Stefan brought up the point ...
... AMSAT official support this mode, maybe help/encourage the developers and start to implement it (testing) on for example FO-29?
The best thing about standards is that there are plenty to choose from!
I'm guessing the only endorsement we'd get on behalf of AMSAT is to find out what works best ... and report back. For phone operation FreeDV seems to be getting a following in the amateur radio world. Perhaps we'll hear on this thread which additional opportunities exist.
FreeDV bandwidth claiming 1/3 the bandwidth of a conventional SSB signal probably won't hurt any of the linear transponders. We don't control FO-29 but suitably equipped stations on each end could probably give it a go ... such as those instances where guys have tried SSTV through a satellite. No special permission was needed. We might need to figure out how FreeDV and Doppler get along together.
We have plenty of time to try this. That HEO proposal is barely more than a verbal proposal and slides from the symposium. It is in that exciting phase where many things are possible and no one can say which way it will go ... or if it will go.
I bet we could have lots of fun with many soundcard modes that fit in a radio's audio bandwidth. FreeDV trying to QSO with a WSJT flavor might not work well however ;-)
-- 73 de JoAnne K9JKM k9jkm@amsat.org