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

Robert Bruninga bruninga at usna.edu
Tue Jul 8 10:40:10 EDT 2008

> What you are asking for is the modification 
> of a signal identified as generated from one 
> station without that station's approval.
> Very slippery slope.

Agree completely, thanks.

> This is not packet where data packets "interleaved" 
> on a frequency.  This is streaming bits where 
> only one transmission at a time is allowed.

Yes, I was assuming the one-transmission was from the repeater
and we could manipulate what those bits were streaming when
there was no-one on the uplink...  Now you are making it clearer
why this is not plug-n-play.

> As for blasting data out on the repeater frequency, 
> do you want this on your local FM repeater using a 
> TNC?  No, because everyone will quit using the 
> repeater.  The same holds true for D-STAR repeater.

Actually, I would love to have it, if that simultaneous data
stream was not heard by the users.  THen they would not have to
have separate APRS and voice radios, but could get both on the
same radio.  Which was the thinking behind most of this thread.
But if we cannot find a clever way to get access to the
repeater's idle DV bits when it is not in use, then I can see
your issues.

Bob, Wb4APR
> > -----Original Message-----
> > From: Robert Bruninga
> > Sent: Tuesday, July 08, 2008 8:51 AM
> > To: 'TAPR APRS Mailing List'
> > Subject: Re: [aprssig] PIC processor for APRS info for 
> D-STAR mobiles?
> >
> > A) Ask for (or hack?) a firmware change to the repeater
> > so that independent access to the DV output bits and input
> > are possible.  This would allow the "APRS streamer engine"
> > manipulate what is going out while watching what is coming
> > IN fact, while one station is talking, and his fix has been
> > received and retransmitted, instead of continuing to stream
> > those same fix report over and over, then other APRS local
> > fixes could be interleaved.
> >
> > B) Without any independent access to the repeater's output
> > stream, then we accept the impossiblity and go to plan B.
> > B is to add a second DSTAR radio at the repeater site which
> > be configured so that it can transmit when-and-only-when,
> > is not someone on the input.  This radio's DV extra bits are
> > used to stream D-PRS translated copies of local APRS Mobiles
> > this area.  This radio does transmit VOICE SILENCE while
this is
> > taking place.  Though an option for "elevator music" or Rush
> > Limbaugh could be made (joke!)...
> >
> > C) Do what we can with D-GATE?  It is a processor connected
to a
> > DV radio, so could it not do the plan B streaming while the
> > repeater was idle?
> >
> > Again, I am not saying either of these are practical.  But
> > they answer why the DSTAR users have been saying it is
> > impossible.  Or is it only because they assumed the source
> > the D-PRS translanted APRS information was going to get to
> > repeater on the uplink of another D-STAR radio, instead of
via a
> > backdoor independent input as I was assuming...

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