Whenever VOIP and GPL’ed software are mentioned I always think of
asterisk. It’s safe to say that asterisk has a history that is as
interesting and as long as that of GNU Radio :-). (Another buzzword to
keep an eye on in this area BTW is “ROIP”).
Anyway asterisk (in addition to being the GPL swiss army knife for VOIP)
has very highly articulated two-way radio and radio repeater module
which is known as app_rpt - their project page (“The fusion of 2-way
radio systems and VOIP”) is at
ohnosec.org.
While the focus of app_rpt historically has been on analog (NBFM) radios
transmitting and receiving on discrete frequencies, our project (op25)
offers a plugin channel driver to extend a bridge between the
asterisk/app_rpt/VOIP world and GNU Radio. When using the USRP hardware
it aims to support a fully generic, multi-channel, FDX two-way radio
infrastructure with a specific focus on P25. We’re always looking for
experimenters and amateurs who are interested in these technologies…
Project pages are
http://op25.osmocom.org/trac/wiki
http://op25.osmocom.org/trac/wiki.png/wiki/RepeaterPage
Lots of work still to do (of course), including all the new goodies
Jonathan Corgan has been mentioning that are in the GR pipeline for
dealing with packet-oriented datacomm protocols…
Best Regards
Max