[OZAPRS] More QRM

[Robert Bruninga]

> How many more users of the VK7 network do you think 
> could use [a] high beacon rate and still get reliable 
> coverage?  

I'm not following this one too closely, and the following
comment is not addressed to this particular argument, but is
just a comment in general.

That is, that it is the product of beacon rate -and- path length
that should be considered.  A high rate -direct- is not as bad
as a medium rate going out 3 hops to 27 digipeaters in all
directions.  That is why we have to be careful about giving
guidelines that only talk about rates and hops independently and
without mention of the word "routine" in the receommendation.  

I have seen a receommendation of 2 minutes and 2 hops for
general use (but I would add the words "for routine general
use".   It is the 24/7 routine operations which are mostly of
little interest to anyone that is the major load on the system.
Getting that routine load under some general recommendations
will go a long way toward providing enough bandwidth for someone
doing a special trip to use a 1 minute rate and shorter path...

So it seems to me, it might be OK to use 1 minute and 1 hop
because it is doubtful that there are more than a few mobiles
within range of any one digi...  Similarly, anyone using 3 hops
mobile ROUTINELY should probably go with a 5 minute rate.  Etc..

So it is helpful when drawing lines in the sand, to include the
conditions under which that line is being drawn...

That is why I like the Proportional Pathing concept.  It is 1
minute direct, every 2 minutes via 1 hop and every 4 minutes via
2 hops and every 8 minutes via 3 hops.  This makes sure that
there is good rapid data close in and less QRM further out where
the interest is less.
See the concept on
http://www.ew.usna.edu/~bruninga/aprs/ProportionalPathing.txt

Just 2 cents...
Bob, Wb4APR



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