>
> Mike wrote: The other main issue is that D-Star is voice centric. The
> digital system
> should be concerned with moving data bits to the correct destination.
Actually, D-STAR protocol is concerned with both data and voice. DV mode
is the most popular, but DD mode, which encapsulates Ethernet frames in
D-STAR frames [on purpose, IP (Internet Protocol) is not the only protocol
someone might run within the Ethernet frames -- the table at
http://en.wikipedia.org/wiki/EtherType ] is designed to handle a variety of
encapsulated protocols. It's actually a good design. The difference
between DV and DD, is one bit in the D-STAR frame header, and the trailing
payload; DV is an interleaved stream with an end of transmission flag, DD
is the Ethernet frame preceded with a 16 bit length field and a closing
32-bit CRC. See http://www.jarl.com/d-star/shogen.pdf -- I have an
opinion on the RPT2 address if this was used as the framework.
I have some issues with the implementation that Icom did, but the protocol
is actually not bad.
Matthew wrote: Another example is that of the slow data; it's not intended
> to be a replacement for a "missing" slow DD mode. It's meant to be used
> in conjunction with the voice data to send files and such while talking.
I don't think it was ever intended for file transfers and such. The
brilliant Dan Smith created D-RATS to address a particular need, but I
think even he would say "data" would be better served outside the DV
stream. It's purpose is undefined in the specification, but it is better
suited for a SMS type service, position reporting, telemetry, etc.
------------------------------
John D. Hays
K7VE
PO Box 1223, Edmonds, WA 98020-1223
<http://k7ve.org/blog> <http://twitter.com/#!/john_hays>
<http://www.facebook.com/john.d.hays>
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