[aprssig] PIC processor for APRS info for D-STAR mobiles?

Mark Miller kramrellim at tx.rr.com
Mon Jul 7 15:26:33 EDT 2008

At 12:57 PM 7/7/2008, Pete Loveall AE5PL Lists wrote:
>You consistently use this term "DV low rate channel".  Understand 
>that there is no "DV low rate channel" (ref: recent post on this 
>SIG).  There is only the DV bit stream.  This is an extremely 
>important concept that you are apparently overlooking in your zeal 
>to make this a data channel.

I think this is where the disconnect might be.  As you know, if we 
were to pipe APRS data (even heavily filtered data) to a DStar 
frequency, it would be very frustrating to DStar users.  Your MIC-E 
comparison is very good.  I think what is being overlooked is that 
the DStar channel is 4800 bps and 3600 bps is voice and 1200 is 
messaging.  So if APRS position messages were sent to a DStar 
frequency, you would be eating up DV bits even though no voice is 
being transmitted.  When you send a message the data rate is 4800 bps 
and the message uses 1200 bps, but you are still sending 4800 
bps.  It is obvious that the messaging part of DStar was to augment 
DStar voice communication by allowing voice and messaging at the same time.

As a DStar user, I am ok with sending my positions to APRS-IS and to 
144.39 MHz, but I really don't want 144.39 MHz traffic on the DStar channel.

Mark N5RFX

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