[aprssig] DIGIpeater - Network performance

Robert Bruninga bruninga at usna.edu
Fri Jan 26 12:48:24 EST 2007


No one jumped on this sentence buried in some of the earlier
emails...

> 1) I live in probably the highest density of APRS and voice
> repeaters on the planet, over 100 voice repeaters and I just
> checked 50 digipeaters heard on RF....

I was frying other fish at the time, but when I noticed this 50
digipeaters heard on RF in the Baltimore-Washington DC area, it
did tweak my interest.  Today, I got back to it and took a
detail look at this.  

Turns out, all but 5 of those digis are using the proper 2 hop
paths and are fully compliant with the New-N paradigm.  Only 1
was so far out of area as to be due to TROPO.  The others all
represent how powerful a 2 hop path is on the Eastern Seaboard.
Now remember, that a 2 HOP path from a digipeater is similar to
a 3 hop path from a user station, since the digi is already at a
high site, so we will see digipeaters one tier beyond where we
should be seeing 2 hop users.  These two images show the digis
and how many are outside of my ALOHA circle.

http://www.ew.usna.edu/~bruninga/aprs/DC-digis.GIF

But since 2 hop users are one tier less than 2 hop digi's, most
of the 240 users I hear on RF these days are within my ALOHA
circle as we hoped:

http://www.ew.usna.edu/~bruninga/aprs/DC-users.GIF

Anyway, this is a lot better picture than it used to be, and
even with all that activity, there is still some quiet time for
most mobiles to get in.

Those areas that are still stuck with RELAY and WIDE
digiepeaters can look forward to improvements such as we have
gained here.  See
http://www.ew.usna.edu/~bruninga/aprs/fix14439.html

Bob, WB4APR





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