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[aprssig] timeslotting on HF ? was > 15. APRS trackers on 10m (Robert Bruninga)

K. Mark Caviezel kmcaviezel at yahoo.com
Sat Nov 26 18:28:00 UTC 2005

Bob, all: 
It seems like some of the chaos we hear on 144.39
could be avoided by having assigned time slots on 10m
(or 30m or any HF band for that matter), and since all
users are hopefully using GPS derived timing, all
users could sign up for a couple slots per hour, and
by transmitting only during one's assigned slot, we
avoid the QRM of packets stepping on each other that I
hear all the time on 144.39.  Now, exactly how we'd
get hams to sign up for time slots and stick to them
is another story, but the reliability increase of
having one or two dedicated slots per hour, for a lot
of APRS applications seems to have an attraction
versus the spray out a packet every few minutes and
hope it gets through which seems to be the current
state of the art.   Seems like this would also be an
absolutely awesome propagation monitoring tool as
well, with 10, 20, 30 or more i-gates around the US
listening to 100's of users each sending location
tagged packets a couple times an hour, there would be
a tremendous amount of real time propagation
information determined, too. 

If each slot was 2 seconds long, that's 1800 slots per
hour.  Each slot could be defined by a two byte code,
and if something like the Pocket Tracker or Open
Tracker came onboard with firmware prewired to support
this type of time slotting this could really
dramatically change how APRS could work on HF.  

Yes, I know there are a ton of reasons why this could
never work, but the benefits of transmitting in a
universally defined and agreed to time slot seem to be
pretty compelling. 
<sliding into my Nomex underware about now.> 

- KMC ng0x Denver, Colorado 


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