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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I have several discontinued Sierra Wireless MP775 mobile GSM/EDGE
radio modems. These devices were originally installed in emergency vehicles to
provide data and voice access along with GPS reporting. They have external RF connections
for GSM/EDGE and GPS signals. The baseband side includes four wire audio, RS-232
serial, USB and some parallel digital I/O for panic switches etc. GSM voice
connections are established by sending AT commands via the RS-232 serial or USB
ports and utilizing a handset connected to the four-wire audio jack. Here is a
link to the Sierra Wireless web pages for the MP775.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><a href="http://www.sierrawireless.com/support/mp775.aspx">http://www.sierrawireless.com/support/mp775.aspx</a><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>My interest comes in finding an inexpensive way to connect
an Asterisk PBX or similar system to the PSTN via GSM when POTS and Internet
service isn’t available or is too costly to connect. In my case, I’m
considering building a house at the end of a long unpopulated stretch of dead
end road and the cost of trenching and cabling from the nearest telco POP is
prohibitive.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I would like to find a way to connect these modems to my
network so they appear as a SIP FXS device. This would require a device generating/reading
AT commands and passing baseband audio on the front end and SIP emulation on
the backend. I’m sure there must be a way to do this with a pc but to
minimize power consumption; I would prefer to use something like a small single
board computer with a Geode processor. The latter, having multiple RS-232 and audio
ports, ought to be capable of handling at least two of the MP775’s.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Has anyone seen any hardware, software or combination that
would allow me to accomplish such an interface?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Regards,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>George<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
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