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[aprssig] SSn-N and the 'new paradigm'

Robert Bruninga bruninga at usna.edu
Wed Feb 23 20:03:07 UTC 2005


>>> Ron Stordahl <ron.stordahl at digikey.com> 2/23/05 11:18:43 AM >>>
>What is the upper limit on the number of characters in 
>SSn-N?  Obviously one wants to keep it short, however 
>I do need to know the limitations.

See the two maps about 50% down this page:
http://www.ew.usna.edu/~bruninga/aprs/fix14439.html

Notice how WIDE6-6 generates 140+ copies over a dozen
states, but MD6-6 only generates about 15 copies.  One
for each DIGI in maryland and that's it.  Only 10% of the
QRM.

That is the advantage of the SSn-N system is that it is
self limiting (to the whole state).  Notice that MD7-7
would generate no more QRM than MD6-6.  And
if a user in the middle of the state uses MD3-3, he
also hits all 15 digis. So MD7-7 is no worse than
MD3-3 in the center.

This works well for the once a week MD State
comms drills for those few APRS statins involved.
Of course we DONT WANT everyone using MD4-4
all the time at all!

This works great in small states or low density
states for state comms needs.  But obviously 
it wont work in California.  There, they might
use the two ARRL Sections.  Or not use it at
all and just use local WIDEn-N since most
comms needs are concentrated...

Bob, Wb4APR

This works in small states.  No one should ever expect
to




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