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[aprssig] The New N-N paradigm CAN WORK

Robert Bruninga bruninga at usna.edu
Thu Oct 28 20:40:11 UTC 2004

>>> Rick Green <rtg at aapsc.com> 10/28/04 10:12:56 AM >>>
>> No, not really.  Each digi owner just decides what LANn-N
>> his digi is part of and changes it immediately.  No coordination
>> required.

>So who decides the basic definition of the LANs and their boundaries?

The DIGI owner or participating interested individuals involved 
in APRS in the area...

> Not at all.  RELAY,WIDE2-2 would work everywhere.
  ...except in sparsely populated areas, where digis and igates are

There are very few places where there is not an Igate
within 3 hops of everywhere.  If there is such a hole
then the first prioirty should be to fill it...

>But the definition of 'local' seems to be an ALOHA circle,
>which contains enough stations to fully utilize the channel, yet not
>over-saturate it.  This definition changes over time and geography.

That is why APRSdos and hopefully all other APRS programs
re-calculate it every half hour or so to recompute and re-display
the actual real-time bounds of the useable "local" ALOHA network...

>Doesn't it make more sense to design a network where the 
>need to analyze the local network is limited to the digi 
>operators, who are assumed to have more local knowledge 
>than the transient mobiles, who can then use a 'worst case' 
>path that will reach the edges of the ALOHA circle and have
>the best probability of reaching an igate even in the remote 
>areas, yet will not over-saturate the network in the dense areas?

That's a mouth full, but the problem is that there is no such
universal path.  (Other than RELAY,WIDE2-2 for mobiles)
And we want "educated" users of the network, sensitive to
what is going on in real time not blind applicance operators
in SoCal who look up on a web page (posted in Nebraska) 
with a recommended WIDE7-7 path...

>I'm trying to define a scheme that would be optimum for 
>the mobiles, ... I believe it unrealistic to expect mobile 
>operators to research every local LAN they pass thru and 
>adjust their path accordingly.

I agree 100%.  That is why there is only one recommendation
in my thinking and it is RELAY,WIDE2-2.   That's it.
1) It works EVERYWHERE because of RELAY
2) It does SOURCE Identifications because all RELAYS
    are supposed to do callsign substitution
3) In WIDEn-N areas, it will go a totoal of 3 hops
4) In NON-WIDEn-N areas it will go 2 hops because
    the local digis will all support "WIDE2-2" as an alias
    for callsign substitution.
5) It limits the damage to the network beyond 3 hops
6) It is ONE universal path that can be posted and
    used by everyone....and still accrue all the advantages
7) Sparse areas who supportt this concept only need to
    make sure they have an IGate at least within 3 hops
    of every digi.

Bingo.  Done.  A universal path that works everywhere,
does not flood, and does not abuse the network,

In 12 years of APRS, I have never seen any better
universal recommendation... 

>Dividing the country into multiple tiled LAN areas requires 
>that mobile users change their paths for optimum use as 
>they travel.

I think you are missing the whole point.  The Mobiles never
change. RELAY,WIDE2-2 should work everywhere.  Yet
getting rid of WIDEn-N in saturated areas helps everyone...
(by replacing it with LANn-N,s and long chain LINKn-N's...
or LOCALn-N's...

de WB4APR< Bob

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