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Alan P. Biddle wrote:
<blockquote cite="mid:77ED0A46CB2347049A735BACB7D49F1D@WA4SCA" type="cite">
<pre wrap="">Hi,
Locally there has been an explosion of interest in APRS, which is good.
That has brought the inevitable argument about using SSIDs, and if so, which
one. Any definite suggestions about a good, current reference on the issue? It
is at once not very important, but also a chance to get things started in
compliance with current best practices.
</pre>
</blockquote>
<br>
SSIDs no longer mean anything. The SSID technique dates back to the
early days of APRS, before specialized APRS hardware A mobile
tracker consisted of a GPS receiver plugged directly into the main
serial port of a dumb TNC. The TNC then transmitted raw unmodified
NMEA strings over the air. <br>
<br>
<br>
Since there was no way to insert symbol control codes into the raw NMEA
data, the callsign SSID was used instead to control which of 12 or so
symbols should be displayed. Today, all APRS devices reformat NMEA
GPS data into much shorter strings, and at the same time, merge control
codes for hundreds of possible symbols and overlay codes into the
packet data payload. If one has both codes in the payload -AND- an
SSID, the SSID will be ignored in favor of the codes in the payload. <br>
<br>
<br>
[Note further that the SSID technique, if used, cannot express the
alpha-numeric overlay codes for the base symbols that are increasingly
common. <br>
<br>
<br>
<hr size="2" width="100%"><br>
--<br>
<br>
Stephen H. Smith wa8lmf (at) aol.com <br>
EchoLink Node: WA8LMF or 14400 [Think bottom of the 2M band]<br>
Skype: WA8LMF<br>
Home Page: <a class="moz-txt-link-freetext" href="http://wa8lmf.net">http://wa8lmf.net</a><br>
<br>
NEW! HF APRS Notes & Guide<br>
<a class="moz-txt-link-freetext" href="http://wa8lmf.net/aprs/HF_APRS_Notes.htm">http://wa8lmf.net/aprs/HF_APRS_Notes.htm</a><br>
<br>
"APRS 101" Explanation of APRS Path Selection & Digipeating <br>
<a class="moz-txt-link-freetext" href="http://wa8lmf.net/DigiPaths">http://wa8lmf.net/DigiPaths</a> <br>
<br>
Updated "Rev H" APRS <a class="moz-txt-link-freetext" href="http://wa8lmf.net/aprs">http://wa8lmf.net/aprs</a><br>
Symbols Set for UI-View, <br>
UIpoint and APRSplus:<br>
<br>
<br>
<br>
<br>
<br>
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