[aprssig] Tracker Smart Pathing

Curt, WE7U archer at eskimo.com
Tue Mar 21 15:38:37 CST 2006

On Tue, 21 Mar 2006, Robert Bruninga wrote:

> >>> "Curt, WE7U" <archer at eskimo.com> 03/21/06 1:09 PM >>>
> >How about using "APAUTO" in the destination field
> > Of course this wouldn't work for Mic-E packets,
> >but would for all other types of APRS packets.
> But *most* mobiles use the Mic-E protocol, and it is
> only mobiles that need the AUTO as they go
> from area to area.
> Hence, a good idea but it only works for the ones
> that dont need it.

Ah, I was wrong.  Here's what the spec says, Mic-E chapter:

"The SSID in the Destination Address field of a Mic-E packet is
coded to specify either a conventional digipeater VIA path
(contained in the Digipeater Addresses field of the AX.25 frame), or
one of 15 generic APRS digipeater paths.  See Chapter 4: APRS Data
in the AX.25 Destination and Source Address Fields."

On page 16 of the PDF it spells out these:

    -0  Use VIA path
    -1  WIDE1-1
    -2  WIDE2-2
    -3  WIDE3-3
    -4  WIDE4-4
    -5  WIDE5-5
    -6  WIDE6-6
    -7  WIDE7-7
    -8  North path
    -9  South path
    -10 East  path
    -11 West  path
    -12 North path + WIDE
    -13 South path + WIDE
    -14 East  path + WIDE
    -15 West  path + WIDE

So...  Mic-E _can_ use the destination SSID to specify things.
Assuming the Kenwoods (and others of course) can be set to any of
these, we'd just have to redefine what the settings mean in the
digipeaters.  As far as I know the scheme called out in the spec
hasn't been implemented anywhere, but I haven't been everywhere.

Curt, WE7U.   APRS Client Comparisons: http://www.eskimo.com/~archer
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