[aprssig] Re: Unreasonable xmission delay = big white elephant in the room

[Jeff Thomas - KD4EVB]

I'll preface this I have little doubt there is
something funky going on with APRS-IS at times, but
from reading this thread I think there is another
angle to be examined.... local RF network loading.

Here we have a mobile beaconing an appropriate (I
guess for the area) WIDE1-1,WIDE2-1 path.  Problem is
(IMHO) the 30 second beacon rate.  This strikes me as
excessive unless needed for a specific situation
(event, emergency ops, etc).  Come on folks, even at
60MPH in 30 seconds you've only gone 1/2 mile at best!
 A few mobiles beaconing at this rate on top of an
already loaded channel can have a serious impact on
local rf network reliability.

Let's take a look:

http://www.findu.com/cgi-bin/near.cgi?call=K4COE

Looks like the ALOHA circle down there is only 30
miles.  Approaching 400 packets an hour (that APRS-IS
is seeing at least).  6 Digi's in that 30 mile radius
(wow).

I can only imagine what the DCD lights on those digi's
look like.  It's one thing to examine the rf level
from a home station, but it's a whole different view
to look at things at the actual Digi site.

I remember a few years ago during the (WIDE,WIDE
versus WIDEn wars) when the local RF network here in
the Ohio Valley was in shambles due to poor configs,
poor paths, and excessive beacon rates.  I could go to
the digi site and wonder if the darn DCD light was
stuck on.  Even have a video somewhere of it, it was a
real eye opener.  Folks if the DCD light is on,
nothing's getting digipeated during that time!

Things in the Ohio Valley are much better today, not
perfect (still lots of digi's using old standards to
my south), but cleaning up the RF side of things has
made local communications much more reliable.  At one
time the locals switched to 440 as 144.390 was a
disaster is terms of loading and reliability.

In short, nothing against K4COE persnoally, but if
this stations setup is typical for that area, I can
only imagine how bad the RF level of things are.

Again, there's definitely something goofy going on
with ARPS-IS at times, but let's not forget the other
side of the equation...the local RF networks.

Just a little food for thought.

73
Jeff
KD4EVB



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