Granted, a 2400 baud modem would optimise the RF side. However, I would cast my vote for 4800, since it could be possible to turn this into a "2-slotted" data protocol, and it would make "subrepeaters" possible, i.e. retransmitting at a frame in the interpacket gap between voice frames (at somewhat lower than 2400 bd).
4800 baud would easily fit available radio. There could be many different implementations as time goes by. SM6FBD /Gullik On Sun, 2012-05-20 at 16:24 +0200, Kristoff Bonne wrote: > Hi, > > > We are looking into the possibility to create an additional modem for > codec2, but for VHF/UHF frequencies. > > As a first "proof-of-concept", this would be to convert my gmsk modem to > a new format to carry codec2 voice. This would have the advantage that > the hardware requirement to run this would be minimal. > > > > Sofar, I see two options: > - A 2400 bps modem: > This would be quite sufficient to contain codec2 voice (at 1400 bps), > additional syncronication patterns + some additional data and even an > options 2/3 FEC for the voice part. > > - A 4800 bps modem: > This would then give even more headroom, e.g. tu use a 1/3 FEC for voice > (which would make it much more robust) and still have headroom for > syncronisation patterns and some additional data > > > > The 2400 bps modem would have the advantage of the lower bandwidth > (better S/N ratio, better suited for e.g. bands with limited bandwidth: > 10 meter, 4 meter). > The 4800 bps modem would have the advantage of the better FEC. > > > Does anybody have a comments on this? > > > > 73 > Kristoff - ON1ARF > > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
