[aprssig] APRS Local Info

Robert Bruninga bruninga at usna.edu
Mon Jul 2 09:51:53 EDT 2007


> >We must get travelers with their D7/D700's 
> >to ask everywhere they go, why they are not 
> >seeing the local recommended voice repeater 
> >frquency on their radios when they enter an area..
>
> Bob, I just had to chuckle at this.  
> After all the time spent trying to reduce 
> channel loading, here we are trying to 
> INCREASE it...

Ah, but that is the beauty of this.

Since these local objects are originated at the DIGI's only, and
since the digis can hear everything on the channel, they will
not TX these local Voice Repeater Objects unless the channel is
*clear*.

This makes them a no-cost, positive addition to the network:
1) They won't collide with anything
2) They take no additional channel capacity
3) They are sent direct, no hops, no QRM out of area
4) Only one per digi is possible.

On the same hand, we must strive to get rid of home-generated
objects for similar purposes.  These packets are not at all like
an object originated at the digipeater.  Home generated objects
have all these negatives:

1) Collide with other packets 
2) Take twice as much channel capacity
3) take at least one hop, maybe more
4) Often use default client 2 or 3 hop path
4) No limit to the ego of the sender and quantity of objects

Hope that helps clarify why this Local Infor Initiative is so
valuable to the APRS network and at no cost.  See the web page:
http://www.ew.usna.edu/~bruninga/localinfo.html

Bob, WB4APR





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