On Fri, 2 Feb 2007, Robert Michel wrote: > Does anybody has experiances/ideas about Voice over GPRS?
See: http://www.cl.cam.ac.uk/~rc277/globe02.pdf They discuss tcp as well as udp performance over GPRS. > How long is the delay? It could maybe used for asyncron > voice communication Talk2Talk (instead of pushing a button) > By using 1KB/s for audio and some overhead, let > us say 2 KB/s 0.24Euro/MB = 24 Cent for 500 seconds, > 60 seconds makes then about 3 cents. When both using > this 6 cents. Hmm that would be interesting when > the user makes often make brakes/pause in their talk. Using speex, you'd need 1.6kb upstream. So bandwidth is not the issue. Latency is. The uplink will have between 0-1 sec of latency, so it's not really an issue . Downlink however, commonly has 2 or 3 second latency, ruining voice in an "interactive" way. In other words, you are probably forced to use a "push to talk" style conversation, meaning long monologues. And that is in good conditions, with a non-mobile connection. Things will get much worse when travelling, especially in the city with many small cells, as you'll be stuck hopping from cell to cell without actually getting much communication done. Paul _______________________________________________ OpenMoko community mailing list community@lists.openmoko.org https://lists.openmoko.org/mailman/listinfo/community