From ge@hpsadr2.sr.hp.com Fri Aug 01 13:44:17 1997 Received: from palrel1.hp.com (palrel1.hp.com [156.153.255.235]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id NAA04534 for ; Fri, 1 Aug 1997 13:44:15 -0500 (CDT) Received: from srmail.sr.hp.com (srmail.sr.hp.com [15.4.45.14]) by palrel1.hp.com (8.8.5/8.8.5) with ESMTP id LAA07690 for ; Fri, 1 Aug 1997 11:44:14 -0700 (PDT) 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 AA055271053; Fri, 1 Aug 1997 11:44:14 -0700 Received: by hpsadr2.sr.hp.com (1.37.109.16/15.5+ECS 3.3) id AA155851052; Fri, 1 Aug 1997 11:44:12 -0700 From: Glenn Elmore Message-Id: <199708011844.AA155851052@hpsadr2.sr.hp.com> Subject: pathloss To: ss@tapr.org (ge) Date: Fri, 1 Aug 1997 11:44:12 -0800 (PDT) In-Reply-To: <199707290330.WAA16555@tapr.org> from "ge" at Jul 28, 97 10:30:58 pm X-Mailer: ELM [version 2.4 PL21] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Barry McLarnon VE3JF commenting on Don's additional path loss reference: > have a reflection with reflection coefficient of -1. Thus, depending on > the phase relationship between the direct and reflected path, you can > have anything from 6 dB enhancement wrt free space to complete > cancellation of the signal. I don't think that the 6 dB enhancement > condition is something you would want to depend on - it's not very > likely that you'll be that lucky, unless you're shooting over a smooth > treeless hill and get the clearance just right. > I don't disagree with your contention that a number of the order of 20 > dB excess path loss is a reasonable thing to work with for grazing paths > in the real world - it's just that 6 dB gain for first fresnel clearance > that I have a problem with. WRT the 6 dB gain number, years ago there was considerable discussion about whether this is *ever* obtainable in any kind of practical situation. Some of the early vhf EME attempts hoped to make use of this. I remember at least one attempt involving someone with a w2 call, which I'm afraid I've forgotten, who was trying to use the 6 dB "setting sun effect" (you see the energy from two suns, for radio this could be 6 dB if it adds constructively) with a large 2M EME array from a New York City high rise. He had a shot to the east towards the water and was trying to do EME at sunrise to get a 6 dB benefit. However, to my knowledge, there was never any improvement attributable to the effect. There was, I believe, some penalty due to having antennas looking at 290 K terra firma instead of a background of cold sky. As Barry suggests, I'm afraid that we'd see the same result in trying to use the effect for digital networks. We'd not get any gain and things are generally worse for operating so close to grazing. I also have some doubts about the 20 dB excess path loss for grazing paths, not because I doubt the theory so much as I think the practice would likely show a good deal more than this. My experience with typical amateur paths is that 'clean grazing' isn't common. Usually there is muck in the way. Worse, in most locales, the index of refraction is wandering around. While it may average 4/3 and usually be greater than unity it ends up effectively steering the Fresnel zones around. This is particularly a problem in marine environments and where the air is not dry and well-stirred. Just getting amateur sites which are LOS out to the horizon in the necessary direction(s) isn't common. Most often there are trees, hills and houses. These typically are good for more than 20 dB excess loss all by themselves. How does it go? "In theory, it works in practice. In practice it doesn't." Glenn n6gn From jfields@hotmail.com Sat Aug 02 09:56:16 1997 Received: from sjmail.bigger.net (sjmail.bigger.net [206.111.129.1]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id JAA01604 for ; Sat, 2 Aug 1997 09:56:14 -0500 (CDT) Received: from p5-133-hitech (sj5k1ac1p10.sj.bigger.net [206.111.130.10]) by sjmail.bigger.net (8.8.5/8.8.5) with SMTP id HAA04336 for ; Sat, 2 Aug 1997 07:56:29 -0700 (PDT) Message-ID: <33E34A1C.6929@hotmail.com> Date: Sat, 02 Aug 1997 07:54:20 -0700 From: Julian Fields Reply-To: jfields@hotmail.com X-Mailer: Mozilla 3.01C-KIT (Win95; U) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: [SS:1650] pathloss References: <199708011844.AA155851052@hpsadr2.sr.hp.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Glenn Elmore wrote: > WRT the 6 dB gain number, years ago there was considerable discussion > about whether this is *ever* obtainable in any kind of practical situation. I have never seen an article on the Fresnel gains or losses you guys are talking about. What is the 1 minute summary of what this is all about? Thanks, Julian From wb9mjn@wb9mjn.ampr.org Sat Aug 02 11:50:48 1997 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 LAA07044 for ; Sat, 2 Aug 1997 11:29:33 -0500 (CDT) Received: from wb9mjn-1.ampr.org by wb9mjn.ampr.org (JNOS1.10i) with SMTP id AA14848 ; Sat, 02 Aug 97 09:47:45 UTC Message-ID: <33E35F02.2C71@wb9mjn.ampr.org> Date: Sat, 02 Aug 1997 11:23:30 -0500 From: Don Lemke Reply-To: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu Organization: Ant-Panel Products X-Mailer: Mozilla 3.01Gold (Win95; U) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: pathloss Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hi Glenn and Barry, The idea of the DDMA-WAN, is that it is a MAN network, made up of very short paths. 500 yards to 5 miles max. Say a mean of 1 mile. If there is a hill in the way, u shoot to a neighbor that goes around it, or to the top of it. Glenn, the EME comparison is not a correct comparison, because of the difference in Noise effects. As u point out, pointing at the ground with an EME Array greatly reduces the receive performance, due to terrestrial noise temperature, versus the celetrial noise temperature. In the DDMA-WAN system, ur always looking at terrestrial noise temperature, whether its a grazing or first Fresnel path. Consequently the anectdote that a person trying to use 1 st Fresnel gain for EME, and was unsuccessful does not prove that the gain did not exist, since there is the probability that the terrestrial noise temperature to celestrial noise temperature ratio may indeed have been bigger than 12 dB. 20 dB is a good number for short range grazing paths, based on experience working out this math. But, long range paths will have less grazing path excess attenuation. Since DDMA-WAN is a short path MAN application, the 20 dB is a good number. My experience is this works in practice. Long before I read the Bullington Paper, i had formulated the "45 mile effect" hypothesis. During band openings, less than 30 mile out stations would be less strong than stations at 45 miles, apparently. The effect I believe is due to the near flat earth conditions of a band opening, and the lesser Fresnell loss of longer grazing paths. Allot of the interferance paths will be shadowed anyway. Which would result in a sub-grazing path, and even more than 20 dB excess attenuation. Since antennas are at roof top levels, not up 100 feet or more on towers. The idea is to not exceed the local terrain variation, but to guide around within it. Knap-of-Earth paths, call it. Even so, the versatility of the azimuthal scan antenna, allows for any unigue path problems to be be overcome, post-installation. Its the versatility of the scanning antenna that makes this practical, given the highly random, unpredicatable nature of low altitude MAN propagation. The refraction variabilty is a key problem on 30 mile point-to-point terestrial paths, ala ATT. But, in this network it would not be so key, in regards to fade out of a path. This is because the paths are not over distances where the curve of the earth can be ignored, and thus the power density of the radiation is NOT distrubited vertically, up into the stratifying layers of the atmosphere. A 1 mile path, mid point, with a 30 degree elevation beamwidth antenna shoots RF up at 15 degrees. Making the -3 dB elevation at the midpoint of the path of only 1400 feet. The shorter the path, the more stable it is. Refraction variability will effect reusability. As interferance paths are over distances where the curve of the earth comes into play. Interferance paths are normally occulted, may become grazing, or even first fresnel, in extreme situations. This is why power control is neccassary. U want interferance due to these paths to be less in receive power, due to the distance, and equal, or less transmitter power. But, yes, the capacity of the network will decrease during periods when the effective earth radius is way less than average. Again, the versatility of a azimuthal scanning antenna can allow for the dynamic reconfiguration of the network paths, to help deal with this. You are also right, Glenn, in our present paradigm, that we do not have sites enuf to do what we want. That s why in the DDMA-WAN paradigm, each user has the azimuthal scan antenna, at maximun data rate, and for short range. The goal being, no third-party sites. But a network composed of, and all infrastructure provided by, the user sites. I call this "Infrastructureless design". The large number of antenna/radios makes it practical to manufacture this equipment. When I first started in Packet Radio, I kinda latched onto the link hardware as my main interest. With the expectation that club's of users would want links, and confederations of clubs would want more links. This never happened, to a point where the enuf of the same stuff was being built, to make it economic. Each group had their own idea as to what they wanted, based on a narrow (our club's needs not the regional networks requirements), short term (what we need this year) planning. To get around this, the DDMA-WAN idea is to have maximun data rate equipment, at all sites, and enuf of this same hardware being built, to make its manufacture economic. Barry, as to wether the 6 dB Fresnel Gain, of the 1st Frenell clearance can be put to practical use, that will require real world experience. I am confident that the grazing loss of 20 dB is a REAL thing, and have experienced it directly in our packet networks here. -- 73, Don. AMPRNet : wb9mjn@wb9mjn.ampr.org[44.72.98.19] Internet: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu Website: http://www.qth.com/antpanel From glenn@santarosa.ampr.org Sun Aug 03 21:48:50 1997 Received: from santarosa.ampr.org (santarosa.ampr.org [44.4.40.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id VAA02523 for ; Sun, 3 Aug 1997 21:48:44 -0500 (CDT) Received: from n6gn.ampr.org by santarosa.ampr.org (JNOS1.11x2GW0) with SMTP id AA16046 ; Sun, 03 Aug 97 19:31:10 PDT Message-ID: <33E54303.55D7@santarosa.ampr.org> Date: Sun, 03 Aug 1997 19:48:35 -0700 From: Glenn Elmore Reply-To: glenn@santarosa.ampr.org Organization: The Garage X-Mailer: Mozilla 3.01 (Win95; I; 16bit) MIME-Version: 1.0 To: ss@tapr.org Subject: pathlosses and amateur networking Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Don writes: > The idea of the DDMA-WAN, is that it is a MAN network, made up of > very short paths. 500 yards to 5 miles max. Say a mean of 1 mile. If > there is a hill in the way, u shoot to a neighbor that goes around it, > or to the top of it. > > Glenn, the EME comparison is not a correct comparison, because of > the difference in Noise effects. As u point out, pointing at the ground > with an EME Array greatly reduces the receive performance, due to > terrestrial noise temperature, versus the celetrial noise temperature. > In the DDMA-WAN system, ur always looking at terrestrial noise > temperature, whether its a grazing or first Fresnel path. > > Consequently the anectdote that a person trying to use 1 st > Fresnel gain for EME, and was unsuccessful does not prove that the gain > did not exist, since there is the probability that the terrestrial noise > temperature to celestrial noise temperature ratio may indeed have been > bigger than 12 dB. It's true that the lack of the additional C/N doesn't prove anything (though noise increase at the horizon can be easily measured and I believe that in this particular case there was no additional C indicated). However, in both situations N is a problem that must be dealt with; each has a need for adequate C/N to achieve communication. I don't know of any real links where this potential increase has been exploited. > 20 dB is a good number for short range grazing paths, based on > experience working out this math. But, long range paths will have less My mention of the difficulty in harnassing the 6 dB improvement factor is really quite incidental to my real nemesis. Even the theoretical 20 dB incremental grazing loss factor you mention is not my biggest concern relative to limitations on the kinds of links I think might be practical in an amateur context. If we could, on average, expect paths which were only 20 dB below freespace loss, I think building a high speed amateur network would be, relatively speaking, a piece of cake. I'm sorry to say that I believe that in an amateur context things are much worse than this. > Allot of the interferance paths will be shadowed anyway. Which > would result in a sub-grazing path, and even more than 20 dB excess > attenuation. Since antennas are at roof top levels, not up 100 feet or > more on towers. The idea is to not exceed the local terrain variation, > but to guide around within it. Knap-of-Earth paths, call it. > > > > Even so, the versatility of the azimuthal scan antenna, allows > for any unigue path problems to be be overcome, post-installation. Its > the versatility of the scanning antenna that makes this practical, > given the highly random, unpredicatable nature of low altitude MAN > propagation. I think you already know of my strong belief in the value of antenna directivity for higher rate communications. Focussed/columated energy for communicating information effectively was central to the paper I presented at the 9th CNC as well as the main point emphasized by the 2 Mbps 10 GHz link, the 900/1200 MHz 230 kbps radios I'm currently using as well as the reason I've recently been playing with semiconductor laser diodes and photodetectors. I agree with you that using directional antennas is a big win for RF networks, even better than power control in the amateur context. The benefits of directive antennas apply to both transmit and receive. I very much agree that they are necessary to 'work around' the local terrain and that typical antennas can't be on 100 foot towers. As I stated in the earlier papers, short paths are crucial. So, what's my problem? It's that the incremental losses associated with getting a vhf-lightwave signal between 'typical' amateur locations, or even between a typical location and a typical hilltop repeater or node, are so much more than 20 dB that even with *free* hardware amateur radio can't support a network which can run fast and well enough to provide the necessary 'interesting' applications which would fund it. As a hobby, we're not close enough together, not organized well enough and not interested in it enough to overcome these problems in order to build significant wider area networks. I think that your estimate of .5 to 5 mile paths is reasonable. Unfortunately my experience with paths of this length between residential users is that at UHF there can easily be 40 or more dB incremental loss from local clutter, foliage and intervening terra firma. From microwave-lightwave the situation is even worse. I am presently typing this from the ham shack on a computer that is networked via two 25-mile RF hops before it hits Ethernet and T1 wire line to the Internet. But... I am only 3 miles away from the T1 'landing' and those miles are over virtually flat terrain. Laser light from 150' above the shack here could easily shine directly on an observer 150' above the ground there. But guess what, there's no way I can carry on a connection using this 10W 230 kbps hardware with antennas at heights of 30' and 60' as they presently are if I pointed directly (and avoided the extra 47 mile trip). There's not only 20 but 40-50 dB of incremental loss on the direct shot at 904 MHz! (not to mention the accompanying multipath) I have carefully measured and monitored this 904 MHz hardware over more than a dozen paths almost continually for the last 5-6 years. These paths have included totally unobstructed high level, high <-> low and low <-> low sites. They have been on mountaintops, flatlands, high and low antennas, commercial, residential and uninhabited. I've examined paths >75 miles and ones under 75 feet. I've watched what happens with a big spread of the K index, rain etc. Paths that have worked well are very predictable and well-behaved, even if they are relatively long. On the 25 mile hop out of the shack things measure exactly as predicted by theory. I can even measure antenna gain over it almost as well as I can using a vector network analyzer across the back yard. Even subtle changes like water on the shake roof the antenna here is looking through are measurable. Some of these good paths are from residential locations to hilltops. They have worked similarly well. Good paths are a joy. The gloom is in the paths and sites that haven't worked. These have, I think without exception, been end-user or end-RF(gateway) locations. As such, we had to use what we had, accept the foliage and clutter, and make-do using antenna height and gain as best we could. Very unfortunately for us all, I think these types of paths and sites are in the majority within the amateur world. Perhaps as difficult as the bad paths themselves is the mindset and opinion of amateurs about vhf-and-up propagation. If I suggest to a local ham here that laserlight, 10 GHz ATV, and even perhaps 1.6 GHZ GPS signals won't propagate well through his neighbor's tree, house or local shopping mall he will agree and say something about "line of sight" or maybe "that stuff is black-magic anyway". But if I suggest that the same forces are at work when he uses his 2M or 70 cM HT to work the local repeater he'll say "nah, it's a good path, it's FULL QUIETING". He misses the fact that only perhaps one *millionth* of the signal power a good path provides is reaching the other end. It is full quieting. It's enough, he's happy. I've already gone over much of this on the web pages: http://www.tapr.org/~n6gn and I'm sure you've seen it already. Plots, pictures and text about some of the above mentioned paths and experiments are there. If readers of this are inclined to think "it can't be that bad" please at least have a look. If this all sounds a bit negative I don't want it to be. I'm not trying to run down the idea of using antenna directivity and protocols to adapt to the local terrain. I think it's a great idea and fundamentally necessary. All my higher speed hardware and OCAR effort has required it. I just don't think it is all enough to make wide area high speed RF amateur networking viable with the user density (both kinds I'm afraid), sites, path lengths and budgets we have to work with. Don, I appreciate your interest and perseverence in furthering amateur activities. Thanks for it. Don't take my discouragement personally, I certainly don't want to pour cold water on anyone who's trying to make a difference. I hope my current pessimism is unfounded. 73 Glenn n6gn From stoskopf@tri.net Mon Aug 04 17:09:46 1997 Received: from styx.tri.net (root@styx.tri.net [205.153.244.6]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id RAA25881 for ; Mon, 4 Aug 1997 17:09:43 -0500 (CDT) Received: from mine (d4.tri.net [205.153.244.119]) by styx.tri.net (8.8.3/8.8.3) with ESMTP id RAA19318 for ; Mon, 4 Aug 1997 17:09:26 -0500 Message-ID: <33E65309.16FD3767@tri.net> Date: Mon, 04 Aug 1997 17:09:13 -0500 From: Lawrence Stoskopf Reply-To: stoskopf@tri.net X-Mailer: Mozilla 4.01 [en] (Win95; I) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: [SS:1650] pathloss X-Priority: 3 (Normal) References: <199708011844.AA155851052@hpsadr2.sr.hp.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit > > > WRT the 6 dB gain number, years ago there was considerable discussion > about whether this is *ever* obtainable in any kind of practical > situation. > Some of the early vhf EME attempts hoped to make use of this. > Just heard Mike Staal of KLM talk at CSVHF about working single yagi stations on 6 M EME when they were able to take advantage of the ground gain you are discussing. W6STI's TA program uses ray tracing to explore this also. N0UU From stoskopf@tri.net Mon Aug 04 21:32:46 1997 Received: from styx.tri.net (root@styx.tri.net [205.153.244.6]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id VAA20726 for ; Mon, 4 Aug 1997 21:32:42 -0500 (CDT) Received: from mine (f4.tri.net [205.153.244.128]) by styx.tri.net (8.8.3/8.8.3) with ESMTP id VAA23767 for ; Mon, 4 Aug 1997 21:32:26 -0500 Message-ID: <33E690B0.F5F8367C@tri.net> Date: Mon, 04 Aug 1997 21:32:16 -0500 From: Lawrence Stoskopf Reply-To: stoskopf@tri.net X-Mailer: Mozilla 4.01 [en] (Win95; I) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: [SS:1654] Re: pathloss X-Priority: 3 (Normal) References: <33E65309.16FD3767@tri.net> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit > > > Just heard Mike Staal of KLM Boy did I blow this. Mike was, years ago, one of the owners of KLM and the designer of the KT-34, etc. Now is the owner, designer par exellance (sp?) at M2, (M squared) and continuing his magic. Sorry about the double post. N0UU From Steve_Rokita-C16786@email.mot.com Tue Aug 05 08:04:25 1997 Received: from motgate.mot.com (motgate.mot.com [129.188.136.100]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id IAA15147 for ; Tue, 5 Aug 1997 08:04:24 -0500 (CDT) Received: from pobox.mot.com (pobox.mot.com [129.188.137.100]) by motgate.mot.com (8.8.5/8.6.10/MOT-3.8) with ESMTP id IAA26710 for ; Tue, 5 Aug 1997 08:04:21 -0500 (CDT) Comments: ( Received on motgate.mot.com from client pobox.mot.com, sender Steve_Rokita-C16786@email.mot.com ) Received: from m-il06-r1.mot.com (m-il06-r1.mot.com [129.188.149.149]) by pobox.mot.com (8.8.5/8.6.10/MOT-3.8) with ESMTP id IAA17317 for ; Tue, 5 Aug 1997 08:04:19 -0500 (CDT) Received: from email1.wes.mot.com by m-il06-r1.mot.com with ESMTP; Tue, 5 Aug 1997 08:04:14 -0500 Received: by email1.wes.mot.com with Internet Mail Service (5.0.1457.3) id ; Tue, 5 Aug 1997 07:57:45 -0500 Message-ID: <51F347B016ADD011963200805FC14562C2AF46@email1.wes.mot.com> From: Steve Rokita-C16786 To: "'ss@tapr.org "@pobox.mot.com Subject: RE: Error Condition Re: RE: 1632] Removal from list Date: Tue, 5 Aug 1997 07:57:44 -0500 X-Priority: 3 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.0.1457.3) Content-Type: text/plain listproc@tapr.org > GET ME OFF THAT LIST > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > > I HAD ENOUGH > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > !! > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > > I'M GOING INSANE > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!###################$$$$$$$$$ > $$ > $$$$$$%%%%%%%%%%%%%% > > WHERE IS THE NURSE ?????????? > > > > -----Original Message----- > > From: lehoda01@starbase.spd.louisville.edu%INTERNET > > > [SMTP:lehoda01#064#starbase.spd.louisville.edu%INTERNET@email.mot.com] > > Sent: Monday, July 21, 1997 7:24 PM > > To: ss@tapr.org%INTERNET > > Subject: [SS:1632] Removal from list > > > > Could I please be removed from this list. > > Thanks, > > Lee From Steve_Rokita-C16786@email.mot.com Tue Aug 05 09:19:01 1997 Received: from motgate.mot.com (motgate.mot.com [129.188.136.100]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id JAA18529 for ; Tue, 5 Aug 1997 09:19:00 -0500 (CDT) Received: from mothost.mot.com (mothost.mot.com [129.188.137.101]) by motgate.mot.com (8.8.5/8.6.10/MOT-3.8) with ESMTP id JAA27782 for ; Tue, 5 Aug 1997 09:18:15 -0500 (CDT) Comments: ( Received on motgate.mot.com from client mothost.mot.com, sender Steve_Rokita-C16786@email.mot.com ) Received: from m-il06-r1.mot.com (m-il06-r1.mot.com [129.188.149.149]) by mothost.mot.com (8.8.5/8.6.10/MOT-3.8) with ESMTP id JAA08650 for ; Tue, 5 Aug 1997 09:18:12 -0500 (CDT) Received: from email1.wes.mot.com by m-il06-r1.mot.com with ESMTP; Tue, 5 Aug 1997 09:18:01 -0500 Received: by email1.wes.mot.com with Internet Mail Service (5.0.1457.3) id ; Tue, 5 Aug 1997 09:11:32 -0500 Message-ID: <51F347B016ADD011963200805FC14562C2AF48@email1.wes.mot.com> From: Steve Rokita-C16786 To: "'ss@tapr.org signoff > -----Original Message----- > From: nielsen@primenet.com%INTERNET > [SMTP:nielsen#064#primenet.com%INTERNET@email.mot.com] > Sent: Tuesday, July 22, 1997 10:55 AM > To: ss@tapr.org%INTERNET > Subject: [SS:1635] Re: Removal from list > > On Tue, 22 Jul 1997, Monte Tremont wrote: > > > I am also trying to get disconnected from all @tapr.org that > > constantly clog my Email. Also lately I now receive a copy of > (as BCC) > > every one else that tries to leave this newsgroup. HELP TAPR > !!! > > > > > > ______________________________ Reply Separator > _________________________________ > > Subject: [SS:1632] Removal from list > > Author: Leo E Hodapp at > INTERNET > > Date: 7/21/97 7:23 PM > > > > > > Could I please be removed from this list. > > Thanks, > > Lee > > > >From the directions: > > Send a message to 'listproc@tapr.org' with one of the following lines > as > the message portion: > > unsubscribe > signoff > > Bob > > ---- > Bob Nielsen Internet: nielsen@primenet.com > Tucson, AZ AMPRnet: w6swe@w6swe.ampr.org > AX.25: w6swe@wb7tls.az.usa.noam > http://www.primenet.com/~nielsen From ge@hpsadr2.sr.hp.com Tue Aug 05 11:57:42 1997 Received: from palrel1.hp.com (palrel1.hp.com [156.153.255.235]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id LAA29000 for ; Tue, 5 Aug 1997 11:56:24 -0500 (CDT) Received: from srmail.sr.hp.com (srmail.sr.hp.com [15.4.45.14]) by palrel1.hp.com (8.8.6/8.8.5) with ESMTP id JAA24859 for ; Tue, 5 Aug 1997 09:56:21 -0700 (PDT) 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 AA026090179; Tue, 5 Aug 1997 09:56:20 -0700 Received: by hpsadr2.sr.hp.com (1.37.109.16/15.5+ECS 3.3) id AA222330178; Tue, 5 Aug 1997 09:56:18 -0700 From: Glenn Elmore Message-Id: <199708051656.AA222330178@hpsadr2.sr.hp.com> Subject: pathloss, grounds and groundgain To: ss@tapr.org Date: Tue, 5 Aug 1997 09:56:17 -0800 (PDT) X-Mailer: ELM [version 2.4 PL21] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit N0UU wrote: > Just heard Mike Staal of KLM talk at CSVHF about working single yagi > stations on 6 M EME when they were able to take advantage of the ground > gain you are discussing. > Mike was, years ago, one of the owners of KLM and > the designer of the KT-34, etc. Now is the owner, designer par > exellance (sp?) at M2, (M squared) and continuing his magic. At low enouggh frequencies, where you can get a well controlled ground environment even out to the far field (non absorbing and with irregularites small enough in terms of a wavelength to make specular reflections possible) it can be possible to use groundgain to advantage. In this sense, I suppose if one considers any situation where the ground is used as part of the antenna that "ground gain" is being exploited. Even a ground mounted quarter wave on HF does this to reflect an image element which is underground. Lou Ancieux, wb6nmt, used a rhombic for 6M EME (maybe about the same time Mike, who was also the "M" in KLM, was referring to at CSVHF). Lou's rhombic was on utility poles out in the middle of a very large plain, acutally the Naval Receiving Facility site near Sonoma Calif, and was also using the ground to generate an image. Perhaps whether one views the ground as providing an image signal which can be received or generating an image antenna, the same 6 dB results. However, from either view, the ground has to be mirrorlike at the wavelength of interest. In the original context that Don was suggesting, one of common amateur sites and vhf-microwave wavelength, I doubt that the availability of that kind of a ground can be counted on. In the multitude of measurements I've made of quite a variety of paths at 900 MHz I have often seen signals reach but I've never yet seem them exceed the free space value. Measurement error has been small enough on most occasions that I could have identified it. In any case, the 6 dB "groundgain" value and even the 20 dB grazing number are relatively small potatoes compared to the degradation that from my experience I'd say the majority of amateur sites and paths encounter. Glenn n6gn From wb9mjn@wb9mjn.ampr.org Thu Aug 07 00:57:37 1997 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 AAA13467 for ; Thu, 7 Aug 1997 00:13:46 -0500 (CDT) Received: from wb9mjn-1.ampr.org by wb9mjn.ampr.org (JNOS1.10i) with SMTP id AA14863 ; Mon, 04 Aug 97 09:42:04 UTC Message-ID: <33E5FF76.1DF7@wb9mjn.ampr.org> Date: Mon, 04 Aug 1997 11:12:55 -0500 From: Don Lemke Reply-To: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu Organization: Ant-Panel Products X-Mailer: Mozilla 3.01Gold (Win95; U) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: pathlosses and amateur networking References: <14860@wb9mjn.ampr.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hi Glenn, > Don writes: > > > The idea of the DDMA-WAN, is that it is a MAN network, made up of > > very short paths. 500 yards to 5 miles max. Say a mean of 1 mile. If > > there is a hill in the way, u shoot to a neighbor that goes around it, > > or to the top of it. > > > > Glenn, the EME comparison is not a correct comparison, because of > > the difference in Noise effects. As u point out, pointing at the ground > > with an EME Array greatly reduces the receive performance, due to > > terrestrial noise temperature, versus the celetrial noise temperature. > > In the DDMA-WAN system, ur always looking at terrestrial noise > > temperature, whether its a grazing or first Fresnel path. > > > > > Consequently the anectdote that a person trying to use 1 st > > Fresnel gain for EME, and was unsuccessful does not prove that the gain > > did not exist, since there is the probability that the terrestrial noise > > temperature to celestrial noise temperature ratio may indeed have been > > bigger than 12 dB. > > It's true that the lack of the additional C/N doesn't prove anything > (though noise increase at the horizon can be easily measured and I > believe > that in this particular case there was no additional C indicated). > However, in both situations N is a problem that must be dealt with; each > has a need for adequate C/N to achieve communication. I don't know of > any real links where this potential increase has been exploited. But Glenn, was the N corrected for in the EME anecdote that u related? I m not relying on a 6 dB less path loss. I am relying on a 20 dB between nearest neighbors, and the next reuse (grazing). > > > 20 dB is a good number for short range grazing paths, based on > > experience working out this math. But, long range paths will have less > > My mention of the difficulty in harnassing the 6 dB improvement > factor is really quite incidental to my real nemesis. Even the > theoretical > 20 dB incremental grazing loss factor you mention is not my biggest > concern relative to limitations on the kinds of links I think might > be practical in an amateur context. If we could, on average, expect > paths which were only 20 dB below freespace loss, I think building a > high > speed amateur network would be, relatively speaking, a piece of cake. > I'm sorry to say that I believe that in an amateur context things > are much worse than this. > DDMA-WAN is versatile point to point, Glenn. U simply do not use bad paths. The antenna points to paths that work. The problem with "Hub Master" is that the antennas are fixed, and the enviorment is variable, within the time constant of the enviorment. > > Allot of the interferance paths will be shadowed anyway. Which > > would result in a sub-grazing path, and even more than 20 dB excess > > attenuation. Since antennas are at roof top levels, not up 100 feet or > > more on towers. The idea is to not exceed the local terrain variation, > > but to guide around within it. Knap-of-Earth paths, call it. > > > > > > > > Even so, the versatility of the azimuthal scan antenna, allows > > for any unigue path problems to be be overcome, post-installation. Its > > the versatility of the scanning antenna that makes this practical, > > given the highly random, unpredicatable nature of low altitude MAN > > propagation. > > I think you already know of my strong belief in the value of antenna > directivity for higher rate communications. Focussed/columated energy > for > communicating information effectively was central to the paper I > presented > at the 9th CNC as well as the main point emphasized by the 2 Mbps 10 GHz > link, the 900/1200 MHz 230 kbps radios I'm currently using as well as > the reason I've recently been playing with semiconductor laser diodes > and photodetectors. > > I agree with you that using directional antennas is a big win for > RF networks, even better than power control in the amateur context. The > benefits of directive antennas apply to both transmit and receive. > I very much agree that they are necessary to 'work around' the local > terrain > and that typical antennas can't be on 100 foot towers. As I stated in > the earlier papers, short paths are crucial. > I guess this is where we compare HubMaster, to DDMA-WAN. HubMaster is too expensive. It needs a radio and feedline and port for each direction, and a switch function to hook all those ports up. THe DDMA-WAN needs only one radio/feedline/port for all directions. DDMA-WAN uses nearest neighbor routing, as proposed by Karn and others, and power control DSSS to get maximun reuse out of the resource. HubMaster is a minuature version of commercial point to point. DDMA-WAN is a new concept to Ham Radio, and probably commercial radio, too. > So, what's my problem? It's that the incremental losses associated > with > getting a vhf-lightwave signal between 'typical' amateur locations, or > even between a typical location and a typical hilltop repeater or node, > are so much more than 20 dB that even with *free* hardware amateur radio > can't support a network which can run fast and well enough to provide > the necessary 'interesting' applications which would fund it. As a > hobby, > we're not close enough together, not organized well enough and not > interested > in it enough to overcome these problems in order to build significant > wider area networks. > > I think that your estimate of .5 to 5 mile paths is reasonable. > Unfortunately my experience with paths of this length between > residential > users is that at UHF there can easily be 40 or more dB incremental loss > from local clutter, foliage and intervening terra firma. From > microwave-lightwave the situation is even worse. > > I am presently typing this from the ham shack on a computer that is > networked via two 25-mile RF hops before it hits Ethernet and T1 wire > line > to the Internet. But... I am only 3 miles away from the T1 'landing' > and > those miles are over virtually flat terrain. Laser light from 150' above > the shack here could easily shine directly on an observer 150' above the > ground there. But guess what, there's no way I can carry on a connection > using this 10W 230 kbps hardware with antennas at heights of 30' and 60' > as they presently are if I pointed directly (and avoided the extra 47 > mile trip). There's not only 20 but 40-50 dB of incremental loss on the > direct shot at 904 MHz! (not to mention the accompanying multipath) > This is exactly why point to point networks need to versatile, in amateur service. And to get enuf versatility, we need standard hardware, and that standard hardware needs to have azimuthal scan capability. And to get azimuthal scan capability we need DMF DSSS for rapid lock-up, and nearest neighbor routing, and automatic power control, so as to not waste the resource. It all follows Glen, buts its not Hubmaster. BTW, allot of 904 multipath can be done away with Panel antennas. This is how GSM even has a chance of working, with a 230 KB/s data rate, and that lousy .3 GMSK modulation! > I have carefully measured and monitored this 904 MHz hardware over more > than a dozen paths almost continually for the last 5-6 years. These > paths > have included totally unobstructed high level, high <-> low and low <-> > low > sites. They have been on mountaintops, flatlands, high and low antennas, > commercial, residential and uninhabited. I've examined paths >75 miles > and > ones under 75 feet. I've watched what happens with a big spread of the K > index, rain etc. > > Paths that have worked well are very predictable and well-behaved, even > if they are relatively long. On the 25 mile hop out of the shack things > measure exactly as predicted by theory. I can even measure antenna gain > over it almost as well as I can using a vector network analyzer across > the back yard. Even subtle changes like water on the shake roof the > antenna > here is looking through are measurable. Some of these good paths are > from > residential locations to hilltops. They have worked similarly well. > Good paths are a joy. > This is why a DDMA-WAN controller would need to actively measure path performance to the nearest neighbors, and keep a table of them, continually. It also needs a way to discover new neighbors, and failed neighbors, continually and automatically. We can t assign a Propagation engineer to each Ham s home qth! The DDMA-WAN hardware has to do this Propagation engineer thing, by itself. And this is not too hard to do, as pointed out by the Flexnet system, or even by sending BER test psuedo Random sequences, as demonstrated by K9NG (and yourself?) to the known nearest neighbors. > The gloom is in the paths and sites that haven't worked. These have, > I think without exception, been end-user or end-RF(gateway) locations. > As such, we had to use what we had, accept the foliage and clutter, and > make-do using antenna height and gain as best we could. > Very unfortunately for us all, I think these types of paths and sites > are in the majority within the amateur world. > With DDMA-WAN , you use the shotgun approach, rather than the commercial point to point approach, of site selection. Everybody gets a DDMA-WAN radio/antenna, and the things figure out what paths work, on their own. Then if there is a hole, u fill it by recruiting a new ham, or if need be, a third party site or heck, an Internet link. This way, the Third Party sites are much lower priority, and do not block network construction. This years money is not all sunk into a place that just does not have a path to any of the others. Sites have become impossible to get, and even if u get one, they may get bad, for the intended usage. Our Gurnee site developed a massive power line noise problem, to the point that it was useless. Our Downtown site was a victim of Reaganomics, when new buildings, partially funded by the government, were put up just west of it. It becomes impossible to get into secured locations , when anybody has any time. Let alone getting people with time, to have time all at the same time. DDMA-WAN puts the resources where people WILL work on em. Rather than off in an ivory tower. > Perhaps as difficult as the bad paths themselves is the mindset and > opinion of amateurs about vhf-and-up propagation. If I suggest to > a local ham here that laserlight, 10 GHz ATV, and even perhaps > 1.6 GHZ GPS signals won't propagate well through his neighbor's tree, > house or local shopping mall he will agree and say something about > "line of sight" or maybe "that stuff is black-magic anyway". But if I > suggest that the same forces are at work when he uses his 2M or > 70 cM HT to work the local repeater he'll say "nah, it's a good > path, it's FULL QUIETING". He misses the fact that only perhaps > one *millionth* of the signal power a good path provides is reaching > the other end. It is full quieting. It's enough, he's happy. > > I've already gone over much of this on the web pages: > http://www.tapr.org/~n6gn > and I'm sure you've seen it already. Plots, pictures and text about > some of the above mentioned paths and experiments are there. If > readers of this are inclined to think "it can't be that bad" > please at least have a look. > > If this all sounds a bit negative I don't want it to be. I'm not trying > to run down the idea of using antenna directivity and protocols to adapt > to the local terrain. I think it's a great idea and fundamentally > necessary. Yes, I ve been where You are Glenn, with this. It was this pessimism that led me to reach out, and see if there was a way around it. And, on the TCP newsgroup this DDMA-WAN idea all kinda just gelled. I may have the clearest vission of it, at the moment, but I hardly am totally responsible for it. And it may not even work, anyway. This is really a research type thing. > All my higher speed hardware and OCAR effort has required it. > I just don't think it is all enough to make wide area high speed > RF amateur networking viable with the user density > (both kinds I'm afraid), sites, path lengths and budgets we have to > work with. > > Don, I appreciate your interest and perseverence in furthering amateur > activities. Thanks for it. Don't take my discouragement personally, > I certainly don't want to pour cold water on anyone who's trying to > make a difference. I hope my current pessimism is unfounded. > > 73 > Glenn n6gn > > Thanks for the comments, Glenn. We ve gotten to a point in Amateur Packet, where the traditional radio technigues just lead to a pessimism. I can agree with that! Which is why I am pushing a non-traditional system. -- 73, Don. AMPRNet : wb9mjn@wb9mjn.ampr.org[44.72.98.19] Internet: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu Website: http://www.qth.com/antpanel From mne@cmu.edu Thu Aug 07 10:43:01 1997 Received: from cmu1.acs.cmu.edu (CMU1.ACS.CMU.EDU [128.2.35.186]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id KAA26701 for ; Thu, 7 Aug 1997 10:43:00 -0500 (CDT) Received: from localhost.localdomain (ASYNC6-5.NET.CS.CMU.EDU [128.2.188.6]) by cmu1.acs.cmu.edu (8.8.5/8.8.5) with ESMTP id LAA10676 for ; Thu, 7 Aug 1997 11:42:55 -0400 (EDT) Sender: matt@cmu.edu Message-ID: <33E9ED1B.D0560645@cmu.edu> Date: Thu, 07 Aug 1997 11:43:23 -0400 From: Matt Ettus Organization: CMU X-Mailer: Mozilla 4.01b6C [en] (X11; I; Linux 2.0.30 i686) MIME-Version: 1.0 To: ss@tapr.org Subject: DDMA X-Priority: 3 (Normal) References: <199708070609.BAA28108@tapr.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Assuming that the rest is "Division Multiple Access", what does the first "D" in DDMA stand for? Thanks Matt From wb9mjn@wb9mjn.ampr.org Thu Aug 07 14:52:13 1997 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 OAA17641 for ; Thu, 7 Aug 1997 14:47:21 -0500 (CDT) Received: from wb9mjn-1.ampr.org by wb9mjn.ampr.org (JNOS1.10i) with SMTP id AA14879 ; Thu, 07 Aug 97 13:04:07 UTC Message-ID: <33EA235C.116D@wb9mjn.ampr.org> Date: Thu, 07 Aug 1997 14:34:52 -0500 From: Don Lemke Reply-To: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu Organization: Ant-Panel Products X-Mailer: Mozilla 3.01Gold (Win95; U) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: DDMA Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hi Matt, re: >Assuming that the rest is "Division Multiple Access", what does the > first "D" in DDMA stand for? > > Thanks The first D stands for Directivity. As in the use of antenna directivity to provide for isolated paths. -- 73, Don. AMPRNet : wb9mjn@wb9mjn.ampr.org[44.72.98.19] Internet: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu Website: http://www.qth.com/antpanel From glenn@santarosa.ampr.org Thu Aug 07 23:56:07 1997 Received: from santarosa.ampr.org (santarosa.ampr.org [44.4.40.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id XAA24547 for ; Thu, 7 Aug 1997 23:56:05 -0500 (CDT) Date: Thu, 07 Aug 97 21:24:10 PST Message-Id: <16088@santarosa.ampr.org> From: glenn@santarosa.ampr.org (Glenn Elmore) To: ss@tapr.org Subject: pathloss and DDMA Don, Thanks for the reply. Sorry to be slow to get back but I guess my entry in the distribution disappeared. I guess our difference is that I am even more pessimistic than you understand. After the last several years, which have certainly had a degree of success in shipping packets around, I am coming to the opinion that the typical amateur location has *no* paths which are good enough to support enough information to develop and maintain the necessary h/w and infrastructure. I'll allow the limit of directionality, use the highest gain antenna or any antenna of your choice which you can practically install at an amateur site and try to find a neighbor to work. Period. Yes, there will be a few but for the most part you won't be able to support enough data to make the whole thing float. At this point if you can't at least get 10 X 56 kbps to the user you'll not have any neighbors who want to participate within quite a large distance, on average. I maintain that the density is so low, hams per unit area, that the 40-70 dB excess loss that exists without large towers (much more than 60' around here) kills the thing. I have extra radios sitting on the floor capable of .5 Mbps but no place to deploy them. I find no place in the EM spectrum where practically sized and located emitters and receptors can communicate at high enough rate to support their own installation (even if we had applications which were somehow much more appealing than the current phoneline competition). I can build hardware that can do many hundreds of Mbps over significant distance if it would do any good. I can't provide the kinds of paths that are necessary to make it work even with complete flexibility to chose the antenna(s). To see what I'm talking about, make a list of all users within 25 miles or so who would be willing to committ to an amateur RF network assuming some level of performance, you name what you think will get them to donate $500 and >2 hours a week. Now, *carefully* analyze the best set of paths between them including extreme detail as to their antenna locations and heights paying particular attention to elevation profiles and intervening foliage, clutter, buildings etc. Next use Longley-Rice, or better yet go *measure* the pathloss between them all (make an measurement of the multipath while you're at it even though we'll assume DSSS to fix it). Now apply Shannon and find what datarate you can support. It will be *very* disappointing if it's anything like I have seen. Maybe I'm just in need of a break but I see no way that any protocol or scheme can beat Shannon and at this point I think SHannon has us beat given our resources and motivation within AR. Glenn n6gn From frussle@erols.com Fri Aug 08 08:06:07 1997 Received: from smtp3.erols.com (smtp3.erols.com [205.252.116.103]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id IAA09341 for ; Fri, 8 Aug 1997 08:06:06 -0500 (CDT) Received: from col-as8s49.erols.com (col-as8s49.erols.com [207.172.129.240]) by smtp3.erols.com (8.8.6/8.8.5) with SMTP id JAA00131; Fri, 8 Aug 1997 09:06:02 -0400 From: frussle@erols.com (Jake Brodsky) To: ss@tapr.org Subject: Re: [SS:1662] pathloss and DDMA Date: Fri, 08 Aug 1997 13:05:20 GMT Organization: Immature Radio Station AB3A Reply-To: frussle@erols.com Message-ID: <33ec0a06.633030@smtp.erols.com> References: <16088@santarosa.ampr.org> In-Reply-To: <16088@santarosa.ampr.org> X-Mailer: Forte Agent 1.5/32.451 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable On Thu, 7 Aug 1997 23:56:53 -0500 (CDT), Glenn wrote: >I guess our difference is that I am even more pessimistic than you >understand. After the last several years, which have certainly had >a degree of success in shipping packets around, I am coming to >the opinion that the typical amateur location has *no* paths >which are good enough to support enough information to develop >and maintain the necessary h/w and infrastructure.=20 I've been following this thread for some time. And I agree with this statement. I work in a communications and telemetry section within a water utility. Among other things, we have built and maintain a T3 6 GHz industrial network. Ham Radio is never going to compete with this scale of money and technology. Given the way that bandwidth usage has exploded, we hams don't have the spectrum, the sites, or the technology to keep up. So are we "doomed"? I think not. > I'll allow the limit of directionality, use the highest gain antenna >or any antenna of your choice which you can practically install at >an amateur site and try to find a neighbor to work. Period.=20 >Yes, there will be a few but for the most part you won't be able >to support enough data to make the whole thing float. You're right. Dishes are expensive to purchase and even more expensive to put on a tower (wind-loading). Radios are even more difficult to build and align for the average ham. > At this point if you can't at least get 10 X 56 kbps to the user >you'll not have any neighbors who want to participate within quite >a large distance, on average. I maintain that the density is so low, >hams per unit area, that the 40-70 dB excess loss that exists without >large towers (much more than 60' around here) kills the thing. True, but do we really need this kind of performance? Is this what Ham Radio is all about? > I have extra radios sitting on the floor capable of .5 Mbps but >no place to deploy them.=20 > I find no place in the EM spectrum where practically sized and >located emitters and receptors can communicate at high enough rate >to support their own installation (even if we had applications which >were somehow much more appealing than the current phoneline = competition). > I can build hardware that can do many hundreds of Mbps over = significant >distance if it would do any good. I can't provide the kinds of paths >that are necessary to make it work even with complete flexibility to >chose the antenna(s). > To see what I'm talking about, make a list of all users within 25 = miles >or so who would be willing to committ to an amateur RF network assuming >some level of performance, you name what you think will get them >to donate $500 and >2 hours a week. Now, *carefully* analyze the best >set of paths between them including extreme detail as to their antenna >locations and heights paying particular attention to elevation profiles >and intervening foliage, clutter, buildings etc. Next use Longley-Rice, >or better yet go *measure* the pathloss between them all (make an >measurement of the multipath while you're at it even though we'll assume >DSSS to fix it). Now apply Shannon and find what datarate you can=20 >support. It will be *very* disappointing if it's anything like I >have seen. > Maybe I'm just in need of a break but I see no way that any >protocol or scheme can beat Shannon and at this point I think >SHannon has us beat given our resources and motivation within AR. No offense Glenn, but maybe your expectations are too high. Ham radio has never been about throughput. In fact, it's just the opposite: Ever since the hobby began, throughput and usefulness have deliberately been limited so that we don't step on any of the big common carrier interests. =20 What we're about is training, study, experimentation, and (most of all) having fun. Practicality, dependability, and capacity are nearly undesirable features if they become commonplace. Did you think SSTV was ever supposed to be practical? What good has amateur RTTY ever been to the public as a whole? EME? =20 Ham Radio was never intended to be a substantial subnet for telegrams, telephony, or the Internet. True, we probably won't be able to match the bandwidth, the reliability, or the availability of commercial services. We'll never even get close. =20 Spread Spectrum communications should be about developing medium to slow speed (<100 kbps), long haul, autonomous radio station gear. We should be developing adaptable radio gear so that we can brag about how little we used to get across very lossy paths. In this respect, bandwidth and power use should be adjustable so that we can work the longest path. Our services to the public in an emergency capacity has always been a function of our independence of a network. When disaster or war destroys common carrier networks, we become a useful medium of communication by virtue of our numbers, our independence of those networks, and technical knowledge/simplicity. Using those features we hams can communicate long after most public common carriers cease functioning. That's what our hobby is about. I make my living building big, expensive, and reliable communications networks. Why would anyone do this for free? 73, Jake Brodsky, AB3A mailto:frussle@erols.com "Beware of the massive impossible!" From jeff@mich.com Fri Aug 08 11:57:55 1997 Received: from home.nuge.com (home.nuge.com [152.160.156.254]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id LAA19265 for ; Fri, 8 Aug 1997 11:57:50 -0500 (CDT) Received: from alfalfa (alfalfa.mich.com [198.108.18.18]) by home.nuge.com (8.7.1/8.7.1) with SMTP id MAA07186 for ; Fri, 8 Aug 1997 12:57:54 -0400 Message-Id: <3.0.3.32.19970808125349.037b13f0@mail.mich.com> X-Sender: jeff@mail.mich.com (Unverified) X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.3 (32) Date: Fri, 08 Aug 1997 12:53:49 -0400 To: ss@tapr.org From: Jeff King Subject: 'Ham' data infrastructure (was: pathloss and DDMA) In-Reply-To: <33ec0a06.633030@smtp.erols.com> References: <16088@santarosa.ampr.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" At 08:07 AM 8/8/97 -0500, Jake Brodsky wrote: >On Thu, 7 Aug 1997 23:56:53 -0500 (CDT), Glenn wrote: > >>I guess our difference is that I am even more pessimistic than you >>understand. > >I've been following this thread for some time. Me too. I make a comment on this about once every 6 months or so. Its time again. Please don't take anything to personal as its more general spouting as opposed to personal commentary. > >> At this point if you can't at least get 10 X 56 kbps to the user >>you'll not have any neighbors who want to participate within quite >>a large distance, on average. I maintain that the density is so low, >>hams per unit area, that the 40-70 dB excess loss that exists without >>large towers (much more than 60' around here) kills the thing. > >True, but do we really need this kind of performance? Is this what >Ham Radio is all about? I believe Glenn is talking about a decent data network. I'd say this is a minimum requirement. At this point I'm only doing 115kbps on a daily basis on amateur radio (STA) and am interested in going faster shortly. > >No offense Glenn, but maybe your expectations are too high. Ham radio >has never been about throughput. In fact, it's just the opposite: >Ever since the hobby began, throughput and usefulness have >deliberately been limited so that we don't step on any of the big >common carrier interests. This is the problem with "ham radio". I'm a AMATEUR RADIO operator and I don't have any preconceptions of what I am capable of doing. I just go do it. I've not been a 'ham' for at least 10 years although I use my amateur license on a daily basis. If you want to operate 150baud rtty then have at it. Just don't try to stop me from my 'high' throughput experimentation/operations. > >Ham Radio was never intended to be a substantial subnet for telegrams, >telephony, or the Internet. Hope this isn't a rule or I'll be in big trouble ;-) >True, we probably won't be able to match >the bandwidth, the reliability, or the availability of commercial >services. We'll never even get close. We certainly can match or exceed the endpoint bandwidth of many commercial services on a individual basis. As the rest of your statement requires the resources of a organization to archive, I'll have to agree with you at this time. > >Spread Spectrum communications should be about developing medium to >slow speed (<100 kbps), long haul, autonomous radio station gear. We >should be developing adaptable radio gear so that we can brag about >how little we used to get across very lossy paths. In this respect, >bandwidth and power use should be adjustable so that we can work the >longest path. While I think high speed should be part of this equation, I agree with this. >That's what our hobby is about. I make my living building big, >expensive, and reliable communications networks. Why would anyone do >this for free? No-one should give their labor for free. This amazes me many times that so many are willing to short change themselves in this regard. I see a sizable market in high speed amateur radio if it could only be marketed to the right people. Most of these people aren't in the amateur service right now. And that brings me to my point. Glenn, you appear to be selling and/or basing your network plans on the existing 'ham' population. Respectfully, I think this is the basis for long term failure. While things may be different were you live, when I have done SS presentations to 'ham' clubs, I would generally get glazed over stares from most of the 'hams'. A few would say they are interested in operating this new 'mode'. One amateur might get "the vision". The rest of the 'hams' were interested in getting onto contesting or what 'bad ham' is doing on the repeater. When I would do similar demonstrations at computer clubs a significant portion of the group could see what SS could do for them. I would be surrounded after the meeting by people asking in depth questions. When it comes to high speed networking, and in particular SS, most 'hams' don't have "the vision". What is "the vision"? It is the ability not to see spread spectrum as simply a new mode but a completely new paradigm for the usage of the radio spectrum. With the (hoped for) changes in the SS rules, the availability of cheap Part 15 equipment and the no-code tech license, I think the future of amateur SS lies in the computer experimenters. In other words, we should stop trying to sell ice cubes to Eskimos. -Jeff King WB8WKA From frussle@erols.com Fri Aug 08 15:26:21 1997 Received: from smtp2.erols.com (smtp2.erols.com [205.252.116.102]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id PAA09866 for ; Fri, 8 Aug 1997 15:26:16 -0500 (CDT) Received: from col-as8s53.erols.com (col-as8s53.erols.com [207.172.129.244]) by smtp2.erols.com (8.8.6/8.8.5) with SMTP id QAA00949 for ; Fri, 8 Aug 1997 16:26:10 -0400 (EDT) From: frussle@erols.com (Jake Brodsky) To: ss@tapr.org Subject: Re: [SS:1664] 'Ham' data infrastructure (was: pathloss and DDMA) Date: Fri, 08 Aug 1997 20:25:25 GMT Organization: Immature Radio Station AB3A Reply-To: frussle@erols.com Message-ID: <33eb6879.949874@smtp.erols.com> References: <3.0.3.32.19970808125349.037b13f0@mail.mich.com> In-Reply-To: <3.0.3.32.19970808125349.037b13f0@mail.mich.com> X-Mailer: Forte Agent 1.5/32.451 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable On Fri, 8 Aug 1997 12:01:27 -0500 (CDT), you wrote: >At 08:07 AM 8/8/97 -0500, Jake Brodsky wrote: >>On Thu, 7 Aug 1997 23:56:53 -0500 (CDT), Glenn wrote: >> >>>I guess our difference is that I am even more pessimistic than you >>>understand.=20 > > > >> >>I've been following this thread for some time. > >Me too. I make a comment on this about once every 6 months or so. Its >time again. Please don't take anything to personal as its more general >spouting as opposed to personal commentary. > >> >>> At this point if you can't at least get 10 X 56 kbps to the user >>>you'll not have any neighbors who want to participate within quite >>>a large distance, on average. I maintain that the density is so low, >>>hams per unit area, that the 40-70 dB excess loss that exists without >>>large towers (much more than 60' around here) kills the thing. >> >>True, but do we really need this kind of performance? Is this what >>Ham Radio is all about? > >I believe Glenn is talking about a decent data network. I'd say this >is a minimum requirement. At this point I'm only doing 115kbps on A minimum requirement for what? Just what do you envision building? >a daily basis on amateur radio (STA) and am interested in going faster >shortly.=20 >>No offense Glenn, but maybe your expectations are too high. Ham radio >>has never been about throughput. In fact, it's just the opposite: >>Ever since the hobby began, throughput and usefulness have >>deliberately been limited so that we don't step on any of the big >>common carrier interests. > >This is the problem with "ham radio". I'm a AMATEUR RADIO operator and >I don't have any preconceptions of what I am capable of doing. I just >go do it. I've not been a 'ham' for at least 10 years although I use >my amateur license on a daily basis. If you want to operate 150baud >rtty then have at it. Just don't try to stop me from my 'high' = throughput >experimentation/operations. I'm not advocating that 150 baud RTTY is good enough for everyone. What I'm trying to say is that organized trunked systems are not likely to get funded in what is, after all, an Amateur (unpaid) operation. =20 >> >>Ham Radio was never intended to be a substantial subnet for telegrams, >>telephony, or the Internet. > >Hope this isn't a rule or I'll be in big trouble ;-) I was writing about intent, not regulation... >>True, we probably won't be able to match >>the bandwidth, the reliability, or the availability of commercial >>services. We'll never even get close. > >We certainly can match or exceed the endpoint bandwidth of many=20 >commercial services on a individual basis. As the rest of your >statement requires the resources of a organization to archive, I'll >have to agree with you at this time. I'm not sure what you mean by this statement. I can purchase an ISDN line from my phone company and beat even that rate, with less effort and less money. If ham operators manage to beat the access speeds to most Internet providers, it won't be for long. ADSL and other technologies can put radio capacity to shame. Face it, we don't have a prayer of matching the reliability and bandwidth of landline communications. =20 >>Spread Spectrum communications should be about developing medium to >>slow speed (<100 kbps), long haul, autonomous radio station gear. We >>should be developing adaptable radio gear so that we can brag about >>how little we used to get across very lossy paths. In this respect, >>bandwidth and power use should be adjustable so that we can work the >>longest path. > >While I think high speed should be part of this equation, I agree with >this. I think high speed would be nice too, but only as a "lets see what it takes to do this" kind of deal, not as a goal in itself... >>That's what our hobby is about. I make my living building big, >>expensive, and reliable communications networks. Why would anyone do >>this for free? > >No-one should give their labor for free. This amazes me many times that >so many are willing to short change themselves in this regard. I see >a sizable market in high speed amateur radio if it could only be >marketed to the right people. Most of these people aren't in the >amateur service right now. And that brings me to my point. > >Glenn, you appear to be selling and/or basing your network plans >on the existing 'ham' population. Respectfully, I think this is the=20 >basis for long term failure. While things may be different were you=20 >live, when I have done SS presentations to 'ham' clubs, I would=20 >generally get glazed over stares from most of the 'hams'. A few would=20 >say they are interested in operating this new 'mode'. One amateur might >get "the vision". The rest of the 'hams' were interested in getting=20 >onto contesting or what 'bad ham' is doing on the repeater. When=20 >I would do similar demonstrations at computer clubs a significant=20 >portion of the group could see what SS could do for them. I would >be surrounded after the meeting by people asking in depth questions. > >When it comes to high speed networking, and in particular SS, most >'hams' don't have "the vision". What is "the vision"? It is the=20 >ability not to see spread spectrum as simply a new mode but a=20 >completely new paradigm for the usage of the radio spectrum. >With the (hoped for) changes in the SS rules, the availability of >cheap Part 15 equipment and the no-code tech license, I think the >future of amateur SS lies in the computer experimenters. > >In other words, we should stop trying to sell ice cubes to >Eskimos. Jeff, what do you envision for the future of Amateur (ham) Radio? A computer hobbyist's network? For what? So they can send radio mail in addition to e-mail? So they can post messages to HamNet like we do in USENET? So they can send a JPEG coast to coast only a few orders of magnitude slower than the far less expensive Internet? =20 I have always contended this hobby is about radio. Radio design, radio technology, radio construction, radio installation, radio operation, radio coordination, etc.... Where is the Computer in Amateur Radio? Sure you can use one with a radio. I can also fly an airplane with a radio. I can use a video camera with a radio (an ATV transmitter for sending video). That doesn't mean I market the hobby to aviators or TV fanatics. There is only one reason our hobby still exists: We train the next generation of scientists, engineers, technicians, and yes, technology managers, about the state of the art of radio. In that light, spread spectrum is just another facet of radio. We have a training ground. Speed and utility are not the issues. They never were; and chances are they never will be allowed to become one, either. Hopefully, we're doing all this because we want to learn about radio --not because we're trying to build Internet II. =20 This hobby will never grow much beyond impracticality. It was never supposed to. It's nice to see that you have managed to find some utility in your learning efforts. But the hobby as a whole will never be more than a testing or a learning ground. The day it does, is the day you'll call it something else: A Job. 73, Jake Brodsky, mailto:frussle@erols.com "Nearly fifty percent of all graduates came from=20 the bottom half of the class." From mne@cmu.edu Fri Aug 08 17:26:14 1997 Received: from cmu1.acs.cmu.edu (CMU1.ACS.CMU.EDU [128.2.35.186]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id RAA18277 for ; Fri, 8 Aug 1997 17:26:12 -0500 (CDT) Received: from localhost.localdomain (ANNEX-1.SLIP.ECE.CMU.EDU [128.2.236.1]) by cmu1.acs.cmu.edu (8.8.5/8.8.5) with ESMTP id SAA23589 for ; Fri, 8 Aug 1997 18:25:23 -0400 (EDT) Sender: matt@cmu.edu Message-ID: <33EB9CF3.732A597E@cmu.edu> Date: Fri, 08 Aug 1997 18:25:55 -0400 From: Matt Ettus Organization: CMU X-Mailer: Mozilla 4.01b6C [en] (X11; I; Linux 2.0.30 i686) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: N6GN's comments X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Your comments on the lack of sufficient density of seriously interested ham is quite true. When we can't even convince people to use TCP/IP instead of NetROM or ROSE or even nothing at all... On the other hand, what about completely avoiding the bad paths issue... Why not a satellite based system, a la VSAT. What about a CDMA VSAT system -- it solves the density problem, the bad paths problem, the routing problem, the coverage problem, etc. Obviously its not a cheap/simple alternative in the near term, but we could get some serious throughput with low power and small dishes. Maybe 10Ghz Uplink, 24 GHz down. Thats 800Mhz of pretty much unused spectrum. No interference problems either... 73 Matt Ettus N2MJI mne@cmu.edu From jeff@mich.com Fri Aug 08 21:23:34 1997 Received: from home.nuge.com (home.nuge.com [152.160.156.254]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id VAA14362 for ; Fri, 8 Aug 1997 21:23:29 -0500 (CDT) Received: from alfalfa (alfalfa.mich.com [198.108.18.18]) by home.nuge.com (8.7.1/8.7.1) with SMTP id WAA09743 for ; Fri, 8 Aug 1997 22:23:39 -0400 Message-Id: <3.0.3.32.19970808221925.034b0b50@mail.mich.com> X-Sender: jeff@mail.mich.com (Unverified) X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.3 (32) Date: Fri, 08 Aug 1997 22:19:25 -0400 To: ss@tapr.org From: Jeff King Subject: Re: 'Ham' data infrastructure (was: pathloss and DDMA) In-Reply-To: <33eb6879.949874@smtp.erols.com> References: <3.0.3.32.19970808125349.037b13f0@mail.mich.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" At 03:32 PM 8/8/97 -0500, Jake Brodsky wrote: > >>>True, we probably won't be able to match >>>the bandwidth, the reliability, or the availability of commercial >>>services. We'll never even get close. >> >>We certainly can match or exceed the endpoint bandwidth of many >>commercial services on a individual basis. As the rest of your >>statement requires the resources of a organization to archive, I'll >>have to agree with you at this time. > >I'm not sure what you mean by this statement. I can purchase an ISDN >line from my phone company and beat even that rate, with less effort >and less money. Glenn was referring to 10X56Kbaud (560kbps), I was thinking of a off the shelf wavelan board at 1megabit per second. A dual ISDN only provides 128Kbps and presently cannot be operated mobile. I'm sure you could make the same statement about the majority of amateur radio... that is I can operate 'DX' far cheaper by calling someone on the phone, I can use the 'autopatch' far cheaper by purchasing a cell phone etc. However, in the case of wireless Internet access, a case can be made that wireless is cheaper in certain instances. In particular third world countries. Don't believe me, ask Dewayne about that. > >If ham operators manage to beat the access speeds to most Internet >providers, it won't be for long. ADSL and other technologies can put >radio capacity to shame. Face it, we don't have a prayer of matching >the reliability and bandwidth of landline communications. Radio does have advantages in certain applications however. >> >>In other words, we should stop trying to sell ice cubes to >>Eskimos. > >Jeff, what do you envision for the future of Amateur (ham) Radio? A >computer hobbyist's network? For what? So they can send radio mail >in addition to e-mail? So they can post messages to HamNet like we do >in USENET? So they can send a JPEG coast to coast only a few orders >of magnitude slower than the far less expensive Internet? I'm not going to get drawn into a "the Internet is not ham radio" argument when that is not even what I was discussing. I'll discuss one possible future of amateur radio later though. > >I have always contended this hobby is about radio. Radio design, >radio technology, radio construction, radio installation, radio >operation, radio coordination, etc.... Where is the Computer in >Amateur Radio? This is certainly your prerogative, but did you realize this is the spread spectrum mailing list? Sorry but lots of embedded controllers (computers) running around here. You also might want to take a look at modern HF radios and the advantage of DSP in them. Soon (or already) you'll find your modern radio is more computer then radio. >There is only one reason our hobby still exists: We train the next >generation of scientists, engineers, technicians, and yes, technology >managers, about the state of the art of radio. In that light, spread >spectrum is just another facet of radio. Spread spectrum _IS_ the future of radio. >We have a training ground. >Speed and utility are not the issues. They never were; and chances >are they never will be allowed to become one, either. Hopefully, >we're doing all this because we want to learn about radio --not >because we're trying to build Internet II. Your arguments are not borne out historically. The ARRL was formed to help relay messages across the country more quickly. Speed and utility are paramount. "Internet II", as you put it, is simply a application some amateurs might want to participate in. You don't have to. I don't have to work DX, talk on repeaters, or any other multitude of interests that is amateur radio. Its called choice. > >This hobby will never grow much beyond impracticality. It was never >supposed to. It's nice to see that you have managed to find some >utility in your learning efforts. But the hobby as a whole will never >be more than a testing or a learning ground. The day it does, is the >day you'll call it something else: A Job. > >73, >Jake Brodsky, mailto:frussle@erols.com >"Nearly fifty percent of all graduates came from >the bottom half of the class." A Job? I love my job. Don't you? I presently design ITS communications systems as well as embedded controller systems. I'd love to see the same thing going on in amateur radio. Amateur radio needs to be vibrant and commercially viable. We need to make friends of the commercial folks, not enemies as we are so inclined to. I'd like to see 4 million new hams operating wireless spread spectrum on the VHF/UHF/Microwave bands. Intelligent computer controlled radios will make accommodating this new load easy. I hope that your vision of amateur radio doesn't continue or I fear the service will be passed to those that can better make use of the resource. Its no longer the cold war, we have robust cellular (AMPS, IS-95 and PCS) systems, and communications has taken on a whole new meaning to socieity. Lets just agree to disagree and leave it at that. -Jeff From wb9mjn@wb9mjn.ampr.org Fri Aug 08 22:28:59 1997 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 WAA18558 for ; Fri, 8 Aug 1997 22:16:35 -0500 (CDT) Received: from wb9mjn-1.ampr.org by wb9mjn.ampr.org (JNOS1.10i) with SMTP id AA14887 ; Fri, 08 Aug 97 12:03:22 UTC Message-ID: <33EB66CC.4EB7@wb9mjn.ampr.org> Date: Fri, 08 Aug 1997 13:34:52 -0500 From: Don Lemke Reply-To: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu Organization: Ant-Panel Products X-Mailer: Mozilla 3.01Gold (Win95; U) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: pathloss and DDMA Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hi Glenn, > I guess our difference is that I am even more pessimistic than you > understand. After the last several years, which have certainly had > a degree of success in shipping packets around, I am coming to > the opinion that the typical amateur location has *no* paths > which are good enough to support enough information to develop > and maintain the necessary h/w and infrastructure. > I'll allow the limit of directionality, use the highest gain antenna > or any antenna of your choice which you can practically install at > an amateur site and try to find a neighbor to work. Period. > Yes, there will be a few but for the most part you won't be able > to support enough data to make the whole thing float. This is very true. So how is this changed? I see DDMA-WAN as the answer to it. Not overnight. Not this decade, but eventually. Some time ago, the president of our local packet club did a search of all the hams in the 60540 zip code (main zip code in my home town - Naperville, IL). The result was quite suprising. The 60540 zip code is an area 4 miles by 2 miles, and there were over 1000 hams. Naperville has 3 other large zip codes as well, all in an area that is 6 by 3 miles. Naperville is about average for the population densities, of the far western Chicago suburbs. Aurora and Bolingbrook to the west and south have more population density. Wheaton/Warrenville and Lisle/Woodridge to the north and east have less population density. There are plenty of hams to do this, IF a good fraction of them participate. Two-Way VHF is a good example. The first repeaters were put on primarily so that hams could talk while they were in their cars. That 5000 dollar repeater, and 1000 dollar trunk mounted Micor were not cheap back then. But, that did not stop hams from doing it. And it all grew from there. Initially, there were not many repeaters. There was not many users. And most hams would say, that it would not amount to much, because most hams were experience brain fade, from being on HF all night. So, say somebody puts on an Internet gateway, and a point-to-point , DSSS link to their home qth. Say Path wise, they get lucky. And because of its point-to-point and DSSS nature, its great. I think we ve seen examples of this so far from several SS group participants, already. But this is an ecomonic dead end. Nobody else can participate, and eventually politics or entropy destroy the arrangement. Politics may make that gateway go away. Entropy may destroy a computer, or radio, before a new one can be funded by the individual. How is using a DDMA-WAN link different in this situation? The Internet gateway, and home qth site has a chance of being in range of somebody else. That third station can now participate, simply by buying his own gear. No modification is needed to the first two stations. The original stations have no extra point-to-point gear is requirment and no extra cost. The third station can just do it, without causing any problems for the first two stations, or waiting for those stations to be improved. 3 stations have a greater chance of being in range of a forth, than 2. 4 stations have a greater chance of being in range of the next participant than 3 stations. And so on. Just like several hundred repeaters have a bigger chance of having one being in range of EVERY ham in a metropolitan area, than the one original 2 meter repeater did back in 1955. And similarily, its no longer a matter of IF one buys the gear, will he be in range. But what are MY nearest neighbors. Just as now, we buy a 2 meter handheld, and go out and find THE closest repeaters. A group of tens of DDMA-WAN sites , all in a network, has a much greater chance of getting a new gateway, if one goes away. Or maintaining network linkage, if a station moves away, or gets zapped by lightning. Or having the resources to put on a third party site, to get over a nasty hill. No point-to-point is not workable in a Ham Radio enviorment. But something like DDMA-WAN has a chance. Its both socially, and physically tenable. Indeed, its because its socially tenable, that it becomes physically tenable, for the arbitrary user site. Whereas point-to-point is only tenable if the physics of a particular path work out. -- 73, Don. AMPRNet : wb9mjn@wb9mjn.ampr.org[44.72.98.19] Internet: wb9mjn%wb9mjn.ampr.org@uugate.aim.utah.edu Website: http://www.qth.com/antpanel From wd5ivd@tapr.org Fri Aug 08 22:31:39 1997 Received: from [208.134.134.40] ([208.134.134.40]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id WAA19330; Fri, 8 Aug 1997 22:31:18 -0500 (CDT) Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Fri, 8 Aug 1997 22:24:44 -0500 To: "TAPR-BB list mailing", "TAPR APRS SIG", "HF SIG list mailing", "NETSIG list mailing", "BBS SIG list mailing", " Spread Spectrum ", " TAPR SYS ", " tapr-tnc ", aprs-fl@tapr.org, " tacgps ", TAPR Regional Freq , " TAPR/AMSAT DSP ", " DSP-93 Build ", " TPRS Board " From: "Greg Jones, WD5IVD" Subject: TAPR Server to be down 8/9/97 I just received a call informing us that the building location where the TAPR.ORG server is located will be without power tomorrow for most of the day. We will be shutting down the server between 7am and 8am and don't expect that it will be available until late Saturday evening when power is restored. Cheers - Greg, WD5IVD ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd ----- "Before you become too entranced with gorgeous gadgets and mesmerizing video displays, let me remind you that information is not knowledge, knowledge is not wisdom, and wisdom is not foresight. Each grows out of the other and we need them all." -Arthur C. Clarke From john.cummings@juno.com Fri Aug 08 23:47:00 1997 Received: from m4.boston.juno.com (m4.boston.juno.com [205.231.101.198]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id XAA26187 for ; Fri, 8 Aug 1997 23:46:58 -0500 (CDT) Received: (from john.cummings@juno.com) by m4.boston.juno.com (queuemail) id AsS13530; Sat, 09 Aug 1997 00:45:58 EDT To: ss@tapr.org Date: Fri, 8 Aug 1997 23:38:54 -0500 Subject: Re: N6GN's comments Message-ID: <19970808.234551.7030.0.john.cummings@juno.com> References: <33EB9CF3.732A597E@cmu.edu> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 0-19,26-27,32-33,39-40,42-47 From: john.cummings@juno.com (John A Cummings) On Fri, 8 Aug 1997 17:28:00 -0500 (CDT) Matt Ettus writes: > >On the other hand, what about completely avoiding the bad paths >issue... > >Why not a satellite based system, a la VSAT. What about a CDMA VSAT >system -- it solves the density problem, the bad paths problem, the >routing problem, the coverage problem, etc. > >Obviously its not a cheap/simple alternative in the near term, but we >could get some serious throughput with low power and small dishes. > >73 >Matt Ettus >N2MJI >mne@cmu.edu > I agree. I've been thinking about it all day, and I came to the same conclusion. Make everyone's path the same, standardize the dish mounted T/R unit, plan on a readily available 3 meter TVRO cast-off dish, etc. My latest thoughts include everyone have a high bps receiver, while uplink data rate could depend dish size and xmtr power. DirectPC data rates with bigger receive antennas (300-400 Kbps), and lower than DBS transponder power! To keep this on topic, have the higher rate QSO's spread their bandwidth wider, so that the SS signals arriving at the geosynchronous satellite have a nearly uniform power per MHz. Some sort of arrangement that does not require "master" stations to carry out the slot reservations of a TDMA system, so that we can maintain amateur anarchy. I remember about ten to thirteen years ago a proposal (by a WD8???) of putting in a amateur radio transponder aboard a commercial C-band satellite, that we'd get a good fit with the existing waveguide using 5.8 GHz uplink and 3.5 GHz downlink with a 10 MHz transponder. I recall something about New Jersey, so would that have been Philco Ford Aerospace, I think (don't know where they've been merged to). THIS is something that I would join TAPR and AMSAT for, to plan and build and donate toward! John A. Cummings N4BKN 1502 Railton Road john.cummings@juno.com Memphis, TN 38111-3802 From wd5ivd@tapr.org Mon Aug 11 00:03:23 1997 Received: from [208.134.134.40] ([208.134.134.40]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id AAA03656; Mon, 11 Aug 1997 00:03:10 -0500 (CDT) Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 11 Aug 1997 00:00:32 -0500 To: "TAPR-BB list mailing", "HF SIG list mailing", " Spread Spectrum " From: "Greg Jones, WD5IVD" Subject: 1997 DCC Call for Papers (Reminder) Call for Papers 1997 ARRL and TAPR Digital Communications Conference October 10-12, 1997 Baltimore, Maryland (minutes from BWI airport) Web: http://www.tapr.org/dcc ----- It's that time again! Time to mark your calendar and think about what to publish for the upcoming 16th Annual ARRL and TAPR Digital Communications Conference. The 1997 ARRL and TAPR Digital Communications Conference will be held October 10-12, 1997 in Baltimore, Maryland. This year's conference location is just minutes away from the BWI (Baltimore/Washington International) Airport. For full details on the conference see http://www.tapr.org/dcc or contact the TAPR office for the DCC information flyer. ----- Call for Conference Proceeding Papers Anyone interested in digital communications is invited to submit a paper for publication in the Conference Proceedings. Presentation at the Conference is not required for publication. If you know of someone who is doing great things with digital communications, be sure to personally tell them about this! Papers are due by August 20th, 1997, and should be submitted to Maty Weinberg, ARRL, 225 Main Street, Newington, CT 06111 or via the Internet to lweinberg@arrl.org. Information on paper submission guidelines are available on-line (http://www.tapr.org/dcc). Submissions can be e-mailed. ----- Contact TAPR to register of for more information on the DCC. Tucson Amateur Packet Radio, 8987-309 E. Tanque Verde Road #337, Tucson, AZ 85749-9399. Phone: (940) 383-0000. Fax: (940) 566-2544. Internet: tapr@tapr.org http://www.tapr.org ---------------------------------------------------------------------------- Tucson Amateur Packet Radio 8987-309 E Tanque Verde Rd #337 * Tucson, Az * 85749-9399 * 940-383-0000 ---------------------------------------------------------------------------- e-mail: tapr@tapr.org ftp: ftp.tapr.org web: ---------------------------------------------------------------------------- From ddennis@physicist.net Tue Aug 12 07:58:47 1997 Received: from smtp.gte.net (smtp.gte.net [207.115.153.29]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id HAA05309 for ; Tue, 12 Aug 1997 07:58:46 -0500 (CDT) Received: from dfw73155.gte.net (dfw73155.gte.net [206.124.73.155]) by smtp.gte.net (SMI-8.6/SMI-SVR4) with SMTP id HAA24860 for ; Tue, 12 Aug 1997 07:59:09 -0500 (CDT) Received: by dfw73155.gte.net with Microsoft Mail id <01BCA6F5.67B75E00@dfw73155.gte.net>; Tue, 12 Aug 1997 07:57:39 -0500 Message-ID: <01BCA6F5.67B75E00@dfw73155.gte.net> From: David Dennis To: "'ss@tapr.org'" Subject: RE: 1664] 'Ham' data infrastructure (was: pathloss and DDMA) Date: Tue, 12 Aug 1997 07:56:43 -0500 MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="---- =_NextPart_000_01BCA6F5.67C826E0" ------ =_NextPart_000_01BCA6F5.67C826E0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit This is about the most well put thing I've read on here in a while. ---------- From: Jeff King[SMTP:jeff@mich.com] Sent: Friday, August 08, 1997 7:01 AM To: ss@tapr.org Subject: [SS:1664] 'Ham' data infrastructure (was: pathloss and DDMA) Glenn, you appear to be selling and/or basing your network plans on the existing 'ham' population. Respectfully, I think this is the basis for long term failure. When it comes to high speed networking, and in particular SS, most 'hams' don't have "the vision". What is "the vision"? It is the ability not to see spread spectrum as simply a new mode but a completely new paradigm for the usage of the radio spectrum. With the (hoped for) changes in the SS rules, the availability of cheap Part 15 equipment and the no-code tech license, I think the future of amateur SS lies in the computer experimenters. In other words, we should stop trying to sell ice cubes to Eskimos. -Jeff King WB8WKA ------ =_NextPart_000_01BCA6F5.67C826E0 Content-Type: application/ms-tnef Content-Transfer-Encoding: base64 eJ8+IicMAQaQCAAEAAAAAAABAAEAAQeQBgAIAAAA5AQAAAAAAADoAAEIgAcAGAAAAElQTS5NaWNy b3NvZnQgTWFpbC5Ob3RlADEIAQ2ABAACAAAAAgACAAEEkAYA9AAAAAEAAAAMAAAAAwAAMAIAAAAL AA8OAAAAAAIB/w8BAAAANQAAAAAAAACBKx+kvqMQGZ1uAN0BD1QCAAAAAHNzQHRhcHIub3JnAFNN VFAAc3NAdGFwci5vcmcAAAAAHgACMAEAAAAFAAAAU01UUAAAAAAeAAMwAQAAAAwAAABzc0B0YXBy Lm9yZwADABUMAQAAAAMA/g8GAAAAHgABMAEAAAAOAAAAJ3NzQHRhcHIub3JnJwAAAAIBCzABAAAA EQAAAFNNVFA6U1NAVEFQUi5PUkcAAAAAAwAAOQAAAAALAEA6AQAAAAIB9g8BAAAABAAAAAAAAAI5 JAEEgAEAPQAAAFJFOiAxNjY0XSAnSGFtJyBkYXRhIGluZnJhc3RydWN0dXJlICh3YXM6IHBhdGhs b3NzIGFuZCBERE1BKQCLEwEFgAMADgAAAM0HCAAMAAcAOAArAAIAVAEBIIADAA4AAADNBwgADAAH ADYAIwACAEoBAQmAAQAhAAAAMjkzRkJBNkVFNzEyRDExMUExMjAwMDQwOTUwNDJFRDMA8AYBA5AG AKQFAAAUAAAACwAjAAAAAAADACYAAAAAAAsAKQABAAAAAwAuAAAAAAADADYAAAAAAEAAOQCgn1Iv H6e8AR4AcAABAAAAPQAAAFJFOiAxNjY0XSAnSGFtJyBkYXRhIGluZnJhc3RydWN0dXJlICh3YXM6 IHBhdGhsb3NzIGFuZCBERE1BKQAAAAACAXEAAQAAABYAAAABvKcfL0Fuuj8qEucR0aEgAECVBC7T AAAeAB4MAQAAAAUAAABTTVRQAAAAAB4AHwwBAAAAFgAAAGRkZW5uaXNAcGh5c2ljaXN0Lm5ldAAA AAMABhBbYNWWAwAHEO0CAAAeAAgQAQAAAGUAAABUSElTSVNBQk9VVFRIRU1PU1RXRUxMUFVUVEhJ TkdJVkVSRUFET05IRVJFSU5BV0hJTEUtLS0tLS0tLS0tRlJPTTpKRUZGS0lOR1NNVFA6SkVGRkBN SUNIQ09NU0VOVDpGUklEAAAAAAIBCRABAAAA8AMAAOwDAACEBgAATFpGdXdqn5v/AAoBDwIVAqQD 5AXrAoMAUBMDVAIAY2gKwHNldO4yBgAGwwKDMgPGBxMCg7ozEw19CoAIzwnZOxX/eDI1NQKACoEN sQtgbvBnMTAzFCALChLyDAGiYwBAIFRoBAAgGwGHAaAIYAVAdGhlIARgonMFQHdlbAMgcBuTwQuA ZyBJJ3Yb4BYA6GFkIAIgIBvQFgAbII0DoGEcQBrwbGUuCoVBCotsaTE4MALRafAtMTQ0DfAM0CDz C1lsMTYKoANgdAWQBUAtXyMXCochywwwIpZGA2E6JyQeIpYMgiBKDcEgSwEdAVtTTVRQOmpRDcFA bWkRsC4FoG3+XSO/JM0GYAIwJf8nCyWwIGlkYXksE3B1ZxJ1HCEwOC4gMTk5IDcgNzowGsBBTXMp ryTNVG8r7ycLBBBAawGQIpAuBbBnL78qvnU+YijAIuAx3ycLKGBTOgEiYDY0XSAnSGF4bScgLfAB kB5RA1BhORwgcnUi4AhwG+Aod/86QDbQCrAbwBWQBBEAcB3AYERETUEpHx8gIzO+NiGXFCIMASKW CoVHHuA0bm4uIHkIYBtQcHDDHaAFwHRvIGIb4BHw1xxwHQI74S8FsWI6QB0Cq0BRBcBuEgB3BbBr HJCdGOFzCoUd4RvCZXgEAJp0HQInEcA5gXBvHKD3C2BFAAIgLgfwB5BAsCLg6mZF4GwuEUkc00Nw HOH/GxMbwgqFQlIEIAIQBcAVkPMdESLAcm1JUAtwCkAWANtGUDx8VxvQA6BpBUApYecHkUEBGvBn aDOgQLAJgH9DBh0BLiA74h5hCrFFAGN/ReEFwDjALiAcAgqFRVJzuzmRAiAnBUARwB1hIhvC9nYE AEYhIkZQS7A5wBsi/VFqPx0wUnNIWQGgAxBMAP55QwAisEDyEfBBQSKQHaL/RpM6cEogOkAzoAdw C1BVEP8ekEMQB+AEYkEgG5EekAqF/ylhC1ASABxgVREH0QqxHbCfTNBKIQWxG8IucGFnG+B+bygA G8JaElWBVmUfBlfnTABM8BvCKGhFwE1BSWH+KUwgEcAZAAeRHmEbwjjA/x2AReAHkC4gG8JRIEpR VLbPW2BYlhvQM/AgUE6xLuDyNUSwcXUFIAeAAjA70/sbwlUwLQWgWAEiwUzwIFDuYwnwEfBHOmUK hUbgOqP3W2E5cDnAZULhX3EgUF7Y/1kCG5AEkESxQLAFEGLiBJD6cx8NSQOgIrAeERxABbD+ZF/h HFAzoF3QReBWMUEA+2HwOmB5HQJVcxxxZJFMIOc2cExjCoVFc03QHAEfDQYtJ9dLoEI4V0tBvzx8 PO8hlxo1Pv0VIQB1MAMAEBAAAAAAAwAREAAAAABAAAcwoE2N4h6nvAFAAAgwoE2N4h6nvAEeAD0A AQAAAAUAAABSRTogAAAAAAMADTT9NwAAkqY= ------ =_NextPart_000_01BCA6F5.67C826E0-- From hilman@camosun.bc.ca Wed Aug 13 16:43:29 1997 Received: from ccins.camosun.bc.ca (ccins.camosun.bc.ca [204.174.56.1]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id QAA04786 for ; Wed, 13 Aug 1997 16:43:28 -0500 (CDT) Received: from hilman.cs.camosun.bc.ca (tb249.cs.camosun.bc.ca [204.174.57.91]) by ccins.camosun.bc.ca (8.8.6/8.8.6-ccins) with SMTP id OAA14136 for ; Wed, 13 Aug 1997 14:43:26 -0700 (PDT) Message-ID: <33F22A48.3A73@camosun.bc.ca> Date: Wed, 13 Aug 1997 14:42:32 -0700 From: Don Hilman X-Mailer: Mozilla 3.0 (Win95; I) MIME-Version: 1.0 To: ss@tapr.org Subject: Prism Chipset Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit I have two applications for a medium speed SS application and am not concerned about "homebrewing" a transciever but would rather work woth a commercial chipset. The Harris Prism was discussed here earlier in the year when it was fairly new , with some comments regarding work projects that were going to use it. 1. Has anyone any recent experience with the chipset? 2. What if any protocol issues are there for network software interfaces to the chipset are there or is it a transparent device with link control handled by the devices themselves? 3. Any comments on distance? 4. What VXO control is used to set base freq? 5. Data rates are indicated to be up to 1Mb..any experience there? From lylej@azstarnet.com Wed Aug 13 21:30:34 1997 Received: from mailhost.azstarnet.com (root@mailhost.azstarnet.com [169.197.1.8]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id VAA01000 for ; Wed, 13 Aug 1997 21:30:26 -0500 (CDT) Received: from ppp15.mmsi.com (dialup06ip33.tus.azstarnet.com [169.197.32.161]) by mailhost.azstarnet.com (8.8.5-nerd/8.8.5) with SMTP id TAA03637 for ; Wed, 13 Aug 1997 19:30:22 -0700 (MST) X-Sent-via: StarNet http://www.azstarnet.com/ Message-Id: <3.0.3.32.19970813192546.0077e010@pop.azstarnet.com> X-Sender: lylej@pop.azstarnet.com X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.3 (32) Date: Wed, 13 Aug 1997 19:25:46 -0700 To: ss@tapr.org From: Lyle Johnson Subject: Re: [SS:1673] Prism Chipset In-Reply-To: <33F22A48.3A73@camosun.bc.ca> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" At 04:48 PM 8/13/97 -0500, you wrote: >I have two applications for a medium speed SS application and am not >concerned about "homebrewing" a transciever but would rather work woth a >commercial chipset. > >The Harris Prism was discussed here earlier in the year when it was >fairly new , with some comments regarding work projects that were >going to use it. > >1. Has anyone any recent experience with the chipset? We've done testing with the pre-built boards and are near the board layout stage with our own spin. >2. What if any protocol issues are there for network software interfaces >to the chipset are there or is it a transparent device with link control >handled by the devices themselves? No tusre I understand the question. You can use a MAC chip and impleent IEEE 802.11, or not use a MAC chip and implmement whateve ryou want within the limitations of the Harris baseband chip (e.g., number of chips/bit etc.). We're doing the latter since compatibility with 802.11 means nothing to us and things we want to do that 802.11 isn't good for do matter to us :-) >3. Any comments on distance? Out ap[plications are out-of-door.s On flat ground (parking lots, open desert) we reliably got more than 1.5 miles using omni antennas and the deafult power output level of 50-100 mW. FCC allows another 10 dB on the trnamsitter so the range shold be able to be better if you add a power amp. >4. What VXO control is used to set base freq? Huh? There is a synthesizer in the chipset which runs from a 22 MHz oscillator, so evetryting depends on the 22 MHz oscillator for RF "channel." >5. Data rates are indicated to be up to 1Mb..any experience there? Will also do 2 Mb/sec in QPSK. We tested at 1 Mb. DOn't need the speed, but we need filters you can buy and they are all "tuned" for 1 Mb since that is 802.11 and that is the mass market driving parts. Check out the harris web page and you can download all sorts of data sheets, etc. Cheers, Lyle From chris@newcomb.com Thu Aug 14 06:43:09 1997 Received: from zeos_two.newcomb.com (newcomb.com [199.125.105.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id GAA23529 for ; Thu, 14 Aug 1997 06:43:00 -0500 (CDT) Received: from CHRIS_ROSE by zeos_two.newcomb.com; (NTMail 3.01.00) id ia005442; Thu, 14 Aug 97 07:42:52 -0400 X-Sender: chrisr@199.125.105.10 X-Mailer: Windows Eudora Pro Version 2.1.2 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: ss@tapr.org From: chris Subject: unscribe please Date: Thu, 14 Aug 97 07:42:52 -0400 X-Info: Evaluation version at zeos_two.newcomb.com Message-Id: 11425224706886@newcomb.com X-Info: Newcomb SMTP From bm@lynx.ve3jf.ampr.org Thu Aug 14 23:12:40 1997 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 XAA07743 for ; Thu, 14 Aug 1997 23:12:35 -0500 (CDT) Received: (from bm@localhost) by lynx.ve3jf.ampr.org (8.6.12/8.6.12) id EAA06283 for ss@tapr.org; Fri, 15 Aug 1997 04:12:06 GMT From: Barry McLarnon VE3JF Message-Id: <199708150412.EAA06283@lynx.ve3jf.ampr.org> Date: Fri, 15 Aug 1997 04:12:05 +0000 (GMT) To: ss@tapr.org Subject: WaveLAN Performance X-Mailer: Ishmail 1.3.1-961106-linux MIME-Version: 1.0 Content-Type: text/plain I'm running a pair of WaveLAN cards across the room between two Linux boxen preparatory to trying them over an outdoor link. Both boxes are Pentiums running the 2.0.30 kernel. I've seen other people report ftp throughputs of the order of 180-190 Kbyte/s for WaveLAN, but the best I've been able to get is in the 85-90 Kbyte/s range (for a 1 MB file). This would seem to indicate that my cards are actually running at the 1 Mbps fallback rate instead of 2 Mbps. But then again, maybe not. I've tried different antenna locations and also attenuation in case there are some overload problems at close range, but the throughput is pretty much the same in all cases. I notice that there were some changes to the WaveLAN driver in the 2.0.30 kernel release - is anyone else using that version with WaveLAN cards, so we can compare notes? Any performance/tuning hints in general? And lastly, has anyone figured out how to interpret the quality numbers which appear in /proc/net/wireless? Here's a sample: Inter-|sta| Quality | Discarded packets face |tus|link level noise| nwid crypt misc eth1: f0 15. 17. 0. 19 0 0 The "level" param seems to indicate signal strength, and "noise" occasionally pops up to 1 or 2, but I haven't seen the "link" param change. 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 bad@uhf.wireless.net Fri Aug 15 07:02:40 1997 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 HAA26414 for ; Fri, 15 Aug 1997 07:02:36 -0500 (CDT) Received: from localhost (bad@localhost) by uhf.wdc.net (8.8.7/8.6.12) with SMTP id IAA00480 for ; Fri, 15 Aug 1997 08:06:52 -0400 (EDT) Date: Fri, 15 Aug 1997 08:06:51 -0400 (EDT) From: Bernie Doehner X-Sender: bad@uhf.wdc.net To: ss@tapr.org Subject: Re: [SS:1676] WaveLAN Performance In-Reply-To: <199708150412.EAA06283@lynx.ve3jf.ampr.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi Barry: > I'm running a pair of WaveLAN cards across the room between two Linux boxen > preparatory to trying them over an outdoor link. Both boxes are Pentiums > running the 2.0.30 kernel. I've seen other people report ftp throughputs of > the order of 180-190 Kbyte/s for WaveLAN, but the best I've been able to get is > in the 85-90 Kbyte/s range (for a 1 MB file). This would seem to indicate that > my cards are actually running at the 1 Mbps fallback rate instead of 2 Mbps. > But then again, maybe not. I've tried different antenna locations and also > attenuation in case there are some overload problems at close range, but the > throughput is pretty much the same in all cases. My personal observations have been that it's very CPU dependent (at least with the FreeBSD driver). I have been getting 190 kbytes/sec 486<->386 while others I know with the same driver have been getting in the low 100's (with Pentiums). Also, the 82586 isn' the best in terms of interrupt performance (which I think is why speed decreases with the faster machines - lost interrupts). Going to win95 clients I have always been getting around 50-70 kbytes/sec max! > I notice that there were some changes to the WaveLAN driver in the 2.0.30 > kernel release - is anyone else using that version with WaveLAN cards, so > we can compare notes? Any performance/tuning hints in general? And lastly, > has anyone figured out how to interpret the quality numbers which appear > in /proc/net/wireless? Here's a sample: > > > The "level" param seems to indicate signal strength, and "noise" occasionally > pops up to 1 or 2, but I haven't seen the "link" param change. > I tried at one point to add a step attenuator and figure out the scale of the level/noise (seemed to me it could somehow be signal/noise??).. I didn't succeed, too much variance in the signal strengths.. The level/noise parameters should track what you see with PTPDIAG in DOS. And yes, the link parameter doesn't change much.. Need a large change in level to noise to make it change. I don't have any time now, but do you by any chance have the 2.0.30 wavelan driver diffs? I am curious what was done to the driver. Thanks/good luck. Bernie From jeff@mich.com Fri Aug 15 09:07:24 1997 Received: from home.nuge.com (home.nuge.com [152.160.156.254]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id JAA02649 for ; Fri, 15 Aug 1997 09:07:21 -0500 (CDT) Received: from alfalfa (alfalfa.mich.com [198.108.18.18]) by home.nuge.com (8.7.1/8.7.1) with SMTP id KAA28098 for ; Fri, 15 Aug 1997 10:07:11 -0400 Message-Id: <3.0.3.32.19970815100301.038d2b60@mail.mich.com> X-Sender: jeff@mail.mich.com (Unverified) X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.3 (32) Date: Fri, 15 Aug 1997 10:03:01 -0400 To: ss@tapr.org From: Jeff King Subject: Re: [SS:1676] WaveLAN Performance In-Reply-To: <199708150412.EAA06283@lynx.ve3jf.ampr.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" At 11:21 PM 8/14/97 -0500, Barry McLarnon VE3JF wrote: >I'm running a pair of WaveLAN cards across the room between two Linux boxen >preparatory to trying them over an outdoor link. Both boxes are Pentiums >running the 2.0.30 kernel. I've seen other people report ftp throughputs of >the order of 180-190 Kbyte/s for WaveLAN, but the best I've been able to get is >in the 85-90 Kbyte/s range (for a 1 MB file). This would seem to indicate that >my cards are actually running at the 1 Mbps fallback rate instead of 2 Mbps. Are these the 900mhz or 2.5ghz versions? Best I've gotten using LINUX has been about 75 Kbyte/s. Was using 133 Pentiums with 900mhz Wavelans. I've got a considerable amount of interference so that has been more the issue for me. I'd be interested in knowing how far you are able to go with them and the antenna/height as well. There is a WaveLan mailing list. Back issues can be found at: http://www.cs.tamu.edu/people/mmehta/links/wavelan.txt >But then again, maybe not. I've tried different antenna locations and also >attenuation in case there are some overload problems at close range, but the >throughput is pretty much the same in all cases. > > Any performance/tuning hints in general? I've discussed this on the list before, but note there is a DC voltage which appears on the coax connector. This is to switch the diversity antenna. I'd strongly suggest putting some sort of DC block on it. I had a set of them degrade over time due to plating across one of the coax connectors. Putting a DC block in stopped this from occurring again. >And lastly, >has anyone figured out how to interpret the quality numbers which appear >in /proc/net/wireless? Here's a sample: > >Inter-|sta| Quality | Discarded packets > face |tus|link level noise| nwid crypt misc > eth1: f0 15. 17. 0. 19 0 0 > >The "level" param seems to indicate signal strength, and "noise" occasionally >pops up to 1 or 2, but I haven't seen the "link" param change. > >Barry Have you checked the source yet? Seems I figured it out at one time but its slipped my mind. Regards, ------------------------------------ | Jeff King Aero Data Systems | | jeff@mich.com P.O. Box 510895 | | (810)471-1787 Livonia, MI 48151 | |F(810)471-0279 United States | ------------------------------------ From bad@uhf.wireless.net Fri Aug 15 11:05:43 1997 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 LAA10450 for ; Fri, 15 Aug 1997 11:05:37 -0500 (CDT) Received: from localhost (bad@localhost) by uhf.wdc.net (8.8.7/8.6.12) with SMTP id MAA01213 for ; Fri, 15 Aug 1997 12:09:59 -0400 (EDT) Date: Fri, 15 Aug 1997 12:09:57 -0400 (EDT) From: Bernie Doehner X-Sender: bad@uhf.wdc.net To: ss@tapr.org Subject: Re: [SS:1678] Re: WaveLAN Performance In-Reply-To: <3.0.3.32.19970815100301.038d2b60@mail.mich.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII The FreeBSD units are 900 MHz. units (full height) used in a residential setting for indoor. My win95 clients are PCMCIA wavelans. Bernie From bm@lynx.ve3jf.ampr.org Fri Aug 15 13:00:20 1997 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 NAA07129 for ; Fri, 15 Aug 1997 13:00:16 -0500 (CDT) Received: (from bm@localhost) by lynx.ve3jf.ampr.org (8.6.12/8.6.12) id RAA07091 for ss@tapr.org; Fri, 15 Aug 1997 17:59:52 GMT From: Barry McLarnon VE3JF Message-Id: <199708151759.RAA07091@lynx.ve3jf.ampr.org> Date: Fri, 15 Aug 1997 17:59:51 +0000 (GMT) To: ss@tapr.org Subject: Re: [SS:1677] Re: WaveLAN Performance In-Reply-To: X-Mailer: Ishmail 1.3.1-961106-linux MIME-Version: 1.0 Content-Type: text/plain Bernie Doehner wrote: > My personal observations have been that it's very CPU dependent (at least > with the FreeBSD driver). I have been getting 190 kbytes/sec 486<->386 > while others I know with the same driver have been getting in the low > 100's (with Pentiums). Also, the 82586 isn' the best in terms of interrupt > performance (which I think is why speed decreases with the faster machines > - lost interrupts). Worse performance with pentiums? Seems odd - I haven't seen that with other devices, such as ethernet cards. > Going to win95 clients I have always been getting around 50-70 kbytes/sec > max! > > > I notice that there were some changes to the WaveLAN driver in the 2.0.30 > > kernel release - is anyone else using that version with WaveLAN cards, so > > we can compare notes? Any performance/tuning hints in general? And lastly, > > has anyone figured out how to interpret the quality numbers which appear > > in /proc/net/wireless? Here's a sample: > > > > > > The "level" param seems to indicate signal strength, and "noise" occasionally > > pops up to 1 or 2, but I haven't seen the "link" param change. > > > > I tried at one point to add a step attenuator and figure out the scale of > the level/noise (seemed to me it could somehow be signal/noise??).. I > didn't succeed, too much variance in the signal strengths.. > > The level/noise parameters should track what you see with PTPDIAG in DOS. > And yes, the link parameter doesn't change much.. Need a large change in > level to noise to make it change. I also had a step attenuator at one end, but as you say, things tend to be erratic. I hope to try the cards in a more controlled lab environment one of these days, and get a better handle on those params, required SNR, etc. > I don't have any time now, but do you by any chance have the 2.0.30 > wavelan driver diffs? I am curious what was done to the driver. ftp://sunsite.unc.edu/pub/Linux/kernel/v2.0/patch-2.0.30.gz Thanks for your comments... 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 MarsGuy@home.cynet.net Thu Aug 21 00:55:58 1997 Received: from home.cynet.net (home.cynet.net [208.196.80.1]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id AAA21327 for ; Thu, 21 Aug 1997 00:55:57 -0500 (CDT) From: MarsGuy@home.cynet.net Received: from mail.cynet.net (ip213.philadelphia12.pa.pub-ip.psi.net [38.26.85.213]) by home.cynet.net (8.7.4/8.6.4) with SMTP id BAA15488; Thu, 21 Aug 1997 01:56:44 -0400 (EDT) Message-Id: <199708210556.BAA15488@home.cynet.net> To: friends.and.family@home.com Date: Wed, 20 Aug 97 23:03:14 EST Subject: Candy is dandy and flowers fine... but giving Mars is marvelous!!! Reply-To: achieve@tharsis.mars.com >>>>>>>>>>>>>>>>>> -oOo- <<<<<<<<<<<<<<<<<< Know somebody who has a birthday coming up soon? Need a unique gift to surprise a loved one? Keeping your eyes open for an anniversary gift? *** Give A "Land Claim" On The Planet MARS! *** Sound too incredible to be true? Believe it!!! http://www.martianconsulate.com/ "Land Claims on MARS!" Thousands of individuals from more than twenty countries on three continents have discovered this fun, unique novelty gift. Please drop by and visit our web site today to learn more! http://www.martianconsulate.com/ The Martian Consulate, L.L.C. maintains a list of Deed Claimants in its Registry securely protected in Geneva, Switzerland. Registrants' names, addresses, "claim" locations and serial numbers are recorded, and by a trust established by The Martian Consulate, L.L.C., will be presented to a government on Mars when such a government is established! Register a loved one today! Each Registrant receives a beautiful 11" x 14" Certificate of Deed Registration and a Survey of Plat (a map which pinpoints a claim location on Mars), and an optional hand addressed gift card. Claim sizes are 1 square mile, priced at US$29.95. Your satisfaction is 100% guaranteed, and we stand behind our Certificates with a thirty day, money back, no-question, no hassle guarantee. http://www.martianconsulate.com/ Visit our site often to find out more about our new Martian Consulate coffee mugs, and upcoming golf shifts and custom embroideried baseball caps! -- The Martian Consulate, L.L.C. -- -- 21st Century Space Novelties -- >>>>>>>>>>>>>>>>> -oOo- <<<<<<<<<<<<<<<<< From andresal@www.ifqsc.sc.usp.br Thu Aug 21 14:43:46 1997 Received: from www.ifqsc.sc.usp.br (www.ifqsc.sc.usp.br [143.107.229.70]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id OAA13061 for ; Thu, 21 Aug 1997 14:43:33 -0500 (CDT) Received: from localhost (andresal@localhost) by www.ifqsc.sc.usp.br (8.8.5/8.8.5) with SMTP id QAA21689 for ; Thu, 21 Aug 1997 16:56:37 GMT Date: Thu, 21 Aug 1997 16:56:37 +0000 (GMT) From: Andre M Salvagnini To: ss@tapr.org Subject: Re: [SS:1681] Candy is dandy and flowers fine... but giving Mars is marvelous!!! In-Reply-To: <199708210556.BAA15488@home.cynet.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII I would like do not receive this kind of messages. It's against internet ettiquete. Thank you Andre Salvagnini PY2NMB Universidade de Sao Paulo - USP Instituto de Fisica de Sao Carlos - IFSC Laboratorio de Instrumentacao Eletronica - LIE / RF-LAB From cfk@pacbell.net Fri Aug 22 08:46:45 1997 Received: from mail-gw.pacbell.net (mail-gw.pacbell.net [206.13.28.25]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id IAA13281 for ; Fri, 22 Aug 1997 08:46:43 -0500 (CDT) Received: from cfk (ppp-206-170-68-46.irvn11.pacbell.net [206.170.68.46]) by mail-gw.pacbell.net (8.8.7/8.7.1+antispam) with SMTP id GAA11542 for ; Fri, 22 Aug 1997 06:46:23 -0700 (PDT) Message-ID: <33FD9B3D.D04@pacbell.net> Date: Fri, 22 Aug 1997 06:59:25 -0700 From: Charles Krinke Reply-To: cfk@pacbell.net Organization: Data Retriever Corp. X-Mailer: Mozilla 3.0Gold (Win95; U) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: [SS:1681] Candy is dandy and flowers fine... but giving Mars is marvelous!!! References: <199708210556.BAA15488@home.cynet.net> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit MarsGuy@home.cynet.net wrote: > > >>>>>>>>>>>>>>>>>> -oOo- <<<<<<<<<<<<<<<<<< > > Know somebody who has a birthday coming up soon? > Need a unique gift to surprise a loved one? > Keeping your eyes open for an anniversary gift? > > *** Give A "Land Claim" On The Planet MARS! *** > > Sound too incredible to be true? Believe it!!! > > http://www.martianconsulate.com/ > > "Land Claims on MARS!" > > Thousands of individuals from more than twenty > countries on three continents have discovered > this fun, unique novelty gift. Please drop by and > visit our web site today to learn more! > > http://www.martianconsulate.com/ > > The Martian Consulate, L.L.C. maintains a list > of Deed Claimants in its Registry securely > protected in Geneva, Switzerland. Registrants' > names, addresses, "claim" locations and serial > numbers are recorded, and by a trust established > by The Martian Consulate, L.L.C., will be > presented to a government on Mars when such a > government is established! Register a loved > one today! Each Registrant receives a beautiful > 11" x 14" Certificate of Deed Registration and > a Survey of Plat (a map which pinpoints a claim > location on Mars), and an optional hand addressed > gift card. Claim sizes are 1 square mile, priced > at US$29.95. Your satisfaction is 100% guaranteed, > and we stand behind our Certificates with a thirty > day, money back, no-question, no hassle guarantee. > > http://www.martianconsulate.com/ > > Visit our site often to find out more about our > new Martian Consulate coffee mugs, and upcoming > golf shifts and custom embroideried baseball caps! > > -- The Martian Consulate, L.L.C. -- > -- 21st Century Space Novelties -- > > >>>>>>>>>>>>>>>>> -oOo- <<<<<<<<<<<<<<<<< DO NOT SEND ANYMORE JUNK MAIL. UNSOLICITED ADDS AUTOMATICALLY PUT YOUR COMPANY INTO THE "NEVER DO BUSINESS WITH THESE GUYS" FILE From bm@lynx.ve3jf.ampr.org Fri Aug 22 23:27:41 1997 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 XAA27024 for ; Fri, 22 Aug 1997 23:27:37 -0500 (CDT) Received: (from bm@localhost) by lynx.ve3jf.ampr.org (8.6.12/8.6.12) id EAA19332 for ss@tapr.org; Sat, 23 Aug 1997 04:27:17 GMT From: Barry McLarnon VE3JF Message-Id: <199708230427.EAA19332@lynx.ve3jf.ampr.org> Date: Sat, 23 Aug 1997 04:27:17 +0000 (GMT) To: ss@tapr.org Subject: Re: [SS:1683] Re: Candy is dandy and flowers fine... but giving Mars is marvelous!!! In-Reply-To: <33FD9B3D.D04@pacbell.net> X-Mailer: Ishmail 1.3.1-961106-linux MIME-Version: 1.0 Content-Type: text/plain Charles Krinke wrote: [repost of spam in its entirety to the list] Sigh... looks like folks are determined to disprove my contention that having a Reply-To: pointing to the list address is a reasonable thing to do. A few more like this and I'll be ready to capitulate, Phil. 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 sgranth@merlin.ebicom.net Sat Aug 23 01:56:04 1997 Received: from Merlin.EbiCom.net (root@Merlin.EbiCom.Net [206.26.194.3]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id BAA20280 for ; Sat, 23 Aug 1997 01:56:03 -0500 (CDT) Received: from default (l1-52.EbiCom.Net [206.26.194.52]) by Merlin.EbiCom.net (8.8.6/8.6.9) with SMTP id BAA01958; Sat, 23 Aug 1997 01:55:44 -0500 Message-Id: <3.0.2.32.19970823015756.00715c88@merlin.ebicom.net> X-Sender: sgranth@merlin.ebicom.net X-Mailer: QUALCOMM Windows Eudora Light Version 3.0.2 (32) Date: Sat, 23 Aug 1997 01:57:56 -0500 To: ss@tapr.org From: Steve Grantham Subject: Is the sysop in? Cc: sgranth@merlin.ebicom.net In-Reply-To: <199708230427.EAA19332@lynx.ve3jf.ampr.org> References: <33FD9B3D.D04@pacbell.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Dear Sysop, I am still receiving the TAPR SS list at my old EMAIL address. I thought I had properly unsubscribed. I guess not. Might you assist me? ________________________NOTICE!____________________________ As of the end of August 1997, I will be discontinuing the use of TEClink as my internet provider. Please change your address book to indicate as my primary EMAIL account. Regards, Steve Grantham, N5DWU * More than just a mode, communications is understanding. * * Check my page at http://www.qsl.net/n5dwu/ms_info.html * ___________________________________________________________ From jbloom@arrl.org Wed Aug 27 14:41:40 1997 Received: from mgate.arrl.org (root@mgate.arrl.org [205.217.201.2]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA03204 for ; Wed, 27 Aug 1997 14:41:38 -0500 (CDT) Received: from jbloom.connix.com by mgate.arrl.org [27363] with smtp for id m0x3nyD-0004ixC; Wed, 27 Aug 97 15:41 EDT Message-ID: <34048382.EFA8FB08@arrl.org> Date: Wed, 27 Aug 1997 15:44:02 -0400 From: Jon Bloom Organization: American Radio Relay League X-Mailer: Mozilla 4.0 [en] (Win95; I) MIME-Version: 1.0 To: ss@tapr.org Subject: Recommended convolutional coding books? X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit I'd like to get smarter (which won't take much) about coding. I noticed in the latest Computer Literacy Bookstores bulletin a book, "Convolutional Coding: Fundamentals and Applications," by L.H. Charles Lee. Before I spend $95 on that, I thought I'd ask if anyone can recommend either that book or a more suitable one. TIA. Jon -- Jon Bloom, KE3Z | jbloom@arrl.org American Radio Relay League | 225 Main St., Newington CT 06111 | From mdf@angoss.com Wed Aug 27 16:34:05 1997 Received: from inamorata.research.angoss.com (blank-94.trends.ca [207.107.140.94]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id QAA10224 for ; Wed, 27 Aug 1997 16:34:03 -0500 (CDT) Received: from mail-hub.angoss.com ([204.92.243.79]) by inamorata.research.angoss.com (8.8.5/8.6.9) with SMTP id RAA23604 for ; Wed, 27 Aug 1997 17:31:37 -0400 (EDT) Received: from hydrogen.research.angoss.com by mail-hub.angoss.com with SMTP (1.38.193.4/16.2) id AA07866; Wed, 27 Aug 1997 17:38:11 -0400 Received: (from mdf@localhost) by hydrogen (950413.SGI.8.6.12/950213.SGI.AUTOCF) id VAA24995 for ss@tapr.org; Wed, 27 Aug 1997 21:35:18 GMT Date: Wed, 27 Aug 1997 21:35:18 GMT From: mdf@angoss.com (Matthew Francey) Message-Id: <199708272135.VAA24995@hydrogen> To: ss@tapr.org Subject: Re: Recommended convolutional coding books? "Digital Modulation and Coding", by Stephen Wilson. It can be heavy going at times though... From HONG-ZH_ZHOU@Non-HP-China-om1.om.hp.com Wed Aug 27 20:07:56 1997 Received: from palrel3.hp.com (palrel3.hp.com [156.153.255.219]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id UAA01430 for ; Wed, 27 Aug 1997 20:07:55 -0500 (CDT) From: HONG-ZH_ZHOU@Non-HP-China-om1.om.hp.com Received: from ctss34.sgp.hp.com (ctss34.sgp.hp.com [15.85.49.7]) by palrel3.hp.com (8.8.5/8.8.5) with ESMTP id SAA18473; Wed, 27 Aug 1997 18:07:49 -0700 (PDT) Received: from localhost by ctss34.sgp.hp.com with SMTP (1.37.109.20/15.5+ECS 3.4 Openmail) id AA007250465; Thu, 28 Aug 1997 09:07:46 +0800 X-Openmail-Hops: 1 Date: Thu, 28 Aug 97 09:07:36 +0800 Message-Id: Subject: for rankings of EE Mime-Version: 1.0 To: ss@tapr.org Cc: W-cdma@usa.net Content-Type: text/plain; charset=US-ASCII; name="Text" Content-Disposition: inline; filename="Text" Content-Transfer-Encoding: 7bit Hi, I wonder if somebody can provide the latest rankings of University of Electrical Engineering in USA and Britain. And I want to know the university , Research institute or company that research in SS , especially in Wideband CDMA. Thanks Zhou Hong w-cdma@usa.net 8/28/1997 From bhaineau@cts.com Wed Aug 27 22:03:43 1997 Received: from mh1.cts.com (root@mh1.cts.com [205.163.24.66]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id WAA09269 for ; Wed, 27 Aug 1997 22:03:40 -0500 (CDT) Received: from cts.com (bhaineau.cts.com [205.163.5.216]) by mh1.cts.com (8.8.5/8.8.5) with ESMTP id UAA07206 for ; Wed, 27 Aug 1997 20:03:36 -0700 (PDT) Apparently-To: Message-ID: <3404EA7F.D0E3905E@cts.com> Date: Wed, 27 Aug 1997 20:03:27 -0800 From: Bruno Haineault X-Mailer: Mozilla 4.02 [en] (Win95; U) MIME-Version: 1.0 To: ss@tapr.org Subject: Re: [SS:1686] Recommended convolutional coding books? References: <34048382.EFA8FB08@arrl.org> Content-Type: multipart/signed; protocol="application/x-pkcs7-signature"; micalg=sha1; boundary="------------ms48A9C1F3E92D48BAC0A55254" This is a cryptographically signed message in MIME format. --------------ms48A9C1F3E92D48BAC0A55254 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Try TAPR's "Wireless Digital Communications Design and Theory". It's a great "introduction" to coding. There are many other books around (and seeing your postal address, I wonder why the ARRL doesn't offer any). 73 from Bruno, VE2EQ/W6 San Marcos, California Jon Bloom wrote: > > I'd like to get smarter (which won't take much) about coding. I noticed > in the latest Computer Literacy Bookstores bulletin a book, > "Convolutional Coding: Fundamentals and Applications," by L.H. Charles > Lee. Before I spend $95 on that, I thought I'd ask if anyone can > recommend either that book or a more suitable one. TIA. > > Jon > -- > Jon Bloom, KE3Z | jbloom@arrl.org > American Radio Relay League | > 225 Main St., Newington CT 06111 | --------------ms48A9C1F3E92D48BAC0A55254 Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIIRRwYJKoZIhvcNAQcCoIIRODCCETQCAQExCzAJBgUrDgMCGgUAMAsGCSqGSIb3DQEHAaCC Dz8wggqJMIIJ8qADAgECAhAE+vqBDG+l3xIVjiIbNpxBMA0GCSqGSIb3DQEBBAUAMGIxETAP BgNVBAcTCEludGVybmV0MRcwFQYDVQQKEw5WZXJpU2lnbiwgSW5jLjE0MDIGA1UECxMrVmVy aVNpZ24gQ2xhc3MgMSBDQSAtIEluZGl2aWR1YWwgU3Vic2NyaWJlcjAeFw05NzA1MjQwMDAw MDBaFw05NzExMjMyMzU5NTlaMIIBDTERMA8GA1UEBxMISW50ZXJuZXQxFzAVBgNVBAoTDlZl cmlTaWduLCBJbmMuMTQwMgYDVQQLEytWZXJpU2lnbiBDbGFzcyAxIENBIC0gSW5kaXZpZHVh bCBTdWJzY3JpYmVyMUYwRAYDVQQLEz13d3cudmVyaXNpZ24uY29tL3JlcG9zaXRvcnkvQ1BT IEluY29ycC4gYnkgUmVmLixMSUFCLkxURChjKTk2MSYwJAYDVQQLEx1EaWdpdGFsIElEIENs 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for ; Thu, 28 Aug 1997 01:00:30 -0400 (EDT) Date: Thu, 28 Aug 1997 01:00:28 -0400 (EDT) From: Bernie Doehner X-Sender: bad@uhf.wdc.net To: ss@tapr.org Subject: Recommendations on coding books - FEC Intro URL Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Also, you might enjoy the following URL, which I wrote as a very basic introduction to FEC for one of my grad classes: http://bugs.wpi.edu:8080/EE535/hwk97/hwk4cd97/bad/bad.html 73 Bernie nu1s From karn@qualcomm.com Thu Aug 28 01:35:59 1997 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 BAA06839 for ; Thu, 28 Aug 1997 01:35:57 -0500 (CDT) Received: (from karn@localhost) by servo.qualcomm.com (8.8.5/1.4/8.7.2/1.13) id XAA26146; Wed, 27 Aug 1997 23:35:25 -0700 (PDT) Date: Wed, 27 Aug 1997 23:35:25 -0700 (PDT) Message-Id: <199708280635.XAA26146@servo.qualcomm.com> From: Phil Karn To: ss@tapr.org In-reply-to: <3404EA7F.D0E3905E@cts.com> (message from Bruno Haineault on Wed, 27 Aug 1997 22:10:24 -0500 (CDT)) Subject: Re: [SS:1689] Re: Recommended convolutional coding books? Well, there's also my Viterbi and Fano software on my web page, which you can tear apart and figure out. I've always found that doing this with other people's code is a good way to learn how something works... Phil From jbloom@arrl.org Thu Aug 28 06:52:28 1997 Received: from comet.connix.com (root@comet.connix.com [198.69.10.4]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id GAA27780 for ; Thu, 28 Aug 1997 06:52:26 -0500 (CDT) Received: from jbloom.connix.com (jbloom.connix.com [205.246.105.188]) by comet.connix.com (8.8.5/8.8.5) with SMTP id HAA05449 for ; Thu, 28 Aug 1997 07:52:22 -0400 (EDT) Message-ID: X-Mailer: XFMail 1.2-alpha [p0] on Linux Sender: jbloom@jbloom.connix.com Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <3404EA7F.D0E3905E@cts.com> Date: Thu, 28 Aug 1997 08:01:48 -0400 (EDT) Organization: American Radio Relay League From: Jon Bloom To: ss@tapr.org Subject: RE: [SS:1689] Re: Recommended convolutional coding books? On 28-Aug-97 Bruno Haineault wrote: >Try TAPR's "Wireless Digital Communications Design and Theory". It's a >great "introduction" to coding. I've seen that, and it provides a good overview of the subject. I'm looking for a more mathematical treatment, though. >There are many other books around (and seeing your postal address, I >wonder why the ARRL doesn't offer any). I think you answered your own question. Jon --- Jon Bloom, KE3Z jbloom@arrl.org From jbloom@arrl.org Thu Aug 28 06:54:15 1997 Received: from comet.connix.com (root@comet.connix.com [198.69.10.4]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id GAA27883 for ; Thu, 28 Aug 1997 06:54:14 -0500 (CDT) Received: from jbloom.connix.com (jbloom.connix.com [205.246.105.188]) by comet.connix.com (8.8.5/8.8.5) with SMTP id HAA05595 for ; Thu, 28 Aug 1997 07:54:11 -0400 (EDT) Message-ID: X-Mailer: XFMail 1.2-alpha [p0] on Linux Sender: jbloom@jbloom.connix.com Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <199708280635.XAA26146@servo.qualcomm.com> Date: Thu, 28 Aug 1997 08:03:37 -0400 (EDT) Organization: American Radio Relay League From: Jon Bloom To: ss@tapr.org Subject: RE: [SS:1691] Re: Recommended convolutional coding books? On 28-Aug-97 Phil Karn wrote: >Well, there's also my Viterbi and Fano software on my web page, which you >can tear apart and figure out. I've always found that doing this with >other people's code is a good way to learn how something works... I'll probably do that at some point, but right now I want to better understand the theory of it. Jon --- Jon Bloom, KE3Z jbloom@arrl.org From RLANIER@mailb.harris.com Thu Aug 28 11:50:56 1997 Received: from sol.corp.Harris.COM (sol.corp.harris.com [137.237.104.14]) by tapr.org (8.7.5/8.7.3/1.9) with ESMTP id LAA19556 for ; Thu, 28 Aug 1997 11:50:54 -0500 (CDT) Received: from mailb.harris.com (eds-email-1.ess.harris.com [130.41.38.127]) by sol.corp.Harris.COM (8.8.5/) with SMTP id MAA17094 for ; Thu, 28 Aug 1997 12:50:46 -0400 (EDT) Received: from ccMail by mailb.harris.com (IMA Internet Exchange 1.04b) id 405abe00; Thu, 28 Aug 97 12:48:32 -0400 Mime-Version: 1.0 Date: Thu, 28 Aug 1997 12:49:36 -0400 Message-ID: <405abe00@mailb.harris.com> Return-receipt-to: RLANIER@mailb.harris.com (RLANIER) From: RLANIER@mailb.harris.com (RLANIER) Subject: Re: [SS:1691] Re: Recommended convolutional coding books? To: ss@tapr.org Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Description: cc:Mail note part As long as what you are tearing apart actually works!!! :) ______________________________ Reply Separator _________________________________ Subject: [SS:1691] Re: Recommended convolutional coding books? Author: ss@tapr.org at smtp Date: 8/28/97 1:37 AM Well, there's also my Viterbi and Fano software on my web page, which you can tear apart and figure out. I've always found that doing this with other people's code is a good way to learn how something works... Phil