[aprssig] Satellite positions: FREQUENCY

Bill Vodall wa7nwp at gmail.com
Wed Oct 19 18:36:36 CDT 2011

>> Also the Igates can selectively do the 'igating...'   The Poll model
>> useful at some times but for an ongoing use I hope the objects will be
>> available continuously without polling..
> Personally, I'd disagree with that one, but that's not part of my current
> query/response design anyway.  I'm a firm believer in "information on
> demand" and not "flood the airways with information that one or two people
> might want to know in the hopes that they happen to receive it".
>  Subscription vs broadcast model.

Note that I'm not presenting a theoretical model or proposed
situation.  This broadcast model I'm discussing here has evolved over
perhaps 7 years of live daily use by a number of folks and is running
today.   It works and we wouldn't go back to a poll system.  The
additional caveat I have to add is that most of this is on an
alternate frequency so we had more bandwidth to work with and less
traffic to share the 20% channel with.   Outside of the busy
metropolitan (Seattle area) this scheme does work well on 144.39.

Bill - WA7NWP

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