[aprssig] Tracker Smart Pathing

Daron J. Wilson daron at wilson.org
Tue Mar 21 10:18:49 CST 2006

> Now, this is a statement I need to check on.  Round these parts I have
> *NEVER* seen "SmartBeaconing" do anything but produce *more* packets than
> any sane fixed beacon rate station.

I don't believe the goal of smart beaconing has ever been to 'produce less
packets', however, it does produce more timely packets.  In a given stretch
of road, if I set my fixed rate to 5 minutes and drive for an hour, it is
quite likely that my smartbeaconing will produce more packets...unless, that
is a straight shot down the highway.  However, with the fixed rate, if I
beacon, then turn and go perpendicular to my original path, I'm 5 miles away
from my previous course before anyone knows my position.  Conversely, they
know the moment I make the turn with smart beaconing.

Perhaps it depends on what you expect for position report accuracy and

> We have a few stations in the area that are running TinyTrakIIs with smart
> beaconing turned on.  When they're operating, I routinely see 3-5 packets
> per minute from them if they're on any kind of windy road --- that is,
> most
> of the ones outside the city.  I think this is due to the corner-pegging
> feature -- great for producing a detailed map of the road up to Sandia
> Crest (where a prominent local digi lives), but not very channel-friendly.
> Sometimes I've even seen that level of output from them even when they're
> on
> freeways.

There must be a sliding scale between channel usage and accuracy of
position.  We don't all transmit every 30 seconds (too much channel usage)
nor do we knock it back to once every hour (not much accuracy).   Rather, we
find that happy medium with recent enough refresh rate to meet our
positioning needs.

Smart beaconing means that you won't find my vehicle sitting at starbucks
for an hour beaconing every 2 minutes :)  It also means that when I'm on the
move, you have a very good idea of where I am, not where I was 5 minutes

In our terrain, when I get to a curvy mountainous road, I beacon quite more
frequently than a straight road, however, due to the canyons and hills the
coverage is reduced, I don't get into a digi on every packet, so it seems to
even itself out a bit.

Daron, N7HQR

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