[aprssig] The new D710 and Smart Beaconing?

Wed May 23 14:06:23 EDT 2007

What I've considred doing is similar, but instead of an absolute distance from your last beacon it'd be distance from your dead-reckoned position based on the last beacon.  It'd be particularly useful with clients like Xastir that do dead reckoning - you'd always know that the tracked station isn't further than a certain distance from its displayed position.

It just happens to take a little more math than I want to squeeze into the OpenTracker.  Maybe I'll do it in the Tracker2.

Scott
N1VG
  _____  

From: Stephen H. Smith [mailto:wa8lmf2 at aol.com]
To: TAPR APRS Mailing List [mailto:aprssig at lists.tapr.org]
Sent: Wed, 23 May 2007 10:59:44 -0700
Subject: Re: [aprssig] The new D710 and Smart Beaconing?

Wes Johnston, AI4PX wrote:
> I set mine highspeed to 45mph.  My line of thinking is that if I'm 
> travelling at a hi rate of speed, I'm probably on a long straight 
> stretch of road and can get away with beacons every xx miles.  If 
> below 45mph, I get corner pegging... if parked, the slow rate.  If you 
> set the high speed to an unreasonable unattainable high speed, then 
> the corner pegging causes transmissions on long slow curves in the 
> interstates.  One such road here in my area has a slow S turn that is 
> 3/4 mile end to end.  It'll cause a transmission entering and exiting 
> the curves.
>  

I think it's the corner pegging component of Smart Beaconing that REALLY 
chokes the APRS channel with excessive transmissions.   It might work in 
the flat midwest where virtually all the major highways and significant 
secondary roads are dead straight and aligned on the  cardinal 
directions [ Ever looked out the window while flying over western 
Illinois, Iowa or Nebraska?   It looks like flying over graph paper! 
].   In the west (where roads curve constantly around mountains or 
switchback their way over mountain passes)  , and in suburban 
subdivisions of carefully  artistically  curved streets, you wind up 
transmitting almost continuously.  

I originally had smart beaconing enabled in APRSplus when I first took 
it mobile in Southern California some years ago.   Several weeks later, 
I happened to see a listing of who made the most transmissions on 144.39 
in SoCal and was shocked to see I had the second largest number of 
transmissions in the area, after a clueless idiot that beacons raw NMEA 
strings every 60 seconds 24/7.   I immediately disabled it.   

I now use what is essentially a modified (and very simple) version of 
Smart Beaconing.  UIview allows you to set the transmit interval based 
on either a fixed number of minutes (like a D700), or on a specified 
change in position when above above a certain speed.     The position 
changes are in increments of either 1KM or 1 Mile.  This intrinsically 
has you beaconing less often when crawling in city traffic, and more 
frequently when you hit the open road at 65+ MPH with no arbitrary 
thresholds of SLOW-MED-FAST.   

You also set a time interval for beacons when position doesn't change 
(or changes very slowly) such as when you park and stop changing 
position (or get gridlocked in a construction zone where your progress 
is less than 1 or 2 MPH).   I have my UIview mobile set to beacon on 
whichever comes first:  a 1 KM change in location --or-- 30 mins elapsed 
time.     

Compared to the full smartbeaconing described above, this reduced my 
beaconing over 95%!        UIview also allows you to manually force a 
beacon at anytime by pressing F9.  This addresses the issue of a final 
updated posit when you park before the 30 min stationary interval 
triggers, and is also useful if you DO want to peg a particularly 
important corner.    

(You can easily do this with a TinyTrack as well.  In addition to the 
normal smart or dumb timed intervals, connect a push button to the input 
that would normally be used for Mic-E PTT triggering. You can then force 
a posit at any time by pushing the button,  withot excessive numbers of 
corner pegs by default.)

BOTTOM LINE:    An astonishing number of people seem to have the urge to 
draw an absolutely perfect track line on other user's maps, via 
aggressive  corner  pegging.    It is SIMPLY IMPOSSIBLE to do this on a 
shared 1200 baud channel ! ! !

--

Stephen H. Smith    wa8lmf (at) aol.com
EchoLink Node:      14400    [Think bottom of the 2M band]
Home Page:          http://wa8lmf.com  --OR--   http://wa8lmf.net

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