[aprssig] SMART Networks

[Rick Green]

On Fri, 28 Mar 2008, Robert Bruninga wrote:

>>> Give us a break, Bob.  The way to manage the
>>> network is to let the digi node operators
>>> define a 'service area' geographically, then
>>> digi any packet originated in that area, and
>>> ignore all others.
>
> Then today we see on the SIG:
>
>> The only thing that is locked out are... digipeaters
>> that are located outside of the Lubbock NWS coverage
>> area.  Sometimes this blocks a legit traveller who
>> operates a digipeater with his own callsign.
>
   Apparently, the budlist function they're using isn't sensitive to ssid.
You're right.  Budlisting seems like a crude kludge to limit QRM.

   My proposal to implement a geographical filter wouldn't be subject to 
that same failure mode.  By looking at the location of the originating 
packet, and digi'ing any packet that:
   1) Is asking for a digi,
   2) Originated within the service area,
   3) Passes the dup filter,
  you avoid issues of budlist maintenance and false rejections of 
transients.
   A simple implementation could be based on the ALOHA circle calculation, 
and would therefore expand and contract with band occupancy.  That would 
suffice in wide-open areas with uniform geography.  I think that some 
areas would eventually want a more general polygon definition capability, 
like maybe some of your appalatian mountain valleys, plus an interstate 
corridor thru the pass, but excluding the metropolitan area over the 
mountain...
   In order to provide the flexible coverage of the simple ALOHA circle, 
we'd have to provide for multiple polygon definitions, each associated 
with some metric of channel utilization, so that in quiet times we allow 
packets to traverse longer distances...

-- 
Rick Green, N8BJX

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."
                                   -Benjamin Franklin