<br><font size=2 face="sans-serif">My answer: sort of.</font>
<br><font size=2 face="sans-serif">One of the limitations of APRS is that
it relies on AX.25 UI, meaning that you can only send small packets of
data. (about 65 to 110 characters, depending on message formatting
type) So you may not be able to send a huge file, but you can use
small messages. UI-view has an addon that allows you to do something
that looks like a chat client, <http://www.apritch.myby.co.uk/addon_agw.htm>
you might be able to send a big file, but you have to do it small chunks
at a time. </font>
<br><font size=2 face="sans-serif">There is also an app that lets you pass
data at the AX.25 layer, UI-Messenger <http://www.kr1st.com/uimsg.htm>
but I am not familiar with it. </font>
<br>
<br><font size=2 face="sans-serif">That doesn't even touch on the practical
aspects of APRS, like the facts leared during disasters. (we can save that
for another time)</font>
<br>
<br><font size=2 face="sans-serif">Having said all that, the current QST
had an article about NBEMS (Narrow Band Emergency Messaging Service) and
K0ECW expressed interest about setting up a trial among Cedar Rapids users.
So far not much else has been heard.</font>
<br><font size=2 face="sans-serif"><br>
David J Huff<br>
Rockwell Collins Inc.<br>
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<td width=40%><font size=1 face="sans-serif"><b>Jerry Pasker <info@n-connect.net></b>
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<br><font size=1 face="sans-serif">Sent by: craprs-bounces+djhuff=rockwellcollins.com@rf.org</font>
<p><font size=1 face="sans-serif">08/05/2009 05:03 PM</font>
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<td valign=top><font size=1 face="sans-serif">[CRAPRS] aprs backbone for
emergency communications</font></table>
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<br><font size=2><tt>Posting from the CRAPRS mailing list:<br>
is it possible to use the large number of aprs high level digipeaters <br>
as ax.25 digipeaters? 1200 baud is slow, and my past experiences
<br>
using it to transfer files (back in the early 90s, for storm chasing) <br>
used to yield a throughput of 600-900 bps when transferring files. <br>
and then even worse at 150-300bps when using a digipeater in the <br>
middle. I know channel congestion would be a huge problem trying
to <br>
use aprs digis, and it would be slow as heck, but in an emergency, <br>
you take what you can get.<br>
<br>
you wouldn't surf the internet with it, and would not even attempt to <br>
transfer even graphical weather map files, but i envision a scenario <br>
where it would be desirable to be able to send simple text traffic <br>
that would be too hard to relay over the air with voice comms <br>
reliably. for example, (from a year ago) a list of houses and names
<br>
of those holding out and staying behind after a a flood evacuation....<br>
<br>
aprs is entirely unnumbered and unconnected, and that's what makes it <br>
work well. it also seems like that would lend itself to useful, but
<br>
slow data communications over a fairly wide area.<br>
<br>
anyone have any info on using digis to connect up to tncs far and <br>
wide, or passing files on 144.390?<br>
<br>
-jerry<br>
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