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[aprssig] 9600? Faster?

VE7GDH ve7gdh at rac.ca
Thu Jul 7 16:05:19 UTC 2005


Earl KD5XB wrote on 07/07/2005

> Well -- are we stuck at 1200?  Or should we try something even
> faster than 9600?

That depends. We aren't running a "for profit" commercial operation. There
aren't any investors lined up to sink billons or even millions of dollars
into APRS. For now, what you see is what you get. APRS is so far based on
available equipment and technology, is paid for by individuals or clubs who
are willing to "donate" equipment to the cause, and the time individuals are
willing to spend to set it up and maintain it. I think we should look with
pride at the early days of radio and realize that much of what we take for
granted now is based on developments by amateur radio operators. Amateurs
were even at the forefront with the development of data transmission by
radio. I think packet radio in general and APRS are a testament to the
dedication of those forward-thinking people that were willing to invest
their time and contribute their talents towards the cause.

So... are we stuck at 1200 bps? It would appear that mobile operation at
9600 bps doesn't fare as well as 1200 bps. Do we want or need to move to
9600? I'm not going to try and give a definitive answer on that. I don't
even own any 9.6kbps TNCs yet. However, as amateurs, we should be looking to
the future. The way I see it, we should make the best of things with the
equipment that is available now. Optimizing the existing network further is
based on a number of things. Right now, it is up to the individual to set
the frequency of their radio, set the power level, program their tracker /
TNC  / D7 / D700 / etc. and it is up to the operators of the digis to
program them to work the most efficiently, and where to physically install
them. When it comes down to it, the D700 is already frequency agile if it is 
coupled with an external program like UI-View32 which can send commands a 
D700 to set the frequency as well as program it for use with the program. 
Not quite a fully automated system, but the capability is there. I don't 
know if the power setting can be adjusted via the same route.

My thoughts are that we should do the best we can with the existing
infrastructure and way of operation, but be looking forward to see what lies
ahead in the future. Perhaps it is wishful thinking, but perhaps we should
be looking at smart frequency-agile radios capable of QSYing to the
appropriate frequency based on data sent from the digis, and adjusting their
transmit power based either on signal strength received from the digis or on
feedback from the digis, with TNCs capable of operating at multiple speeds.
Specifying a digi paths or moving to NSR (no source routing) is really a
discussion about the existing infrastructure. If our APRS network evolves
into something more like the cellular telephone network, routing and
optimization is something that will be built into the hardware & software
that runs it on both ends. Do we want to do this? Do we want to just stick
with the existing APRS system? Can there be enough agreement  to make such a
move actually happen? Will APRS just get  blended into other data
transmission on amateur frequencies or will it even be the other way a
round? Will it be a mix of terrestrial and satellite equipment? Time will
tell.

In the meantime, we have a workable APRS system, but it is either going to
carry on "as is" with no huge advances in the technology and no big
increases in the number of people involved with it in at least in the larger
cities where the frequency is often already at the saturation point, and no
big changes in the way it operates, or we are going to advance. Whether it
will be a "paradigm" shift to new technology, or if it will be done in
incremental steps with small changes to the existing network, time will
tell. For now, help educate those around you. Retire less than smart
trackers. Move from TNC based trackers to something with more intelligence.
Preferably use smart beaconing instead of fixed timing if your equipment is
capable. Run a non-abusive path. Run the lowest power you can. Digi
operators can install more low-level digis. Digis can get smarter.
Discussing 1200 vs 9600 is very valid. It's up to us how or if APRS will
evolve.

73 es cul - Keith VE7GDH
--
"I may be lost, but I know exactly where I am!"






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