This is really a question of bandwidth. The D-STAR Digital Voice system was designed to fit in a 6.25 kHz. bandwidth. Under the chosen GMSK modulation that allows 4800 bps of data to pass over the "channel" - the DV specification calls for this to be split between 2400 bps for voice encoding, 1200 bps for Forward Error Correction of the voice encoding, and the remaining 1200 bps being left for various data services on the signal. (Technically, one could encode the full 4800 bps to DD, the Ethernet encapsulation protocol for D-STAR, but it is not in the specification, or supported by the Icom radios - PA4YBR has done some experimentation in this area.). Higher Data Rates would require more bandwidth.
Ken Sprouse wrote: > > > I was looking for radios that would be able topass signaficant > amounts of data in addtion to a voice channel all at thesame time. > Perhaps I am expecting to much. -- John D. Hays Amateur Radio Station K7VE <http://k7ve.ampr.org> PO Box 1223 Edmonds, WA 98020-1223 VOIP/SIP: [email protected] <sip:[email protected]> Email: [email protected] <mailto:[email protected]> [Non-text portions of this message have been removed]
