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

Pete Loveall AE5PL Lists hamlists at ametx.com
Fri Jul 4 23:58:23 EDT 2008

Unfortunately, this just shows your ignorance of the D-STAR protocol and how the Icom radios utilize it.  I tried to impart this knowledge to you privately but you obviously won't take my word on it.  Very simply: there is no GPS "protocol" in the D-STAR digital voice specification.  There is no data protocol on the digital voice (DV) mode of D-STAR.  The Icom radios use a communications mechanism that is not available to the user of the radio for imparting the canned message that is transmitted from one radio to another.  The D-STAR DV protocol is a -voice- protocol that carries a very low speed data subchannel that is pre-allocated for synchronization and vendor specific operation.  To think of the D-STAR DV operation as a data mode is to completely misunderstand how it works.  I know you want to extend APRS to the Icom radios, but the protocol is not designed for it and the radio's use in D-STAR DV mode is for -voice-.

D-PRS was developed over a couple of years to accommodate the shortcomings of sending data via an unprotected channel with the full knowledge that GPS data and text messaging is not what the D-STAR protocol is designed for and when used exclusively in that mode interferes with voice communications.  When GPS data is transmitted as the radios are designed, when the operator is talking, then the information is complimentary; not in conflict.

This is an example of you wanting to put a square peg in a round hole.  This is the same misbegotten attitude which keeps APRS from becoming more usable (your "new paradigm" still insists on trying to source route AX.25 which is terribly abused world-wide, usually unintentionally).  Icom VHF and UHF radios run digital voice mode.  Key word is -voice-.  "Digital" does not mean data.  The radios do not work the way you want them to and they simply don't communicate that way.  Unfortunately, your misdirected post will cause someone to pursue this without any knowledge of how the D-STAR protocol works or the ill effects their efforts will have on the D-STAR network.


Pete Loveall AE5PL
pete at ae5pl dot net

> -----Original Message-----
> From: Robert Bruninga
> Sent: Friday, July 04, 2008 10:21 PM
> To: 'TAPR APRS Mailing List'
> Subject: [aprssig] PIC processor for APRS info for D-STAR mobiles?
> D-PRS by Pete and D-GATE by Rich have done a wonderful job of
> bringing D-STAR mobiles over onto the APRS maps.  I am starting
> to see more and more of these mobiles on APRS.
> But now as Yeasu joins Kenwood as anotehr TWO-WAY APRS radio,
> displaying local information to the front panel for the mobile
> operator, I am wondering what we can do for displaying useful
> local info to the D-STAR operators?

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