I was not trying to start a D-STAR discussion! I was simply saying that there are 4800 bps GMSK sound card modems being worked on and pointed to the groups where that discussion is underway. Ignore the protocol and content and look at the modem design in software. Then go from there.
D-STAR DV has already been used via satellite and it worked fine is what I understood. But was just an experiment not a proposal for a new satellite mode. 73, Tom n4zpt Art McBride wrote: > D-Star protocol is 4.8kb/sec for voice 1.2 kb for FEC and 1.2kb for data. It > is GMSK data, transmit rate is 3.6KHz max transmission rate, (7.2kb NRZ), > deviation is 1.8 KHz for a modulation index of 0.5. BW per Carlson's rule > is 7.2 KHz > A vocoder module provides for the voice compression. The Data side is used > for Call Sign, Name, City/ State, Brag Tape, GPS position, and Texting all > done with voice simultaneously. D-Star is not very successful in mobile > operation. I have had lots of conversations go R2D2 from a truck or car > passing me. From a fixed position range is surprisingly good. When used on a > Satellite this narrow mode I suspect is very sensitive to Doppler as well as > multipath. Circular antennas on both ends will solve multipath, but Doppler > shift must be dealt with. > Art, > KC6UQH > > -----Original Message----- > From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On > Behalf Of Nathaniel S. Parsons > Sent: Saturday, April 10, 2010 10:02 PM > To: Tom Azlin N4ZPT > Cc: AMSAT-BB > Subject: [amsat-bb] Re: BeeSat at 4800 GMSK > > Ah, thanks for clarifying. Unfortunately, if I understand you correctly, we > would have to talk to our satellite via digital voice, or at 128kbps, which > would be great if we could! > > -Nate > > On Sat, Apr 10, 2010 at 10:15 PM, Tom Azlin N4ZPT <n4...@cox.net> wrote: > >> Well, make that the digital voice part of the protocol. The high speed >> digital data part is up to 128kbps which was not what I was thinking of. >> >> 73, tom n4zpt >> >> Tom Azlin N4ZPT wrote: >> >>> Hi Nate, >>> >>> the D-STAR protocol is only GMSK at 4800 bps and they selected a >>> time-bandwidth product of 0.5. 4,800 bps or 4k8 is perhaps not talked > about >>> as that IS the standard for D-STAR. So the software there might be >>> adaptable. that is the reason I thought to suggest it. >>> >>> Good luck and 73, Tom n4zpt >>> >>> >>> >>> Nathaniel S. Parsons wrote: >>> >>>> Hi Tom, >>>> >>>> My mind had indeed played a trick on me, and I remembered MFSK as MSK. >>>> >>>> As far as the DStar group goes, I don't see any mention of 4800 bps or >>>> 4k8 >>>> kbps on the public page, so if it's not the group's focus, I don't want >>>> to >>>> have to rely on that solution. >>>> >>>> Thanks, >>>> -Nate KC2SVI >>>> >>> _______________________________________________ >>> >>> Sent via amsat...@amsat.org. Opinions expressed are those of the author. >>> Not an AMSAT-NA member? Join now to support the amateur satellite > program! >>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >>> >>> > _______________________________________________ > Sent via amsat...@amsat.org. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > > __________ Information from ESET NOD32 Antivirus, version of virus signature > database 5016 (20100410) __________ > > The message was checked by ESET NOD32 Antivirus. > > http://www.eset.com > > > > > __________ Information from ESET NOD32 Antivirus, version of virus signature > database 5016 (20100410) __________ > > The message was checked by ESET NOD32 Antivirus. > > http://www.eset.com > > > > __________ Information from ESET NOD32 Antivirus, version of virus signature > database 5016 (20100410) __________ > > The message was checked by ESET NOD32 Antivirus. > > http://www.eset.com > > > _______________________________________________ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
