From bounce-ss-6751@lists.tapr.org Tue Aug 1 00:08:10 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id AAA04782 for ; Tue, 1 Aug 2000 00:08:10 -0500 (CDT) Date: Mon, 31 Jul 2000 22:06:12 -0700 (PDT) From: Chris Arndt To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: Nova Wireless routers and Re: Video over Wireless LAN In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk I posted a little info on the Novas as a reply to another post. I'm working on getting a web page up with more real world info than the Nova website. I've been running my internet connection over some Cisco Aironet wireless bridges (2 hops) for a couple of months now, and playing with the Novas off and on. Your feelings about 2.4 ghz vs 900 mhz are pretty accurate, especially if you are looking at direct sequence. I did an informal 2.4 drive by test along a road perpendicular to the 2 mile long test path that allowed me to go from line of sight to one up to several lines of trees. It doesn't take much to wipe out 2.4. That's why I need 2 hops for my connection. The Novas can run up to 800 mw, and have 7 selectable bit rates over 2 different modulation methods. The lower you go in speed the more range you have. I'm not sure how easily/cheaply you could test the path without using a pair of Novas, especially to get results comparable to the Novas with low loss cable and gain antennas. An Engenius long range cordless uses the same band and power (I think), and can have an outdoor antenna on the base, but you'd still be stuck with the "long range" flex antenna on the handset. I have used my Engenius out to the same LOS location from which I have tested the Novas, 4.7 miles from home, which is on a hill. Maybe you could borrow a pair of 800 mhz SMR handhelds and use talk around. We have to approximate the ERP from those and compare it to the Nova ERP. Or see how far you can hear the mobile side of an analog cell phone on an old scanner. ;-) What kind of speed can you live with? There's another product made by Wireless Mountain, the Power Rover, that is serial, 115 kbaud (I think) and a ffreq hopper, so it should have better punch. www.wirelessmountain.com I'm gonna get a pair of these to play with soon, and I'll have more info then. Chris On Mon, 31 Jul 2000, Eric S. Johansson wrote: > > > Chris Arndt wrote: > > > BTW, one of the purposes listed for this list is reviewing current ss > > devices. Is anyone interested in hearing more about the NovaRoams? > > I would be interested. I would also be interested in hearing opinions on path > issues. This is something I'm very interested in because I want to run a link > between my house and friends. We are 1.1 mi. apart with no earth obstructions > but we are both significantly overshadowed by trees. I would have to guess > that approximately 30 percent of the path would be through trees. Towers are > not an option given that these are hundred foot pines. > > My current level of understanding leads me to believe that 2.4 GHz won't make > it but 900 MHz might. I would be really interested in hearing if there are > simple/cheap ways of testing out paths for situations like this. > > ---eric > > > > --- > You are currently subscribed to ss as: carndt@slonet.org > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 1 05:19:19 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id FAA18295 for ; Tue, 1 Aug 2000 05:19:17 -0500 (CDT) Message-ID: Reply-To: "TAPR Spread Spectrum Special Interest Group" From: "Fred" To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] TAPR FHSS radio project Date: Tue, 1 Aug 2000 06:17:09 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V4.72.2106.4 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio X-Message-Id: <000801bffba1$a769d2e0$d0b051d1@Fred.dnaco.net> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Check out the update on the FHSS radio project on the TAPR page. Progress is being made. Fred KE8TQ Hams Do It With High Frequency in Dayton Ohio and around the world --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 1 21:49:16 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id VAA00934 for ; Tue, 1 Aug 2000 21:49:15 -0500 (CDT) Date: Tue, 1 Aug 2000 22:42:01 -0400 (EDT) From: Jim Ussailis Subject: [ss] Re: ss digest: July 31, 2000 To: "TAPR Spread Spectrum Special Interest Group" cc: ss digest recipients In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Regarding propagation losses at 2.4 GHz & 900 MHz: Space loss goes up by 6 dB every time frequency is doubled. That is the first part. Higher frequencies suffer more multipath and foilage loss at higher frequencies. There is not too much theory here (at least not published). Unfortunately, almost everyting I've found discusses penetration in, through, and around buildings. This is where the research $$ is. My experience tells me that multipath from foilage is stronger that attenuation thru foilage at 2.4 GHz. This is based on range observation (about 6 mile range) between a 12 foot transmit antenna and 24 foot Cassegrain antenna. Both antennas were on 800 ft+ hills above countryside. Frequency is 2.7 to 2.8 GHz. During strong winds in the valley, measurements using this range yielded strong nuls and 5.8 dB increases above average signal levels. Bell Labs has made actual building measurements, but mostly around 900 MHz. Results are available in IEEE Trans on Ant & prop, as well as Ant & Prop Mag. Look back between 5 and 15 years ago. There was a very good article in Ant & Prop Mag last year. Most likely, the April or May issue. Ant. & Prop Mag. is a monthly newsletter published by the IEEE Ant. & Prop Society. Available at most EE college libraries. This article dealt with proapgation thru walls, floors, etc. Lastly, I remember an article of prop at 50 MHz through jungle foilage in India. Somewhere in Radio Science, about 10 years ago. JIm Ussailis W1EQO / VE1EQO On Tue, 1 Aug 2000, TAPR Spread Spectrum Special Interest Group digest wrote: > TAPR Spread Spectrum Special Interest Group Digest for Monday, July 31, 2000. > > 1. RE: TAPR or other Wireless NIC on PCMCIA to PCI adapter > 2. Video over Wireless LAN > 3. Nova Wireless routers and Re: Video over Wireless LAN > 4. Re: Nova Wireless routers and Re: Video over Wireless LAN > 5. Re: Nova Wireless routers and Re: Video over Wireless LAN > 6. Re: Nova Wireless routers and Re: Video over Wireless LAN > > ---------------------------------------------------------------------- > > Subject: RE: TAPR or other Wireless NIC on PCMCIA to PCI adapter > From: adesjard@cme.com > Date: Mon, 31 Jul 2000 06:33:29 -0500 > X-Message-Number: 1 > > Everett, > > Aironet (now Cisco), Lucent, Nokia, and Symbol all sell adapters to do just > what you propose. I do not know if they are interoperable, or only work > with their own cards. Nokia has probably the lowest MSRP, with most bits to > be found under the $100 range for the 11Mb DS stuff. > > Alan DesJardins N5VXL > RF Network Engineer > Chicago Mercantile Exchange > Technology Division / Network Operations > 30 S. Wacker Drive > Chicago, IL 60606 > 312-338-2853 > adesjard@cme.com > > > -----Original Message----- > From: bounce-ss-12965@lists.tapr.org > [mailto:bounce-ss-12965@lists.tapr.org]On Behalf Of Everett F Batey > Sent: Saturday, July 29, 2000 2:57 AM > To: TAPR Spread Spectrum Special Interest Group > Cc: Everett F Batey > Subject: [ss] TAPR or other Wireless NIC on PCMCIA to PCI adapter > > > > I am looking for TAPR or other Wireless NIC on PCMCIA to PCI adapters. > I want to be able to use some 2.3/4GB wireless NIC in my laptop's > PCMCIA slot under Linux, BSD or W.98 as well as use same on any PC > of opportunity with a spare PCI slot .. > > Recommendations on card adapter ? > > Recommendations on cards if I limited the field ? > > How many places to look for drivers for diff cards under Linux or F.BSD ? > > TIA / Everett / > > > -- > + http://www.vhwy.com efb@vhwy.com WA6CRE@arrl.net http://www.cotdazr.org > + > + PocketNet Mail to efbatey@mobile.att.net / Cell/VoiceMail 805 340-6471 > + > + Unix BSD, Sun, HP SCO Linux Security Cisco Routing DataFellows QMail DNS > + > > > --- > You are currently subscribed to ss as: adesjard@cme.com > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > ---------------------------------------------------------------------- > > Subject: Video over Wireless LAN > From: "Marius Hauki" > Date: Mon, 31 Jul 2000 14:18:14 +0200 > X-Message-Number: 2 > > I wonder if anybody on this list has done any testing with > video transmission over Wireless LAN (11Mb CDMA units). > > 73 de LA9EEA > Marius Hauki > > > > ---------------------------------------------------------------------- > > Subject: Nova Wireless routers and Re: Video over Wireless LAN > From: Chris Arndt > Date: Mon, 31 Jul 2000 07:15:15 -0700 (PDT) > X-Message-Number: 3 > > Although I haven't done it exclusively on my Cicso Aironet BR340s, it > works, and pretty well. The BRs are my internet connection, so everything, > including my webcams and Axis cams (see below) run over it. > > I have done _mobile_ video with Nova Engineering NovaRoam 900 mhz DSSS > wireless routers. That works pretty well, too, but the Nova units are > slower than 802.11B, up to 1.008 Mb. > > www.nova-eng.com > > The easiest way I have found to integrate this is with Axis 2100 network > cameras. These are an entire digital camera and Linux server in a camera > housing. They have 10/100 baseT ethernet jacks, serial ports and a > discrete input and output, and run on 12vdc. www.axis.com > > On a fast connection, like 802.11B, the Axis cameras can serve up to 10 > video streams at up to 10 frames per second. They can be throttled to > whatever speed you need for their connection. > > BTW, one of the purposes listed for this list is reviewing current ss > devices. Is anyone interested in hearing more about the NovaRoams? > > Chris > > On Mon, 31 Jul 2000, Marius Hauki wrote: > > > I wonder if anybody on this list has done any testing with > > video transmission over Wireless LAN (11Mb CDMA units). > > > > 73 de LA9EEA > > Marius Hauki > > > > > > > > --- > > You are currently subscribed to ss as: carndt@slonet.org > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > ---------------------------------------------------------------------- > > Subject: Re: Nova Wireless routers and Re: Video over Wireless LAN > From: "Eric S. Johansson" > Date: Mon, 31 Jul 2000 11:15:09 -0400 > X-Message-Number: 4 > > > > Chris Arndt wrote: > > > BTW, one of the purposes listed for this list is reviewing current ss > > devices. Is anyone interested in hearing more about the NovaRoams? > > I would be interested. I would also be interested in hearing opinions on path > issues. This is something I'm very interested in because I want to run a link > between my house and friends. We are 1.1 mi. apart with no earth obstructions > but we are both significantly overshadowed by trees. I would have to guess > that approximately 30 percent of the path would be through trees. Towers are > not an option given that these are hundred foot pines. > > My current level of understanding leads me to believe that 2.4 GHz won't make > it but 900 MHz might. I would be really interested in hearing if there are > simple/cheap ways of testing out paths for situations like this. > > ---eric > > > > ---------------------------------------------------------------------- > > Subject: Re: Nova Wireless routers and Re: Video over Wireless LAN > From: John Hansen > Date: Mon, 31 Jul 2000 12:11:27 -0400 > X-Message-Number: 5 > > At 07:15 AM 7/31/00 -0700, you wrote: > >I have done _mobile_ video with Nova Engineering NovaRoam 900 mhz DSSS > >wireless routers. That works pretty well, too, but the Nova units are > >slower than 802.11B, up to 1.008 Mb. > > > >www.nova-eng.com > > Interesting web pages. Who sells these and what do they cost? > > John W2FS > > > ---------------------------------------------------------------------- > > Subject: Re: Nova Wireless routers and Re: Video over Wireless LAN > From: Chris Arndt > Date: Mon, 31 Jul 2000 09:23:28 -0700 (PDT) > X-Message-Number: 6 > > I became a VAR for Nova to buy the 3 I have, so I can resell them. They > list for about $1900, but I can discount that some, especially for > amateurs or in quantities. > > They come with a 12v power supply, and Nova sells type accepted mag mount, > omni and Yagi base antennas, and a rubber duck. Also mobile mounting > brackets, and 12vdc power cords with lighter plugs. The units have a > reverse TNC antenna connection, RJ45 network jack and a serial port for > programming. > > The serial port can also be routed separately from the ethernet, to create > a wireless serial connection. > > Each unit can be set up to repeat, also. > > Chris > > On Mon, 31 Jul 2000, John Hansen wrote: > > > At 07:15 AM 7/31/00 -0700, you wrote: > > >I have done _mobile_ video with Nova Engineering NovaRoam 900 mhz DSSS > > >wireless routers. That works pretty well, too, but the Nova units are > > >slower than 802.11B, up to 1.008 Mb. > > > > > >www.nova-eng.com > > > > Interesting web pages. Who sells these and what do they cost? > > > > John W2FS > > > > > > --- > > You are currently subscribed to ss as: carndt@slonet.org > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > --- > > END OF DIGEST > > --- > You are currently subscribed to ss as: ussailis@shaysnet.com > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 1 21:54:25 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id VAA01811 for ; Tue, 1 Aug 2000 21:54:24 -0500 (CDT) Date: Tue, 1 Aug 2000 22:49:45 -0400 (EDT) From: Jim Ussailis Subject: [ss] Re: ss digest: July 31, 2000 To: "TAPR Spread Spectrum Special Interest Group" cc: ss digest recipients In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Has anyone attempted DS-SS television yet?? Jim Ussailis W1EQO / VE1EQO ussailis@shaysnet.com --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Wed Aug 2 03:55:10 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id DAA02146 for ; Wed, 2 Aug 2000 03:55:09 -0500 (CDT) Message-ID: Date: Wed, 02 Aug 2000 11:34:02 +0300 From: Catalin Enescu Organization: DATEK TELECOM S.A. X-Accept-Language: en MIME-Version: 1.0 To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Voice over IP Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <3987DCFA.1C55EE83@datek.ro> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk I wonder if anybody has done any testing with VoIP equipments over Wireless LAN (11 MB units). Catalin Enescu --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Wed Aug 2 07:50:35 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id HAA26189 for ; Wed, 2 Aug 2000 07:50:34 -0500 (CDT) Message-ID: From: "Paul McInnish" TO: "TAPR Spread Spectrum Special Interest Group" CC: "ss digest recipients" References: Subject: [ss] Re: ss digest: July 31, 2000 Date: Wed, 2 Aug 2000 08:46:46 -0400 Organization: Digital Wireless Corporation MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 X-MDaemon-Deliver-To: ss@lists.tapr.org X-Return-Path: pmcinnish@digiwrls.com List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <001001bffc7f$b80eff60$3a00a8c0@oemcomputer> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Actual practice does NOT support this! We have had 900 MHz and currently - only - 2.4 GHz SS transceivers. Actual range tests also DO NOT support this! It would not make any sense for us to discontinue product that works better for a product line that is inferior! 2.4 GHz does present some interesting multi-path problems but with a proper site survey, sometime, multipath can be brought into play and actually improve the reliability of communications. This is not as easily accomplished with 900 MHz. Paul McInnish - K4BET Manager, Business Development Digital Wireless Corp. One Meca Way Norcross, GA 30093, USA Pho: 770.564.5540, Ext. 2342 Fax: 770.564.5541 Cellular Phone: 678.429.2124 OEM E-mail: k4bet@digital-wireless.com http://www.digital-wireless.com SSuRFnet E-mail: k4bet@ssurfnet.com http://www.ssurfnet.com Visit with us at ISA Expo 2000! Booth 1843 21 - 24 August, 2000 New Orleans, LA USA http://www.isa.org/events/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ New address (bigger and much nicer); Effective 14 August 2000: Digital Wireless Corporation 5375 Oakbrook Parkway Norcross, GA 30093 USA Pho: 678.684.2000 Fax: 678.684.2001 ----- Original Message ----- From: "Jim Ussailis" To: "TAPR Spread Spectrum Special Interest Group" Cc: "ss digest recipients" Sent: Tuesday, August 01, 2000 10:42 PM Subject: [ss] Re: ss digest: July 31, 2000 : Regarding propagation losses at 2.4 GHz & 900 MHz: : : Space loss goes up by 6 dB every time frequency is doubled. That is the : first part. : : Higher frequencies suffer more multipath and foilage loss at higher : frequencies. There is not too much theory here (at least not published). : Unfortunately, almost everyting I've found discusses penetration in, : through, and around buildings. This is where the research $$ is. : : My experience tells me that multipath from foilage is stronger that : attenuation thru : foilage at 2.4 GHz. This is based on range observation (about 6 mile : range) between a 12 foot transmit antenna and 24 foot Cassegrain antenna. : Both antennas were on 800 ft+ hills above countryside. Frequency is 2.7 : to 2.8 GHz. : : During strong winds in the valley, measurements using this range yielded : strong nuls and 5.8 dB increases above average signal levels. : : Bell Labs has made actual building measurements, but mostly around 900 MHz. : Results are available in IEEE Trans on Ant & prop, as well as Ant & Prop : Mag. Look back between 5 and 15 years ago. : : There was a very good article in Ant & Prop Mag last year. Most likely, : the April or May issue. Ant. & Prop Mag. is a monthly newsletter : published by the IEEE Ant. & Prop Society. Available at most EE college : libraries. This article dealt with proapgation thru walls, floors, etc. : : Lastly, I remember an article of prop at 50 MHz through jungle foilage in : India. Somewhere in Radio Science, about 10 years ago. : : : JIm Ussailis W1EQO / VE1EQO : : : On Tue, 1 Aug 2000, TAPR Spread Spectrum Special Interest Group digest wrote: : : > TAPR Spread Spectrum Special Interest Group Digest for Monday, July 31, 2000. : > : > 1. RE: TAPR or other Wireless NIC on PCMCIA to PCI adapter : > 2. Video over Wireless LAN : > 3. Nova Wireless routers and Re: Video over Wireless LAN : > 4. Re: Nova Wireless routers and Re: Video over Wireless LAN : > 5. Re: Nova Wireless routers and Re: Video over Wireless LAN : > 6. Re: Nova Wireless routers and Re: Video over Wireless LAN : > : > ---------------------------------------------------------------------- : > : > Subject: RE: TAPR or other Wireless NIC on PCMCIA to PCI adapter : > From: adesjard@cme.com : > Date: Mon, 31 Jul 2000 06:33:29 -0500 : > X-Message-Number: 1 : > : > Everett, : > : > Aironet (now Cisco), Lucent, Nokia, and Symbol all sell adapters to do just : > what you propose. I do not know if they are interoperable, or only work : > with their own cards. Nokia has probably the lowest MSRP, with most bits to : > be found under the $100 range for the 11Mb DS stuff. : > : > Alan DesJardins N5VXL : > RF Network Engineer : > Chicago Mercantile Exchange : > Technology Division / Network Operations : > 30 S. Wacker Drive : > Chicago, IL 60606 : > 312-338-2853 : > adesjard@cme.com : > : > : > -----Original Message----- : > From: bounce-ss-12965@lists.tapr.org : > [mailto:bounce-ss-12965@lists.tapr.org]On Behalf Of Everett F Batey : > Sent: Saturday, July 29, 2000 2:57 AM : > To: TAPR Spread Spectrum Special Interest Group : > Cc: Everett F Batey : > Subject: [ss] TAPR or other Wireless NIC on PCMCIA to PCI adapter : > : > : > : > I am looking for TAPR or other Wireless NIC on PCMCIA to PCI adapters. : > I want to be able to use some 2.3/4GB wireless NIC in my laptop's : > PCMCIA slot under Linux, BSD or W.98 as well as use same on any PC : > of opportunity with a spare PCI slot .. : > : > Recommendations on card adapter ? : > : > Recommendations on cards if I limited the field ? : > : > How many places to look for drivers for diff cards under Linux or F.BSD ? : > : > TIA / Everett / : > : > : > -- : > + http://www.vhwy.com efb@vhwy.com WA6CRE@arrl.net http://www.cotdazr.org : > + : > + PocketNet Mail to efbatey@mobile.att.net / Cell/VoiceMail 805 340-6471 : > + : > + Unix BSD, Sun, HP SCO Linux Security Cisco Routing DataFellows QMail DNS : > + : > : > : > --- : > You are currently subscribed to ss as: adesjard@cme.com : > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org : > : > : > : > ---------------------------------------------------------------------- : > : > Subject: Video over Wireless LAN : > From: "Marius Hauki" : > Date: Mon, 31 Jul 2000 14:18:14 +0200 : > X-Message-Number: 2 : > : > I wonder if anybody on this list has done any testing with : > video transmission over Wireless LAN (11Mb CDMA units). : > : > 73 de LA9EEA : > Marius Hauki : > : > : > : > ---------------------------------------------------------------------- : > : > Subject: Nova Wireless routers and Re: Video over Wireless LAN : > From: Chris Arndt : > Date: Mon, 31 Jul 2000 07:15:15 -0700 (PDT) : > X-Message-Number: 3 : > : > Although I haven't done it exclusively on my Cicso Aironet BR340s, it : > works, and pretty well. The BRs are my internet connection, so everything, : > including my webcams and Axis cams (see below) run over it. : > : > I have done _mobile_ video with Nova Engineering NovaRoam 900 mhz DSSS : > wireless routers. That works pretty well, too, but the Nova units are : > slower than 802.11B, up to 1.008 Mb. : > : > www.nova-eng.com : > : > The easiest way I have found to integrate this is with Axis 2100 network : > cameras. These are an entire digital camera and Linux server in a camera : > housing. They have 10/100 baseT ethernet jacks, serial ports and a : > discrete input and output, and run on 12vdc. www.axis.com : > : > On a fast connection, like 802.11B, the Axis cameras can serve up to 10 : > video streams at up to 10 frames per second. They can be throttled to : > whatever speed you need for their connection. : > : > BTW, one of the purposes listed for this list is reviewing current ss : > devices. Is anyone interested in hearing more about the NovaRoams? : > : > Chris : > : > On Mon, 31 Jul 2000, Marius Hauki wrote: : > : > > I wonder if anybody on this list has done any testing with : > > video transmission over Wireless LAN (11Mb CDMA units). : > > : > > 73 de LA9EEA : > > Marius Hauki : > > : > > : > > : > > --- : > > You are currently subscribed to ss as: carndt@slonet.org : > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org : > > : > > : > : > : > ---------------------------------------------------------------------- : > : > Subject: Re: Nova Wireless routers and Re: Video over Wireless LAN : > From: "Eric S. Johansson" : > Date: Mon, 31 Jul 2000 11:15:09 -0400 : > X-Message-Number: 4 : > : > : > : > Chris Arndt wrote: : > : > > BTW, one of the purposes listed for this list is reviewing current ss : > > devices. Is anyone interested in hearing more about the NovaRoams? : > : > I would be interested. I would also be interested in hearing opinions on path : > issues. This is something I'm very interested in because I want to run a link : > between my house and friends. We are 1.1 mi. apart with no earth obstructions : > but we are both significantly overshadowed by trees. I would have to guess : > that approximately 30 percent of the path would be through trees. Towers are : > not an option given that these are hundred foot pines. : > : > My current level of understanding leads me to believe that 2.4 GHz won't make : > it but 900 MHz might. I would be really interested in hearing if there are : > simple/cheap ways of testing out paths for situations like this. : > : > ---eric : > : > : > : > ---------------------------------------------------------------------- : > : > Subject: Re: Nova Wireless routers and Re: Video over Wireless LAN : > From: John Hansen : > Date: Mon, 31 Jul 2000 12:11:27 -0400 : > X-Message-Number: 5 : > : > At 07:15 AM 7/31/00 -0700, you wrote: : > >I have done _mobile_ video with Nova Engineering NovaRoam 900 mhz DSSS : > >wireless routers. That works pretty well, too, but the Nova units are : > >slower than 802.11B, up to 1.008 Mb. : > > : > >www.nova-eng.com : > : > Interesting web pages. Who sells these and what do they cost? : > : > John W2FS : > : > : > ---------------------------------------------------------------------- : > : > Subject: Re: Nova Wireless routers and Re: Video over Wireless LAN : > From: Chris Arndt : > Date: Mon, 31 Jul 2000 09:23:28 -0700 (PDT) : > X-Message-Number: 6 : > : > I became a VAR for Nova to buy the 3 I have, so I can resell them. They : > list for about $1900, but I can discount that some, especially for : > amateurs or in quantities. : > : > They come with a 12v power supply, and Nova sells type accepted mag mount, : > omni and Yagi base antennas, and a rubber duck. Also mobile mounting : > brackets, and 12vdc power cords with lighter plugs. The units have a : > reverse TNC antenna connection, RJ45 network jack and a serial port for : > programming. : > : > The serial port can also be routed separately from the ethernet, to create : > a wireless serial connection. : > : > Each unit can be set up to repeat, also. : > : > Chris : > : > On Mon, 31 Jul 2000, John Hansen wrote: : > : > > At 07:15 AM 7/31/00 -0700, you wrote: : > > >I have done _mobile_ video with Nova Engineering NovaRoam 900 mhz DSSS : > > >wireless routers. That works pretty well, too, but the Nova units are : > > >slower than 802.11B, up to 1.008 Mb. : > > > : > > >www.nova-eng.com : > > : > > Interesting web pages. Who sells these and what do they cost? : > > : > > John W2FS : > > : > > : > > --- : > > You are currently subscribed to ss as: carndt@slonet.org : > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org : > > : > > : > : > : > : > : > --- : > : > END OF DIGEST : > : > --- : > You are currently subscribed to ss as: ussailis@shaysnet.com : > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org : > : > : : --- : You are currently subscribed to ss as: k4bet@digital-wireless.com : To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org : : --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Wed Aug 2 09:29:09 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id JAA07590 for ; Wed, 2 Aug 2000 09:29:06 -0500 (CDT) Message-Id: X-Sender: rschroeder@exchange01.bnl.gov Date: Wed, 02 Aug 2000 10:27:49 -0400 To: "TAPR Spread Spectrum Special Interest Group" From: Ron Schroeder Subject: [ss] Re: 900 vs. 2.4 In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <3.0.6.32.20000802102749.00ab1d90@exchange01.bnl.gov> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk At 08:46 AM 8/2/00 -0400, you wrote: >Actual practice does NOT support this! We have had 900 MHz and currently - >only - 2.4 GHz SS transceivers. Actual range tests also DO NOT support >this! It would not make any sense for us to discontinue product that works >better for a product line that is inferior! > >2.4 GHz does present some interesting multi-path problems but with a proper >site survey, sometime, multipath can be brought into play and actually >improve the reliability of communications. This is not as easily >accomplished with 900 MHz. > >Paul McInnish - K4BET >Manager, Business Development >Digital Wireless Corp. Hi Paul, My experience with the Panasonic 2.4G/900MHz SS cordless phones shows the 900MHz link to be much more robust than the 2.4GHz link. Would this be due to TX power and RX sensitivity or to propagation? Thanks, Ron WD8CDH ---------------------------------------------------------------------- Ron Schroeder WD8CDH E. E. S. wd8cdh@bnl.gov rjs@bnl.gov ron@112motors.com 631 344-4561 Day 631 286-5677 Nite *note change of area code to 631 from 516 --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Wed Aug 2 09:55:28 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id JAA13962 for ; Wed, 2 Aug 2000 09:55:27 -0500 (CDT) Message-ID: From: "Paul McInnish" TO: "TAPR Spread Spectrum Special Interest Group" References: Subject: [ss] Re: 900 vs. 2.4 Date: Wed, 2 Aug 2000 10:46:07 -0400 Organization: Digital Wireless Corporation MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 X-MDaemon-Deliver-To: ss@lists.tapr.org X-Return-Path: pmcinnish@digiwrls.com List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <008201bffc90$6486a8a0$3a00a8c0@oemcomputer> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Ron: Partially all those items mentioned... but goes way beyond those you mentioned... band pass skirts, soft & hard filtering, DSP, noise figures of receiver, noise floor, etc., etc. Overhead capabilities, error correction capabilities. As an example... our I/O port speed for our basic module is 230.4kbps.... the over the air data rate is 460.8kbps. This additional over-head bandwidth is where all the radio "house keeping" chores are performed... registration, synchronization, error correction, header transmission, etc., etc. Takes some fairly sophisticated firmware to control and utilize all of this.... but... what can I say? Our intellectual property is not so much the hardware (some uniqueness there also) but the 13 years of development of the embedded firmware that makes the radio "arc, spark, smoke & go" (hi hi). Paul McInnish - K4BET Manager, Business Development Digital Wireless Corp. ----- Original Message ----- From: "Ron Schroeder" To: "TAPR Spread Spectrum Special Interest Group" Sent: Wednesday, August 02, 2000 10:27 AM Subject: [ss] Re: 900 vs. 2.4 : At 08:46 AM 8/2/00 -0400, you wrote: : >Actual practice does NOT support this! We have had 900 MHz and currently - : >only - 2.4 GHz SS transceivers. Actual range tests also DO NOT support : >this! It would not make any sense for us to discontinue product that works : >better for a product line that is inferior! : > : >2.4 GHz does present some interesting multi-path problems but with a proper : >site survey, sometime, multipath can be brought into play and actually : >improve the reliability of communications. This is not as easily : >accomplished with 900 MHz. : > : >Paul McInnish - K4BET : >Manager, Business Development : >Digital Wireless Corp. : : Hi Paul, : : My experience with the Panasonic 2.4G/900MHz SS cordless phones shows the : 900MHz link to be much more robust than the 2.4GHz link. Would this be due : to TX power and RX sensitivity or to propagation? : : Thanks, : : Ron WD8CDH : ---------------------------------------------------------------------- : Ron Schroeder : WD8CDH : E. E. S. : wd8cdh@bnl.gov : rjs@bnl.gov : ron@112motors.com : 631 344-4561 Day : 631 286-5677 Nite : *note change of area code to 631 from 516 : : : --- : You are currently subscribed to ss as: k4bet@digital-wireless.com : To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org : : --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Wed Aug 2 20:40:04 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id UAA23862 for ; Wed, 2 Aug 2000 20:40:04 -0500 (CDT) Date: Wed, 2 Aug 2000 21:39:48 -0400 (EDT) From: Jim Ussailis Subject: [ss] Re: ss digest: August 01, 2000 To: "TAPR Spread Spectrum Special Interest Group" cc: ss digest recipients In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk A comment on data rate & sensitivity / range. The trick to getting a very good range (for a fixed transmitter power) on a data system is to reduce the receiver bandwidth. The sensitivity changes by 10 Log (new bandwidth / previous bandwidth). Of course reducing the bandwidth reduces the data rate. Nothing free. The problem with this is that for many systems reducing the data rate does not reduce the receiver bandwidth. That is generally fixed by the IF or video filters. Unless adaptive filters are employed. --- Does anyone out there know where I can find a schematic for a Costas loop detector? Sure would be a BIG help. ---W1EQO ussailis@shaysnet.com --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Wed Aug 2 20:51:54 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id UAA25970 for ; Wed, 2 Aug 2000 20:51:53 -0500 (CDT) From: "Lyle Johnson" To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: ss digest: August 01, 2000 Date: Wed, 2 Aug 2000 18:47:34 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal In-Reply-To: Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2615.200 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk >Does anyone out there know where I can find a schematic for a Costas loop >detector? Sure would be a BIG help. Try this link... http://www.hamradio.si/psk23cm.html Lyle --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Thu Aug 3 06:53:47 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id GAA17529 for ; Thu, 3 Aug 2000 06:53:47 -0500 (CDT) X-Originating-IP: [209.122.107.2] From: "venumadhav josyula" To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: ss digest: August 01, 2000 Date: Thu, 03 Aug 2000 11:52:42 GMT Mime-Version: 1.0 Content-Type: text/plain; format=flowed Message-ID: X-OriginalArrivalTime: 03 Aug 2000 11:52:42.0976 (UTC) FILETIME=[54F5CE00:01BFFD41] List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Hello jim, In what context are u talking. What for high date services, where u would not want to reduce your data rate. Are there any other ways to improve sensitivity/range. I am talking in sense to HDR services proposed by QUALCOMM. Generally speaking, about variable data rates SS system. thanking you yours sincerely venu >From: Jim Ussailis >Reply-To: "TAPR Spread Spectrum Special Interest Group" >To: "TAPR Spread Spectrum Special Interest Group" >CC: ss digest recipients >Subject: [ss] Re: ss digest: August 01, 2000 >Date: Wed, 2 Aug 2000 21:39:48 -0400 (EDT) >MIME-Version: 1.0 >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id >MHotMailBB52189800BCD820F3C6CC11D9180C240; Wed Aug 02 18:40:41 2000 >From bounce-ss-17222@lists.tapr.org Wed Aug 02 18:45:28 2000 >Return-Path: >In-Reply-To: > >Message-ID: > >List-Unsubscribe: >List-Software: Lyris Server version 3.0 >List-Subscribe: >List-Owner: >X-List-Host: Tucson Amateur Packet Radio >X-Message-Id: >Sender: bounce-ss-17222@lists.tapr.org >Precedence: bulk > >A comment on data rate & sensitivity / range. > >The trick to getting a very good range (for a fixed transmitter power) on a >data system is to reduce the receiver bandwidth. The sensitivity changes >by 10 Log (new bandwidth / previous bandwidth). Of course reducing >the bandwidth reduces the data rate. Nothing free. > >The problem with this is that for many systems reducing the data rate >does not reduce the receiver bandwidth. That is generally fixed by the IF >or video filters. Unless adaptive filters are employed. > >--- > >Does anyone out there know where I can find a schematic for a Costas loop >detector? Sure would be a BIG help. > > >---W1EQO > >ussailis@shaysnet.com > > >--- >You are currently subscribed to ss as: venumadhavj@hotmail.com >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Fri Aug 4 21:27:32 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id VAA02618 for ; Fri, 4 Aug 2000 21:27:31 -0500 (CDT) Date: Fri, 4 Aug 2000 22:27:36 -0400 (EDT) From: Jim Ussailis Subject: [ss] Re: ss digest: August 03, 2000 To: "TAPR Spread Spectrum Special Interest Group" cc: ss digest recipients In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Well, that's the problem. Everybody wants a faster data rate. If everything else is a constant, range must suffer, or one must transmit more info/bit. The info/bit stuff is covered by Shannon. There is a maximum that he provides, then there is a lessor maximum given real hardware (as opposed to theoretical hardware). So, my point is, unless you want a slower data rate, you must increase power to get more range. There is no free lunch! Jim, W1EQO On Fri, 4 Aug 2000, TAPR Spread Spectrum Special Interest Group digest wrote: > TAPR Spread Spectrum Special Interest Group Digest for Thursday, August 03, 2000. > > 1. Re: ss digest: August 01, 2000 > > ---------------------------------------------------------------------- > > Subject: Re: ss digest: August 01, 2000 > From: "venumadhav josyula" > Date: Thu, 03 Aug 2000 11:52:42 GMT > X-Message-Number: 1 > > Hello jim, > > In what context are u talking. What for high date services, where u would > not want to reduce your data rate. Are there any other ways to improve > sensitivity/range. I am talking in sense to HDR services proposed by > QUALCOMM. Generally speaking, about variable data rates SS > system. > > thanking you > yours sincerely > venu > > > > >From: Jim Ussailis > >Reply-To: "TAPR Spread Spectrum Special Interest Group" > >To: "TAPR Spread Spectrum Special Interest Group" > >CC: ss digest recipients > >Subject: [ss] Re: ss digest: August 01, 2000 > >Date: Wed, 2 Aug 2000 21:39:48 -0400 (EDT) > >MIME-Version: 1.0 > >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id > >MHotMailBB52189800BCD820F3C6CC11D9180C240; Wed Aug 02 18:40:41 2000 > >From bounce-ss-17222@lists.tapr.org Wed Aug 02 18:45:28 2000 > >Return-Path: > >In-Reply-To: > > > >Message-ID: > > > >List-Unsubscribe: > >List-Software: Lyris Server version 3.0 > >List-Subscribe: > >List-Owner: > >X-List-Host: Tucson Amateur Packet Radio > >X-Message-Id: > >Sender: bounce-ss-17222@lists.tapr.org > >Precedence: bulk > > > >A comment on data rate & sensitivity / range. > > > >The trick to getting a very good range (for a fixed transmitter power) on a > >data system is to reduce the receiver bandwidth. The sensitivity changes > >by 10 Log (new bandwidth / previous bandwidth). Of course reducing > >the bandwidth reduces the data rate. Nothing free. > > > >The problem with this is that for many systems reducing the data rate > >does not reduce the receiver bandwidth. That is generally fixed by the IF > >or video filters. Unless adaptive filters are employed. > > > >--- > > > >Does anyone out there know where I can find a schematic for a Costas loop > >detector? Sure would be a BIG help. > > > > > >---W1EQO > > > >ussailis@shaysnet.com > > > > > >--- > >You are currently subscribed to ss as: venumadhavj@hotmail.com > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > ________________________________________________________________________ > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > > > > --- > > END OF DIGEST > > --- > You are currently subscribed to ss as: ussailis@shaysnet.com > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Fri Aug 4 22:38:22 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id WAA15674 for ; Fri, 4 Aug 2000 22:38:09 -0500 (CDT) X-Originating-IP: [24.163.110.179] From: "venumadhav josyula" To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: ss digest: August 03, 2000 Date: Sat, 05 Aug 2000 03:35:51 GMT Mime-Version: 1.0 Content-Type: text/plain; format=flowed Message-ID: X-OriginalArrivalTime: 05 Aug 2000 03:35:52.0044 (UTC) FILETIME=[411612C0:01BFFE8E] List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk But whole issue for wireles service providers is provide multimedia services through ur network nad integrate with the present ip/atm networks. So in order to provide those you will require varying data rates and depending upon the application. That needs to be provided. Plus services require raonably good range and your devices need to be more capable. I agree with you about dependability of capacity on shannon's theorem, but my question is'nt it possible to maintain high date rate using multicarrier modulation scheme such as OFDM, and provide reasonably good coding schemes to improve the range. Thus making system less sensitive to frequency errors. Because as your data rate (but this HDR is only possible with some kind of MC* scheme) is increased, your system becomes more sentive to frequency errors and hence provision needs to be made to combat those. Sir I am asking this because, I doing and reearch dessertation on this topic since I am an student. cheers venu * MULTI-CARRIER. >From: Jim Ussailis >Reply-To: "TAPR Spread Spectrum Special Interest Group" >To: "TAPR Spread Spectrum Special Interest Group" >CC: ss digest recipients >Subject: [ss] Re: ss digest: August 03, 2000 >Date: Fri, 4 Aug 2000 22:27:36 -0400 (EDT) >MIME-Version: 1.0 >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id >MHotMailBB54C6A90031D82197EBCC11D9180CF30; Fri Aug 04 19:27:54 2000 >From bounce-ss-17222@lists.tapr.org Fri Aug 04 19:29:33 2000 >Return-Path: >In-Reply-To: > >Message-ID: > >List-Unsubscribe: >List-Software: Lyris Server version 3.0 >List-Subscribe: >List-Owner: >X-List-Host: Tucson Amateur Packet Radio >X-Message-Id: >Sender: bounce-ss-17222@lists.tapr.org >Precedence: bulk > >Well, that's the problem. Everybody wants a faster data rate. If >everything else is a constant, range must suffer, or one must transmit >more info/bit. > >The info/bit stuff is covered by Shannon. There is a maximum that he >provides, then there is a lessor maximum given real hardware (as opposed >to theoretical hardware). > >So, my point is, unless you want a slower data rate, you must increase >power to get more range. There is no free lunch! > >Jim, W1EQO > > >On Fri, 4 Aug 2000, TAPR Spread Spectrum Special Interest Group digest >wrote: > > > TAPR Spread Spectrum Special Interest Group Digest for Thursday, August >03, 2000. > > > > 1. Re: ss digest: August 01, 2000 > > > > ---------------------------------------------------------------------- > > > > Subject: Re: ss digest: August 01, 2000 > > From: "venumadhav josyula" > > Date: Thu, 03 Aug 2000 11:52:42 GMT > > X-Message-Number: 1 > > > > Hello jim, > > > > In what context are u talking. What for high date services, where u >would > > not want to reduce your data rate. Are there any other ways to improve > > sensitivity/range. I am talking in sense to HDR services proposed by > > QUALCOMM. Generally speaking, about variable data rates SS > > system. > > > > thanking you > > yours sincerely > > venu > > > > > > > > >From: Jim Ussailis > > >Reply-To: "TAPR Spread Spectrum Special Interest Group" > > > >To: "TAPR Spread Spectrum Special Interest Group" > > >CC: ss digest recipients > > >Subject: [ss] Re: ss digest: August 01, 2000 > > >Date: Wed, 2 Aug 2000 21:39:48 -0400 (EDT) > > >MIME-Version: 1.0 > > >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id > > >MHotMailBB52189800BCD820F3C6CC11D9180C240; Wed Aug 02 18:40:41 2000 > > >From bounce-ss-17222@lists.tapr.org Wed Aug 02 18:45:28 2000 > > >Return-Path: > > >In-Reply-To: > > > > > > >Message-ID: > > > > > > >List-Unsubscribe: > > >List-Software: Lyris Server version 3.0 > > >List-Subscribe: > > >List-Owner: > > >X-List-Host: Tucson Amateur Packet Radio > > >X-Message-Id: > > > >Sender: bounce-ss-17222@lists.tapr.org > > >Precedence: bulk > > > > > >A comment on data rate & sensitivity / range. > > > > > >The trick to getting a very good range (for a fixed transmitter power) >on a > > >data system is to reduce the receiver bandwidth. The sensitivity >changes > > >by 10 Log (new bandwidth / previous bandwidth). Of course reducing > > >the bandwidth reduces the data rate. Nothing free. > > > > > >The problem with this is that for many systems reducing the data rate > > >does not reduce the receiver bandwidth. That is generally fixed by the >IF > > >or video filters. Unless adaptive filters are employed. > > > > > >--- > > > > > >Does anyone out there know where I can find a schematic for a Costas >loop > > >detector? Sure would be a BIG help. > > > > > > > > >---W1EQO > > > > > >ussailis@shaysnet.com > > > > > > > > >--- > > >You are currently subscribed to ss as: venumadhavj@hotmail.com > > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > ________________________________________________________________________ > > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > > > > > > > > > --- > > > > END OF DIGEST > > > > --- > > You are currently subscribed to ss as: ussailis@shaysnet.com > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > >--- >You are currently subscribed to ss as: venumadhavj@hotmail.com >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Sat Aug 5 00:03:24 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id AAA04927 for ; Sat, 5 Aug 2000 00:03:21 -0500 (CDT) Message-ID: From: "jeff millar" To: "TAPR Spread Spectrum Special Interest Group" References: Subject: [ss] Re: ss digest: August 03, 2000 Date: Sat, 5 Aug 2000 01:00:44 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4029.2901 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <002101bffe9a$1e5ea100$0201a8c0@home> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk I've been reading about modulation formats, coding, etc quite a bit lately. Here's some top level conclusions... OFDM doesn't do anything unique with respect to the Shannon limit. What it does is allow for good signal reception in the presence of multipath. because it splits the data stream up over many separate carriers transmitting at low speed....and each very slow stream is immune to multipath. It's up to the designer to apply a modulation and coding to each carrier to optimize performance. The upcoming IEEE 802.11 OFDM variant will define a common approach for that application. By the way, OFDM would be great for microwave repeaters intended work with mobiles. Mobile flutter (chop) increases in frequency, proportional to operating frequency. At 10 GHz, its a 400Hz buzz. With OFDM, all that stuff disappears. In theory, Someone could make a voice bandwidth OFDM system with a PC and a sound card. Any takers? Another by the way. OFDM is _not_ spread spectrum. The carriers are packed together so tightly, they overlap...that's what the "orthogonal" part of the name means. Coding is commonly used to get closer to the Shannon limit. Without coding, a link might only get to 3-10% of theoretical capacity. Traditional block codes such as Reed-Solomon might push that to 20%. Recently, "Turbo" codes which iteratively process the data have pushed capacity to >80%. Turbo codes are just starting to appear in products and require a complex ASIC or lots of processing. They also introduce significantly increased delay compared to other earlier approaches. Turbo codes work by modeling the strongest interference and subtracting it from the signal, then subtracting the next strongest interferer, etc until the best possible signal is recovered. If you're interested in the latest algorithms that improve capacity...possibly even "beating Shannon" (depends on your definition), check out Bell Labs Space Time Adaptive Processing (BLAST). They use multiple transmitters/antennas and multiple receivers/antennas and transmit different portions of the data stream from each transmitter and receive all the stream on each receiver. Laboratory experiments show upwards of 30 bits/sec per Hz of bandwidth...(1 Mbps in a 30 kHz channel) This this is not ready for prime time, takes gobs of computer power, and requires several advanced degrees in signal processing and math to work with it. But with chips getting more powerful and spectrum costing $B, it will get popular in 10 years or so. BLAST works with Turbo codes techniques (iterative subtraction) to sort out all the overlapping carriers and multipath effects....sounds like magic but it really works. hope this helps, jeff wa1hco ----- Original Message ----- From: "venumadhav josyula" To: "TAPR Spread Spectrum Special Interest Group" Sent: Friday, August 04, 2000 11:35 PM Subject: [ss] Re: ss digest: August 03, 2000 > > But whole issue for wireles service providers is provide multimedia services > through ur network nad integrate with the present ip/atm networks. So in > order to provide those > you will require varying data rates and depending upon the application. That > needs to be provided. Plus services require raonably good range and your > devices need to be more capable. > > I agree with you about dependability of capacity on shannon's theorem, but > my question is'nt it possible to maintain high date rate using multicarrier > modulation scheme such as OFDM, and provide reasonably good coding schemes > to improve the range. Thus making system less sensitive to frequency errors. > > Because as your data rate (but this HDR is only possible with some kind of > MC* scheme) is increased, your system becomes more sentive to frequency > errors and hence provision needs to be made to combat those. > > Sir I am asking this because, I doing and reearch dessertation on this topic > since I am an student. > > cheers > venu > > * MULTI-CARRIER. > >From: Jim Ussailis > >Reply-To: "TAPR Spread Spectrum Special Interest Group" > >To: "TAPR Spread Spectrum Special Interest Group" > >CC: ss digest recipients > >Subject: [ss] Re: ss digest: August 03, 2000 > >Date: Fri, 4 Aug 2000 22:27:36 -0400 (EDT) > >MIME-Version: 1.0 > >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id > >MHotMailBB54C6A90031D82197EBCC11D9180CF30; Fri Aug 04 19:27:54 2000 > >From bounce-ss-17222@lists.tapr.org Fri Aug 04 19:29:33 2000 > >Return-Path: > >In-Reply-To: > > > >Message-ID: > > > >List-Unsubscribe: > >List-Software: Lyris Server version 3.0 > >List-Subscribe: > >List-Owner: > >X-List-Host: Tucson Amateur Packet Radio > >X-Message-Id: > >Sender: bounce-ss-17222@lists.tapr.org > >Precedence: bulk > > > >Well, that's the problem. Everybody wants a faster data rate. If > >everything else is a constant, range must suffer, or one must transmit > >more info/bit. > > > >The info/bit stuff is covered by Shannon. There is a maximum that he > >provides, then there is a lessor maximum given real hardware (as opposed > >to theoretical hardware). > > > >So, my point is, unless you want a slower data rate, you must increase > >power to get more range. There is no free lunch! > > > >Jim, W1EQO > > > > > >On Fri, 4 Aug 2000, TAPR Spread Spectrum Special Interest Group digest > >wrote: > > > > > TAPR Spread Spectrum Special Interest Group Digest for Thursday, August > >03, 2000. > > > > > > 1. Re: ss digest: August 01, 2000 > > > > > > ---------------------------------------------------------------------- > > > > > > Subject: Re: ss digest: August 01, 2000 > > > From: "venumadhav josyula" > > > Date: Thu, 03 Aug 2000 11:52:42 GMT > > > X-Message-Number: 1 > > > > > > Hello jim, > > > > > > In what context are u talking. What for high date services, where u > >would > > > not want to reduce your data rate. Are there any other ways to improve > > > sensitivity/range. I am talking in sense to HDR services proposed by > > > QUALCOMM. Generally speaking, about variable data rates SS > > > system. > > > > > > thanking you > > > yours sincerely > > > venu > > > > > > > > > > > > >From: Jim Ussailis > > > >Reply-To: "TAPR Spread Spectrum Special Interest Group" > > > > > >To: "TAPR Spread Spectrum Special Interest Group" > > > >CC: ss digest recipients > > > >Subject: [ss] Re: ss digest: August 01, 2000 > > > >Date: Wed, 2 Aug 2000 21:39:48 -0400 (EDT) > > > >MIME-Version: 1.0 > > > >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id > > > >MHotMailBB52189800BCD820F3C6CC11D9180C240; Wed Aug 02 18:40:41 2000 > > > >From bounce-ss-17222@lists.tapr.org Wed Aug 02 18:45:28 2000 > > > >Return-Path: > > > >In-Reply-To: > > > > > > > > > >Message-ID: > > > > > > > > > >List-Unsubscribe: > > > >List-Software: Lyris Server version 3.0 > > > >List-Subscribe: > > > >List-Owner: > > > >X-List-Host: Tucson Amateur Packet Radio > > > >X-Message-Id: > > > > > >Sender: bounce-ss-17222@lists.tapr.org > > > >Precedence: bulk > > > > > > > >A comment on data rate & sensitivity / range. > > > > > > > >The trick to getting a very good range (for a fixed transmitter power) > >on a > > > >data system is to reduce the receiver bandwidth. The sensitivity > >changes > > > >by 10 Log (new bandwidth / previous bandwidth). Of course reducing > > > >the bandwidth reduces the data rate. Nothing free. > > > > > > > >The problem with this is that for many systems reducing the data rate > > > >does not reduce the receiver bandwidth. That is generally fixed by the > >IF > > > >or video filters. Unless adaptive filters are employed. > > > > > > > >--- > > > > > > > >Does anyone out there know where I can find a schematic for a Costas > >loop > > > >detector? Sure would be a BIG help. > > > > > > > > > > > >---W1EQO > > > > > > > >ussailis@shaysnet.com > > > > > > > > > > > >--- > > > >You are currently subscribed to ss as: venumadhavj@hotmail.com > > > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > > ________________________________________________________________________ > > > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > > > > > > > > > > > > > > --- > > > > > > END OF DIGEST > > > > > > --- > > > You are currently subscribed to ss as: ussailis@shaysnet.com > > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > >--- > >You are currently subscribed to ss as: venumadhavj@hotmail.com > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > ________________________________________________________________________ > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > > --- > You are currently subscribed to ss as: JEFF@WA1HCO.MV.COM > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Sun Aug 6 19:47:29 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id TAA06874 for ; Sun, 6 Aug 2000 19:47:26 -0500 (CDT) Date: Sun, 6 Aug 2000 20:47:10 -0400 (EDT) From: Jim Ussailis Subject: [ss] Re: ss digest: August 04, 2000 To: "TAPR Spread Spectrum Special Interest Group" cc: ss digest recipients In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Range vs data rate....Lets look at several things: 1. Yes, you can use a higher level modulation scheme to get a better data rate. But there is a practical limit. That limit is generally imposed by phase or amplitude error across the receiver passband, or by signal-to-carrier level. The first item kills receivers. Either there is a lot of phase error in a passband, (as with Butterworth / Tchebvychev filters) or there is a large amplitude error in the passband (as with Bessel and some butterworth filters). 2. The second problem is entropy. This is a consequence of the second law of thermodynamics. It says, simply, "There ain't any free lunch!" This is probably beyond what people want plugging their email with here. But Shannon's work comes out of this. So it comes down to the following problem...Yes, you could cook-up an adaptive bandpass scheme that would allow long range / slow data rate some of the time, but...The transmitter -to- receiver path is usually fixed, so the path wouldn't work all of the time. If the product only works some of the time, people usually won't buy it. The answer, then, is somewhat country based. Many countries in the EEC allow 1/2 Watt for unlicensed communication. Here it is under 1 milliWatt, unless spread-spectrum modulation is used. Finally, what will happen when people want broadband wireless, say, across town? Here in the New England States, "across town" equals 4 or 5 miles, often more. Sure won't work with 1 mW. Not be too reliable with 1/2 Watt. I've rambled enough. Jim, W1EQO On Sat, 5 Aug 2000, TAPR Spread Spectrum Special Interest Group digest wrote: > TAPR Spread Spectrum Special Interest Group Digest for Friday, August 04, 2000. > > 1. Re: ss digest: August 03, 2000 > 2. Re: ss digest: August 03, 2000 > > ---------------------------------------------------------------------- > > Subject: Re: ss digest: August 03, 2000 > From: Jim Ussailis > Date: Fri, 4 Aug 2000 22:27:36 -0400 (EDT) > X-Message-Number: 1 > > Well, that's the problem. Everybody wants a faster data rate. If > everything else is a constant, range must suffer, or one must transmit > more info/bit. > > The info/bit stuff is covered by Shannon. There is a maximum that he > provides, then there is a lessor maximum given real hardware (as opposed > to theoretical hardware). > > So, my point is, unless you want a slower data rate, you must increase > power to get more range. There is no free lunch! > > Jim, W1EQO > > > On Fri, 4 Aug 2000, TAPR Spread Spectrum Special Interest Group digest wrote: > > > TAPR Spread Spectrum Special Interest Group Digest for Thursday, August 03, 2000. > > > > 1. Re: ss digest: August 01, 2000 > > > > ---------------------------------------------------------------------- > > > > Subject: Re: ss digest: August 01, 2000 > > From: "venumadhav josyula" > > Date: Thu, 03 Aug 2000 11:52:42 GMT > > X-Message-Number: 1 > > > > Hello jim, > > > > In what context are u talking. What for high date services, where u would > > not want to reduce your data rate. Are there any other ways to improve > > sensitivity/range. I am talking in sense to HDR services proposed by > > QUALCOMM. Generally speaking, about variable data rates SS > > system. > > > > thanking you > > yours sincerely > > venu > > > > > > > > >From: Jim Ussailis > > >Reply-To: "TAPR Spread Spectrum Special Interest Group" > > >To: "TAPR Spread Spectrum Special Interest Group" > > >CC: ss digest recipients > > >Subject: [ss] Re: ss digest: August 01, 2000 > > >Date: Wed, 2 Aug 2000 21:39:48 -0400 (EDT) > > >MIME-Version: 1.0 > > >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id > > >MHotMailBB52189800BCD820F3C6CC11D9180C240; Wed Aug 02 18:40:41 2000 > > >From bounce-ss-17222@lists.tapr.org Wed Aug 02 18:45:28 2000 > > >Return-Path: > > >In-Reply-To: > > > > > >Message-ID: > > > > > >List-Unsubscribe: > > >List-Software: Lyris Server version 3.0 > > >List-Subscribe: > > >List-Owner: > > >X-List-Host: Tucson Amateur Packet Radio > > >X-Message-Id: > > >Sender: bounce-ss-17222@lists.tapr.org > > >Precedence: bulk > > > > > >A comment on data rate & sensitivity / range. > > > > > >The trick to getting a very good range (for a fixed transmitter power) on a > > >data system is to reduce the receiver bandwidth. The sensitivity changes > > >by 10 Log (new bandwidth / previous bandwidth). Of course reducing > > >the bandwidth reduces the data rate. Nothing free. > > > > > >The problem with this is that for many systems reducing the data rate > > >does not reduce the receiver bandwidth. That is generally fixed by the IF > > >or video filters. Unless adaptive filters are employed. > > > > > >--- > > > > > >Does anyone out there know where I can find a schematic for a Costas loop > > >detector? Sure would be a BIG help. > > > > > > > > >---W1EQO > > > > > >ussailis@shaysnet.com > > > > > > > > >--- > > >You are currently subscribed to ss as: venumadhavj@hotmail.com > > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > ________________________________________________________________________ > > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > > > > > > > > > --- > > > > END OF DIGEST > > > > --- > > You are currently subscribed to ss as: ussailis@shaysnet.com > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > ---------------------------------------------------------------------- > > Subject: Re: ss digest: August 03, 2000 > From: "venumadhav josyula" > Date: Sat, 05 Aug 2000 03:35:51 GMT > X-Message-Number: 2 > > > But whole issue for wireles service providers is provide multimedia services > through ur network nad integrate with the present ip/atm networks. So in > order to provide those > you will require varying data rates and depending upon the application. That > needs to be provided. Plus services require raonably good range and your > devices need to be more capable. > > I agree with you about dependability of capacity on shannon's theorem, but > my question is'nt it possible to maintain high date rate using multicarrier > modulation scheme such as OFDM, and provide reasonably good coding schemes > to improve the range. Thus making system less sensitive to frequency errors. > > Because as your data rate (but this HDR is only possible with some kind of > MC* scheme) is increased, your system becomes more sentive to frequency > errors and hence provision needs to be made to combat those. > > Sir I am asking this because, I doing and reearch dessertation on this topic > since I am an student. > > cheers > venu > > * MULTI-CARRIER. > >From: Jim Ussailis > >Reply-To: "TAPR Spread Spectrum Special Interest Group" > >To: "TAPR Spread Spectrum Special Interest Group" > >CC: ss digest recipients > >Subject: [ss] Re: ss digest: August 03, 2000 > >Date: Fri, 4 Aug 2000 22:27:36 -0400 (EDT) > >MIME-Version: 1.0 > >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id > >MHotMailBB54C6A90031D82197EBCC11D9180CF30; Fri Aug 04 19:27:54 2000 > >From bounce-ss-17222@lists.tapr.org Fri Aug 04 19:29:33 2000 > >Return-Path: > >In-Reply-To: > > > >Message-ID: > > > >List-Unsubscribe: > >List-Software: Lyris Server version 3.0 > >List-Subscribe: > >List-Owner: > >X-List-Host: Tucson Amateur Packet Radio > >X-Message-Id: > >Sender: bounce-ss-17222@lists.tapr.org > >Precedence: bulk > > > >Well, that's the problem. Everybody wants a faster data rate. If > >everything else is a constant, range must suffer, or one must transmit > >more info/bit. > > > >The info/bit stuff is covered by Shannon. There is a maximum that he > >provides, then there is a lessor maximum given real hardware (as opposed > >to theoretical hardware). > > > >So, my point is, unless you want a slower data rate, you must increase > >power to get more range. There is no free lunch! > > > >Jim, W1EQO > > > > > >On Fri, 4 Aug 2000, TAPR Spread Spectrum Special Interest Group digest > >wrote: > > > > > TAPR Spread Spectrum Special Interest Group Digest for Thursday, August > >03, 2000. > > > > > > 1. Re: ss digest: August 01, 2000 > > > > > > ---------------------------------------------------------------------- > > > > > > Subject: Re: ss digest: August 01, 2000 > > > From: "venumadhav josyula" > > > Date: Thu, 03 Aug 2000 11:52:42 GMT > > > X-Message-Number: 1 > > > > > > Hello jim, > > > > > > In what context are u talking. What for high date services, where u > >would > > > not want to reduce your data rate. Are there any other ways to improve > > > sensitivity/range. I am talking in sense to HDR services proposed by > > > QUALCOMM. Generally speaking, about variable data rates SS > > > system. > > > > > > thanking you > > > yours sincerely > > > venu > > > > > > > > > > > > >From: Jim Ussailis > > > >Reply-To: "TAPR Spread Spectrum Special Interest Group" > > > > > >To: "TAPR Spread Spectrum Special Interest Group" > > > >CC: ss digest recipients > > > >Subject: [ss] Re: ss digest: August 01, 2000 > > > >Date: Wed, 2 Aug 2000 21:39:48 -0400 (EDT) > > > >MIME-Version: 1.0 > > > >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id > > > >MHotMailBB52189800BCD820F3C6CC11D9180C240; Wed Aug 02 18:40:41 2000 > > > >From bounce-ss-17222@lists.tapr.org Wed Aug 02 18:45:28 2000 > > > >Return-Path: > > > >In-Reply-To: > > > > > > > > > >Message-ID: > > > > > > > > > >List-Unsubscribe: > > > >List-Software: Lyris Server version 3.0 > > > >List-Subscribe: > > > >List-Owner: > > > >X-List-Host: Tucson Amateur Packet Radio > > > >X-Message-Id: > > > > > >Sender: bounce-ss-17222@lists.tapr.org > > > >Precedence: bulk > > > > > > > >A comment on data rate & sensitivity / range. > > > > > > > >The trick to getting a very good range (for a fixed transmitter power) > >on a > > > >data system is to reduce the receiver bandwidth. The sensitivity > >changes > > > >by 10 Log (new bandwidth / previous bandwidth). Of course reducing > > > >the bandwidth reduces the data rate. Nothing free. > > > > > > > >The problem with this is that for many systems reducing the data rate > > > >does not reduce the receiver bandwidth. That is generally fixed by the > >IF > > > >or video filters. Unless adaptive filters are employed. > > > > > > > >--- > > > > > > > >Does anyone out there know where I can find a schematic for a Costas > >loop > > > >detector? Sure would be a BIG help. > > > > > > > > > > > >---W1EQO > > > > > > > >ussailis@shaysnet.com > > > > > > > > > > > >--- > > > >You are currently subscribed to ss as: venumadhavj@hotmail.com > > > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > > ________________________________________________________________________ > > > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > > > > > > > > > > > > > > --- > > > > > > END OF DIGEST > > > > > > --- > > > You are currently subscribed to ss as: ussailis@shaysnet.com > > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > >--- > >You are currently subscribed to ss as: venumadhavj@hotmail.com > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > ________________________________________________________________________ > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > > > > --- > > END OF DIGEST > > --- > You are currently subscribed to ss as: ussailis@shaysnet.com > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Sun Aug 6 19:56:08 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id TAA08510 for ; Sun, 6 Aug 2000 19:56:03 -0500 (CDT) Date: Sun, 6 Aug 2000 20:55:49 -0400 (EDT) From: Jim Ussailis Subject: [ss] Re: ss digest: August 05, 2000 To: "TAPR Spread Spectrum Special Interest Group" cc: ss digest recipients In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Jeff, Where do I find out about this coding scheme. Two items puzzle me: 1. The olde ECM trick of beating multipath is to use "leading-edge gating." That is use a very small leading edge of the pulse. Others use a trick like this, they use very short pulses, to beat multipath. 2. Mathematically, orthogonal means "at right angles," or non-overlapping. DS-SS codes are usually selected to be orthogonal. Jim, W1EQO ussailis@shaysnet.com On Sun, 6 Aug 2000, TAPR Spread Spectrum Special Interest Group digest wrote: > TAPR Spread Spectrum Special Interest Group Digest for Saturday, August 05, 2000. > > 1. Re: ss digest: August 03, 2000 > > ---------------------------------------------------------------------- > > Subject: Re: ss digest: August 03, 2000 > From: "jeff millar" > Date: Sat, 5 Aug 2000 01:00:44 -0400 > X-Message-Number: 1 > > I've been reading about modulation formats, coding, etc quite a bit lately. > Here's some top level conclusions... > > OFDM doesn't do anything unique with respect to the Shannon limit. What it > does is allow for good signal reception in the presence of multipath. > because it splits the data stream up over many separate carriers > transmitting at low speed....and each very slow stream is immune to > multipath. It's up to the designer to apply a modulation and coding to each > carrier to optimize performance. The upcoming IEEE 802.11 OFDM variant will > define a common approach for that application. > > By the way, OFDM would be great for microwave repeaters intended work with > mobiles. Mobile flutter (chop) increases in frequency, proportional to > operating frequency. At 10 GHz, its a 400Hz buzz. With OFDM, all that > stuff disappears. In theory, Someone could make a voice bandwidth OFDM > system with a PC and a sound card. Any takers? > > Another by the way. OFDM is _not_ spread spectrum. The carriers are packed > together so tightly, they overlap...that's what the "orthogonal" part of the > name means. > > Coding is commonly used to get closer to the Shannon limit. Without coding, > a link might only get to 3-10% of theoretical capacity. Traditional block > codes such as Reed-Solomon might push that to 20%. Recently, "Turbo" codes > which iteratively process the data have pushed capacity to >80%. Turbo > codes are just starting to appear in products and require a complex ASIC or > lots of processing. They also introduce significantly increased delay > compared to other earlier approaches. Turbo codes work by modeling the > strongest interference and subtracting it from the signal, then subtracting > the next strongest interferer, etc until the best possible signal is > recovered. > > If you're interested in the latest algorithms that improve > capacity...possibly even "beating Shannon" (depends on your definition), > check out Bell Labs Space Time Adaptive Processing (BLAST). They use > multiple transmitters/antennas and multiple receivers/antennas and transmit > different portions of the data stream from each transmitter and receive all > the stream on each receiver. Laboratory experiments show upwards of 30 > bits/sec per Hz of bandwidth...(1 Mbps in a 30 kHz channel) This this is > not ready for prime time, takes gobs of computer power, and requires several > advanced degrees in signal processing and math to work with it. But with > chips getting more powerful and spectrum costing $B, it will get popular in > 10 years or so. BLAST works with Turbo codes techniques (iterative > subtraction) to sort out all the overlapping carriers and multipath > effects....sounds like magic but it really works. > > hope this helps, > > jeff > wa1hco > > ----- Original Message ----- > From: "venumadhav josyula" > To: "TAPR Spread Spectrum Special Interest Group" > Sent: Friday, August 04, 2000 11:35 PM > Subject: [ss] Re: ss digest: August 03, 2000 > > > > > > But whole issue for wireles service providers is provide multimedia > services > > through ur network nad integrate with the present ip/atm networks. So in > > order to provide those > > you will require varying data rates and depending upon the application. > That > > needs to be provided. Plus services require raonably good range and your > > devices need to be more capable. > > > > I agree with you about dependability of capacity on shannon's theorem, but > > my question is'nt it possible to maintain high date rate using > multicarrier > > modulation scheme such as OFDM, and provide reasonably good coding schemes > > to improve the range. Thus making system less sensitive to frequency > errors. > > > > Because as your data rate (but this HDR is only possible with some kind of > > MC* scheme) is increased, your system becomes more sentive to frequency > > errors and hence provision needs to be made to combat those. > > > > Sir I am asking this because, I doing and reearch dessertation on this > topic > > since I am an student. > > > > cheers > > venu > > > > * MULTI-CARRIER. > > >From: Jim Ussailis > > >Reply-To: "TAPR Spread Spectrum Special Interest Group" > > > >To: "TAPR Spread Spectrum Special Interest Group" > > >CC: ss digest recipients > > >Subject: [ss] Re: ss digest: August 03, 2000 > > >Date: Fri, 4 Aug 2000 22:27:36 -0400 (EDT) > > >MIME-Version: 1.0 > > >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id > > >MHotMailBB54C6A90031D82197EBCC11D9180CF30; Fri Aug 04 19:27:54 2000 > > >From bounce-ss-17222@lists.tapr.org Fri Aug 04 19:29:33 2000 > > >Return-Path: > > >In-Reply-To: > > > > > > >Message-ID: > > > > g> > > >List-Unsubscribe: > > >List-Software: Lyris Server version 3.0 > > >List-Subscribe: > > >List-Owner: > > >X-List-Host: Tucson Amateur Packet Radio > > >X-Message-Id: > > >Sender: bounce-ss-17222@lists.tapr.org > > >Precedence: bulk > > > > > >Well, that's the problem. Everybody wants a faster data rate. If > > >everything else is a constant, range must suffer, or one must transmit > > >more info/bit. > > > > > >The info/bit stuff is covered by Shannon. There is a maximum that he > > >provides, then there is a lessor maximum given real hardware (as opposed > > >to theoretical hardware). > > > > > >So, my point is, unless you want a slower data rate, you must increase > > >power to get more range. There is no free lunch! > > > > > >Jim, W1EQO > > > > > > > > >On Fri, 4 Aug 2000, TAPR Spread Spectrum Special Interest Group digest > > >wrote: > > > > > > > TAPR Spread Spectrum Special Interest Group Digest for Thursday, > August > > >03, 2000. > > > > > > > > 1. Re: ss digest: August 01, 2000 > > > > > > > > ---------------------------------------------------------------------- > > > > > > > > Subject: Re: ss digest: August 01, 2000 > > > > From: "venumadhav josyula" > > > > Date: Thu, 03 Aug 2000 11:52:42 GMT > > > > X-Message-Number: 1 > > > > > > > > Hello jim, > > > > > > > > In what context are u talking. What for high date services, where u > > >would > > > > not want to reduce your data rate. Are there any other ways to improve > > > > sensitivity/range. I am talking in sense to HDR services proposed by > > > > QUALCOMM. Generally speaking, about variable data rates SS > > > > system. > > > > > > > > thanking you > > > > yours sincerely > > > > venu > > > > > > > > > > > > > > > > >From: Jim Ussailis > > > > >Reply-To: "TAPR Spread Spectrum Special Interest Group" > > > > > > > >To: "TAPR Spread Spectrum Special Interest Group" > > > > >CC: ss digest recipients > > > > >Subject: [ss] Re: ss digest: August 01, 2000 > > > > >Date: Wed, 2 Aug 2000 21:39:48 -0400 (EDT) > > > > >MIME-Version: 1.0 > > > > >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id > > > > >MHotMailBB52189800BCD820F3C6CC11D9180C240; Wed Aug 02 18:40:41 2000 > > > > >From bounce-ss-17222@lists.tapr.org Wed Aug 02 18:45:28 2000 > > > > >Return-Path: > > > > >In-Reply-To: > > > > > > > > > > > > > >Message-ID: > > > > > > > > > g> > > > > >List-Unsubscribe: > > > > >List-Software: Lyris Server version 3.0 > > > > >List-Subscribe: > > > > >List-Owner: > > > > >X-List-Host: Tucson Amateur Packet Radio > > > > >X-Message-Id: > > > > > > > >Sender: bounce-ss-17222@lists.tapr.org > > > > >Precedence: bulk > > > > > > > > > >A comment on data rate & sensitivity / range. > > > > > > > > > >The trick to getting a very good range (for a fixed transmitter > power) > > >on a > > > > >data system is to reduce the receiver bandwidth. The sensitivity > > >changes > > > > >by 10 Log (new bandwidth / previous bandwidth). Of course reducing > > > > >the bandwidth reduces the data rate. Nothing free. > > > > > > > > > >The problem with this is that for many systems reducing the data rate > > > > >does not reduce the receiver bandwidth. That is generally fixed by > the > > >IF > > > > >or video filters. Unless adaptive filters are employed. > > > > > > > > > >--- > > > > > > > > > >Does anyone out there know where I can find a schematic for a Costas > > >loop > > > > >detector? Sure would be a BIG help. > > > > > > > > > > > > > > >---W1EQO > > > > > > > > > >ussailis@shaysnet.com > > > > > > > > > > > > > > >--- > > > > >You are currently subscribed to ss as: venumadhavj@hotmail.com > > > > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > > > > > > ________________________________________________________________________ > > > > Get Your Private, Free E-mail from MSN Hotmail at > http://www.hotmail.com > > > > > > > > > > > > > > > > > > > > --- > > > > > > > > END OF DIGEST > > > > > > > > --- > > > > You are currently subscribed to ss as: ussailis@shaysnet.com > > > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > > > > > >--- > > >You are currently subscribed to ss as: venumadhavj@hotmail.com > > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > ________________________________________________________________________ > > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > > > > > --- > > You are currently subscribed to ss as: JEFF@WA1HCO.MV.COM > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > --- > > END OF DIGEST > > --- > You are currently subscribed to ss as: ussailis@shaysnet.com > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Sun Aug 6 22:23:58 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id WAA01111 for ; Sun, 6 Aug 2000 22:23:54 -0500 (CDT) Message-ID: From: "jeff millar" To: "TAPR Spread Spectrum Special Interest Group" References: Subject: [ss] Re: ss digest: August 05, 2000 Date: Sun, 6 Aug 2000 23:14:37 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4029.2901 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <000601c0001d$a07be6a0$0201a8c0@home> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Here's a few pointers to OFDM sites. The europeans have the best descriptions because they've already selected it for digital radio and video broadcasting http://www.ert.rwth-aachen.de/Projekte/Theo/OFDM/node1.html http://www.wilan.com/ofdm/main.html http://www.winlab.rutgers.edu/~sinhar/ofdm.html Multipath causes two effects, overlapping symbols if the symbol rate exceeds the delay dispersion and carrier cancelation (mobile flutter). OFDM attacks the first by slowing the modulation rate. The transmitted bit stream is demultiplexed into many (100's to 1000's) of separate streams and each modulates a separate carrier. The symbol time increases by 100's or 1000's and the effect of multipath is reduced. Delay dispersion no longer causes intersymbol interference. For example assume a 1M bps data stream and 1024 carriers. Allowed delay dispersion increases from about 1 us to 1 ms. Flutter is handled a different way. The data stream get run through a forward error correction, such as Reed-Solomon, and receivers can decode correctly even in the presence of dropouts. In addition, the individual carriers probably drop out at different times due to frequency diversity...keeping the coding effective. The term orthogonal is used because the carriers are independent of each other in a mathmatical sense...as is normal for a frequency division multiplex. But OFDM packs the carriers very close together and doesn't bother to tightly filter them. The carriers are generated by an Inverse FFT (time to frequency domain) and received by a forward FFT. Each carrier looks like a sinc function in the frequency domain...a central peak with ripples and zero crossings away from the central peak. The adjacent carriers land exactly on the zero crossing. The diagrams look exactly like zero intersymbol interference in the time domain filtering but mapped into the frequency domain. Orthogonality is maintained by frequency locking to the transmitted signal and maintaining lots of precision in the receiver's FFT. hope this helps, jeff wa1hco ----- Original Message ----- From: "Jim Ussailis" To: "TAPR Spread Spectrum Special Interest Group" Cc: "ss digest recipients" Sent: Sunday, August 06, 2000 8:55 PM Subject: [ss] Re: ss digest: August 05, 2000 > Jeff, > > Where do I find out about this coding scheme. Two items puzzle me: > > 1. The olde ECM trick of beating multipath is to use "leading-edge > gating." That is use a very small leading edge of the pulse. Others use a > trick like this, they use very short pulses, to beat multipath. > > 2. Mathematically, orthogonal means "at right angles," or > non-overlapping. DS-SS codes are usually selected to be orthogonal. > > > Jim, W1EQO > > ussailis@shaysnet.com > > On Sun, 6 Aug 2000, TAPR Spread Spectrum Special Interest Group digest wrote: > > > TAPR Spread Spectrum Special Interest Group Digest for Saturday, August 05, 2000. > > > > 1. Re: ss digest: August 03, 2000 > > > > ---------------------------------------------------------------------- > > > > Subject: Re: ss digest: August 03, 2000 > > From: "jeff millar" > > Date: Sat, 5 Aug 2000 01:00:44 -0400 > > X-Message-Number: 1 > > > > I've been reading about modulation formats, coding, etc quite a bit lately. > > Here's some top level conclusions... > > > > OFDM doesn't do anything unique with respect to the Shannon limit. What it > > does is allow for good signal reception in the presence of multipath. > > because it splits the data stream up over many separate carriers > > transmitting at low speed....and each very slow stream is immune to > > multipath. It's up to the designer to apply a modulation and coding to each > > carrier to optimize performance. The upcoming IEEE 802.11 OFDM variant will > > define a common approach for that application. > > > > By the way, OFDM would be great for microwave repeaters intended work with > > mobiles. Mobile flutter (chop) increases in frequency, proportional to > > operating frequency. At 10 GHz, its a 400Hz buzz. With OFDM, all that > > stuff disappears. In theory, Someone could make a voice bandwidth OFDM > > system with a PC and a sound card. Any takers? > > > > Another by the way. OFDM is _not_ spread spectrum. The carriers are packed > > together so tightly, they overlap...that's what the "orthogonal" part of the > > name means. > > > > Coding is commonly used to get closer to the Shannon limit. Without coding, > > a link might only get to 3-10% of theoretical capacity. Traditional block > > codes such as Reed-Solomon might push that to 20%. Recently, "Turbo" codes > > which iteratively process the data have pushed capacity to >80%. Turbo > > codes are just starting to appear in products and require a complex ASIC or > > lots of processing. They also introduce significantly increased delay > > compared to other earlier approaches. Turbo codes work by modeling the > > strongest interference and subtracting it from the signal, then subtracting > > the next strongest interferer, etc until the best possible signal is > > recovered. > > > > If you're interested in the latest algorithms that improve > > capacity...possibly even "beating Shannon" (depends on your definition), > > check out Bell Labs Space Time Adaptive Processing (BLAST). They use > > multiple transmitters/antennas and multiple receivers/antennas and transmit > > different portions of the data stream from each transmitter and receive all > > the stream on each receiver. Laboratory experiments show upwards of 30 > > bits/sec per Hz of bandwidth...(1 Mbps in a 30 kHz channel) This this is > > not ready for prime time, takes gobs of computer power, and requires several > > advanced degrees in signal processing and math to work with it. But with > > chips getting more powerful and spectrum costing $B, it will get popular in > > 10 years or so. BLAST works with Turbo codes techniques (iterative > > subtraction) to sort out all the overlapping carriers and multipath > > effects....sounds like magic but it really works. > > > > hope this helps, > > > > jeff > > wa1hco > > > > ----- Original Message ----- > > From: "venumadhav josyula" > > To: "TAPR Spread Spectrum Special Interest Group" > > Sent: Friday, August 04, 2000 11:35 PM > > Subject: [ss] Re: ss digest: August 03, 2000 > > > > > > > > > > But whole issue for wireles service providers is provide multimedia > > services > > > through ur network nad integrate with the present ip/atm networks. So in > > > order to provide those > > > you will require varying data rates and depending upon the application. > > That > > > needs to be provided. Plus services require raonably good range and your > > > devices need to be more capable. > > > > > > I agree with you about dependability of capacity on shannon's theorem, but > > > my question is'nt it possible to maintain high date rate using > > multicarrier > > > modulation scheme such as OFDM, and provide reasonably good coding schemes > > > to improve the range. Thus making system less sensitive to frequency > > errors. > > > > > > Because as your data rate (but this HDR is only possible with some kind of > > > MC* scheme) is increased, your system becomes more sentive to frequency > > > errors and hence provision needs to be made to combat those. > > > > > > Sir I am asking this because, I doing and reearch dessertation on this > > topic > > > since I am an student. > > > > > > cheers > > > venu > > > > > > * MULTI-CARRIER. > > > >From: Jim Ussailis > > > >Reply-To: "TAPR Spread Spectrum Special Interest Group" > > > > > >To: "TAPR Spread Spectrum Special Interest Group" > > > >CC: ss digest recipients > > > >Subject: [ss] Re: ss digest: August 03, 2000 > > > >Date: Fri, 4 Aug 2000 22:27:36 -0400 (EDT) > > > >MIME-Version: 1.0 > > > >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id > > > >MHotMailBB54C6A90031D82197EBCC11D9180CF30; Fri Aug 04 19:27:54 2000 > > > >From bounce-ss-17222@lists.tapr.org Fri Aug 04 19:29:33 2000 > > > >Return-Path: > > > >In-Reply-To: > > > > > > > > > >Message-ID: > > > > > > > g> > > > >List-Unsubscribe: > > > >List-Software: Lyris Server version 3.0 > > > >List-Subscribe: > > > >List-Owner: > > > >X-List-Host: Tucson Amateur Packet Radio > > > >X-Message-Id: > > > >Sender: bounce-ss-17222@lists.tapr.org > > > >Precedence: bulk > > > > > > > >Well, that's the problem. Everybody wants a faster data rate. If > > > >everything else is a constant, range must suffer, or one must transmit > > > >more info/bit. > > > > > > > >The info/bit stuff is covered by Shannon. There is a maximum that he > > > >provides, then there is a lessor maximum given real hardware (as opposed > > > >to theoretical hardware). > > > > > > > >So, my point is, unless you want a slower data rate, you must increase > > > >power to get more range. There is no free lunch! > > > > > > > >Jim, W1EQO > > > > > > > > > > > >On Fri, 4 Aug 2000, TAPR Spread Spectrum Special Interest Group digest > > > >wrote: > > > > > > > > > TAPR Spread Spectrum Special Interest Group Digest for Thursday, > > August > > > >03, 2000. > > > > > > > > > > 1. Re: ss digest: August 01, 2000 > > > > > > > > > > ---------------------------------------------------------------------- > > > > > > > > > > Subject: Re: ss digest: August 01, 2000 > > > > > From: "venumadhav josyula" > > > > > Date: Thu, 03 Aug 2000 11:52:42 GMT > > > > > X-Message-Number: 1 > > > > > > > > > > Hello jim, > > > > > > > > > > In what context are u talking. What for high date services, where u > > > >would > > > > > not want to reduce your data rate. Are there any other ways to improve > > > > > sensitivity/range. I am talking in sense to HDR services proposed by > > > > > QUALCOMM. Generally speaking, about variable data rates SS > > > > > system. > > > > > > > > > > thanking you > > > > > yours sincerely > > > > > venu > > > > > > > > > > > > > > > > > > > > >From: Jim Ussailis > > > > > >Reply-To: "TAPR Spread Spectrum Special Interest Group" > > > > > > > > > >To: "TAPR Spread Spectrum Special Interest Group" > > > > > >CC: ss digest recipients > > > > > >Subject: [ss] Re: ss digest: August 01, 2000 > > > > > >Date: Wed, 2 Aug 2000 21:39:48 -0400 (EDT) > > > > > >MIME-Version: 1.0 > > > > > >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id > > > > > >MHotMailBB52189800BCD820F3C6CC11D9180C240; Wed Aug 02 18:40:41 2000 > > > > > >From bounce-ss-17222@lists.tapr.org Wed Aug 02 18:45:28 2000 > > > > > >Return-Path: > > > > > >In-Reply-To: > > > > > > > > > > > > > > > > > >Message-ID: > > > > > > > > > > > > > g> > > > > > >List-Unsubscribe: > > > > > >List-Software: Lyris Server version 3.0 > > > > > >List-Subscribe: > > > > > >List-Owner: > > > > > >X-List-Host: Tucson Amateur Packet Radio > > > > > >X-Message-Id: > > > > > > > > > >Sender: bounce-ss-17222@lists.tapr.org > > > > > >Precedence: bulk > > > > > > > > > > > >A comment on data rate & sensitivity / range. > > > > > > > > > > > >The trick to getting a very good range (for a fixed transmitter > > power) > > > >on a > > > > > >data system is to reduce the receiver bandwidth. The sensitivity > > > >changes > > > > > >by 10 Log (new bandwidth / previous bandwidth). Of course reducing > > > > > >the bandwidth reduces the data rate. Nothing free. > > > > > > > > > > > >The problem with this is that for many systems reducing the data rate > > > > > >does not reduce the receiver bandwidth. That is generally fixed by > > the > > > >IF > > > > > >or video filters. Unless adaptive filters are employed. > > > > > > > > > > > >--- > > > > > > > > > > > >Does anyone out there know where I can find a schematic for a Costas > > > >loop > > > > > >detector? Sure would be a BIG help. > > > > > > > > > > > > > > > > > >---W1EQO > > > > > > > > > > > >ussailis@shaysnet.com > > > > > > > > > > > > > > > > > >--- > > > > > >You are currently subscribed to ss as: venumadhavj@hotmail.com > > > > > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > > > > > > > > > > ________________________________________________________________________ > > > > > Get Your Private, Free E-mail from MSN Hotmail at > > http://www.hotmail.com > > > > > > > > > > > > > > > > > > > > > > > > > --- > > > > > > > > > > END OF DIGEST > > > > > > > > > > --- > > > > > You are currently subscribed to ss as: ussailis@shaysnet.com > > > > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > > > > > > > > > >--- > > > >You are currently subscribed to ss as: venumadhavj@hotmail.com > > > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > > ________________________________________________________________________ > > > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > > > > > > > > --- > > > You are currently subscribed to ss as: JEFF@WA1HCO.MV.COM > > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > > > > > > > > --- > > > > END OF DIGEST > > > > --- > > You are currently subscribed to ss as: ussailis@shaysnet.com > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > --- > You are currently subscribed to ss as: JEFF@WA1HCO.MV.COM > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Mon Aug 7 09:10:09 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id JAA08239 for ; Mon, 7 Aug 2000 09:10:06 -0500 (CDT) From: "Kenneth H. Sinclair" To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: ss digest: August 05, 2000 Date: Mon, 7 Aug 2000 10:08:27 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6600 Importance: Normal List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk BLAST is described in several references from here: http://www-out.bell-labs.com/project/blast/ It's sort of like a rake receiver where the rake fingers can track separate signals, with smart antennas, coding, and lots of signal processing on both sides. You get around the Shannon limit on channel capacity because it's not really a single channel anymore, but multiple channels conveyed through the bit of spatial diversity created by multipath. I find it ingenious, but very complicated. I'm very curious to see how it pans out in the real world. I'm not really a believer in the "we need lots of capacity to provide multimedia services" camp, though. That's a solution (or more precisely, a pile of capital) in search of a problem. -----Original Message----- From: bounce-ss-9486@lists.tapr.org [mailto:bounce-ss-9486@lists.tapr.org]On Behalf Of Jim Ussailis Sent: Sunday, August 06, 2000 8:56 PM To: TAPR Spread Spectrum Special Interest Group Cc: ss digest recipients Subject: [ss] Re: ss digest: August 05, 2000 Jeff, Where do I find out about this coding scheme. Two items puzzle me: 1. The olde ECM trick of beating multipath is to use "leading-edge gating." That is use a very small leading edge of the pulse. Others use a trick like this, they use very short pulses, to beat multipath. 2. Mathematically, orthogonal means "at right angles," or non-overlapping. DS-SS codes are usually selected to be orthogonal. Jim, W1EQO ussailis@shaysnet.com On Sun, 6 Aug 2000, TAPR Spread Spectrum Special Interest Group digest wrote: > TAPR Spread Spectrum Special Interest Group Digest for Saturday, August 05, 2000. > > 1. Re: ss digest: August 03, 2000 > > ---------------------------------------------------------------------- > > Subject: Re: ss digest: August 03, 2000 > From: "jeff millar" > Date: Sat, 5 Aug 2000 01:00:44 -0400 > X-Message-Number: 1 > > I've been reading about modulation formats, coding, etc quite a bit lately. > Here's some top level conclusions... > > OFDM doesn't do anything unique with respect to the Shannon limit. What it > does is allow for good signal reception in the presence of multipath. > because it splits the data stream up over many separate carriers > transmitting at low speed....and each very slow stream is immune to > multipath. It's up to the designer to apply a modulation and coding to each > carrier to optimize performance. The upcoming IEEE 802.11 OFDM variant will > define a common approach for that application. > > By the way, OFDM would be great for microwave repeaters intended work with > mobiles. Mobile flutter (chop) increases in frequency, proportional to > operating frequency. At 10 GHz, its a 400Hz buzz. With OFDM, all that > stuff disappears. In theory, Someone could make a voice bandwidth OFDM > system with a PC and a sound card. Any takers? > > Another by the way. OFDM is _not_ spread spectrum. The carriers are packed > together so tightly, they overlap...that's what the "orthogonal" part of the > name means. > > Coding is commonly used to get closer to the Shannon limit. Without coding, > a link might only get to 3-10% of theoretical capacity. Traditional block > codes such as Reed-Solomon might push that to 20%. Recently, "Turbo" codes > which iteratively process the data have pushed capacity to >80%. Turbo > codes are just starting to appear in products and require a complex ASIC or > lots of processing. They also introduce significantly increased delay > compared to other earlier approaches. Turbo codes work by modeling the > strongest interference and subtracting it from the signal, then subtracting > the next strongest interferer, etc until the best possible signal is > recovered. > > If you're interested in the latest algorithms that improve > capacity...possibly even "beating Shannon" (depends on your definition), > check out Bell Labs Space Time Adaptive Processing (BLAST). They use > multiple transmitters/antennas and multiple receivers/antennas and transmit > different portions of the data stream from each transmitter and receive all > the stream on each receiver. Laboratory experiments show upwards of 30 > bits/sec per Hz of bandwidth...(1 Mbps in a 30 kHz channel) This this is > not ready for prime time, takes gobs of computer power, and requires several > advanced degrees in signal processing and math to work with it. But with > chips getting more powerful and spectrum costing $B, it will get popular in > 10 years or so. BLAST works with Turbo codes techniques (iterative > subtraction) to sort out all the overlapping carriers and multipath > effects....sounds like magic but it really works. > > hope this helps, > > jeff > wa1hco > > ----- Original Message ----- > From: "venumadhav josyula" > To: "TAPR Spread Spectrum Special Interest Group" > Sent: Friday, August 04, 2000 11:35 PM > Subject: [ss] Re: ss digest: August 03, 2000 > > > > > > But whole issue for wireles service providers is provide multimedia > services > > through ur network nad integrate with the present ip/atm networks. So in > > order to provide those > > you will require varying data rates and depending upon the application. > That > > needs to be provided. Plus services require raonably good range and your > > devices need to be more capable. > > > > I agree with you about dependability of capacity on shannon's theorem, but > > my question is'nt it possible to maintain high date rate using > multicarrier > > modulation scheme such as OFDM, and provide reasonably good coding schemes > > to improve the range. Thus making system less sensitive to frequency > errors. > > > > Because as your data rate (but this HDR is only possible with some kind of > > MC* scheme) is increased, your system becomes more sentive to frequency > > errors and hence provision needs to be made to combat those. > > > > Sir I am asking this because, I doing and reearch dessertation on this > topic > > since I am an student. > > > > cheers > > venu > > > > * MULTI-CARRIER. > > >From: Jim Ussailis > > >Reply-To: "TAPR Spread Spectrum Special Interest Group" > > > >To: "TAPR Spread Spectrum Special Interest Group" > > >CC: ss digest recipients > > >Subject: [ss] Re: ss digest: August 03, 2000 > > >Date: Fri, 4 Aug 2000 22:27:36 -0400 (EDT) > > >MIME-Version: 1.0 > > >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id > > >MHotMailBB54C6A90031D82197EBCC11D9180CF30; Fri Aug 04 19:27:54 2000 > > >From bounce-ss-17222@lists.tapr.org Fri Aug 04 19:29:33 2000 > > >Return-Path: > > >In-Reply-To: > > > > > > >Message-ID: > > > > g> > > >List-Unsubscribe: > > >List-Software: Lyris Server version 3.0 > > >List-Subscribe: > > >List-Owner: > > >X-List-Host: Tucson Amateur Packet Radio > > >X-Message-Id: > > >Sender: bounce-ss-17222@lists.tapr.org > > >Precedence: bulk > > > > > >Well, that's the problem. Everybody wants a faster data rate. If > > >everything else is a constant, range must suffer, or one must transmit > > >more info/bit. > > > > > >The info/bit stuff is covered by Shannon. There is a maximum that he > > >provides, then there is a lessor maximum given real hardware (as opposed > > >to theoretical hardware). > > > > > >So, my point is, unless you want a slower data rate, you must increase > > >power to get more range. There is no free lunch! > > > > > >Jim, W1EQO > > > > > > > > >On Fri, 4 Aug 2000, TAPR Spread Spectrum Special Interest Group digest > > >wrote: > > > > > > > TAPR Spread Spectrum Special Interest Group Digest for Thursday, > August > > >03, 2000. > > > > > > > > 1. Re: ss digest: August 01, 2000 > > > > > > > > ---------------------------------------------------------------------- > > > > > > > > Subject: Re: ss digest: August 01, 2000 > > > > From: "venumadhav josyula" > > > > Date: Thu, 03 Aug 2000 11:52:42 GMT > > > > X-Message-Number: 1 > > > > > > > > Hello jim, > > > > > > > > In what context are u talking. What for high date services, where u > > >would > > > > not want to reduce your data rate. Are there any other ways to improve > > > > sensitivity/range. I am talking in sense to HDR services proposed by > > > > QUALCOMM. Generally speaking, about variable data rates SS > > > > system. > > > > > > > > thanking you > > > > yours sincerely > > > > venu > > > > > > > > > > > > > > > > >From: Jim Ussailis > > > > >Reply-To: "TAPR Spread Spectrum Special Interest Group" > > > > > > > >To: "TAPR Spread Spectrum Special Interest Group" > > > > >CC: ss digest recipients > > > > >Subject: [ss] Re: ss digest: August 01, 2000 > > > > >Date: Wed, 2 Aug 2000 21:39:48 -0400 (EDT) > > > > >MIME-Version: 1.0 > > > > >Received: from [204.17.217.24] by hotmail.com (3.2) with ESMTP id > > > > >MHotMailBB52189800BCD820F3C6CC11D9180C240; Wed Aug 02 18:40:41 2000 > > > > >From bounce-ss-17222@lists.tapr.org Wed Aug 02 18:45:28 2000 > > > > >Return-Path: > > > > >In-Reply-To: > > > > > > > > > > > > > >Message-ID: > > > > > > > > > g> > > > > >List-Unsubscribe: > > > > >List-Software: Lyris Server version 3.0 > > > > >List-Subscribe: > > > > >List-Owner: > > > > >X-List-Host: Tucson Amateur Packet Radio > > > > >X-Message-Id: > > > > > > > >Sender: bounce-ss-17222@lists.tapr.org > > > > >Precedence: bulk > > > > > > > > > >A comment on data rate & sensitivity / range. > > > > > > > > > >The trick to getting a very good range (for a fixed transmitter > power) > > >on a > > > > >data system is to reduce the receiver bandwidth. The sensitivity > > >changes > > > > >by 10 Log (new bandwidth / previous bandwidth). Of course reducing > > > > >the bandwidth reduces the data rate. Nothing free. > > > > > > > > > >The problem with this is that for many systems reducing the data rate > > > > >does not reduce the receiver bandwidth. That is generally fixed by > the > > >IF > > > > >or video filters. Unless adaptive filters are employed. > > > > > > > > > >--- > > > > > > > > > >Does anyone out there know where I can find a schematic for a Costas > > >loop > > > > >detector? Sure would be a BIG help. > > > > > > > > > > > > > > >---W1EQO > > > > > > > > > >ussailis@shaysnet.com > > > > > > > > > > > > > > >--- > > > > >You are currently subscribed to ss as: venumadhavj@hotmail.com > > > > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > > > > > > ________________________________________________________________________ > > > > Get Your Private, Free E-mail from MSN Hotmail at > http://www.hotmail.com > > > > > > > > > > > > > > > > > > > > --- > > > > > > > > END OF DIGEST > > > > > > > > --- > > > > You are currently subscribed to ss as: ussailis@shaysnet.com > > > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > > > > > >--- > > >You are currently subscribed to ss as: venumadhavj@hotmail.com > > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > ________________________________________________________________________ > > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > > > > > --- > > You are currently subscribed to ss as: JEFF@WA1HCO.MV.COM > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > > > --- > > END OF DIGEST > > --- > You are currently subscribed to ss as: ussailis@shaysnet.com > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > --- You are currently subscribed to ss as: khs@ieee.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 8 18:12:41 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id SAA05375 for ; Tue, 8 Aug 2000 18:12:41 -0500 (CDT) Message-Id: Message-Id: <4.1.20000808163354.0093b500@postoffice.worldnet.att.net> X-Sender: whitings@postoffice.worldnet.att.net Date: Tue, 08 Aug 2000 16:40:57 -0500 To: "TAPR Spread Spectrum Special Interest Group" From: The Whiting Household Subject: [ss] Voice over IP Cc: cenescu@datek.ro (Catalin Enescu) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <4.1.20000808163354.0093b500@postoffice.worldnet.att.net> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Catalin Enescu asked "I wonder if anybody has done any testing with VoIP equipments over Wireless LAN (11 MB units)." Anyone contemplating this might be interested in Gilbert Held's book "Voice & Data Internetworking," McGraw-Hill, 2000. This is a guide for transporting real-time voice over networks designed for data transmission. Cheers/ Rick W0TN --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 8 21:33:59 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id VAA10374 for ; Tue, 8 Aug 2000 21:33:58 -0500 (CDT) Message-Id: From: "Chuck Hast" To: "TAPR Spread Spectrum Special Interest Group" Date: Tue, 08 Aug 2000 22:32:39 -0500 Reply-To: "TAPR Spread Spectrum Special Interest Group" Priority: Normal MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Subject: [ss] Re: Voice over IP List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio X-Message-Id: <200008090232.WAA06220@smtp-server.tampabay.rr.com> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk I was at WAVE in Sarasota FL last weekend, amoung the other things they showed us was a small box with 8 ports on it, into each port you plugged a POTs (Plain Old Telephone) you could set it up to where when one phone was taken off hook it would cause the corresponding one to ring on the other end of a IP link, this case a SPEEDLAN set up at 11mb. They have these things linked over wire and wireless links all over the world. In fact they use the SPEEDLAN product to do a lot of "last mile" links where wire or fibre is not economical. You could also set this box up such that when you took your phone off hook it would do the same on the other end, and of course that end was hooked to a CO, and would return dialtone and allow the remote phone to dial and also would send ring down to the remote phone. You could also of course have the IP connection go into a PC which would act as a PBX or CO and have the full path being IP rather than a mix of IP and circuit switched. So indeed there is at least a reasonable amount of VoIP being done over such links. On Wed, 02 Aug 2000 11:34:02 +0300, Catalin Enescu wrote: >I wonder if anybody has done any testing with VoIP equipments over >Wireless LAN (11 MB units). > >Catalin Enescu > > >--- >You are currently subscribed to ss as: kp4djt@tampabay.rr.com >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > Chuck Hast e-mail kp4djt@tampabay.rr.com ---- FPAC ---- www.qsl.net/fpac/ --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 8 22:04:25 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id WAA13205 for ; Tue, 8 Aug 2000 22:04:25 -0500 (CDT) Message-ID: From: "jeff millar" To: "TAPR Spread Spectrum Special Interest Group" References: Subject: [ss] Re: Voice over IP Date: Tue, 8 Aug 2000 23:02:31 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4029.2901 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <001501c001ae$43b13c80$0201a8c0@home> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Don't hold us in suspense! Who makes it and what does it cost? jeff wa1hco ----- Original Message ----- From: "Chuck Hast" To: "TAPR Spread Spectrum Special Interest Group" Sent: Tuesday, August 08, 2000 11:32 PM Subject: [ss] Re: Voice over IP > I was at WAVE in Sarasota FL last weekend, amoung the other things > they showed us was a small box with 8 ports on it, into each port you > plugged a POTs (Plain Old Telephone) you could set it up to where > when one phone was taken off hook it would cause the corresponding > one to ring on the other end of a IP link, this case a SPEEDLAN set > up at 11mb. They have these things linked over wire and wireless links > all over the world. In fact they use the SPEEDLAN product to do a lot > of "last mile" links where wire or fibre is not economical. You could also > set this box up such that when you took your phone off hook it would > do the same on the other end, and of course that end was hooked to > a CO, and would return dialtone and allow the remote phone to dial > and also would send ring down to the remote phone. You could also > of course have the IP connection go into a PC which would act as a > PBX or CO and have the full path being IP rather than a mix of IP > and circuit switched. > > So indeed there is at least a reasonable amount of VoIP being done > over such links. > > > On Wed, 02 Aug 2000 11:34:02 +0300, Catalin Enescu wrote: > > >I wonder if anybody has done any testing with VoIP equipments over > >Wireless LAN (11 MB units). > > > >Catalin Enescu > > > > > >--- > >You are currently subscribed to ss as: kp4djt@tampabay.rr.com > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > Chuck Hast e-mail kp4djt@tampabay.rr.com > > ---- FPAC ---- > www.qsl.net/fpac/ > > > --- > You are currently subscribed to ss as: JEFF@WA1HCO.MV.COM > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 8 22:40:24 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id WAA16712 for ; Tue, 8 Aug 2000 22:40:22 -0500 (CDT) Date: Tue, 8 Aug 2000 23:37:49 -0400 (EDT) From: Jim Ussailis Sender: bounce-ss-6751@lists.tapr.org Reply-To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: ss digest: August 06, 2000 To: "TAPR Spread Spectrum Special Interest Group" cc: ss digest recipients In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio X-Message-Id: Precedence: bulk Jeff, Thanks. Quite a different approach than I would have thought of. I'll look at the references this weekend. I hope the one from Aachen is in English :) Jim, W1EQO --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Wed Aug 9 01:44:20 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id BAA15829 for ; Wed, 9 Aug 2000 01:44:20 -0500 (CDT) Message-ID: From: "jeff millar" To: "TAPR Spread Spectrum Special Interest Group" Cc: References: <200008082012540080.04F55D2F@mail.in-con.com> <200008082017030990.04F92D86@mail.in-con.com> <200008082053200790.051A65ED@mail.in-con.com> <200008082157500190.0555732D@mail.in-con.com> Subject: [ss] Re: Voice over IP Date: Wed, 9 Aug 2000 02:40:43 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4029.2901 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <000e01c001cc$bf3128c0$0201a8c0@home> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk done ----- Original Message ----- From: "Chris Arndt" To: Sent: Wednesday, August 09, 2000 12:57 AM Subject: Re: [ss] Re: Voice over IP > Jeff, could you please fwd this on to the list for me? I seem to be having > trouble sending to it tonight. > > Thanks! > > Chris KD6DSI > > Another option is the Quicknet Internet Line Jack and Internet Phone jack, > in ISA or PC card form factors. The Phone Jack has a POTS jack for a phone, > the Line Jack adds a port for a CO line. Either one accepts DTMF from the > phone, and creates ring cycle on an incoming IP call to ring the phone. > > A Line Jack at one end and a Phone jack at the other with IP in the middle > create a complete virtual circuit, or they can be used separately for other > IP telephony applications. > > *********** REPLY SEPARATOR *********** > > On 8/8/00, at 7:34 PM, Chuck Hast wrote: > > >I was at WAVE in Sarasota FL last weekend, amoung the other things > >they showed us was a small box with 8 ports on it, into each port you > >plugged a POTs (Plain Old Telephone) you could set it up to where > >when one phone was taken off hook it would cause the corresponding > >one to ring on the other end of a IP link, this case a SPEEDLAN set > >up at 11mb. They have these things linked over wire and wireless links > >all over the world. In fact they use the SPEEDLAN product to do a lot > >of "last mile" links where wire or fibre is not economical. You could also > >set this box up such that when you took your phone off hook it would > >do the same on the other end, and of course that end was hooked to > >a CO, and would return dialtone and allow the remote phone to dial > >and also would send ring down to the remote phone. You could also > >of course have the IP connection go into a PC which would act as a > >PBX or CO and have the full path being IP rather than a mix of IP > >and circuit switched. > > > >So indeed there is at least a reasonable amount of VoIP being done > >over such links. > > > > > >On Wed, 02 Aug 2000 11:34:02 +0300, Catalin Enescu wrote: > > > >>I wonder if anybody has done any testing with VoIP equipments over > >>Wireless LAN (11 MB units). > >> > >>Catalin Enescu > >> > >> > >>--- > >>You are currently subscribed to ss as: kp4djt@tampabay.rr.com > >>To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > >> > > > >Chuck Hast e-mail kp4djt@tampabay.rr.com > > > > ---- FPAC ---- > >www.qsl.net/fpac/ > > > > > >--- > >You are currently subscribed to ss as: carndt@slonet.org > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Wed Aug 9 06:27:44 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id GAA17778 for ; Wed, 9 Aug 2000 06:27:43 -0500 (CDT) Message-ID: From: "Hast, Chuck" To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: Voice over IP Date: Wed, 9 Aug 2000 07:21:10 -0400 MIME-Version: 1.0 Content-Type: text/plain List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <0D7B0EF78F72D311B95F0008C7F3D0A0B790FB@dallas.utilpart.com> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Go to www.speedlan.com That is where I saw it. Actually I played with it while I was there. By way these people appear to be interested in the amateur community. I visited WAVE with a group of hams who are interested in SS locally. > -----Original Message----- > From: jeff millar [SMTP:jeff@wa1hco.mv.com] > Sent: Tuesday, August 08, 2000 23:03 > To: TAPR Spread Spectrum Special Interest Group > Subject: [ss] Re: Voice over IP > > Don't hold us in suspense! Who makes it and what does it cost? > > jeff wa1hco > ----- Original Message ----- > From: "Chuck Hast" > To: "TAPR Spread Spectrum Special Interest Group" > Sent: Tuesday, August 08, 2000 11:32 PM > Subject: [ss] Re: Voice over IP > > > > I was at WAVE in Sarasota FL last weekend, amoung the other things > > they showed us was a small box with 8 ports on it, into each port you > > plugged a POTs (Plain Old Telephone) you could set it up to where > > when one phone was taken off hook it would cause the corresponding > > one to ring on the other end of a IP link, this case a SPEEDLAN set > > up at 11mb. They have these things linked over wire and wireless links > > all over the world. In fact they use the SPEEDLAN product to do a lot > > of "last mile" links where wire or fibre is not economical. You could > also > > set this box up such that when you took your phone off hook it would > > do the same on the other end, and of course that end was hooked to > > a CO, and would return dialtone and allow the remote phone to dial > > and also would send ring down to the remote phone. You could also > > of course have the IP connection go into a PC which would act as a > > PBX or CO and have the full path being IP rather than a mix of IP > > and circuit switched. > > > > So indeed there is at least a reasonable amount of VoIP being done > > over such links. > > > > > > On Wed, 02 Aug 2000 11:34:02 +0300, Catalin Enescu wrote: > > > > >I wonder if anybody has done any testing with VoIP equipments over > > >Wireless LAN (11 MB units). > > > > > >Catalin Enescu > > > > > > > > >--- > > >You are currently subscribed to ss as: kp4djt@tampabay.rr.com > > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > Chuck Hast e-mail > kp4djt@tampabay.rr.com > > > > ---- FPAC ---- > > www.qsl.net/fpac/ > > > > > > --- > > You are currently subscribed to ss as: JEFF@WA1HCO.MV.COM > > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > > > > --- > You are currently subscribed to ss as: wchast@utilpart.com > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Wed Aug 9 06:33:26 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id GAA17984 for ; Wed, 9 Aug 2000 06:33:24 -0500 (CDT) From: adesjard@cme.com Reply-To: "TAPR Spread Spectrum Special Interest Group" Sender: bounce-ss-6751@lists.tapr.org To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] RE: Voice over IP Date: Wed, 9 Aug 2000 06:31:31 -0500 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal Importance: Normal In-Reply-To: <27ACC5D88FCAD311991700805FEA31D620B2AA@sntsex01-bk.merc.chicago.cme.com> X-MimeOLE: Produced By Microsoft MimeOLE V4.72.2106.4 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio X-Message-Id: <27ACC5D88FCAD311991700805FEA31D619B3C3@sntsex01-bk.merc.chicago.cme.com> Precedence: bulk Just an addition to this thread - Cisco - since the takeover of Aironet - has been working on adding QOS flags for VOIP on 802.11b gear. Symbol has been doing this for nearly 2 years now. Alan DesJardins N5VXL RF Network Engineer Chicago Mercantile Exchange Technology Division / Network Operations 30 S. Wacker Drive Chicago, IL 60606 312-338-2853 adesjard@cme.com -----Original Message----- From: bounce-ss-12965@lists.tapr.org [mailto:bounce-ss-12965@lists.tapr.org]On Behalf Of The Whiting Household Sent: Tuesday, August 08, 2000 4:41 PM To: TAPR Spread Spectrum Special Interest Group Cc: Catalin Enescu Subject: [ss] Voice over IP Catalin Enescu asked "I wonder if anybody has done any testing with VoIP equipments over Wireless LAN (11 MB units)." Anyone contemplating this might be interested in Gilbert Held's book "Voice & Data Internetworking," McGraw-Hill, 2000. This is a guide for transporting real-time voice over networks designed for data transmission. Cheers/ Rick W0TN --- You are currently subscribed to ss as: adesjard@cme.com To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Thu Aug 10 13:49:56 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id NAA21511 for ; Thu, 10 Aug 2000 13:49:54 -0500 (CDT) From: To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: dsss pn codes(paul) Date: Thu, 10 Aug 2000 23:09:23 +0430 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <20000810183923.FBXW19886.mta2@[212.48.4.50]> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk > > > Hello, > I plan to use a pn code with 16 bit shift register, I was wondering if > someone can give me the feedback tap points for a m-length code. > Thank you > Avraham Kurtz > > > --- > You are currently subscribed to ss as: RV9J@VIRGILIO.IT > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > please let me know if you 've received my last mail that showed the polinomio to use in a PN RANDOM GEN! i'll await yr reply regards paul RV9J@VIRGILIO.IT ---------------------------------------------- Virgilio Mail - Il tuo indirizzo E-mail gratis http://mail.virgilio.it --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Thu Aug 10 20:05:17 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id UAA18171 for ; Thu, 10 Aug 2000 20:05:16 -0500 (CDT) Message-ID: From: "Robert Alred" To: "TAPR Spread Spectrum Special Interest Group" References: Subject: [ss] Re: ss digest: August 09, 2000 Date: Thu, 10 Aug 2000 21:17:07 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6600 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <002801c00331$de758b20$0300a8c6@speedy> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk The 802.11 Committee is working on adding multimedia QOS into the standard this is being pushed by both symbol and Cisco. Lucent has mostly seemed to drop out of the committee with the retirement of Vic. VOIP does run fine today on 802.11 as long as you over engineer the system. Larger file activity will mess with your voice quality. 802.11 adds to the delay because of its listen before transmit and backoff routines. VOIP can only take less than 150 ms overall delay for toll quality of course we are used to talking half-duplex so we can take more delay. Jitter is another major concern with any voice over data technology, but more so with wireless because the above mentioned problems. Jitter is when the delay between packets changes. 50 ms is usually the limit of jitter delay. Jitters biggest enemy is larger MTU sizes. Currently Symbol and spectralink make voice over 802.11 technology. Symbols phone is only released on their frequency hopper at this time. Look for an 802.11b next year. Symbols phone is also an H.323 phone that runs g.711 and g.729 codecs. The spectralink phone runs a proprietary protocol to their own gateway meant to interface into PBX's at corporate locations. Spectralink has their own quality of service that many vendors are adding to their AP's. For single VOIP calls over 802.11 that do not have to compete with data you will be fine. I have done several test using Netmeeting over this type of link. If you are going to run over the Internet no QOS will help once you are off the wireless net work. You should strive to keep Delay, jitter and packet loss to a minimum. Robert Ralred@mindspring.com N1PDR --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 22 07:31:31 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id HAA09981 for ; Tue, 22 Aug 2000 07:31:30 -0500 (CDT) Message-ID: From: "Hast, Chuck" To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Idle or Dead Date: Tue, 22 Aug 2000 08:29:49 -0400 MIME-Version: 1.0 Content-Type: text/plain List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <0D7B0EF78F72D311B95F0008C7F3D0A0B79132@dallas.utilpart.com> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Did something happen? This list got very quiet. --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 22 07:42:30 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id HAA10957 for ; Tue, 22 Aug 2000 07:42:30 -0500 (CDT) Date: Tue, 22 Aug 2000 22:40:59 +1000 From: Hamish Moffatt To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: Idle or Dead Message-ID: Mail-Followup-To: TAPR Spread Spectrum Special Interest Group References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii User-Agent: Mutt/1.0.1i In-Reply-To: ; from wchast@utilpart.com on Tue, Aug 22, 2000 at 08:29:49AM -0400 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <20000822224059.B29411@silly.cloud.net.au> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk On Tue, Aug 22, 2000 at 08:29:49AM -0400, Hast, Chuck wrote: > Did something happen? This list got very quiet. It has been quiet. Here's an ugly and illegal but amusing idea I've been thinking about. Modern radios have good frequency synthesis and computer control. Similarly, we can synchronise our computer clocks very precisely using ntp (network time protocol). Could we write a program which would basically frequency hop over a selected band at say 1 hop or 2 hops per second? Hamish -- Hamish Moffatt VK3SB --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 22 08:33:09 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id IAA18615 for ; Tue, 22 Aug 2000 08:33:08 -0500 (CDT) Message-ID: From: "Hast, Chuck" To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: Idle or Dead Date: Tue, 22 Aug 2000 09:30:26 -0400 MIME-Version: 1.0 Content-Type: text/plain List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <0D7B0EF78F72D311B95F0008C7F3D0A0B79135@dallas.utilpart.com> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk I would love to do that on the 2m band. Jump from guard band to guard band between the useless repeaters around here. Better yet, somehow look ahead and jump to idle repeater channels! Now that is real spectrum re-use. I still believe that if we do not start looking at new technology, sooner or later the buzzards are going to come home to roost, and we are going to find our hobby without bandwidth to do anything new. Look at what was paid for spectrum in Germany last week, I think it was US$ 3.3 BILLION. Just think how happy they would be to get our bits and pieces of spectrum?!?!? > -----Original Message----- > From: Hamish Moffatt [SMTP:hamish@cloud.net.au] > Sent: Tuesday, August 22, 2000 08:41 > To: TAPR Spread Spectrum Special Interest Group > Subject: [ss] Re: Idle or Dead > > On Tue, Aug 22, 2000 at 08:29:49AM -0400, Hast, Chuck wrote: > > Did something happen? This list got very quiet. > > It has been quiet. > > Here's an ugly and illegal but amusing idea I've been thinking about. > Modern radios have good frequency synthesis and computer control. > Similarly, we can synchronise our computer clocks very precisely > using ntp (network time protocol). > > Could we write a program which would basically frequency hop over > a selected band at say 1 hop or 2 hops per second? > > > Hamish > -- > Hamish Moffatt VK3SB > > --- > You are currently subscribed to ss as: wchast@utilpart.com > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 22 09:06:28 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id JAA22583 for ; Tue, 22 Aug 2000 09:06:26 -0500 (CDT) Date: Wed, 23 Aug 2000 00:05:01 +1000 From: Hamish Moffatt To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: Idle or Dead Message-ID: Mail-Followup-To: TAPR Spread Spectrum Special Interest Group References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii User-Agent: Mutt/1.0.1i In-Reply-To: ; from wchast@utilpart.com on Tue, Aug 22, 2000 at 09:30:26AM -0400 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <20000823000501.A29995@silly.cloud.net.au> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk On Tue, Aug 22, 2000 at 09:30:26AM -0400, Hast, Chuck wrote: > I would love to do that on the 2m band. Jump from guard band to > guard band between the useless repeaters around here. Better > yet, somehow look ahead and jump to idle repeater channels! > Now that is real spectrum re-use. Well, I suppose we could be legal and do it on 70cm; I was thinking of just going for it on 10 metres. Plenty of bandwidth and no one would ever notice, especially here in VK. I'm just not sure that the clock synchronisation using ntp is accurate enough to get good speech flow across hops. GPS synchronisation might be required. > last week, I think it was US$ 3.3 BILLION. Just think how happy > they would be to get our bits and pieces of spectrum?!?!? Many billions were spent in the UK recently on 3G wireless licenses. Hamish -- Hamish Moffatt VK3SB --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 22 09:31:36 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id JAA25676 for ; Tue, 22 Aug 2000 09:31:33 -0500 (CDT) Message-ID: From: "Hast, Chuck" To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: Idle or Dead Date: Tue, 22 Aug 2000 10:29:41 -0400 MIME-Version: 1.0 Content-Type: text/plain List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <0D7B0EF78F72D311B95F0008C7F3D0A0B79137@dallas.utilpart.com> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk I would use GPS, then you can have a unit that you can walk around with and travel, not having to worry about keeping a IP link to get synch Yes the UK one was a real blaster too, then there were the auctions in this country, if we do not think they would like to have our spectrum we are deluded. > -----Original Message----- > From: Hamish Moffatt [SMTP:hamish@cloud.net.au] > Sent: Tuesday, August 22, 2000 10:05 > To: TAPR Spread Spectrum Special Interest Group > Subject: [ss] Re: Idle or Dead > > > Well, I suppose we could be legal and do it on 70cm; I was thinking > of just going for it on 10 metres. Plenty of bandwidth and no one > would ever notice, especially here in VK. I'm just not sure that > the clock synchronisation using ntp is accurate enough to get > good speech flow across hops. GPS synchronisation might be required. > > > > Many billions were spent in the UK recently on 3G wireless licenses. > > > Hamish > -- > Hamish Moffatt VK3SB > > --- > You are currently subscribed to ss as: wchast@utilpart.com > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 22 13:04:08 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id NAA04364 for ; Tue, 22 Aug 2000 13:04:08 -0500 (CDT) Message-Id: X-Sender: esj@localhost Date: Tue, 22 Aug 2000 14:00:55 -0400 To: "TAPR Spread Spectrum Special Interest Group" From: "Eric S. Johansson" Subject: [ss] "new" modulation technique VMSK/2 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <4.3.2.7.0.20000822135718.029cc7b8@localhost> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk http://www.ednmag.com/ednmag/reg/2000/08172000/17hiw.htm how real is this? if it is real, we could do 300k bits/sec in the same bandwidth as currently used with today's packet radio. --- eric --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 22 13:56:42 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id NAA11368 for ; Tue, 22 Aug 2000 13:56:40 -0500 (CDT) From: Jake Brodsky To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: "new" modulation technique VMSK/2 Date: Tue, 22 Aug 2000 14:53:06 -0400 Reply-To: "TAPR Spread Spectrum Special Interest Group" Message-ID: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by tapr.org id NAA11368 On Tue, 22 Aug 2000 14:00:55 -0400, you wrote: >http://www.ednmag.com/ednmag/reg/2000/08172000/17hiw.htm > >how real is this? if it is real, we could do 300k bits/sec in the same >bandwidth as currently used with today's packet radio. It's real. The only part of the story they haven't reported is that you'll need a very good signal to noise ratio to use this technique. I guess they assume you'd know that. No matter what they say, you can't get away from Shannon's law. (Though I have seen some very creative work-arounds...) Jake Brodsky, mailto:frussle@erols.com "Nearly fifty percent of all graduates came from the bottom half of the class." --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 22 14:55:28 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id OAA23500 for ; Tue, 22 Aug 2000 14:55:27 -0500 (CDT) Message-Id: X-Sender: karel@worldcom.nl Date: Tue, 22 Aug 2000 03:37:01 -0500 To: "TAPR Spread Spectrum Special Interest Group" From: karel Subject: [ss] Re: "new" modulation technique VMSK/2 In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-MDaemon-Deliver-To: ss@lists.tapr.org List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <4.1.20000822033032.009da230@worldcom.nl> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Do you think that VMSK modulation would also work on shortwave? I have been looking for systems that would be capable to transmit 14k4 or better 28k8 on shortwave. I'am currently working on 2 projects for ALRED, a latin-american educational radio network. Some radio are so far away that no other solution is practical without shortwave. Analoge shortwave is not good enough for radio distribution. ALRED uses PAS-3 as a distribution channel as a backchannel, to let participate the radio stations (non-commercial) we use internet, but as a wrote not all have the possiblity. Using satelite channels to do so would be to expensive. greetings Karel Fassotte HC-PE2KFA At 02:53 PM 8/22/00 -0400, you wrote: >On Tue, 22 Aug 2000 14:00:55 -0400, you wrote: > >>http://www.ednmag.com/ednmag/reg/2000/08172000/17hiw.htm >> >>how real is this? if it is real, we could do 300k bits/sec in the same >>bandwidth as currently used with today's packet radio. > >It's real. The only part of the story they haven't reported is that >you'll need a very good signal to noise ratio to use this technique. >I guess they assume you'd know that. > >No matter what they say, you can't get away from Shannon's law. >(Though I have seen some very creative work-arounds...) > >Jake Brodsky, mailto:frussle@erols.com >"Nearly fifty percent of all graduates came from >the bottom half of the class." > >--- >You are currently subscribed to ss as: karel@worldcom.nl >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 22 15:26:39 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id PAA29674 for ; Tue, 22 Aug 2000 15:26:36 -0500 (CDT) From: Jake Brodsky To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: "new" modulation technique VMSK/2 Date: Tue, 22 Aug 2000 16:13:02 -0400 Reply-To: "TAPR Spread Spectrum Special Interest Group" Message-ID: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by tapr.org id PAA29674 On Tue, 22 Aug 2000 03:37:01 -0500, you wrote: >Do you think that VMSK modulation would also work on shortwave? According to the article this sort of thing is still very much in development. It appears that the writer thinks one application could be on MW. >I have been looking for systems that would be capable to transmit 14k4 or >better 28k8 on shortwave. The problems are endless. It's not just a matter of receiver dynamic range, there is also selective fading (multipath), interference, static noise, and by the way, how are you going to get that signal to noise ratio unless you have a very clean transmitter? >I'am currently working on 2 projects for ALRED, a latin-american >educational radio network. Some radio are so far away that no other >solution is practical without shortwave. Analoge shortwave is not good >enough for radio distribution. >ALRED uses PAS-3 as a distribution channel as a backchannel, to let >participate the radio stations (non-commercial) we use internet, but as a >wrote not all have the possiblity. Using satelite channels to do so would >be to expensive. Expensive? Compared to what? I don't envision VMSK/2 becoming "cheap" any time soon. In any case, I'll reiterate: It still seems to be very much in development. When the real product emerges from the mist of vaporware, I'll look harder... Jake Brodsky, mailto:frussle@erols.com "Nearly fifty percent of all graduates came from the bottom half of the class." --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 22 16:18:33 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id QAA07818 for ; Tue, 22 Aug 2000 16:18:31 -0500 (CDT) Date: Tue, 22 Aug 2000 15:58:54 -0500 From: Jeffrey Austen Subject: [ss] Re: "new" modulation technique VMSK/2 X-Sender: jausten@gemini.tntech.edu To: "TAPR Spread Spectrum Special Interest Group" Message-id: MIME-version: 1.0 Content-type: text/plain; charset=us-ascii List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk >http://www.ednmag.com/ednmag/reg/2000/08172000/17hiw.htm > >how real is this? if it is real, we could do 300k bits/sec in the same >bandwidth as currently used with today's packet radio. It's not, at least at the high spectral efficiencies which are claimed. According to Shannon's theorem for 19 bps/Hz the SNR needs to be 57 dB. This might be achievable on a telephone line under near ideal conditions. However, for 90 bps/Hz it needs to be 271 dB, which would require an absurd amount of power (over a factor of 10^20 (10 to the power 20) more than the previous case!). There are several other rather absurd points in the article. Among them are that baseband filtering is more difficult (or impossible) than passband filtering and that narrowband phase modulation has zero bandwidth. Jeff, k9ja --- Jeffrey Austen | Tennessee Technological University jausten@tntech.edu | Box 5004 +1-931-372-3485 | Cookeville Tennessee 38505 U.S.A. --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 22 16:34:03 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id QAA15414 for ; Tue, 22 Aug 2000 16:34:02 -0500 (CDT) Message-Id: X-Sender: esj@localhost Date: Tue, 22 Aug 2000 17:26:59 -0400 To: "TAPR Spread Spectrum Special Interest Group" From: "Eric S. Johansson" Subject: [ss] Re: "new" modulation technique VMSK/2 In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <4.3.2.7.0.20000822171436.02a06768@localhost> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk At 02:53 PM 8/22/2000 -0400, you wrote: >On Tue, 22 Aug 2000 14:00:55 -0400, you wrote: > > >http://www.ednmag.com/ednmag/reg/2000/08172000/17hiw.htm > > > >how real is this? if it is real, we could do 300k bits/sec in the same > >bandwidth as currently used with today's packet radio. > >It's real. The only part of the story they haven't reported is that >you'll need a very good signal to noise ratio to use this technique. >I guess they assume you'd know that. well actually, I wouldn't know that because I'm not RF literate enough. Anyway, what struck me was that it seemed to be extremely sensitive to multipath type symbol smearing. this is, of course, assuming I understood the diagrams I was reading. like the various QAM modulation schemes, I suspect this one will be mostly used on wires and not Wireless. although, slowing down the symbol rate from 90b/hz to 30b/hz might make practical for amateur radio. You must admit that moving to 50-100 kbits per second in 4 kHz bandwidth would be amusing and somewhat more high-tech than the current packet scene. >No matter what they say, you can't get away from Shannon's law. >(Though I have seen some very creative work-arounds...) laws were meant to be broken ;-) ---eric --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 22 19:42:39 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id TAA21471 for ; Tue, 22 Aug 2000 19:42:34 -0500 (CDT) From: Dale Heatherington To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: "new" modulation technique VMSK/2 Date: Tue, 22 Aug 2000 20:28:52 -0400 Content-Type: text/plain References: In-Reply-To: MIME-Version: 1.0 Message-Id: Content-Transfer-Encoding: 8bit List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <00082220383505.00995@lab1> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk This smells like a scam to me. They even claim it works with 7db carrier to noise, not 271 db! >From http://www.networkalpha.com/index2.html : ------------- VMSK ideally operates at below 7.0 dB Carrier to Noise Ratio (CNR) for an acceptable bit (digital) error rate, so an additional 18 dB of line loss can be tolerated. The bandwidth efficiency is much greater; this results in an additional gain in signal/noise ratio. The secret to VMSK's success lies in its very narrow-to-trivial bandwidth. In conclusion the VMSK provides a far better solution for solving the wire line bandwidth problem. ------------- Do some searches on AlphaCom and VMSK and see what else you get. Here's a sample : ---------- Join The VMSK Technology Revolution!! An Incredible High Speed Bandwidth Technology called VMSK is about to explode on the world of telecommunications and YOU can be a part of it. Join me as an independent distributor for AlphaCom Communications as they introduce this revolutionary and patented technology to the world. Click on the link to learn more OR get left behind in the World Wide Wait!! Website:AlphaCom Opportunity ----------- On Tue, 22 Aug 2000, Jeffrey Austen wrote: > >http://www.ednmag.com/ednmag/reg/2000/08172000/17hiw.htm > > > >how real is this? if it is real, we could do 300k bits/sec in the same > >bandwidth as currently used with today's packet radio. > > It's not, at least at the high spectral efficiencies which are claimed. > According to Shannon's theorem for 19 bps/Hz the SNR needs to be 57 dB. > This might be achievable on a telephone line under near ideal conditions. > However, for 90 bps/Hz it needs to be 271 dB, which would require an absurd > amount of power (over a factor of 10^20 (10 to the power 20) more than the > previous case!). > > There are several other rather absurd points in the article. Among them are > that baseband filtering is more difficult (or impossible) than passband > filtering and that narrowband phase modulation has zero bandwidth. > > Jeff, k9ja > > --- > Jeffrey Austen | Tennessee Technological University > jausten@tntech.edu | Box 5004 > +1-931-372-3485 | Cookeville Tennessee 38505 U.S.A. > > > > --- > You are currently subscribed to ss as: ss@wa4dsy.net > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org -- Dale Heatherington dale@wa4dsy.net Web Page http://www.wa4dsy.net Sent by KMail for Linux --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 22 20:16:13 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id UAA26554 for ; Tue, 22 Aug 2000 20:16:12 -0500 (CDT) Message-ID: Reply-To: "TAPR Spread Spectrum Special Interest Group" From: "KF6QDP" To: "TAPR Spread Spectrum Special Interest Group" References: Subject: [ss] Re: "new" modulation technique VMSK/2 Date: Tue, 22 Aug 2000 18:05:30 -0700 X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio X-Message-Id: <018c01c00c9e$3c2b2340$93880018@ocnsd1.sdca.home.com> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Karel, 9k6 and 19k2 "non-compressed" data modes do exist on HF. Both MS-188-110B and STANAG5066 describe them. We have been running tests using 9k6 bps (SSB) and 19k2 bps (2-ISB). These modems are presently "costly" but you know what... even the "big guys" are using sound card based modems for this now ;-) They use modes like 64QAM and the higher data rates do require near-perfect HF channels ;-) We have many systems running CLOVER-2000 modems with "perceived" throughputs in the 5k-6kbps range (adaptive compression algorithms). - Check-out "WaveScience" (http://www.wavescience.com) and Rockwell-Collins (Q9600 modem) Bruno Haineault, KF6QDP/VE2EQ Oceanside, California ----- Original Message ----- From: "karel" To: "TAPR Spread Spectrum Special Interest Group" Sent: Tuesday, August 22, 2000 01:37 Subject: [ss] Re: "new" modulation technique VMSK/2 > Do you think that VMSK modulation would also work on shortwave? > I have been looking for systems that would be capable to transmit 14k4 or > better 28k8 on shortwave. > I'am currently working on 2 projects for ALRED, a latin-american > educational radio network. Some radio are so far away that no other > solution is practical without shortwave. Analoge shortwave is not good > enough for radio distribution. > ALRED uses PAS-3 as a distribution channel as a backchannel, to let > participate the radio stations (non-commercial) we use internet, but as a > wrote not all have the possiblity. Using satelite channels to do so would > be to expensive. > greetings > Karel Fassotte > HC-PE2KFA --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Sat Aug 26 08:27:14 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id IAA18897 for ; Sat, 26 Aug 2000 08:27:12 -0500 (CDT) Message-Id: X-Sender: karel@worldcom.nl Date: Fri, 25 Aug 2000 08:34:01 -0500 To: "TAPR Spread Spectrum Special Interest Group" From: karel Subject: [ss] Re: "new" modulation technique VMSK/2 In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-MDaemon-Deliver-To: ss@lists.tapr.org List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <4.1.20000825082316.0097c640@worldcom.nl> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Yes Bruno I all ready have information from collins,Harris,Marauder about there product line in mil spec modems. You write even the big guys use sound cards. Do these solutions also comply with the mil spec.? We also have some experience with clover 2000. However the troughput we percieved wase al little bit less than 2Kb. Could you give me some information where to look for the sound card solutions. Wich software do they use? Perhaps you can give me some info to get the picture clear. Normaly we would not use more than 1 hop with good radio links. Thanks Karel At 06:05 PM 8/22/00 -0700, you wrote: >Karel, > >9k6 and 19k2 "non-compressed" data modes do exist on HF. Both MS-188-110B >and STANAG5066 describe them. We have been running tests using 9k6 bps (SSB) >and 19k2 bps (2-ISB). These modems are presently "costly" but you know >what... even the "big guys" are using sound card based modems for this now >;-) They use modes like 64QAM and the higher data rates do require >near-perfect HF channels ;-) > >We have many systems running CLOVER-2000 modems with "perceived" throughputs >in the 5k-6kbps range (adaptive compression algorithms). - > >Check-out "WaveScience" (http://www.wavescience.com) and Rockwell-Collins >(Q9600 modem) > >Bruno Haineault, KF6QDP/VE2EQ >Oceanside, California > > >----- Original Message ----- >From: "karel" >To: "TAPR Spread Spectrum Special Interest Group" >Sent: Tuesday, August 22, 2000 01:37 >Subject: [ss] Re: "new" modulation technique VMSK/2 > > >> Do you think that VMSK modulation would also work on shortwave? >> I have been looking for systems that would be capable to transmit 14k4 or >> better 28k8 on shortwave. >> I'am currently working on 2 projects for ALRED, a latin-american >> educational radio network. Some radio are so far away that no other >> solution is practical without shortwave. Analoge shortwave is not good >> enough for radio distribution. >> ALRED uses PAS-3 as a distribution channel as a backchannel, to let >> participate the radio stations (non-commercial) we use internet, but as a >> wrote not all have the possiblity. Using satelite channels to do so would >> be to expensive. >> greetings >> Karel Fassotte >> HC-PE2KFA > > > > >--- >You are currently subscribed to ss as: karel@worldcom.nl >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Sat Aug 26 08:58:13 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id IAA23681 for ; Sat, 26 Aug 2000 08:58:13 -0500 (CDT) Message-Id: X-Sender: karel@worldcom.nl Date: Fri, 25 Aug 2000 09:02:14 -0500 To: "TAPR Spread Spectrum Special Interest Group" From: karel Subject: [ss] Re: "new" modulation technique VMSK/2 In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-MDaemon-Deliver-To: ss@lists.tapr.org List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <4.1.20000825083426.009ea540@worldcom.nl> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Hello Jack I have allready some information about the mil spec modem of Collins, Harris and Wavescience. They comply with the mil std-188-110a and b stanag 4285 and 4529 ect. Using ISB Collins says it will transmit up to 28k8. However if there are new modes that are more effecient and fast. I' am very interested. However these modems are not very cheap. Harris modems sell for about 5000 dollar, the software also 5000 dollar. The radio stations members of Aler do not have a commercial goal. So we have to select the best and cheapest solutions. You write expensive, compared to what? Well Vsat terminals sell for about 10,000 US dollar, not including the operational costs. The theoritacal basics of VMSK look all right. What I dont know is the experience in the real world. If we could get our hands on a reliable product that would do the job within the budget or the ALRED members it would mean a break through for emerging projects of ALER and other human rights organisations. We did a lot of experimentations with analog links on shortwave and they look very promising. We also used clover 2000 in a project in the republic of Congo. That worked fine for mail, even at far distances, several thousands kilometers. The real troughput of the system however is not enough for what we need now. We would like to send compressed audiofiles as attachments to mails. The vocoder compression software we now use is very effective and sounds natural. If it would be possible we would like to use realtime digital voice systems. But because we don't work for big companies, the budget is limmited and we have to look for the technical most advanced and cost effective solutions. The efforts made by Digital Radio Mondial (DRM) and US Digital Radio to get digital MW and Sortwave are very promissing. However they use bandwith for broadcast purpose. Using Mpeg-4 and andvanced digital modulation they get 22Kb over the air. Because the digital modulators are for the broadcast market, they will not be very cheap. If one of you has some more ideas, please write! Karel At 04:13 PM 8/22/00 -0400, you wrote: >On Tue, 22 Aug 2000 03:37:01 -0500, you wrote: > >>Do you think that VMSK modulation would also work on shortwave? > >According to the article this sort of thing is still very much in >development. It appears that the writer thinks one application could >be on MW. > >>I have been looking for systems that would be capable to transmit 14k4 or >>better 28k8 on shortwave. > >The problems are endless. It's not just a matter of receiver dynamic >range, there is also selective fading (multipath), interference, >static noise, and by the way, how are you going to get that signal to >noise ratio unless you have a very clean transmitter? > >>I'am currently working on 2 projects for ALRED, a latin-american >>educational radio network. Some radio are so far away that no other >>solution is practical without shortwave. Analoge shortwave is not good >>enough for radio distribution. >>ALRED uses PAS-3 as a distribution channel as a backchannel, to let >>participate the radio stations (non-commercial) we use internet, but as a >>wrote not all have the possiblity. Using satelite channels to do so would >>be to expensive. > >Expensive? Compared to what? I don't envision VMSK/2 becoming >"cheap" any time soon. In any case, I'll reiterate: It still seems to >be very much in development. > >When the real product emerges from the mist of vaporware, I'll look >harder... > >Jake Brodsky, mailto:frussle@erols.com >"Nearly fifty percent of all graduates came from >the bottom half of the class." > >--- >You are currently subscribed to ss as: karel@worldcom.nl >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Sat Aug 26 17:59:42 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id RAA27993 for ; Sat, 26 Aug 2000 17:59:37 -0500 (CDT) Message-Id: X-Sender: brett@localhost Date: Sat, 26 Aug 2000 16:56:23 -0600 To: "TAPR Spread Spectrum Special Interest Group" From: Brett Glass Subject: [ss] Re: "new" modulation technique VMSK/2 In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <4.3.2.7.2.20000826165239.00c036f0@localhost> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk At 12:00 PM 8/22/2000, Eric S. Johansson wrote: >http://www.ednmag.com/ednmag/reg/2000/08172000/17hiw.htm > >how real is this? It looks real but not necessarily that reliable in practice. It relies on EXTREMELY tight timing of the zero crossings in the signal -- similar to what's being done on hard drives nowadays. (There are, and always have been, a lot of similarities between modulation schemes for magnetic recording and those used for RF applications.) Noise or phase distortion could really mess up such a modulation scheme. --Brett --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Sat Aug 26 18:39:55 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id SAA02183 for ; Sat, 26 Aug 2000 18:39:53 -0500 (CDT) From: Jake Brodsky To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: "new" modulation technique VMSK/2 Date: Tue, 22 Aug 2000 16:13:02 -0400 Reply-To: "TAPR Spread Spectrum Special Interest Group" Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii List-Unsubscribe: List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Software: Lyris Server version 3.0 List-Subscribe: List-Subscribe: List-Owner: List-Owner: X-List-Host: Tucson Amateur Packet Radio X-List-Host: Tucson Amateur Packet Radio X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk X-MDMail-Server: MDaemon v2.0 rU b1 32 X-MDaemon-Deliver-To: tlang@freeway.apana.org.au Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by tapr.org id SAA02183 On Tue, 22 Aug 2000 03:37:01 -0500, you wrote: >Do you think that VMSK modulation would also work on shortwave? According to the article this sort of thing is still very much in development. It appears that the writer thinks one application could be on MW. >I have been looking for systems that would be capable to transmit 14k4 or >better 28k8 on shortwave. The problems are endless. It's not just a matter of receiver dynamic range, there is also selective fading (multipath), interference, static noise, and by the way, how are you going to get that signal to noise ratio unless you have a very clean transmitter? >I'am currently working on 2 projects for ALRED, a latin-american >educational radio network. Some radio are so far away that no other >solution is practical without shortwave. Analoge shortwave is not good >enough for radio distribution. >ALRED uses PAS-3 as a distribution channel as a backchannel, to let >participate the radio stations (non-commercial) we use internet, but as a >wrote not all have the possiblity. Using satelite channels to do so would >be to expensive. Expensive? Compared to what? I don't envision VMSK/2 becoming "cheap" any time soon. In any case, I'll reiterate: It still seems to be very much in development. When the real product emerges from the mist of vaporware, I'll look harder... Jake Brodsky, mailto:frussle@erols.com "Nearly fifty percent of all graduates came from the bottom half of the class." --- You are currently subscribed to ss as: tlang@freeway.apana.org.au To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Mon Aug 28 09:31:01 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id JAA04468 for ; Mon, 28 Aug 2000 09:31:00 -0500 (CDT) From: "Steven R. Bible" To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] ANNOUNCEMENT: ARRL/TAPR 19th Annual DCC Sep. 22-24 Date: Mon, 28 Aug 2000 10:23:35 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6700 Importance: Normal List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Notice: September 1, 2000 is the last day to receive the special hotel room rate of $89/night single or double and the pre-registration price for the conference. ARRL and TAPR 19th Annual Digital Communications Conference September 22-24, 2000 - Orlando, Florida For more information see: http://www.tapr.org/dcc Information Mark your calendar and start making plans to attend the year's premier event in digital communications. The 19th Annual ARRL and TAPR Digital Communications Conference will be held September 22-24, 2000, in Orlando, Florida - just minutes from the Orlando International Airport. The ARRL and TAPR Digital Communications Conference is an international forum for radio amateurs in digital communications, networking, and related technologies to meet, publish their work, and present new ideas and techniques for discussion. Presenters and attendees will have the opportunity to exchange ideas and learn about recent hardware and software advances, theories, experimental results, and practical applications. The Digital Communications Conference is not just for the digital expert, but also for digitally oriented amateurs of all levels of experience. A Conference for the Beginner as well The conference is not just for the digital expert. As in years past an entire session strand with beginning, intermediate, and advanced presentations on selected topics in digital communications will be offered. Some of the topics will include: APRS, Satellite Communications, TCP/IP, Digital Radio, Spread Spectrum and other introductory topics. Come to the conference and hear these topics presented by the experts! Area Attractions The Orlando Florida area is famous for its attractions and vacation spots. Disney World, Universal Studios, and Sea World (just to name a few) are within 15 minutes of the hotel. Shuttle service from the hotel will be available for a small fee. Cape Canaveral and Cocoa Beach are a 30 minute drive East of the hotel. Symposia, Seminars and Banquet Two symposia/seminars will be held which allow those with additional time and interest to make the most of the Conference. For those who may have interest in just one symposium or seminar, registration for the conference is not required to attend these activities. This allows maximum flexibility for those who may want to participate during the Digital Communications Conference, but do not have an entire weekend to devote to the event. The Fourth APRS National Symposium will be held on Friday and will be moderated by Steve Dimse, K4HG (the developer of javAPRS). It will likely include many APRS software authors, such as Bob Bruninga, WB4APR (the father ofAPRS), Keith Sproul, WU2Z, Mark Sproul, KB2ICI (the developers of MacAPRS and WinAPRS), Brent Hildebrand, KH2Z (the developer of APRSPLUS), Mike Musick, N0QBF (developer of PocketAPRS), and other nationally known APRS leaders. Join this group for the afternoon and evening for in-depth discussions and presentations on the current and future status of APRS. This is a unique opportunity to gain insight into this fast-growing digital aspect of amateur operations that combines computers, packet radio, and GPS (Global Positioning System). On Saturday night the DCC Banquet will be held. A guest speaker will speak after the banquet and a prize drawing will top the evening. The Grand Prize is a Palm VII Personal Digital Assistant and Synergy Systems LLC has donated two M12 development kits and many more. The Sunday morning seminar will be focused on PIC development, design, and programming. This five-and-a-half hour seminar will focus on the things you need to know now in order to understand and begin to participate in PIC development. Co-Hosts The 2000 ARRL and TAPR Digital Communications Conference local co-hosts will be: Lake Monroe Amateur Radio Society (http://www.qsl.net/lmars/), Orange County ARES/RACES (http://evcom.net/~jvoisin/ares.htm), Seminole County ARES/RACES (http://wwww.geocities.com/capecanaveral/launchpad/4773), and Orlando Amateur Radio Club (http://www.oarc.org/). International Co-Hosts PRUG (Packet Radio User Group of Japan) will be the International co-host for a third year running. PRUG will be hosting an informal social Friday evening before their seminar and symposium is held. Visit http://www.prug.or.jp for more information about PRUG. Hotel Conference presentations, meetings, and seminars will be held at the Orlando Airport Marriott. It is highly recommended that you book your room prior to arriving. A special DCC room rate of $89/single and $89/double per night has been blocked for 50 rooms and is available until September 1st, 2000. Once the 50 rooms have been reserved, room rates will increase. So be sure to book your rooms early! The hotel provides transportation to and from the Orlando International Airport. Please contact the hotel to arrange specific transportation needs. Orlando Airport Marriott (conference hotel) 7499 Augusta Drive Orlando, FL 32822 Phone 407-851-9000, Fax 407-857-6211 (http://marriotthotels.com/MCOAP/) What you can expect at DCC 2000 - A full day of papers and breakouts for the beginner to the advanced - Two seminars/symposiums - The fifth annual Student Paper session. - A banquet with Special Guest Speaker. - Informal get-togethers throughout the weekend. - TAPR Membership Meeting - An event at which the most important new developments in amateur digital communications are announced. - Digital 'movers and shakers' from all over the world in attendance. There are few activities where your participation can be so much fun and important! What a great way to share and renew your enthusiasm for digital amateur radio! A get-together with colleagues and bringing each other up to date on your latest work -- all this, and more, for an unforgettable weekend of amateur radio and digital communications. We hope to see you at the ARRL and TAPR Digital Communications Conference on September 22-24, 2000! Full information on the conference and hotel information can be obtained by contacting: Tucson Amateur Packet Radio Phone: (940) 383-0000. Fax: (940) 566-2544 Email: tapr@tapr.org Web: http://www.tapr.org Registration Form Contact the TAPR office by Phone 940-383-0000, Fax 940-566-2544, or Internet: http://www.tapr.org and tapr@tapr.org to register or for additional information. Conference Registration includes: Conference Proceedings, Sessions, Meetings, and Lunch on Saturday. - Pre-Registration (before Sept 1st) $45.00 ______ - Registration (after Sept 1) or at door $55.00 ______ - Saturday Evening Dinner (Limited Space) Dinner with Guest Speaker Prize Drawing $30.00 ______ Symposia/Seminars - 4th Annual APRS National Symposium Friday, 1pm - 7pm. $25.00 ______ - Sunday Seminar PIC Design, Development, and Programming Sunday, 8:30 am - 2 pm. $20.00 ______ TOTAL ______ Name/Call: Street Address: City/State/Zip: Country: Phone Number: Email: Charge my credit card (circle one): VISA MasterCard Acct: Expiration Date: Signature on card: Mail completed registration form with check to: TAPR 8987-309 E Tanque Verde Rd #3378 Tucson, AZ 85749-9399 Or check http://www.tapr.org/dcc for an on-line registration form. A registration packet will be mailed in September upon receipt of registration form and payment. --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 29 03:11:36 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id DAA04388 for ; Tue, 29 Aug 2000 03:11:36 -0500 (CDT) Date: Tue, 29 Aug 2000 01:09:24 -0700 Message-Id: From: Phil Karn To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: "new" modulation technique VMSK/2 Reply-to: "TAPR Spread Spectrum Special Interest Group" References: List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio X-Message-Id: <200008290809.BAA25926@homer.ka9q.net> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk >This smells like a scam to me. Absolutely. VMSK is a 100% pure scam. The only thing I can't decide is whether they're honestly deluding themselves, or if they're consciously out to scam everybody. The multilevel marketing scheme Dale cites (I found it too) doesn't bode well for the "don't attribute to malice that which can be adequately explained by stupidity" rule. I sent off a critical letter to the author of the EDN article, and I clearly struck a nerve. He also forwarded my letter to the "inventor" of VMSK/2, who responded similarly. What's funny (as in strange, not humorous) is that this scheme is nearly identical to that described in an article printed in 73 Magazine (that bastion of peer-reviewed technical excellence) in the early 1990s, as I recall. At the time I posted a review of this scheme. I showed that it may well have succeeded in creating a signal with zero occupied bandwidth according to the legal FCC part 97 definition of that term. How? Simple. A binary-modulated PM signal with a deviation of less than +/- 90 degrees will have residual carrier. If you simply decrease the deviation to a very low amount, which is all these schemes do, you are left with most of your transmitter power in the carrier and very little in the sidebands. Now look at the FCC definition of occupied bandwidth in part 97.3(a)(8): Bandwidth. The width of a frequency band outside of which the mean power of the transmitted signal is attenuated at least 26 dB below the mean power of the transmitted signal within the band. 26 dB is a power ratio of 400:1, so this means that the legal bandwidth is that which contains 399/400ths of the total emission. Let's say we phase modulate +/- 0.05 radians. The carrier amplitude will be cos(0.05), which is approximately 1. The sideband amplitude will be sin(0.05), which is approximately 0.05. This corresponds to a sideband power of 20log10(0.05) = -26 dB relative to the carrier. See what happened? The sidebands are now so weak as to be excluded from the bandwidth definition, so our signal bandwidth is now legally zero! Of course, this is just a legal fiction. The sidebands are still there, and if you remove or interfere with them, the signal can no longer be demodulated. The VMSK scam is exactly the same. They show spectrum analyzer displays with a single narrow carrier spike. The all-essential sidebands are lost in the noise. Worse, you've wasted most of your power on a useless carrier, so you now need 26 dB more signal to perform as well as suppressed-carrier BPSK. Phil --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Tue Aug 29 09:00:55 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id JAA14720 for ; Tue, 29 Aug 2000 09:00:55 -0500 (CDT) From: "Lyle Johnson" To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: "new" modulation technique VMSK/2 Date: Tue, 29 Aug 2000 06:57:24 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal In-Reply-To: Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2615.200 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Phil, On the other hand, maybe a pure carrier carries enough about the "intelligence" being conveyed to... ah, but I'm being judgmental :-) Enjoy! Lyle --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Wed Aug 30 17:45:21 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id RAA08090 for ; Wed, 30 Aug 2000 17:45:21 -0500 (CDT) X-Sent: 30 Aug 2000 22:43:13 GMT Message-ID: From: "Fernando M. I. Carreiro" To: "TAPR Spread Spectrum Special Interest Group" References: Subject: [ss] Re: "new" modulation technique VMSK/2 Date: Wed, 30 Aug 2000 23:43:09 +0100 Organization: FMIC MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <004a01c012d3$af042de0$0400000a@fmic.net> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk >This smells like a scam to me. Hello fellow HAMS, I´ve been monitoring this thread of messages, because I have a particular interest in VMSK. Personally I do not know if it is a scam on not on the business side of things, but on the technical side I do believe it is not. Although I do not have the technical resources to built a full-on VMSK radio, I have implemented some of it's ideas in a diversity of projects. I have used the concept in projects from high speed binary communication over single wire to high speed IR communications. What I can tell you, is it does work on the levels that I have used it. The concepts are not a scam. I have known about VPSK, VMSK and VMSK/2 for more than 2 years, and have been using some of its concepts for over a year. I agree that I had some difficulty in the beginning, while trying to implement it, due to the, then narrow minded way of looking at things. Once I began to get into a new way of thought I began to overcome the difficulties. One of the things I discovered, is that in order to gain the high speed at narrow bandwidth, I had it increase the resolution of the bit or wave sampling ( I prefer to work with PIC uC tools instead of pure gates) in order to achieve the high speeds. I had to tweak the use of the PIC and use PWM and CCP capture to achieve the high resolution, instead of gates or high speed ADC and DAC. Also, you cannot just inject VMSK into your 3kHz Audio Mic input on your Radio. VMSK has to be mixed with your RF carrier which has be offset and side-band filtered. VMSK works in a way similar to AM. You could maybe pre-mix the VMSK in order to lower the centre frequency and then inject it into you Mic Port, but I have not yet had the time to test this theory. I probably will soon, just to prove the point. I suggest that you people stop attacking things just because you don't understand it. Be humble at first, by experimenting with it seriously, before throwing it aside. You always draw knowledge from it - even if it is not as good as you thought. Don't just be a seagull - be a Jonathon Livingston Seagull (for those that really understand what this is!) Fernando Carreiro - ZS6BLF (fmi@carreiro) PS! My thanks to Marcelo Puhl who first brought VMSK to my attention some years back. --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Wed Aug 30 19:10:44 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id TAA21418 for ; Wed, 30 Aug 2000 19:10:44 -0500 (CDT) From: Dale Heatherington To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: "new" modulation technique VMSK/2 Date: Wed, 30 Aug 2000 19:39:45 -0400 Content-Type: text/plain References: In-Reply-To: MIME-Version: 1.0 Message-Id: Content-Transfer-Encoding: 8bit List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <0008302009350A.00715@lab1> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk On Wed, 30 Aug 2000, Fernando M. I. Carreiro wrote: > One of the things I discovered, is that in order to gain the high speed at narrow > bandwidth, I had it increase the resolution of the bit or wave sampling ( I prefer to > work with PIC uC tools instead of pure gates) in order to achieve the high speeds. I had > to tweak the use of the PIC and use PWM and CCP capture to achieve the high resolution, > instead of gates or high speed ADC and DAC. > > Also, you cannot just inject VMSK into your 3kHz Audio Mic input on your Radio. VMSK > has to be mixed with your RF carrier which has be offset and side-band filtered. VMSK > works in a way similar to AM. You could maybe pre-mix the VMSK in order to lower the > centre frequency and then inject it into you Mic Port, but I have not yet had the time > to test this theory. I probably will soon, just to prove the point. I'm looking forwared to seeing the point proved. I'd like to know what happens when you add some noise to the VMSK signal traveling on your wire. It seems to me that if you need very precise resolution in the sampling of the received signal , a small amount of noise would corrupt it. Real world applications will have noise. Find out the minumum carrier to noise ratio to successfully recover data. I'd also like to know what happens if you run the VMSK signal through a very narrow high order band pass filter. If the VMSK signals bandwidth is really smaller than the filter bandwidth it should come out the other end unchanged. Real world applications will have bandwidth limits. Find out what minimum bandwidth filter is required to successfully pass a given data rate. > > I suggest that you people stop attacking things just because you don't understand > it. Be humble at first, by experimenting with it seriously, before throwing it aside. > You always draw knowledge from it - even if it is not as good as you thought. Extraordinary claims require extraordinary proof and the burden of proof is on he who makes the claim. I'd like to see some proof or even some credible evidence. Show me! -- Dale Heatherington dale@wa4dsy.net Web Page http://www.wa4dsy.net Sent by KMail for Linux --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Wed Aug 30 19:39:07 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id TAA26066 for ; Wed, 30 Aug 2000 19:39:05 -0500 (CDT) Message-ID: Date: Wed, 30 Aug 2000 20:38:06 -0400 From: Jim Sanford Reply-To: "TAPR Spread Spectrum Special Interest Group" Organization: WB4GCS X-Accept-Language: en MIME-Version: 1.0 To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Re: "new" modulation technique VMSK/2 References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio X-Message-Id: <39ADA8ED.AAF851D5@home.com> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Phil: Thanks for confirming my instincts when I read the EDN article. Glad I didn't waste any time researching it. 73, Jim wb4gcs@amsat.org Phil Karn wrote: > >This smells like a scam to me. > > Absolutely. VMSK is a 100% pure scam. The only thing I can't decide is > whether they're honestly deluding themselves, or if they're > consciously out to scam everybody. The multilevel marketing scheme > Dale cites (I found it too) doesn't bode well for the "don't attribute > to malice that which can be adequately explained by stupidity" rule. > > I sent off a critical letter to the author of the EDN article, and I > clearly struck a nerve. He also forwarded my letter to the "inventor" > of VMSK/2, who responded similarly. > > What's funny (as in strange, not humorous) is that this scheme is > nearly identical to that described in an article printed in 73 > Magazine (that bastion of peer-reviewed technical excellence) in the > early 1990s, as I recall. > > At the time I posted a review of this scheme. I showed that it may > well have succeeded in creating a signal with zero occupied bandwidth > according to the legal FCC part 97 definition of that term. > > How? Simple. A binary-modulated PM signal with a deviation of less > than +/- 90 degrees will have residual carrier. If you simply decrease > the deviation to a very low amount, which is all these schemes do, you > are left with most of your transmitter power in the carrier and very > little in the sidebands. > > Now look at the FCC definition of occupied bandwidth in part > 97.3(a)(8): > > Bandwidth. The width of a frequency band outside of which the mean > power of the transmitted signal is attenuated at least 26 dB > below the mean power of the transmitted signal within the band. > > 26 dB is a power ratio of 400:1, so this means that the legal > bandwidth is that which contains 399/400ths of the total emission. > > Let's say we phase modulate +/- 0.05 radians. The carrier amplitude > will be cos(0.05), which is approximately 1. The sideband amplitude > will be sin(0.05), which is approximately 0.05. This corresponds to > a sideband power of 20log10(0.05) = -26 dB relative to the carrier. > > See what happened? The sidebands are now so weak as to be excluded > from the bandwidth definition, so our signal bandwidth is now legally > zero! > > Of course, this is just a legal fiction. The sidebands are still > there, and if you remove or interfere with them, the signal can no > longer be demodulated. > > The VMSK scam is exactly the same. They show spectrum analyzer > displays with a single narrow carrier spike. The all-essential > sidebands are lost in the noise. Worse, you've wasted most of your > power on a useless carrier, so you now need 26 dB more signal to > perform as well as suppressed-carrier BPSK. > > Phil > > --- > You are currently subscribed to ss as: WB4GCS@AMSAT.ORG > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Wed Aug 30 19:56:47 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id TAA00266 for ; Wed, 30 Aug 2000 19:56:46 -0500 (CDT) Message-Id: X-Sender: carlos@aler1.aler.org.ec Date: Tue, 29 Aug 2000 20:00:25 -0500 To: "TAPR Spread Spectrum Special Interest Group" From: karel Subject: [ss] Re: "new" modulation technique VMSK/2 In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-MDaemon-Deliver-To: ss@lists.tapr.org List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <4.1.20000829195235.009e6100@aler1.aler.org.ec> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Phil your really ironical. I like that a lot. From the teoritical point of vieuw it seems possible for me, especialy in microwave links, that don't have phase variations. I would like you to be judgemental. I'am not that experienced as you are, thats why I would like to know the insides. Greetings Karel At 06:57 AM 8/29/00 -0700, you wrote: >Phil, > >On the other hand, maybe a pure carrier carries enough about the >"intelligence" being conveyed to... ah, but I'm being judgmental :-) > >Enjoy! > >Lyle > > > >--- >You are currently subscribed to ss as: karel@worldcom.nl >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Wed Aug 30 20:20:26 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id UAA03505 for ; Wed, 30 Aug 2000 20:20:25 -0500 (CDT) X-Sent: 31 Aug 2000 01:17:52 GMT Message-ID: From: "Fernando M. I. Carreiro" To: "TAPR Spread Spectrum Special Interest Group" References: Subject: [ss] Re: "new" modulation technique VMSK/2 Date: Thu, 31 Aug 2000 02:17:51 +0100 Organization: FMIC MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <00d801c012e9$49d8aa70$0400000a@fmic.net> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Hello again, in response to: Eric S. Johansson > interesting. where can one find out more information about this modulation technique? You can find more details at the following link: http://www.vmskglobal.com/engineer.html You will also find some PDF material at the end of the link page. >would it be possible to use a single sideband radio as a testbed? use a vmsk modulator the signal in the AudioSpectrum, do all the filtering necessary, and pump it into a single sideband radio?? I have no idea. As I mentioned, I don't have the resources to implement a VMSK radio, but from the details in the documentation it might be a little more tricky than that. However, as I said before - try it out yourself. It is the best way to evaluate it, and when you done, you will have the knowledge to go one to more advanced projects as the Full-on VMSK Radio. I personally would love to built one, but don't have the resources for this at the moment. in response to: Dale Heatherington >I'd like to see some proof or even some credible evidence. I don't have to prove anything. I am not the inventor or in any way associated with the VMSK people. I am simply a user of the concepts, and have found valuable uses for it in my own domain. You and others are free to do what you want with the information that surrounds you. My message was just to tell people that they should not discard it on sole basis that someone else said it was invalid or valid for that matter - but that they should try it out for themselves before drawing their own conclusions. >I'm looking forwared to seeing the point proved. The point proven, is for myself, to be satisfied that my theory of down mixing can work. It is in no-way mentioned in the VMSK documentation. I don't even know if I can implement it or not. I believe that with a few tricks and changes to the original concept, that it will work - but I will have to try it out in order to prove it to myself. If it be the case, that I do get around to experimenting with it, and the results are positive, I will most certainly distribute the details about it to those that are interested, but not to prove a point to someone else who is not willing to try it out for himself. >It seems to me that if you need very precise resolution in the sampling of the received signal , a small amount of noise would corrupt it. Real world applications will have noise. Yes that would be the most obvious conclusion one would draw. That fact that the single wire project is working in the Real World in a highly hazardous environment with plenty of interference, is enough proof for me. Of course as I said, it is not a standard implementation, but uses very strange and tweaky behaviour. Then again VMSK is not standard, but a tweaky method. It took me many months to remap my conventional limiting thoughts into a working solution. Each project and situation required its on adaptation of the concepts. The VMSK details are out there (I have already mentioned the links), but my individual implementations are my own. To All: Please note, I am not interested in any heated debate about this subject. I am happy with the knowledge and experience that the VMSK concepts have given me. When I get some time to do it, I will most gladly share that information with others that are also willing the experiment with it. All I ask is that you don't just condemn things just for the sake of it. For example, now days we take for granted having a radio received in the car or home to hear your favourite music. When this concept was first introduced to the people at MARCONI, it was considered so ludicrous that the gave away that patent rights to receiver units to the man that came up with the idea. That is the reason why today, MARCONI does not manufacture any receivers, and any projects they come up with go via their sister company. Fernando Carreiro (fmi@carreiro.com) --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Thu Aug 31 00:11:22 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id AAA08180 for ; Thu, 31 Aug 2000 00:11:17 -0500 (CDT) Message-ID: From: "Bobbie Johnson" To: "TAPR Spread Spectrum Special Interest Group" References: Subject: [ss] Re: "new" modulation technique VMSK/2 Date: Thu, 31 Aug 2000 01:00:53 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <004e01c01308$7240f660$b96384d8@vnet.net> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Thanks for not 'being judgemental' Phil. I'm sure that the intelligence being transferred by this 'pure carrier' thread is in sync with the intelligence of those... hrrrmph... excuse me. Thanks de Bobbie ----- Original Message ----- From: "karel" To: "TAPR Spread Spectrum Special Interest Group" Sent: Tuesday, August 29, 2000 9:00 PM Subject: [ss] Re: "new" modulation technique VMSK/2 > Phil your really ironical. I like that a lot. From the teoritical point of > vieuw it seems possible for me, especialy in microwave links, that don't > have phase variations. I would like you to be judgemental. I'am not that > experienced as you are, thats why I would like to know the insides. > Greetings Karel > > At 06:57 AM 8/29/00 -0700, you wrote: > >Phil, > > > >On the other hand, maybe a pure carrier carries enough about the > >"intelligence" being conveyed to... ah, but I'm being judgmental :-) > > > >Enjoy! > > > >Lyle > > > > > > > >--- > >You are currently subscribed to ss as: karel@worldcom.nl > >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > > > > --- > You are currently subscribed to ss as: BOBBIEJ@VNET.NET > To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org > --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Thu Aug 31 01:48:00 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id BAA16334 for ; Thu, 31 Aug 2000 01:47:59 -0500 (CDT) Date: Wed, 30 Aug 2000 23:47:35 -0700 Message-Id: From: Phil Karn To: "TAPR Spread Spectrum Special Interest Group" Cc: ss@lists.tapr.org, "karn@ka9q.net" (fmi@carreiro.com) Subject: [ss] Re: "new" modulation technique VMSK/2 References: List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <200008310647.XAA01310@patty.ka9q.net> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk > You can find more details at the following link: >http://www.vmskglobal.com/engineer.html This stuff is really sad. It reads like the "tech speak" inserted in a typical Star Trek episode: "Mr. La Forge! Reverse the polarity of the phase inducers! Modulate the tachyon beam! Make it so!" A person who actually knows the subject matter will recognize many of the individual terms, but they are strung together as gibberish. These guys could have saved a lot of money and effort if they'd only taken the time to read and understand a good comm theory textbook, starting with fourier transform theory. Then they might have understood how to properly use their spectrum analyzer. Phil --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Thu Aug 31 11:49:44 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id LAA28228 for ; Thu, 31 Aug 2000 11:49:40 -0500 (CDT) Date: Thu, 31 Aug 2000 12:48:31 -0400 (EDT) From: Jim Ussailis Subject: [ss] Re: ss digest: August 30, 2000 To: "TAPR Spread Spectrum Special Interest Group" cc: ss digest recipients In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Phase variations in microwave links. This is the problem with many schemes that try to jam higher data rates into a microwave link. First there is multipath. One big phase variation. Then there are the filters. RF isn't too much of a problem because it is usually a wide passband filter. The IF filter is often a BIG problem. For those interested in this VSMK thread, look in any good book on Butterworth filters, and check out the passband phase change for any practical filter. Ouch! Receivers that must maintain a small phase deviation over the passband use Elliptical filters (or is it Bessel, I forget which), which have poor skirt selectivity. I also thank those who indicate I shouldn't waste time looking at VSMK/2. Jim Ussailis W1EQO --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Thu Aug 31 13:25:52 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id NAA12549 for ; Thu, 31 Aug 2000 13:25:51 -0500 (CDT) Date: Thu, 31 Aug 2000 11:22:57 -0700 Message-Id: From: Phil Karn To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] VMSK Reply-to: "TAPR Spread Spectrum Special Interest Group" List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio X-Message-Id: <200008311822.LAA02995@homer.ka9q.net> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk I got some sort of weird message from the list server complaining about a Message-Id header being in the body of my message, which I didn't have. Not knowing if it got through, I'll try again. > You can find more details at the following link: >http://www.vmskglobal.com/engineer.html This stuff is really sad. It reads like the "tech speak" inserted in a typical Star Trek episode: "Mr. La Forge! Reverse the polarity of the phase inducers! Modulate the tachyon beam! Make it so!" A person who actually knows the subject matter will recognize many of the individual terms, but they are strung together as gibberish. These guys could have saved a lot of money and effort if they'd only taken the time to read and understand a good comm theory textbook, starting with fourier transform theory. Then they might have understood how to properly use their spectrum analyzer. Phil --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Thu Aug 31 15:16:58 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id PAA29242 for ; Thu, 31 Aug 2000 15:16:58 -0500 (CDT) X-Sent: 31 Aug 2000 20:15:16 GMT Message-ID: From: "Fernando M. I. Carreiro" To: "TAPR Spread Spectrum Special Interest Group" Subject: [ss] Fw: Re: "new" modulation technique VMSK/2 Date: Thu, 31 Aug 2000 21:15:22 +0100 Organization: FMIC MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <006401c01388$328a7a70$0400000a@fmic.net> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Hello Kerry, >Very intereted in your comments. Do you have some website or source to introduce VMSK? No, I am afraid I don't have any personal website on VMSK. The documentation I used was older than the updated versions on the address: http://www.vmskglobal.com/engineer.html. Please make your own evaluation of the subject. It's the best way to learn. Taking tips from anyone (including me) can accidentally take you on a erroneous route. All I have been trying to say in my previous messages, is that no one an claim anything to anyone until he or she is walked that road, and even then it is a personal experience which will differ from everyone else's. At the moment I am busy on a project which does not give me too much free time, but within +-20 days, I will have time to sift through my code and extract the parts in question, and make them available to all. If by then you have played around with it too, it will be good to have a honest view-point of your evaluation on the board too. If you think about it, why would the VMSK people go to so much trouble over several years (at least 4 years), to release bogus technical information, free on the Internet. If they were charging people for the information, then I could understand why so many think it is a scam. - But no, you can download the data, and build your own test projects. Sure, there are weak points, but that's the reason we become HAMs - To learn, to experiment and to improve on the ideas of others. Fernando (fmi@carreiro.com) --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org From bounce-ss-6751@lists.tapr.org Thu Aug 31 16:06:48 2000 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id QAA10045 for ; Thu, 31 Aug 2000 16:06:47 -0500 (CDT) Message-Id: X-Sender: kf7tp@mail.cybertrails.com Date: Thu, 31 Aug 2000 14:01:45 -0700 To: "TAPR Spread Spectrum Special Interest Group" From: Keith Justice Subject: [ss] Re: VMSK In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Spread Spectrum Special Interest Group" X-Message-Id: <4.3.2.20000831135155.00afbc80@mail.cybertrails.com> Sender: bounce-ss-6751@lists.tapr.org Precedence: bulk Phil, first one came through ok to me. I want to add my thanks to those who have already expressed their gratitude for Phil's analysis. I hope anyone who is so inclined will go ahead and experiment with it, and share their experience with the rest of us. Seems to me, even if appropriate narrow bandwidth filters can be implemented, multipathing and similar non-gaussian effects are going to mess things up. Meanwhile, I have a lot of other projects in the queue, and will anxiously await results from others on vmsk's effectiveness over terrestrial paths. Keith At 11:22 AM 8/31/2000 -0700, you wrote: >I got some sort of weird message from the list server complaining about >a Message-Id header being in the body of my message, which I didn't have. >Not knowing if it got through, I'll try again. > > > You can find more details at the following link: > >http://www.vmskglobal.com/engineer.html > >This stuff is really sad. It reads like the "tech speak" inserted in a >typical Star Trek episode: > >"Mr. La Forge! Reverse the polarity of the phase inducers! Modulate >the tachyon beam! Make it so!" > >A person who actually knows the subject matter will recognize many of >the individual terms, but they are strung together as gibberish. > >These guys could have saved a lot of money and effort if they'd only >taken the time to read and understand a good comm theory textbook, >starting with fourier transform theory. Then they might have >understood how to properly use their spectrum analyzer. > >Phil > >--- >You are currently subscribed to ss as: kf7tp@cybertrails.com >To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org Keith Justice, KF7TP 6759 Wagonwheel Lane Lakeside, AZ 85929 LL: 520-537-8657 Occ. in Mesa, AZ: 480-461-8687 kf7tp@cybertrails.com kf7tp@kf7tp.ampr.org --- You are currently subscribed to ss as: lyris.ss@tapr.org To unsubscribe send a blank email to leave-ss-6751T@lists.tapr.org