS will be the Part 95 allocation. Combined with FM, the FCC can easily cut down on 95% of its enforcement budget. (Part 95 == CB Radio). Just think what 4 Watts and 100 hopping channels would do for the utility. Wouldn't be good for data, but great for voice. > 2) Does the Hopping allow the radios to be placed back to back on > seperate antennas to form a Link or Repeater ? Would there be any advantage in that? As sold, I believe most of these devices use a scheme similar to what we know as "digipeaters." You "digi" through a central node to another device. Most just allow one "digi" rather than the AX.25 8 "digis." At the higher speeds I wouldn't want to confine everyone to the same hopping channel. Although for emergency operations, that seems like a good idea. That is, reduce the throughput to increase the utility. For example, a plane crashes in an open field thirty miles outside of the city. One vehicle goes to the site, strings a phone and a 10Base-T concentrator. Another vehicle heads for high ground at the 15 mile radius, and operates as a "digi" between the site and the Internet Hub. I wouldn't expect the "scene" to be fully connected to the internet, only transfering Jet (TM) database entries, for example, from a local LAN, or possibly MS-Mail. > 3) Any body running Voice over these radios ? Like using one of the > lossy data compressions available for PC or MAC. That's an interesting area. The 115 kbps speed of the FreeWave devices makes voice as easy as using internet voice applications, or even applications designed to combine data and voice. Steve From bm@lynx.ve3jf.ampr.org Sun Dec 29 13:05:15 1996 Received: from lynx.ve3jf.ampr.org (lynx.ve3jf.ampr.org [44.135.96.100]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id NAA02431 for ; Sun, 29 Dec 1996 13:04:46 -0600 (CST) Received: (from bm@localhost) by lynx.ve3jf.ampr.org (8.6.12/8.6.12) id TAA12305 for ss@tapr.org; Sun, 29 Dec 1996 19:01:45 GMT From: Barry McLarnon VE3JF Message-Id: <199612291901.TAA12305@lynx.ve3jf.ampr.org> Subject: Re: [SS:725] Re: .. To: ss@tapr.org Date: Sun, 29 Dec 1996 19:01:45 +0000 (GMT) In-Reply-To: <199612281915.LAA02879@wireless.net> from "Robert A. Buaas" at Dec 28, 96 01:22:58 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Bob K6KGS wrote: > In [SS:719], Jeff King wrote: > > >RX sensitivity of the WaveLan is around -78db. The FreeWave is -110db. > >Coupled with the higher power of the FreeWave, that gives it about a > >29db system gain advantage over the Wavelan. Also, the FreeWave is a > >frequency > >hopper and as such, is more resistant to inband interference then > >the Wavelan which is a low process gain direct sequence radio (I > >think its around 10-11db process gain). > > >-Jeff WB8WKA > > A comment (for clarification): The WaveLAN system uses DQPSK modulation > and a 11-bit Barker code to spread a 2Mbps signal across 22MHz of spectrum. > Conventional wisdom says that the spreading gain is 10 log 11, a value > just larger than 10dB (the required minimum under Part 15). I have > less information about the FreeWave, but I do know that it's FM signal > is normally hopping around over 100+ hopping channels. Assuming that > the channels don't overlap (another Part 15 assumption) and that the > number of channels is exactly 100, the process gain is 10 log 100 or > 20 dB. Since the number is slightly larger, perhaps the gain is nearer > 21 dB. It's worth noting also, there there is roughly an order of > magnitude difference in datarate ratio between the two systems--one order > of magnitude is usually considered 10 dB (taken as a pwer ratio). > > A question: Normally, receiver sensitivities are measured in dBm at > corresponding BER. In the numbers cited, do we have any information > that tells us that the BER's are equivalent, so that we are comparing > apples with apples? If the numbers are representative of equivalent > BER's (a large IF), then the 32 dB difference is really 22 dB in > merit (when one considers the datarate ratio). I suspect the number is > nearer 10 dB, but it sure would be nice to know for sure. Time for some back-of-the-envelope calculations... FreeWave: The manufacturer claims that the modem achieves 10E-4 BER at the -110 dBm signal level. Since it is, I think, noncoherent FSK, this would require an Eb/N0 of about 12.5 dB. If I recall correctly, the raw bit rate of the modem is about 173 kbps. Assuming for the moment that the bandwidth efficiency is 1 bps/Hz, the required SNR is also 12.5 dB, and the thermal noise power is about -121.5 dBm in a 173 KHz bandwidth. Since the modem is described as "GFSK", the bandwidth efficiency could be higher than 1 - perhaps as high as 1.6 (like in the GSM cellular system), but that doesn't really change the analysis. So, if the front end of the modem was noiseless, the required signal level for 10E-4 BER would be -121.5 + 12.5 = -109 dBm. If we assume a reasonable noise figure, say 3 dB, then it becomes -106 dBm. So, either the claimed figure of -110 dBm is too good to be true, or some of my assumptions are false - probably the latter. :-) Comments? WaveLAN: It appears from the specs in the Lucent web pages that the -78 dBm figure is for 10E-8 BER. The modem is DQPSK, which is nearly equivalent to coherently demodulated QPSK at low BER... the required Eb/N0 for 10E-8 BER should be about 13 dB, and the SNR then about 16 dB. Assuming that the (despread) bandwidth is close to 1 MHz, the thermal noise power is -114 dBm. An article I have on WaveLAN suggests that the noise figure is about 7 dB, so this would bring the noise power up to -107 dBm. With no implementation loss, the modem should then deliver 10E-8 BER with signal power at the input of -107 + 16 = -91 dBm. This is 13 dB better than their spec, which indicates some serious shortcomings in the modem implementation, or again, some faulty assumptions on my part. For 10E-4 BER, the required signal power should be about -94 dBm... so in theory, it should only be of the order of 12 dB higher than for FreeWave, but theory doesn't seem to match reality in this case. So, based on this admittedly fuzzy analysis, FreeWave seems to be an overachiever, and WaveLAN an underachiever. It would be nice to get some hard BER data on these units, but the problem is that it's usually very hard to get at the raw modems to get the bits in and out. Quite apart from the differences in performance due to different bandwidths, noise figures and modem implementations, the FreeWave units will clearly have a big edge over WaveLAN if strong narrowband interference is encountered. They will also be less vulnerable to ISI caused by multipath, by virtue of the longer symbol length. The bottom line is: what you gain in speed, you lose in range and robustness. Barry -- Barry McLarnon VE3JF/VA3TCP | Internet: bm@hydra.carleton.ca Ottawa Amateur Radio Club | AMPRnet: bm@lynx.ve3jf.ampr.org Packet Working Group | Web: http://hydra.carleton.ca From buaas@wireless.net Sun Dec 29 14:17:52 1996 Received: from wireless.net (wireless.net [198.253.254.1]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id OAA06027 for ; Sun, 29 Dec 1996 14:17:47 -0600 (CST) Received: (from buaas@localhost) by wireless.net (8.7.6/8.6.12) id MAA04593 for ss@tapr.org; Sun, 29 Dec 1996 12:18:53 -0800 (PST) Date: Sun, 29 Dec 1996 12:18:53 -0800 (PST) From: "Robert A. Buaas" Message-Id: <199612292018.MAA04593@wireless.net> To: ss@tapr.org Subject: Re: [SS:730] Re: Freewave Radio Operation To expand on what Steve Sampson wrote, specifically: > 3) Any body running Voice over these radios ? Like using one of the > lossy data compressions available for PC or MAC. That's an interesting area. The 115 kbps speed of the FreeWave devices makes voice as easy as using internet voice applications, or even applications designed to combine data and voice. I do this routinely, as does Bernie Doerner NU1S. We like a Windows95 application SpeakFreely (http://www.fourmilab.ch/) that uses a compliant sound card with a mic attached, uses UDP to talk across the Internet. This app is a long way up the protocol stack from the PPP link over a FreeWave (or ethernet link using WaveLAN), but the connectivity and the conversation works just fine. Bernie has a notebook with built-in microphone and PCMCIA-version of WaveLAN, and he's been spotted while Nike-mobile (walking around the campus of WPI) while voice reporting his coverage findings. Now that's WIRELESS voice. Happy New Year all!! best regards/bob K6KGS From kevin.jessup@mail.mei.com Sun Dec 29 14:22:19 1996 Received: from meipws.mis.mei.com (meipws.mis.mei.com [151.186.40.1]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id OAA06394 for ; Sun, 29 Dec 1996 14:22:18 -0600 (CST) Received: from caffeine.isdn.mei.com by meipws.mis.mei.com (PMDF V5.0-5 #5043) id <01IDL2TMU56O8Y0IG4@meipws.mis.mei.com> for ss@tapr.org; Sun, 29 Dec 1996 14:16:25 -0600 (CST) Date: Sun, 29 Dec 1996 14:20:17 -0600 From: Kevin Jessup Subject: Re: [SS:730] Re: Freewave Radio Operation X-Sender: jessupkp@meipws.mis.mei.com To: ss@tapr.org Message-id: <01IDL2TMWTMQ8Y0IG4@meipws.mis.mei.com> MIME-version: 1.0 X-Mailer: Windows Eudora Version 2.1 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT At 12:14 PM 12/29/96 -0600, Steve Sampson wrote: >Ron Cole wrote: >> 3) Any body running Voice over these radios ? Like using one of the >> lossy data compressions available for PC or MAC. >That's an interesting area. The 115 kbps speed of the FreeWave devices >makes voice as easy as using internet voice applications, or even >applications designed to combine data and voice. Yes. I'm running CU-SeeMe (video, audio and text) between home and work on my NT box with an ISDN line. Works great. Also, doesn't the TDMA cellular standard work fine with compressed 9600 baud voice? The FreeWaves have more than enough to handle telephone quality audio. I've played with the commercial versions of the FreeWave SS radios. Nice rigs. Now that I can get a decent price on these via TAPR, I just can NOT find any other hams in the Milwaukee area (I'm actually 20 miles North of Milwaukee) interested in digital other than AMTOR, PACTOR or 1200 baud 2-meter work. Bummer. Maybe I'll just buy two and do my own work. I've been trying to drum up interest in SS around here for the past three years. Even put on a demo at a couple of the area clubs, complete with a $25,000 spectrum analyzer and both HF and DS SS equipment. But no luck. Nobody wants to experiment around here. FreeWave purchase or not, I need to get a membership application and dues into TAPR. Thanks for all your effort! Kevin, n9sqb -- "Rest enough for the individual man - [but] too Kevin Jessup much or too soon and we call it Death. But for software engineer MAN, no rest and no ending. He must go on, Marquette Medical Systems conquest beyond conquest...and when he has http://www.mei.com conquered all the depths of space and all the kevin.jessup@mail.mei.com mysteries of time, still he will be beginning." PGP encrypted Email preferred -- H.G. Wells, Things To Come From wb9mjn@wb9mjn.ampr.org Sun Dec 29 16:24:43 1996 Received: from wb9mjn.ampr.org (wb9mjn.ampr.org [44.72.98.19]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id QAA12710 for ; Sun, 29 Dec 1996 16:23:56 -0600 (CST) From: wb9mjn@wb9mjn.ampr.org Date: Sun, 29 Dec 96 15:56:05 UTC Message-Id: <11813@wb9mjn.ampr.org> To: ss@tapr.org Subject: Re: [SS:731] Re: .. In-Reply-To: your message of Sun Dec 29 13:10:31 1996 <199612291901.TAA12305@lynx.ve3jf.ampr.org> Hi Barry, Been looking at ur numbers, and can t see where u went wrong with the Freewave figuring. The only guess would be that they are using coherent GFSK, and that might result in a better Eb/N0 to start with. Here s some comments to the group, in general, about Noise. A -110 dBm for 10e-4 specification is for a test situation. Where the test equipment represents a ambient temperature source. In the real world, connected to an antenna, there are two additional noise sources. Line loss, and enviormental RF noise. For example, a 2 dB Noise Figure, radio, tested on a bench, would see noise equivalent to a 290 degree Kelvin from a generator, plus 169.6 degrees due to the noise performance of the front end, for a total of 459.6 degrees Kelvin. Attached to an antenna, using Reference Data for Radio Engineers reference I used for my "Cellular Area Coverage Transport Networks" ARRL CNC paper, the suburban level of noise at 900 Mhz, is 2 dB above ambient, or 460 degrees. A 1 dB transmission line loss , in combination with the noise figure yields a 288.6 degree Kelvin additional noise temperature. For a new total of 748.6 degrees Kelvin. Thus, a radio that tested with -110 dBm 10e-4 BER from a generator will have a 10e-4 BER at 107.9 dBm. The RF Path calculation have to deliver a signal in excess of this -107.9 dBm level to get 10e-4 or better BER performance NOT -110 dBm. The equation used for these calculations is: Tequiv. = Tant + (LF-1) Tambient Tant is the enviormental Noise level at the antenna, or the ambient room temperature for an ideal piece of test equipment. Tambient is the Ambient temperature of the enviorment, 290 degrees Kelvin in this example. L is the Loss Factor of the RF path between the Antenna, and the receiver, that is 10 to the (Attenuation in dB/10). F is the Noise Factor of the receiver. That is, 10 to the (Noise Figure in dB/10). The enviormental Noise temperature, according to the reference, can vary between 2 dB above ambient (suburban) to as much as 17 dB above ambient (urban). That s at 900 Mhz. So, the point is, that a specification like -110 dBm for 10e-4 BER is not a directly useable number. It needs to be modified by the system parameters to get a number that is useful. Note, that the Line loss effected noise level, but it also effects the path loss. So, that 1 dB in the example has a negative impact, again.  73, Don. Mailbox : WB9MJN @ N9HSI.IL.USA.NA AMPRNet : wb9mjn@wb9mjn.ampr.org[44.72.98.19] Internet: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu From ddennis@metronet.com Sun Dec 29 22:30:20 1996 Received: from metronet.com (root@mail.metronet.com [192.245.137.6]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id WAA01130 for ; Sun, 29 Dec 1996 22:30:17 -0600 (CST) Received: from dal132.metronet.com by metronet.com with SMTP id AA17271 (5.67a/IDA1.5hp for ); Sun, 29 Dec 1996 22:30:58 -0600 Received: by dal132.metronet.com with Microsoft Mail id <01BBF5D7.C6637080@dal132.metronet.com>; Sun, 29 Dec 1996 22:29:37 -0600 Message-Id: <01BBF5D7.C6637080@dal132.metronet.com> From: David Dennis To: "'ss@tapr.org'" Subject: RE: 725] Re: Date: Sun, 29 Dec 1996 12:04:41 -0600 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit A question: Normally, receiver sensitivities are measured in dBm at corresponding BER. In the numbers cited, do we have any information that tells us that the BER's are equivalent, so that we are comparing apples with apples? If the numbers are representative of equivalent BER's (a large IF), then the 32 dB difference is really 22 dB in merit (when one considers the datarate ratio). I suspect the number is nearer 10 dB, but it sure would be nice to know for sure. Very best Holiday Wishes to all on the list. /bob K6KGS This is an excellent point. I was thinking the same thing while reading all the quotes about power budgets. From wd5ivd@tapr.org Sun Dec 29 22:32:28 1996 Received: from [128.83.113.93] (slip-b-13.ots.utexas.edu [128.83.113.93]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id WAA01282 for ; Sun, 29 Dec 1996 22:32:23 -0600 (CST) Message-Id: In-Reply-To: <11805@wb9mjn.ampr.org> References: your message of Sat Dec 28 19:34:03 1996 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sun, 29 Dec 1996 22:05:23 -0600 To: ss@tapr.org From: "Greg Jones, WD5IVD" Subject: Re: [SS:728] Re: Freewave Radio Operation Hi Ron. I have two Freewave radios setting back to back right now -- one using a vert and the other horz beam (all the antennas I had around for the test). They are operating on two different channels (i.e. hop sequences) and feeding the serial connections between them. Wanted to test it this for an upcoming event where we need one hop to get to the far end site, but didn't want to install a computer or something else at the temp site for the event. While the Freewave radios support a repeater mode, no one in their right mind would want to lose 50% throughput, when all that is required is a second radio to send the data along on a second channel. While many radios might not work transmitting next to each other, the Freewaves on different hop channels certainly do -- at least the pairs I have going here. Cheers - Greg >Don (mjn) wrote : > Hi Ron, > > On the idea of multiple radios, at a single site. No radios can operate >with the Receiver front end overloaded. The signal out of these radios is >30 dBm. Few receivers, can operate with a 30 dBm signal. Antenna isolations >is possible tho. I make a patch antenna, with is unidirectional, with in >excess of 20 dB F/B ratio. Altho I have not verifyed this, with an additional >10 to 20 dB of spacing isolation, 50 to 60 dB of isolation between radios >at a site could be obtained. And there is good probability that the freewave >radios will be able to operate with a -20 to -30 dBm interfering signal level, >on a different hopping code! Sounds like a good experiment!! > > ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd ----- From wd5ivd@tapr.org Sun Dec 29 22:32:36 1996 Received: from [128.83.113.93] (slip-b-13.ots.utexas.edu [128.83.113.93]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id WAA01307 for ; Sun, 29 Dec 1996 22:32:31 -0600 (CST) Message-Id: In-Reply-To: <32C6B330.2FA7@oklahoma.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sun, 29 Dec 1996 22:17:15 -0600 To: ss@tapr.org From: "Greg Jones, WD5IVD" Subject: Re: [SS:730] Re: Freewave Radio Operation >Ron Cole wrote: >> >> Well I have a few questions about the Freewave Radios. >> >> 1) Since these are Part 15 Radios, What changes are being made that >> cause them to have to be operated under part 97, and thus the >> restrictions that imposes? > >I can envision the need for some sites to require more power than >allowed under Part 15 rules. The only people that can use more power >is the Government and users operating under the TAPR STA. While on >first blush, there seems to be no advantage in operating under Part 97, >it is only because the current devices are designed for limited bands. > The answer to this is easy. No changes are being made to the equipment for the most part. What changes are made to other types of commerical equipment that are used under Part 97 on 440, 2, and other bands -- answer is probably none. The TAPR SS STA allows for better antennas and the ability to use other codes than currently defined under Part 97. The reason for wanting to change the rules in order to use existing equipment and technology being developed commerically is because it is Part 97. As amateurs we want to be doing amateur radio. We could easily be off doing part 15 stuff, but by not pursuing the usefulness of 900Mhz and other bands for Part 97 operations, we forfeit any rights in the future when Part 97 modes want to be doing things when a secondary services is already there. The reason for both RM-8737 and the TAPR SS STA is because as amateurs we want to be doing things under Part 97, not Part 15 or other regulations. Dewayne and myself both hope that the TAPR SS STA will allow many more hams to look at the mode and get involved with operating. No telling what the potential is when you get more people involved with diverse talents. Cheers - Greg ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd ----- From ddennis@metronet.com Sun Dec 29 22:59:09 1996 Received: from metronet.com (root@mail.metronet.com [192.245.137.6]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id WAA02866 for ; Sun, 29 Dec 1996 22:59:05 -0600 (CST) Received: from dal132.metronet.com by metronet.com with SMTP id AA22151 (5.67a/IDA1.5hp for ); Sun, 29 Dec 1996 22:59:47 -0600 Received: by dal132.metronet.com with Microsoft Mail id <01BBF5DB.CD370A80@dal132.metronet.com>; Sun, 29 Dec 1996 22:58:27 -0600 Message-Id: <01BBF5DB.CD370A80@dal132.metronet.com> From: David Dennis To: "'ss@tapr.org'" Subject: RE: 731] Re: .. Date: Sun, 29 Dec 1996 22:56:06 -0600 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Bob K6KGS wrote: Time for some back-of-the-envelope calculations... FreeWave: The manufacturer claims that the modem achieves 10E-4 BER at the -110 dBm signal level. Since it is, I think, noncoherent FSK, this would require an Eb/N0 of about 12.5 dB. If I recall correctly, the raw bit rate of the modem is about 173 kbps. I may be wrong but I think you may mean 173kBd. Assuming for the moment that the bandwidth efficiency is 1 bps/Hz, Here again I may be wrong and I surely would like to know but I think if this is NRZ data then you can assume 2 Baud / Hz. the required SNR is also 12.5 dB, and the thermal noise power is about -121.5 dBm in a 173 KHz bandwidth. Since the modem is described as "GFSK", the bandwidth efficiency could be higher than 1 - perhaps as high as 1.6 (like in the GSM cellular system), but that doesn't really change the analysis. So, if the front end of the modem was noiseless, the required signal level for 10E-4 BER would be -121.5 + 12.5 = -109 dBm. If we assume a reasonable noise figure, say 3 dB, then it becomes -106 dBm. So, either the claimed figure of -110 dBm is too good to be true, or some of my assumptions are false - probably the latter. :-) Comments? WaveLAN: It appears from the specs in the Lucent web pages that the -78 dBm figure is for 10E-8 BER. The modem is DQPSK, which is nearly equivalent to coherently demodulated QPSK at low BER... the required Eb/N0 for 10E-8 BER should be about 13 dB, and the SNR then about 16 dB. Assuming that the (despread) bandwidth is close to 1 MHz, the thermal noise power is -114 dBm. An article I have on WaveLAN suggests that the noise figure is about 7 dB, so this would bring the noise power up to -107 dBm. With no implementation loss, the modem should then deliver 10E-8 BER with signal power at the input of -107 + 16 = -91 dBm. This is 13 dB better than their spec, which indicates some serious shortcomings in the modem implementation, or again, some faulty assumptions on my part. For 10E-4 BER, the required signal power should be about -94 dBm... so in theory, it should only be of the order of 12 dB higher than for FreeWave, but theory doesn't seem to match reality in this case. So, based on this admittedly fuzzy analysis, FreeWave seems to be an overachiever, and WaveLAN an underachiever. It would be nice to get some hard BER data on these units, but the problem is that it's usually very hard to get at the raw modems to get the bits in and out. Quite apart from the differences in performance due to different bandwidths, noise figures and modem implementations, the FreeWave units will clearly have a big edge over WaveLAN if strong narrowband interference is encountered. They will also be less vulnerable to ISI caused by multipath, by virtue of the longer symbol length. The bottom line is: what you gain in speed, you lose in range and robustness. Barry Where can I find some info that relates S/N required for a specific BER? In the fiber optic systems I work with we assume 10.9dB for a BER 1e-9 but I dont know what to assume for different BERs. From wd5ivd@tapr.org Sun Dec 29 23:43:35 1996 Received: from [129.120.111.42] (knezek2.coe.unt.edu [129.120.111.42]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id XAA06349 for ; Sun, 29 Dec 1996 23:43:27 -0600 (CST) Message-Id: In-Reply-To: <01BBF5DB.CD370A80@dal132.metronet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sun, 29 Dec 1996 23:48:53 -0600 To: ss@tapr.org From: "Greg Jones, WD5IVD" Subject: Re: [SS:738] RE: 731] Re: .. >Barry > > Where can I find some info that relates S/N required for a specific >BER? > In the fiber optic systems I work with we assume 10.9dB for a BER >1e-9 but > I dont know what to assume for different BERs. Tom McDermott's, N5EG, new book has an entire chapter related to this issue. Look over the contents http://www.tapr.org/tapr/html/pub.wdcdat.html Chapter 2 is the one you might want to look at. Cheers - Greg ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd ----- From dewayne@warpspeed.com Mon Dec 30 06:37:26 1996 Received: from warpspeed.com (WA8DZP@odo.warpspeed.com [204.118.182.20]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id GAA02054 for ; Mon, 30 Dec 1996 06:37:18 -0600 (CST) Received: from [204.118.182.20] by warpspeed.com with ESMTP (Apple Internet Mail Server 2.0a8); Mon, 30 Dec 1996 04:36:59 -0800 Message-Id: In-Reply-To: References: <11805@wb9mjn.ampr.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 30 Dec 1996 04:30:21 -0800 To: ss@tapr.org From: Dewayne Hendricks Subject: Re: [SS:736] Re: Freewave Radio Operation At 22:46 -0600 12/29/96, Greg Jones, WD5IVD wrote: >While many radios might not work transmitting next to each other, the >Freewaves on different hop channels certainly do -- at least the pairs I >have going here. I can confirm this. I recently helped the FreeWave people setup a radio link to their local ISP from their Boulder facility. I setup a PC running NOS and have five radios connected to it at 115 Kbps. One of the radios is a pt-pt link to the ISP, and the other four radios are pt-pt links to their employees homes. All of the radios operate on different hopping patterns and although their respective antennas are in quite close proximity they don't interfer with each other. -- Dewayne -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dewayne Hendricks, WA8DZP ! AOL: HENDRICKS Warp Speed Imagineering ! Internet: dewayne@warpspeed.com 43730 Vista Del Mar ! Packet Radio: WA8DZP @ K3MC.#NOCAL.CA.USA.NOAM Fremont, CA 94539-3204 ! WWW: Fax: (510) 770-9854 ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From karn@qualcomm.com Mon Dec 30 06:41:42 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id GAA02121 for ; Mon, 30 Dec 1996 06:41:40 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id EAA14254; Mon, 30 Dec 1996 04:41:09 -0800 (PST) Date: Mon, 30 Dec 1996 04:41:09 -0800 (PST) From: Phil Karn Message-Id: <199612301241.EAA14254@servo.qualcomm.com> To: ss@tapr.org In-reply-to: <199612281915.LAA02879@wireless.net> (buaas@wireless.net) Subject: Re: [SS:725] Re: .. Remember also if you're going to compare the sensitivities of different radios you also have to allow for the different data rates. It's not fair to say that radio A is 30 dB "better" then radio B if radio B runs at 1000x the data rate... Phil From wd5ivd@tapr.org Mon Dec 30 07:19:15 1996 Received: from [129.120.111.42] (knezek2.coe.unt.edu [129.120.111.42]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id HAA03425 for ; Mon, 30 Dec 1996 07:19:08 -0600 (CST) Message-Id: In-Reply-To: <199612301241.EAA14254@servo.qualcomm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 30 Dec 1996 07:17:29 -0600 To: ss@tapr.org From: "Greg Jones, WD5IVD" Subject: Re: [SS:741] Re: .. Phil, Someone said the other day that FHSS have no process gain. Is this a correct statement ? I had thought that FHSS and DSSS both had process gain. Did I miss something ? Cheers - Greg >Remember also if you're going to compare the sensitivities of different >radios you also have to allow for the different data rates. It's not fair >to say that radio A is 30 dB "better" then radio B if radio B runs at >1000x the data rate... > >Phil ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd ----- From morganb@inetport.com Mon Dec 30 11:50:00 1996 Received: from admin.inetport.com (inetport.com [206.64.12.2]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id LAA17859 for ; Mon, 30 Dec 1996 11:49:59 -0600 (CST) Received: from mail.inetport.com (pm1_105.inetport.com [206.64.12.105]) by admin.inetport.com (8.7.5/8.7.3) with SMTP id LAA29368 for ; Mon, 30 Dec 1996 11:52:22 -0600 (CST) Date: Mon, 30 Dec 1996 11:52:22 -0600 (CST) Message-Id: <199612301752.LAA29368@admin.inetport.com> X-Sender: morganb@inetport.com X-Mailer: Windows Eudora Version 1.4.4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: morganb@inetport.com (Robert B. Morgan) Subject: Re: .. Process Gain Phil and Greg conversed: >Phil, > >Someone said the other day that FHSS have no process gain. Is this a >correct statement ? I had thought that FHSS and DSSS both had process gain. > >Did I miss something ? > >Cheers - Greg > > >>Remember also if you're going to compare the sensitivities of different >>radios you also have to allow for the different data rates. It's not fair >>to say that radio A is 30 dB "better" then radio B if radio B runs at >>1000x the data rate... >> >>Phil ------------------ Lemme see if I can take a stab at a few things, mostly quoting from textbooks, rather than my limited SS knowledge; They both have process gain. Presumably if the hopping rate of an FH system were to somehow approach the chip rate of a DS system, they would approach each other in behavior. That isn't likely to happen tomorrow (although the way technology races along I get nervous making such predictions). Conventional thinking says that for DS the chiprate is much greater than the datarate, while for FH the datarate is (much) greater than the hopping rate. A FH system is nothing more than a narrowband system that is moving around, mostly hiding its presence and dodging QRM. As far as I am aware, they both have process gain calculated by the same general formula of how much space they spread a datarate over. Note that I am referring to a 173 kb system as "narrowband" - that's pretty wide, and I suspect that is why it hides itself pretty well on the frequency, aside from hopping. A DS system could, and some routinely do, have sufficient process gain to recover a signal that is weaker than the thermal noise figure of it's front end would permit a narrowband signal from recovering. The GPS system is a case in point. Quoting from a textbook (Spread Spectrum systems with commercial applications, 3rd ed, Robert Dixon, 1994, John Wiley, TK5102.5.D55, pp370-371 and an excellent reference) the author says that GPS is speced to deliver -135 dBm at the earth's surface. (About 0.035 uV) For 9 MHz bandwidth, receiver thermal noise is -104 dBm. The receivers routinely operate at -30 dB SNR. Answer: 10.23 Mcps rate, 9.0 MHz BW, and only 50 bps datarate, which yields 10*log(9.0E06/50)= 52.5 dB process gain. Inputting SNR of -30 db, and using the process gain yields a positive SNR at the IF of 22 dB, and they work. But note the datarate, 50 bps. Fine for positioning, but not to surf the web. FH radios just DON'T do this. They have to have a positive SNR at their inputs. Any hop where it goes negative will yield garbage on that hop, and in fact determines the BER. I think that their value to us is that they avoid QRM and to function at all, have to have error correcting coding built in. I think that I could (over)generalize by saying that DS systems are useful to work in the presence of broad gaussian noise or what we like to refer to as QRN (impulse noise possibly excepted), and that FH systems are useful to avoid QRM either from narrowband sources or from other FH units on different codes. Their process gain operates in a way to allow lots of them to spread out over a given band and avoid each other, and avoid some fixed freq narrowband stations, and also avoid any significant interference from themselves to narrow systems by virtue of their extremely low keyup time on any particular hop channel. My impression of the Freewave radios in particular is that they have mixed a high on-air datarate (the 173 kb) with a hopping pattern that spends very little time on the air at any channel, and there are lots of channels in its pattern, so when the radio does happen to transmit on a particular channel that another narrowband user is listening to, the burst of data is both short AND WIDE, and the narrowband listener just doesn't hear it. This is borne out by my listening to it at VERY short range with a narrowband service analyzer, I just can't copy it unless I turn on its continuous PTT test function unless I am within a few feet of it. Similar to Greg's comment about the phone nearby. Process gain for a FH system says something about how well we can pack lots of data from lots of users in a given chunk of band allocation, compared to how well the same space could be allocated by traditional techniques of assigning individual narrowband channels. We let the hopping algorithm allocate it instead of the frequency coordinator, and efficiently pack more in the band. I think we also get a little bit of additional re-use in that the SS radios can probably share the band with some population of narrowband intermittent (PTT or packet) stations, and not bother each other too much. I can only hope the above may help to improve some of our understandings of SS, I am in quite a bit over my head here. The above textbook is an excellent reference, I can highly recommend it. I got to check it out for an extended time over the holidays, and soemone else has already recalled it, its in demand. This book does actually discuss some of the things that go on in the 902-928 ISM band, among others, although it slightly predates the Freewave radio. It did somewhat contradict the advantages of the performance of the FH freewave radio, and I am almost beginning to wonder if the Freewave might actually be a little bit of a DS hybrid, possibly not pure FH? I don't think we have gotten a close look at what actually goes on in that radio. It appears that they have done their homework though. 73, and a prosperous new year to all, de Bob WB5AOH Robert Morgan Austin Texas morganb@admin.inetport.com From buaas@wireless.net Mon Dec 30 12:51:15 1996 Received: from wireless.net (wireless.net [198.253.254.1]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id MAA21070 for ; Mon, 30 Dec 1996 12:51:11 -0600 (CST) Received: (from buaas@localhost) by wireless.net (8.7.6/8.6.12) id KAA06134 for ss@tapr.org; Mon, 30 Dec 1996 10:52:42 -0800 (PST) Date: Mon, 30 Dec 1996 10:52:42 -0800 (PST) From: "Robert A. Buaas" Message-Id: <199612301852.KAA06134@wireless.net> To: ss@tapr.org Subject: Re: multiple FreeWaves at one site In [SS:736] "Greg Jones, WD5IVD" wrote: >I have two Freewave radios setting back to back right now -- one using a >vert and the other horz beam (all the antennas I had around for the test). >They are operating on two different channels (i.e. hop sequences) and >feeding the serial connections between them. >While many radios might not work transmitting next to each other, the >Freewaves on different hop channels certainly do -- at least the pairs I >have going here. In [SS:740] Dewayne Hendricks wrote: >I can confirm this. I recently helped the FreeWave people setup a >radio link to their local ISP from their Boulder facility. I setup a PC >running NOS and have five radios connected to it at 115 Kbps. One of the >radios is a pt-pt link to the ISP, and the other four radios are pt-pt >links to their employees homes. All of the radios operate on different >hopping patterns and although their respective antennas are in quite close >proximity they don't interfer with each other. It strikes me that we could do everyone a service by conducting this more scientifically, and determine exactly how well it works: Greg: (since you have exactly two radios, back to back) would you do the following: (a) with one link disabled, run enough FTP's over the working link to determine its best throughput, and document the number for us. (b) re-enable the downed link, connect it back-to-back with the first link, and rerun the FTP's over the 2-hop path, and document that result(s). By pushing the two-link system really hard, you'll eventually force one transmitter at the center of the system to be active at exactly the same time the other receiver is expecting data, and we'd expect to statistically measure the impact. FreeWaves transmit in short bursts, leaving large windows for receiving (yet the receiver logic is only powered-up for short periods of time inside these windows). Since these radios have a repeater mode of sorts, having the results from the test above would tell us how much we get in return for having the second radio, antenna, etc. best regards/bob K6KGS From wd5ivd@tapr.org Mon Dec 30 15:08:30 1996 Received: from [129.120.111.42] (knezek2.coe.unt.edu [129.120.111.42]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id PAA27937 for ; Mon, 30 Dec 1996 15:08:26 -0600 (CST) Message-Id: In-Reply-To: <199612301852.KAA06134@wireless.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 30 Dec 1996 15:11:35 -0600 To: ss@tapr.org From: "Greg Jones, WD5IVD" Subject: Re: [SS:744] Re: multiple FreeWaves at one site >Greg: (since you have exactly two radios, back to back) would you >do the following: > (a) with one link disabled, run enough FTP's over the working link > to determine its best throughput, and document the number for us. > (b) re-enable the downed link, connect it back-to-back with the > first link, and rerun the FTP's over the 2-hop path, and document > that result(s). > I already did this. The results were no difference. I could see no drop off in throughput wioth a single point or running through the pair. Since I was testing while downloading several megs of files from the TAPR.ORG system for the upcoming '97 CD-ROM I am sure there should have been considerable overlap. >Since these radios have a repeater mode of sorts, having the >results from the test above would tell us how much we get in >return for having the second radio, antenna, etc. I haven't played with the repeater function and will probably leave that to the others getting radios in the middle of January. Can't do everything. Cheers - Greg ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd ----- From dhoyer@ccm.frontiercorp.com Mon Dec 30 15:14:55 1996 Received: from node1.frontiernet.net (node1.frontiernet.net [205.232.174.11]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id PAA28514 for ; Mon, 30 Dec 1996 15:14:52 -0600 (CST) Received: from ccm.frontiercorp.com (ccm.frontiercorp.com [204.168.13.16]) by node1.frontiernet.net (8.8.2/8.8.2) with SMTP id PAA23958 for ; Mon, 30 Dec 1996 15:55:06 -0500 Received: from ccMail by ccm.frontiercorp.com (SMTPLINK V2.11 PreRelease 4) id AA851990274; Mon, 30 Dec 96 14:52:05 EST Date: Mon, 30 Dec 96 14:52:05 EST From: "Dan Hoyer" Message-Id: <9611308519.AA851990274@ccm.frontiercorp.com> To: ss@tapr.org Subject: Re: [SS:718] Re: SS digest 197 >> Date: Fri, 27 Dec 1996 18:40:49 -0600 >> From: "Greg Jones, WD5IVD" > > To: ss@tapr.org >> Subject: Re: ss >> Message-ID: > > >> >> that gets more SS radios into the amateur service. There are people >> already using WaveLan and I hope that in the long term TAPR or some other >> amateur will be able produce some radio that does what amateur radio >needs, > not just a commercial version convertered or operated under Part >97. >What is the advantage of this 115kbps SS radio, when the WaveLAN >does 2Mbps, and costs about the same (US$ 400)? >The WaveLan also has >DOS, Linux, and NT drivers. The 900MHz WaveLan has 7dBm less power >though. Hmmm, that's a good question about the advantages. As I see it here are some major advantages: Unlike the WaveLan that is a board installed in the computer, (unless you use the OEM WaveMODEM version of the WaveLAN hardware) the FreeWave radio operates as an RS232 full duplex async link transparently to the end devices connected to it, therefore it does not need special drivers. This makes it a good choice for -any- computing platform. (or even a back to back link with something like an ISDN landline) Also according to the specs it has an AT command set mode available making it look like a Hayes type modem device. This mode would be useful for an environment that does not directly support direct-connect async, but instead supports modems. dhoyer@frontiercorp.com ka9vmi >--------------------------------------------------------------------------- >BogoMIPS Research Labs -- bogosity research & simulation -- VE7JPM -- >jmorriso@bogomips.com ve7jpm@ve7jpm.ampr.org jmorriso@ve7ubc.ampr.org >--------------------------------------------------------------------------- From wpns@world.std.com Mon Dec 30 15:42:00 1996 Received: from europe.std.com (europe.std.com [199.172.62.20]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id PAA00813 for ; Mon, 30 Dec 1996 15:41:59 -0600 (CST) Received: from world.std.com by europe.std.com (8.7.5/BZS-8-1.0) id QAA08452; Mon, 30 Dec 1996 16:41:56 -0500 (EST) Received: by world.std.com (5.65c/Spike-2.0) id AA26536; Mon, 30 Dec 1996 16:42:02 -0500 From: wpns@world.std.com (William Smith) Message-Id: <199612302142.AA26536@world.std.com> Subject: Re: [SS:743] Re: avoiding interference with narrowband sources To: ss@tapr.org Date: Mon, 30 Dec 1996 16:42:02 -0500 (EST) In-Reply-To: <199612301752.LAA29368@admin.inetport.com> from "Robert B. Morgan" at Dec 30, 96 11:52:12 am X-Mailer: ELM [version 2.4 PL25] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit There's been some discussion of avoiding QRM with/to narrowband sources, anyone doing anything in the Boston area that would like to check out the mutual performance/interference characteristics of a SS system at 915 MHz with a low-power FMTV setup centered at 915.00? -- Willie Smith wpns@world.std.com N1JBJ@amsat.org #define NII Information SuperCollider From wb9mjn@wb9mjn.ampr.org Mon Dec 30 16:24:20 1996 Received: from wb9mjn.ampr.org (wb9mjn.ampr.org [44.72.98.19]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id QAA03078 for ; Mon, 30 Dec 1996 16:23:59 -0600 (CST) From: wb9mjn@wb9mjn.ampr.org Date: Mon, 30 Dec 96 16:15:31 UTC Message-Id: <11830@wb9mjn.ampr.org> To: ss@tapr.org Subject: Re: [SS:743] Re: .. Process Gain In-Reply-To: your message of Mon Dec 30 11:52:12 1996 <199612301752.LAA29368@admin.inetport.com> Hi Bob and Greg, While talking to Mel Whitten on the phone, he said that the Freewaves are hopping at 10 ms. Mel came down to visit u at a TPRS meeting to check out the radios. I was then talking to Don Lemley, on a repeater, and we were going over the FH and FEC, and how FEC is an integral part of FH-SS that has process gain. If a hit happens, a FH-SS system with process gain will just recover the bits with its FEC. As long as the FEC isn t overpowered, the FH-SS system will have a process gain equal to # of full bandwidth channels in the hopped spectrum devided. That is, some FH-SS systems do not hop a full bandwidth. At 173 Kbps, 10 ms is bigger than many packets. 10 ms being 1.73 KBits. So, Don made the conjecture, which I could not refute, that the radios may just be doing ARQ, instead of FEC and ARQ. In which case, I m pointing out that these radios would have no process gain. But, it really doesn t matter, since the noise performance of the radios is set by the thermal effects in most cases. Since, the spread spectrum is so large, and the usership so small that the C/I is very big. And the probability of a hit is less than the ther- mally set BER would cause. And if theres a hit, the radios just ARQ. 73, Don. Mailbox : WB9MJN @ N9HSI.IL.USA.NA AMPRNet : wb9mjn@wb9mjn.ampr.org[44.72.98.19] Internet: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu From wb9mjn@wb9mjn.ampr.org Mon Dec 30 16:31:32 1996 Received: from wb9mjn.ampr.org (wb9mjn.ampr.org [44.72.98.19]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id QAA03463 for ; Mon, 30 Dec 1996 16:31:24 -0600 (CST) From: wb9mjn@wb9mjn.ampr.org Date: Mon, 30 Dec 96 16:30:09 UTC Message-Id: <11833@wb9mjn.ampr.org> To: ss@tapr.org Subject: Re: [SS:747] Re: avoiding interference with narrowband sources In-Reply-To: your message of Mon Dec 30 15:47:28 1996 <199612302142.AA26536@world.std.com> Hi Willie, I would suggest, if the 915 FMTV system isn t seeing interferance now, they are not going to see interferance when the TAPR STA guys come on the air. I had a IFR 1200 S Service Monitor / Spectrum Analyzer looking at the signal on that band, thru one of the Ham/LAN Panel 915 antennas the other day, and there s plenty of FH activity here in Chicagoland. I can t believe the same is not true in Boston. That is NON-HAM FH activty! 73, Don. Mailbox : WB9MJN @ N9HSI.IL.USA.NA AMPRNet : wb9mjn@wb9mjn.ampr.org[44.72.98.19] Internet: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu From bm@hydra.carleton.ca Mon Dec 30 18:18:41 1996 Received: from hydra.carleton.ca (hydra.carleton.ca [134.117.12.18]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id SAA09337 for ; Mon, 30 Dec 1996 18:18:39 -0600 (CST) Received: (from bm@localhost) by hydra.carleton.ca (8.6.12/8.6.12) id TAA22866 for ss@tapr.org; Mon, 30 Dec 1996 19:17:30 -0500 From: Barry McLarnon VE3JF Message-Id: <199612310017.TAA22866@hydra.carleton.ca> Subject: Freewave SS LAN (fwd) To: ss@tapr.org Date: Mon, 30 Dec 1996 19:17:30 -0500 (EST) X-Mailer: ELM [version 2.4 PL23] Content-Type: text This message got snagged by a listserver bug, so I'm forwarding it... -Barry Forwarded message: > From ss@tapr.org Mon Dec 30 03:22:38 1996 > From: ss@tapr.org > Date: Mon, 30 Dec 1996 02:23:42 -0600 (CST) > Message-Id: <199612300819.DAA13524@mailnfs0.tiac.net> > Reply-To: ss@tapr.org > Originator: ss@tapr.org > Sender: ss@tapr.org > Precedence: bulk > To: bm@hydra.carleton.ca > Subject: [SS:739] Notification: message ignored > X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas > X-Comment: Tucson Amateur Packet Radio Spread Spectrum > Content-Transfer-Encoding: 7bit > Content-Type: text/plain; charset="us-ascii" > MIME-Version: 1.0 > X-Mailer: James Archer's Registered PMMail 1.53 For OS/2 > > Found X-Listprocessor-Version: id in message body; message ignored > > The message is included below: > ----------------------------------------------------------------------------- > >From jarcher@tiac.net Mon Dec 30 02:20:23 1996 > Received: from maildeliver0.tiac.net (maildeliver0.tiac.net [199.0.65.19]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id CAA20835 for ; Mon, 30 Dec 1996 02:20:21 -0600 (CST) > Received: from mailnfs0.tiac.net (mailnfs0.tiac.net [199.0.65.17]) by maildeliver0.tiac.net (8.8.0/8.8) with ESMTP id DAA14814; Mon, 30 Dec 1996 03:20:02 -0500 (EST) > Received: from localhost.tiac.net (jarcher.tiac.net [206.119.13.90]) by mailnfs0.tiac.net (8.8.0/8.8) with SMTP id DAA13524; Mon, 30 Dec 1996 03:19:59 -0500 (EST) > Message-Id: <199612300819.DAA13524@mailnfs0.tiac.net> > From: "Jim Archer" > To: "ss@tapr.org" > Date: Mon, 30 Dec 96 03:18:44 -0400 > Reply-To: "Jim Archer" > Priority: Normal > X-Mailer: James Archer's Registered PMMail 1.53 For OS/2 > MIME-Version: 1.0 > Content-Type: text/plain; charset="us-ascii" > Content-Transfer-Encoding: 7bit > Subject: Freewave SS LAN > > -----BEGIN PGP SIGNED MESSAGE----- > > Hi All... > > I apolagize if sime of these questions are old or simple, but > I'm a bit new to spread spectrum. > > I read a note about the Freewave SS radios, and got the idea to > get together with a bunch of my friends and deploy a radio LAN > with them. I was discussing it tonight with them, and we thought > up some questions we could not answer. I would appreciate any > help or advice someone can offer. I am sorry if this is too much > to ask in one fell swoop... > > Technical Questions: > > We would initially have about 4 sites, some of which would be > hidden transmitters from each other. Also, the distances > involved may exceed 10 air miles, so directonal antennas may be > required. How do we do this? Do we put up a site in the middle > with a PC and a radio and make it digipeat? If we did that, > would it cut our throughput in half, or would a protocol like > TCP with an adjustable window size reduce this problem? > > If we can modify our serial ports to exceed 115K, can we use the > full 127K baud rate that the Freewave radio can supply, or is > the serial port on the radio limited to 115k? Does the radio > even plug into the computer via a serial port? > > What other things are needed than the radio and other stuff > included by TAPR? I saw that they supply the radio, case, power > cube, and whip antenna. Is there any big expensive piece > missing? > > Are any software drivers available to make this think look like > a network adapter available? We are running Linux and OS/2, but > some people may want to run Win 95 or NT. We are all > professional software developers with experience doing drivers, > so we could write them, but I am wondering if they are done yet. > > What frequency is legal for ham operation, and how do we make > these radios do it? I saw that no modifications were made to the > radios, so I guess they must be coming on the right frequency. > Was this a special arrangement with the manufacturer? > > If a number of transmitters were transmitting on different > hopping algorathims, could we build a receiver that used DSP > technology to receive them all at the same time? Do the radios > transmit and receive on different frequencies? Can the radios > use different physical frequency bands, so that several if one > freq band is operating at capacity, we could use another, and > tie the two together with some kind of routing software? > > Legal Questions: > > How do we use the Freewave radios under part 15? If we wanted to > use them under part 15, would we have to not use gain antennas, > or would we have ti use less than 1 watt out of the radio? Does > part 15 limit ERP or power out of the radio? Power into the > antenna maybe? Are their other provisions of part 15 that would > make this illegal, like a restriction of distance we can > transmit? > > > > Thanks again to everyone who tolerated all these questions!!! > > Jim, KF1T > > ***************************************************************** > * PGP Key available from: www.tiac.net/users/jarcher > * > * Fingerprint: > * 56 BA 7B 48 22 5C 1D BD CB 15 F2 AC B3 32 24 A8 > ***************************************************************** > > > > -----BEGIN PGP SIGNATURE----- > Version: 2.6.2 > > iQCVAwUBMsd7KuM94M/jnRzVAQGTrQP/ZncRJtX7Enpg2bOHEb8IWfBSoFpokzbz > stzG9OlGXe11I9lJuXllm0AQ/AW7OAlIfNRN3aYL7SO7cNn+UzzsD8rC2nKOCT1N > unDH2b18R9Ulh2b6/Hmc4SBfVe8YBX902Ucy0n4hj4Ch77zEY8YMU+XbMXsHYqza > et27qqZyuOY= > =0kcd > -----END PGP SIGNATURE----- > -- Barry McLarnon VE3JF/VA3TCP | Internet: bm@hydra.carleton.ca Ottawa Amateur Radio Club | AMPRnet: bm@lynx.ve3jf.ampr.org Packet Working Group | Web: http://hydra.carleton.ca From bm@lynx.ve3jf.ampr.org Mon Dec 30 19:08:11 1996 Received: from lynx.ve3jf.ampr.org (lynx.ve3jf.ampr.org [44.135.96.100]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id TAA11613 for ; Mon, 30 Dec 1996 19:08:07 -0600 (CST) Received: (from bm@localhost) by lynx.ve3jf.ampr.org (8.6.12/8.6.12) id BAA14115 for ss@tapr.org; Tue, 31 Dec 1996 01:05:00 GMT From: Barry McLarnon VE3JF Message-Id: <199612310105.BAA14115@lynx.ve3jf.ampr.org> Subject: Re: [SS:748] Re: .. Process Gain To: ss@tapr.org Date: Tue, 31 Dec 1996 01:05:00 +0000 (GMT) In-Reply-To: <11830@wb9mjn.ampr.org> from "wb9mjn@wb9mjn.ampr.org" at Dec 30, 96 04:29:57 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Don said: > Been looking at ur numbers, and can t see where u went wrong with the >Freewave figuring. The only guess would be that they are using coherent >GFSK, and that might result in a better Eb/N0 to start with. Possible, but unlikely... coherent demodulation is quite difficult to implement in an FH system. And in a later message: > While talking to Mel Whitten on the phone, he said that the Freewaves > are hopping at 10 ms. Mel came down to visit u at a TPRS meeting to check > out the radios. > > I was then talking to Don Lemley, on a repeater, and we were going over > the FH and FEC, and how FEC is an integral part of FH-SS that has process > gain. If a hit happens, a FH-SS system with process gain will just recover > the bits with its FEC. As long as the FEC isn t overpowered, the FH-SS system > will have a process gain equal to # of full bandwidth channels in the hopped > spectrum devided. That is, some FH-SS systems do not hop a full bandwidth. > > At 173 Kbps, 10 ms is bigger than many packets. 10 ms being 1.73 KBits. > So, Don made the conjecture, which I could not refute, that the radios may > just be doing ARQ, instead of FEC and ARQ. In which case, I m pointing out > that these radios would have no process gain. But, it really doesn t matter, > since the noise performance of the radios is set by the thermal effects in > most cases. Since, the spread spectrum is so large, and the usership so small > that the C/I is very big. And the probability of a hit is less than the ther- > mally set BER would cause. And if theres a hit, the radios just ARQ. Hmmm... are you confusing "coding gain" with "process[ing] gain"? The process gain, for either DS or FH, is essentially the bandwidth expansion factor. This is a separate issue from whether FEC is implemented - with or without it, the FreeWave radios definitely have process gain (admittedly, the concepts of process gain, coding gain and diversity gain tend to blur together, especially in the case of DS and fast-FH). In any event, I suspect that Don L is correct in supposing that the FreeWaves do not use FEC, although FEC would offer a possible explanation for my earlier "too good to be true" BER analysis. Barry -- Barry McLarnon VE3JF/VA3TCP | Internet: bm@hydra.carleton.ca Ottawa Amateur Radio Club | AMPRnet: bm@lynx.ve3jf.ampr.org Packet Working Group | Web: http://hydra.carleton.ca From wd5ivd@tapr.org Mon Dec 30 20:17:37 1996 Received: from [129.120.111.42] (knezek2.coe.unt.edu [129.120.111.42]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id UAA14622 for ; Mon, 30 Dec 1996 20:17:32 -0600 (CST) Message-Id: In-Reply-To: <199612310017.TAA22866@hydra.carleton.ca> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 30 Dec 1996 20:14:43 -0600 To: ss@tapr.org From: "Greg Jones, WD5IVD" Subject: Re: [SS:750] Freewave SS LAN (fwd) >> Technical Questions: >> >> We would initially have about 4 sites, some of which would be >> hidden transmitters from each other. Also, the distances >> involved may exceed 10 air miles, so directonal antennas may be >> required. How do we do this? Do we put up a site in the middle >> with a PC and a radio and make it digipeat? If we did that, >> would it cut our throughput in half, or would a protocol like >> TCP with an adjustable window size reduce this problem? I would highly suggest you do all point-to-point connections on any backbone links. All connections between these major sites would be on individual channels. This increases the cost of links, but we have to think about designing good links instead of cutting costs and operational throghput I would highly suggest you use beams on all your point to point links. Horz. We plan on running TCP/IP across both the networks I am working on both in Dallas/Denton and Austin. Very easy to run WinSock or MacSlip on either Mac or Windows platforms into the nodes (which will be Linux based router -- hopefully running off of 4Meg Flash only -- Allan Finne is working on that now). These local access channels would then run off a horz omni of some design (possibly a slot, which Bob Morgan is developing). Based on rough calc using the radios in point-to-multipoint, figure to try to limit no more than 5 or 6 users per local access channel. This will allow best throughput overall. >> If we can modify our serial ports to exceed 115K, can we use the >> full 127K baud rate that the Freewave radio can supply, or is >> the serial port on the radio limited to 115k? Does the radio >> even plug into the computer via a serial port? Hard to say. The radios run at 173Kbaud. I don't think anyone has tried it yet, so we don't know what the outcome might be in either point-to-point or point-to-multi. We do know that having 16550A or BETTER are very important to making it work at high speed. >> What other things are needed than the radio and other stuff >> included by TAPR? I saw that they supply the radio, case, power >> cube, and whip antenna. Is there any big expensive piece >> missing? No snub antenna. You are looking at all the normal stuff for a site. After years of building networks site, and these seem to be no different, you should expect to drop at least $1000 dollars per major network node site. Beams, feedline, power (btty?, UPS?, your choice), switch (386,486,other?), etc. >> Are any software drivers available to make this think look like >> a network adapter available? We are running Linux and OS/2, but >> some people may want to run Win 95 or NT. We are all >> professional software developers with experience doing drivers, >> so we could write them, but I am wondering if they are done yet. As above, simply run SLIP across the links. Then you can use existing stacks to do communications. This e-mail is being typed in Eudora on my Mac which will shortly connect across a pair of Freewave radios over 4 miles. My mac is using an older version of MacTCP (becuase OTP doesn't work yet for direct connection) and MacSLIP. Over on the PC >> What frequency is legal for ham operation, and how do we make >> these radios do it? I saw that no modifications were made to the >> radios, so I guess they must be coming on the right frequency. >> Was this a special arrangement with the manufacturer? They operate across the ham band 902-928. Perfect legal under the TAPR SS STA for operations. You will have to meet the STA requirements to operate them. >> If a number of transmitters were transmitting on different >> hopping algorathims, could we build a receiver that used DSP >> technology to receive them all at the same time? Do the radios >> transmit and receive on different frequencies? Can the radios >> use different physical frequency bands, so that several if one >> freq band is operating at capacity, we could use another, and >> tie the two together with some kind of routing software? I'll leave that up to someone in the know. Anything is possible, but the question is, is there a DSP(s) that will do it and could you afford them. Cheers - Greg ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd ----- From davek@komacke.com Mon Dec 30 20:59:29 1996 Received: from sydney.komacke.com (root@sjx-ca81-18.ix.netcom.com [207.94.112.50]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id UAA17313 for ; Mon, 30 Dec 1996 20:59:22 -0600 (CST) Received: from musty.kobie.komacke.com (musty.kobie.komacke.com [192.168.2.2]) by sydney.komacke.com (8.7.6/8.7.3) with SMTP id SAA03212 for ; Mon, 30 Dec 1996 18:59:16 -0800 Message-Id: <3.0.1.32.19961230185913.006b45e4@sydney> X-Header1: Finger for my PGP key X-Sender: davepost@sydney X-Mailer: Windows Eudora Pro Version 3.0.1 beta 3 (32) Date: Mon, 30 Dec 1996 18:59:16 -0800 To: ss@tapr.org From: Dave Koberstein Subject: Re: [SS:743] Re: .. Process Gain Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Hi All, Good discussion by Robert below but I'd like to change a conclusion. FH radios operate just as well as DS radios in the presence of gaussian noise. The point left out in the discussion below is that the FH radio uses a receiver bandwidth the width of the narrowband-modulated signal. A DS radio uses a receiver bandwidth "n" times wider and so receives "n" times as much noise power. Since a DS radio needs a much wider receiver bandwidth, it receives much more noise. However, it processes out the additional noise by unspreading the signal. In fact, all things being equal, a DS signal has no advantage against broadband or thermal noise compared to a non-SS signal. The non-SS signal can use correspondingly narrow receiver bandwidths and therefore have correspondingly less thermal noise power to degrade S/N. The advantage of DS and FH is resistance to relatively narrowband interferors or relatively narrowband power loss (i.e. multipath). They don't resist wideband thermal noise. To quote out of context: to do so would violate the laws of physics. (Really, it would violate our current understanding of information theory.) At 11:52 AM 12/30/96 -0600, you wrote: >A DS system could, and some routinely do, have sufficient process gain >to recover a signal that is weaker than the thermal noise figure of it's >front end would permit a narrowband signal from recovering. The GPS >system is a case in point. Quoting from a textbook (Spread Spectrum >systems with commercial applications, 3rd ed, Robert Dixon, 1994, >John Wiley, TK5102.5.D55, pp370-371 and an excellent reference) the >author says that GPS is speced to deliver -135 dBm at the earth's surface. >(About 0.035 uV) For 9 MHz bandwidth, receiver thermal noise is -104 dBm. >The receivers routinely operate at -30 dB SNR. Answer: 10.23 Mcps rate, >9.0 MHz BW, and only 50 bps datarate, which yields 10*log(9.0E06/50)= >52.5 dB process gain. Inputting SNR of -30 db, and using the process >gain yields a positive SNR at the IF of 22 dB, and they work. But note >the datarate, 50 bps. Fine for positioning, but not to surf the web. > >FH radios just DON'T do this. They have to have a positive SNR at their >inputs. Any hop where it goes negative will yield garbage on that hop, >and in fact determines the BER. I think that their value to us is >that they avoid QRM and to function at all, have to have error correcting >coding built in. I think that I could (over)generalize by saying that >DS systems are useful to work in the presence of broad gaussian noise >or what we like to refer to as QRN (impulse noise possibly excepted), >and that FH systems are useful to avoid QRM either from narrowband >sources or from other FH units on different codes. Their process gain >operates in a way to allow lots of them to spread out over a given band >and avoid each other, and avoid some fixed freq narrowband stations, >and also avoid any significant interference from themselves to narrow >systems by virtue of their extremely low keyup time on any particular >hop channel. My impression of the Freewave radios in particular is that >they have mixed a high on-air datarate (the 173 kb) with a hopping pattern >that spends very little time on the air at any channel, and there are >lots of channels in its pattern, so when the radio does happen to transmit >on a particular channel that another narrowband user is listening to, >the burst of data is both short AND WIDE, and the narrowband listener >just doesn't hear it. This is borne out by my listening to it at VERY >short range with a narrowband service analyzer, I just can't copy it >unless I turn on its continuous PTT test function unless I am within >a few feet of it. Similar to Greg's comment about the phone nearby. > >Process gain for a FH system says something about how well we can pack >lots of data from lots of users in a given chunk of band allocation, >compared to how well the same space could be allocated by traditional >techniques of assigning individual narrowband channels. We let the >hopping algorithm allocate it instead of the frequency coordinator, >and efficiently pack more in the band. I think we also get a little >bit of additional re-use in that the SS radios can probably share the >band with some population of narrowband intermittent (PTT or packet) >stations, and not bother each other too much. > -------------------- End of Original ---------------------------------- ____________________________________________________________ Dave Koberstein work: davek@proxim.com / http://www.proxim.com keep in touch: davek@komacke.com / http://www.komacke.com ham internet: n9dk@n9dk.ampr.org [44.4.12.172] (ax.25/PBBS: n9dk@w6yx.#nocal.ca.usa.noam) From wb9mjn@wb9mjn.ampr.org Mon Dec 30 21:05:53 1996 Received: from wb9mjn.ampr.org (wb9mjn.ampr.org [44.72.98.19]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id VAA18059 for ; Mon, 30 Dec 1996 21:05:44 -0600 (CST) From: wb9mjn@wb9mjn.ampr.org Date: Mon, 30 Dec 96 21:02:46 UTC Message-Id: <11840@wb9mjn.ampr.org> To: ss@tapr.org Subject: Re: [SS:751] Re: .. Process Gain In-Reply-To: your message of Mon Dec 30 19:08:26 1996 <199612310105.BAA14115@lynx.ve3jf.ampr.org> Hi Barry, I probably am confusing coding and process gains. But a FH system without FEC will have interferance, no matter what the bandwidth expansion factor, so can it be claimed to have any process gain? Since interfering signals do not require any gain over the FH signal, to cause interferance. I had forgot about the coherent difficulties in a FH system. That is pointed out in the Dixon book. BTW, I m a Don L, too, hi. 73, Don. Mailbox : WB9MJN @ N9HSI.IL.USA.NA AMPRNet : wb9mjn@wb9mjn.ampr.org[44.72.98.19] Internet: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu From karn@qualcomm.com Tue Dec 31 04:21:52 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id EAA17911 for ; Tue, 31 Dec 1996 04:21:51 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id CAA16144; Tue, 31 Dec 1996 02:21:19 -0800 (PST) Date: Tue, 31 Dec 1996 02:21:19 -0800 (PST) From: Phil Karn Message-Id: <199612311021.CAA16144@servo.qualcomm.com> To: ss@tapr.org In-reply-to: <11813@wb9mjn.ampr.org> Subject: Re: [SS:734] Re: .. It seems to me that your BER-vs-dBm measurements are rather meaningless without some way to tell whether you're being limited by demodulator performance or front-end performance. Front end performance from unit to unit can easily vary by many more dB than demodulator performance, especially if everybody uses the same simple noncoherent demodulators without any FEC. The distinction is important because it's relatively easy to compensate for a noisy front end in a Part 15 unit by adding an external preamp, but there's little you can do to compensate for an inefficient demodulator given that these devices are closed black boxes. (Perhaps some external FEC would help, but not if the packet and bit synchronization mechanisms are already marginal to begin with, or if there are built-in packet level CRCs that can't be disabled). The only way to tell is with a Eb/N0 test set that amplifies the input signal and adds a controlled amount of wideband noise that swamps the noise contributed by the receiver front end. Then you can get a measurement of the demodulator's performance independent of the front end noise figure. There are commercial test sets designed specifically for these measurements; I have one by Scientific Atlanta sitting in my office. (Unfortunately it only works at a 70MHz IF, which makes it inconvenient for anything that doesn't have a 70MHz IF). If you have a wideband noise source, a spectrum analyzer, some RF gain blocks and a hybrid combiner, you can come up with a pretty good replacement of what this test set does. I'd be very interested in any quantitative results if anybody tries this. Phil From karn@qualcomm.com Tue Dec 31 04:42:37 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id EAA18430 for ; Tue, 31 Dec 1996 04:42:35 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id CAA16203; Tue, 31 Dec 1996 02:42:04 -0800 (PST) Date: Tue, 31 Dec 1996 02:42:04 -0800 (PST) From: Phil Karn Message-Id: <199612311042.CAA16203@servo.qualcomm.com> To: ss@tapr.org In-reply-to: <01BBF5DB.CD370A80@dal132.metronet.com> (message from David Dennis on Sun, 29 Dec 1996 23:05:13 -0600 (CST)) Subject: Re: [SS:738] RE: 731] Re: .. Where can I find some info that relates S/N required for a specific BER? In the fiber optic systems I work with we assume 10.9dB for a BER 1e-9 but I dont know what to assume for different BERs. This depends on the modulation method, FEC (if any) and the optimality of the implementation. Not only can different modems require different Eb/N0s for a given BER, but the slope of those curves can vary dramatically (particularly with FEC). So it is hard to give any hard and fast answers, especially given the "black box" nature of these modems. The best I can suggest is that comparative measurements be made at comparable BERs. Phil From karn@qualcomm.com Tue Dec 31 04:51:00 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id EAA18792 for ; Tue, 31 Dec 1996 04:50:59 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id CAA16214; Tue, 31 Dec 1996 02:50:27 -0800 (PST) Date: Tue, 31 Dec 1996 02:50:27 -0800 (PST) From: Phil Karn Message-Id: <199612311050.CAA16214@servo.qualcomm.com> To: ss@tapr.org In-reply-to: (wd5ivd@tapr.org) Subject: Re: [SS:742] Re: .. >Someone said the other day that FHSS have no process gain. Is this a >correct statement ? I had thought that FHSS and DSSS both had process gain. Sure FHSS has process gain. It's just the number of hopping channels. The nature of the interference is different than DSSS (it comes in occasional strong bursts rather than as a continuous thermal-like background) but that can actually be an advantage if good burst-error-correcting FEC is used. Phil From karn@qualcomm.com Tue Dec 31 05:53:55 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id FAA20704 for ; Tue, 31 Dec 1996 05:53:53 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id DAA16314; Tue, 31 Dec 1996 03:53:22 -0800 (PST) Date: Tue, 31 Dec 1996 03:53:22 -0800 (PST) From: Phil Karn Message-Id: <199612311153.DAA16314@servo.qualcomm.com> To: ss@tapr.org In-reply-to: <199612301752.LAA29368@admin.inetport.com> (morganb@inetport.com) Subject: Re: [SS:743] Re: .. Process Gain An additional comment on Bob Morgan's good discussion of process gain: The reason FH radios generally hop slower than their data rate is not a limitation of the technology. With direct digital synthesizers (DDSes) there is no real limit to how fast you can hop. The limit comes from the inability, in most real-world frequency hopping environments, to maintain carrier phase coherence across a hop. The medium is often dispersive, i.e., it has a propagation delay that depends on frequency, so even with accurate frequency references at both ends there is a random and unpredictable phase jump across the hop. So if the hop is shorter than its symbol time, the symbol energy that is spread out over multiple hops must be recombined noncoherently, and this is less efficient than coherent combining. Note that this applies even to "noncoherent" modulation methods like FSK and DPSK. They're "noncoherent" only in not requiring the receiver to estimate carrier phase over some largish number of symbol intervals; the receiver still performs a coherent integration over each individual symbol time. Direct sequence doesn't have this problem. You can coherently integrate in direct sequence over as many PN chips as you like, up to the coherence time limit of the channel (which is the inverse of the doppler spread, which in turn depends on how fast the stations and/or the propagation medium is moving with respect to one another). Phil From karn@qualcomm.com Tue Dec 31 06:10:10 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id GAA21373 for ; Tue, 31 Dec 1996 06:10:08 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id EAA16338; Tue, 31 Dec 1996 04:09:37 -0800 (PST) Date: Tue, 31 Dec 1996 04:09:37 -0800 (PST) From: Phil Karn Message-Id: <199612311209.EAA16338@servo.qualcomm.com> To: ss@tapr.org In-reply-to: <3.0.1.32.19961230185913.006b45e4@sydney> (message from Dave Koberstein on Mon, 30 Dec 1996 21:04:11 -0600 (CST)) Subject: Re: [SS:753] Re: .. Process Gain >The advantage of DS and FH is resistance to relatively narrowband >interferors or relatively narrowband power loss (i.e. multipath). They >don't resist wideband thermal noise. To quote out of context: to do so >would violate the laws of physics. (Really, it would violate our current >understanding of information theory.) Unless you consider FEC to be a form of spread spectrum, in which case going wider *does* help you against wideband thermal noise. I know, the usual definition of spread spectrum doesn't include FEC, but I argue that they do look very much alike. In fact, DSSS can be seen as a special case of coding with a low-rate random code that has no gain as compared to a code chosen for good distance properties. Phil From bm@lynx.ve3jf.ampr.org Tue Dec 31 08:33:49 1996 Received: from lynx.ve3jf.ampr.org (lynx.ve3jf.ampr.org [44.135.96.100]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id IAA27517 for ; Tue, 31 Dec 1996 08:33:40 -0600 (CST) Received: (from bm@localhost) by lynx.ve3jf.ampr.org (8.6.12/8.6.12) id OAA18314 for ss@tapr.org; Tue, 31 Dec 1996 14:30:25 GMT From: Barry McLarnon VE3JF Message-Id: <199612311430.OAA18314@lynx.ve3jf.ampr.org> Subject: Another bounced message... To: ss@tapr.org Date: Tue, 31 Dec 1996 14:30:25 +0000 (GMT) X-Mailer: ELM [version 2.4 PL23] Content-Type: text Here's another message from Jim Archer... unfortunately, there is a bug in Listproc which causes it to reject PGP-encoded messages (it thinks they are bounced list mail). Fixing it involves rebuilding Listproc from the sources... Lee (keeper of the TAPR server) will have to do that. In the meantime, the only workaround is to not use PGP in mail to the list. -Barry Forwarded message: > From ss@tapr.org Tue Dec 31 04:53:10 1996 > From: ss@tapr.org > Date: Mon, 30 Dec 1996 22:55:47 -0600 (CST) > Message-Id: <199612310450.XAA13167@mailnfs0.tiac.net> > Reply-To: ss@tapr.org > Originator: ss@tapr.org > Sender: ss@tapr.org > Precedence: bulk > To: bm@hydra.carleton.ca > Subject: [SS:754] Notification: message ignored > X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas > X-Comment: Tucson Amateur Packet Radio Spread Spectrum > Content-Transfer-Encoding: 7bit > Content-Type: text/plain; charset="us-ascii" > MIME-Version: 1.0 > X-Mailer: James Archer's Registered PMMail 1.53 For OS/2 > > Found X-Listprocessor-Version: id in message body; message ignored > > The message is included below: > ----------------------------------------------------------------------------- > >From jarcher@tiac.net Mon Dec 30 22:51:05 1996 > Received: from maildeliver0.tiac.net (maildeliver0.tiac.net [199.0.65.19]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id WAA25163 for ; Mon, 30 Dec 1996 22:51:03 -0600 (CST) > Received: from mailnfs0.tiac.net (mailnfs0.tiac.net [199.0.65.17]) by maildeliver0.tiac.net (8.8.0/8.8) with ESMTP id XAA08734; Mon, 30 Dec 1996 23:50:53 -0500 (EST) > Received: from localhost.tiac.net (jarcher.tiac.net [206.119.13.90]) by mailnfs0.tiac.net (8.8.0/8.8) with SMTP id XAA13167; Mon, 30 Dec 1996 23:50:49 -0500 (EST) > Message-Id: <199612310450.XAA13167@mailnfs0.tiac.net> > From: "Jim Archer" > To: "ss@tapr.org" > Date: Mon, 30 Dec 96 23:50:46 -0400 > Reply-To: "Jim Archer" > Priority: Normal > X-Mailer: James Archer's Registered PMMail 1.53 For OS/2 > MIME-Version: 1.0 > Content-Type: text/plain; charset="us-ascii" > Content-Transfer-Encoding: 7bit > Subject: Re: [SS:752] Re: Freewave SS LAN (fwd) > > -----BEGIN PGP SIGNED MESSAGE----- > > On Mon, 30 Dec 1996 20:18:39 -0600 (CST), Greg Jones, WD5IVD > wrote: > > Thanks, Greg... But you lost me on a few things... > > > >>> We would initially have about 4 sites, some of which would be > >>> hidden transmitters from each other. Also, the distances > >>> involved may exceed 10 air miles, so directonal antennas may be > >>> required. How do we do this? Do we put up a site in the middle > >>> with a PC and a radio and make it digipeat? If we did that, > >>> would it cut our throughput in half, or would a protocol like > >>> TCP with an adjustable window size reduce this problem? > > > >I would highly suggest you do all point-to-point connections on any > >backbone links. All connections between these major sites would be on > >individual channels. This increases the cost of links, but we have to > >think about designing good links instead of cutting costs and operational > >throghput > > Currently, we are planning just one major site, I guess, > depending on what a major site is. If I were building a wired > LAN, I would tie my servers together with some type of high > speed backbone (and I have done this) and use something like > 10BaseT or Token Ring from each server for its immediate users. > Of course, each server would route, especially if they were > Netware, but that gets off topic... Anyhow, this is all normal, > but there is no hidden transmitter problem. > > When doing this by radio, how do we deal with the fact that all > radios can't hear each other? Do we have to take advantage of > geography to put a "server" in every vally, with each server > handling local users on a different virtual channel (hopping > scheme), and then tie all the servers together either by > landline or a different radio virtual channel? > > I guess if we did this, we don't need to digipeat, except > between the servers. > > >I would highly suggest you use beams on all your point to point links. Horz. > > OK. > > >rough calc using the radios in point-to-multipoint, figure to try to limit > >no more than 5 or 6 users per local access channel. This will allow best > >throughput overall. > > What defines a "local access channel?" Is this a different > hopping algorathim on the same frequence band, or an actual > different frequency band? Also, what kind of throughput should > we expect? > > > Thanks again for your help, Greg! > > Jim > > ***************************************************************** > * PGP Key available from: www.tiac.net/users/jarcher > * > * Fingerprint: > * 56 BA 7B 48 22 5C 1D BD CB 15 F2 AC B3 32 24 A8 > ***************************************************************** > > > > -----BEGIN PGP SIGNATURE----- > Version: 2.6.2 > > iQCVAwUBMsibquM94M/jnRzVAQFz7QP/UZMCNoARKS7s89egzYFpAhmLs8yc+8Ti > ZqHCb5zJNvey/Eebm6RpDAg92SC1l8A6YbQwDw6i4aY1/BpWG6lfdQ8DwjXWxdtD > JBxK9rR4epNsCmF56ozEZF/T4QuSYn/gbRj5Ao7PwRbtXTjchCxJbVBKfirqMJao > OODF/t7UYjA= > =HdpZ > -----END PGP SIGNATURE----- > -- Barry McLarnon VE3JF/VA3TCP | Internet: bm@hydra.carleton.ca Ottawa Amateur Radio Club | AMPRnet: bm@lynx.ve3jf.ampr.org Packet Working Group | Web: http://hydra.carleton.ca From bad@uhf.wireless.net Tue Dec 31 10:35:25 1996 Received: from uhf.wdc.net (uhf.wdc.net [198.147.74.44]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id KAA05195 for ; Tue, 31 Dec 1996 10:35:22 -0600 (CST) Received: from localhost (bad@localhost) by uhf.wdc.net (8.8.4/8.6.12) with SMTP id LAA03656 for ; Tue, 31 Dec 1996 11:37:59 -0500 (EST) Date: Tue, 31 Dec 1996 11:37:59 -0500 (EST) From: Bernie Doehner To: ss@tapr.org Subject: Re: [SS:745] Re: multiple FreeWaves at one site In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Mon, 30 Dec 1996, Greg Jones, WD5IVD wrote: > > I already did this. The results were no difference. I could see no drop > off in throughput wioth a single point or running through the pair. Since > I was testing while downloading several megs of files from the TAPR.ORG > system for the upcoming '97 CD-ROM I am sure there should have been > considerable overlap. Hold on a second.. Isn't your internet connection rate limiting your download in this configuration (what is your ftp throughput, downloading directly from TAPR.ORG to your Freewave gateway?)? Could you please rerun your tests, but this time download a file from one end point of your Freewave link to the other (instead of fetching files from the internet)? Thanks! Bernie From djk@tobit.co.uk Tue Dec 31 10:42:31 1996 Received: from dirku.tobit.co.uk (dirku.demon.co.uk [158.152.30.189]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id KAA05446 for ; Tue, 31 Dec 1996 10:42:25 -0600 (CST) Received: (qmail 860 invoked by uid 500); 31 Dec 1996 16:42:17 -0000 Date: Tue, 31 Dec 1996 16:42:17 +0000 (GMT) From: Dirk Koopman Reply-To: djk@tobit.co.uk To: Phil Karn cc: ss@tapr.org Subject: Re: [SS:758] Re: .. Process Gain In-Reply-To: <199612311153.DAA16314@servo.qualcomm.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Tue, 31 Dec 1996, Phil Karn wrote: > An additional comment on Bob Morgan's good discussion of process gain: > > > Direct sequence doesn't have this problem. You can coherently > integrate in direct sequence over as many PN chips as you like, up to > the coherence time limit of the channel (which is the inverse of the > doppler spread, which in turn depends on how fast the stations and/or > the propagation medium is moving with respect to one another). In real world situations with some of these 1Mb + DS systems what is the likely doppler shift that these units can tolerate (very approximately)? How (much) is it likely to increase the acquisition time? Dirk -- Dirk-Jan Koopman Tel/Fax: +44 1362 696076 Mobile: +44 973 333806 Computer Consultant Email: djk@tobit.co.uk or G1TLH@GB7TLH.#35.GBR.EU "The typewriting machine, when played with expression, is no more annoying than the piano when played by a sister or near relation." --Oscar Wilde From ssampson@oklahoma.net Tue Dec 31 10:44:15 1996 Received: from dns.okc (dns.oklahoma.net [208.2.112.2]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id KAA05482 for ; Tue, 31 Dec 1996 10:44:14 -0600 (CST) Received: from ssampson.okc.oklahoma.net by dns.okc (SMI-8.6/SMI-SVR4) id KAA03082; Tue, 31 Dec 1996 10:48:26 -0600 Message-ID: <32C94204.66C@oklahoma.net> Date: Tue, 31 Dec 1996 10:40:36 -0600 From: Steve Sampson Organization: Amateur Radio Station N5OWK X-Mailer: Mozilla 3.01Gold (Win95; I) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: Backbone References: <199612311430.OAA18314@lynx.ve3jf.ampr.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit > Thanks, Greg... But you lost me on a few things... > > When doing this by radio, how do we deal with the fact that all > radios can't hear each other? What do you want to do? 1. Do you want to create a backbone for a low-baud AX.25 network? 2. Do you want to Network several workstations? Extrapolate your usage. Down the road you will no doubt be running multiple network connections to multiple servers/workstations. It's hard to visualize a radio network in ethernet terms, as the radios can't be in parallel. If you stick with a serial network, sooner or later it will collapse, with the nodes in the middle doing all the work. Probably the best bet is to group the nodes that can hear each other together, and select one as the server. Then this server will connect to another server. There's no cut and dried book method. The thing to keep in mind, is how the end points throughput is tuned. If the end points must cycle through four servers to get to each other, this may be the limiting bandwidth factor of the network. Short answer, limit the routers in any network, maximize the users on a leg (within applications performance. For example, more than five users on a leg using Microsoft Access, or Borland DBase would be ludicrous). What that means in radio context, is to elect a router, and have the cell use that to point to. In the worse-case it will be three nodes. In the best-case, it will be 15 (the maximum hopping channels). Sometimes "anything" is "something." Steve From davek@komacke.com Tue Dec 31 13:17:22 1996 Received: from sydney.komacke.com (root@sjx-ca65-21.ix.netcom.com [206.217.121.85]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id NAA14608 for ; Tue, 31 Dec 1996 13:17:19 -0600 (CST) Received: from musty.kobie.komacke.com (musty.kobie.komacke.com [192.168.2.2]) by sydney.komacke.com (8.7.6/8.7.3) with SMTP id LAA12784 for ; Tue, 31 Dec 1996 11:17:10 -0800 Message-Id: <3.0.1.32.19961231111705.006ac058@sydney> X-Header1: Finger for my PGP key X-Sender: davepost@sydney X-Mailer: Windows Eudora Pro Version 3.0.1 beta 3 (32) Date: Tue, 31 Dec 1996 11:17:11 -0800 To: ss@tapr.org From: Dave Koberstein Subject: Re: [SS:759] Re: .. Process Gain Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Hmmm... Thinking of FEC at SS is interesting and I'll go with that. But is it true that it will beat wideband thermal noise? As we add longer FEC codes (increasing the number of errors we can correct for), we have to increase the signaling rate (to keep the information rate constant). That means wider bandwidths, more noise power, and worse S/N. I don't know how to express what a given FEC code gives you for reduced bit error rate. Can you comment on that? At 06:16 AM 12/31/96 -0600, you wrote: >>The advantage of DS and FH is resistance to relatively narrowband >>interferors or relatively narrowband power loss (i.e. multipath). They >>don't resist wideband thermal noise. To quote out of context: to do so >>would violate the laws of physics. (Really, it would violate our current >>understanding of information theory.) > >Unless you consider FEC to be a form of spread spectrum, in which case >going wider *does* help you against wideband thermal noise. I know, >the usual definition of spread spectrum doesn't include FEC, but I >argue that they do look very much alike. In fact, DSSS can be seen as >a special case of coding with a low-rate random code that has no >gain as compared to a code chosen for good distance properties. > >Phil > > -------------------- End of Original ---------------------------------- ____________________________________________________________ Dave Koberstein work: davek@proxim.com / http://www.proxim.com keep in touch: davek@komacke.com / http://www.komacke.com ham internet: n9dk@n9dk.ampr.org [44.4.12.172] (ax.25/PBBS: n9dk@w6yx.#nocal.ca.usa.noam) From karn@qualcomm.com Tue Dec 31 20:24:41 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id UAA06464 for ; Tue, 31 Dec 1996 20:24:40 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id SAA17835; Tue, 31 Dec 1996 18:24:07 -0800 (PST) Date: Tue, 31 Dec 1996 18:24:07 -0800 (PST) From: Phil Karn Message-Id: <199701010224.SAA17835@servo.qualcomm.com> To: ss@tapr.org In-reply-to: (message from Dirk Koopman on Tue, 31 Dec 1996 10:47:50 -0600 (CST)) Subject: Re: [SS:762] Re: .. Process Gain >In real world situations with some of these 1Mb + DS systems what is the >likely doppler shift that these units can tolerate (very approximately)? Doppler is less of a problem the faster you go. At megabit rates, it's virtually a non-problem even on satellites. Note this applies to the user data rate, not the chipping rate -- it's the post-despreading bandwidth that counts. A wide post-despreading filter (as would be used on a high rate link) will easily accomodate a lot of doppler shift, as will the relatively wide carrier loop filters. At lower data rates (and correspondingly lower C/N0 ratios) the data and carrier loop filters are all much narrower, and are therefore much more sensitive to doppler. GPS is probably the worst case. The data rate is only 50 bps and there is significant satellite and platform doppler shift (though the satellite motion component is not nearly as great as it would be if the satellites were in low orbits). Acquisition from a cold start often takes as long as 15 minutes, largely because the receivers have to brute-force search a large three-dimensional space consisting of 32 PN codes (one for each satellite, though not all are in use) times plus & minus several kilohertz worth of 50Hz channels (doppler shift) times 1023 possible time offsets for the 1023-chip C/A code. It has to dwell on each point in the search space long enough to accumulate sufficient energy from the output to detect the signal. And even after it acquires a satellite, it takes a minimum of 30 seconds to collect a complete frame of time code and ephemeris information for that satellite. "Warm start" reacquisition with a current ephemeris and clock can be pretty fast because the receiver can search only those PN codes that are known to be visible, and at the approximate doppler and timing offsets predicted by the last known satellite data, clock, and receiver position. Phil From karn@qualcomm.com Tue Dec 31 20:36:54 1996 Received: from servo.qualcomm.com (servo.qualcomm.com [129.46.101.170]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id UAA07194 for ; Tue, 31 Dec 1996 20:36:52 -0600 (CST) Received: (from karn@localhost) by servo.qualcomm.com (8.8.4/1.4/8.7.2/1.9) id SAA17883; Tue, 31 Dec 1996 18:36:20 -0800 (PST) Date: Tue, 31 Dec 1996 18:36:20 -0800 (PST) From: Phil Karn Message-Id: <199701010236.SAA17883@servo.qualcomm.com> To: ss@tapr.org In-reply-to: <3.0.1.32.19961231111705.006ac058@sydney> (message from Dave Koberstein on Tue, 31 Dec 1996 13:17:50 -0600 (CST)) Subject: Re: [SS:764] Re: .. Process Gain >Hmmm... Thinking of FEC at SS is interesting and I'll go with that. But >is it true that it will beat wideband thermal noise? As we add longer FEC >codes (increasing the number of errors we can correct for), we have to >increase the signaling rate (to keep the information rate constant). That >means wider bandwidths, more noise power, and worse S/N. Yes, FEC will beat thermal noise -- to a point. That point is the Shannon limit for an infinite bandwidth channel: -1.6 dB Eb/N0. Note the units; Eb is the energy in joules per *user data bit* (NOT energy per chip, or energy per coded modulation symbol or anything else), and N0 is the thermal noise spectral density in watts/hertz. Since joules = watts/hz, the ratio is dimensionless. Example: Qualcomm CDMA is a direct sequence spread system. The two directions (mobile to cell and cell to mobile) use different modulation schemes, but both use interleaved convolutional coding with Viterbi decoding, and their overall Eb/N0 performances are comparable: about 3-4 dB on a nonfading channel and about 7 dB on a fading channel. Most of the extra power required on a fading channel is because of the limited interleaving available due to delay constraints (this is, after all, a voice system). Phil