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[aprssig] WIDEn-N, LINKn-N, LANn-N and SSn-N digis

Robert Bruninga bruninga at usna.edu
Fri Jul 30 19:47:34 UTC 2004


The new n-N paradigm tries to cut down on the total
FLOODING concept of WIDEn-N to try to get packets
more directed where they are intended instead of just
flooding everyone everywhere.

The problem is that in the typical KPC-3+ TNC you 
only get two n-N options.  This email suggests how
you can get a total of EIGHT UI Aliases, and FOUR
total n-N systems!

An example would be a digi that happens to
be at a crossroads between two different LINKn-N
chains AND needs to still support WIDEn-N becuse
it is in a realtively sparse area and can handle it,
but also the operators wanted it to respond to their
STATEn-N system too!  Thus needing 4 n-N calls.

The answer is simple.  Just hook two TNC's in 
parallel to the same RF receiver and transmitter.
Let the original TNC support all the original modes
it normally supports, RELAY,WIDE,SS,SAR,
WIDEn-N, whatever.  Then add the new 
n-N's and other aliases into the new TNC (but
making sure to have no dupes!).  Then when a 
packet comes in, it will get digipeated by any of the 
SUM of the possible methods, but the two TNC's
will never collide... (as long as they have all
different settings).  Though you do have a potential
confilct in the NAME Of the digi itself so make one
W3XYZ-11 and the other be a tactical call-11 where
everone will know that the two are at the same
location..

Yes, it costs another TNC, but it DOES solve
the problem!

For more info on the "new n-N paradigm" please see

http://www.ew.usna.edu/~bruninga/aprs/fix14439.html

And LASTLY, remember, the whole purpose of the
new n-N paradigm is to CUT DOWN on flooded 
traffic, not to look for more ways to bring in more.
So this combination scenario would only apply in a
sparse area where multiple "backbones" or
specific needs cross or converge...  Dont put one
of these downtown unless you eliminate WIDEn-N
entirely from the mix...

Bob, WB4APR




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