a very promising project based for now on the USRP (universal radio
peripheral):
http://openbts.sourceforge.net/
"The OpenBTS Project is an effort to construct an open-source Unix
application that uses the Universal Software Radio Peripheral (USRP)
to present a GSM air interface ("Um") to standard GSM handset and uses
the Asterisk software PBX to connect calls. The combination of the
ubiquitous GSM air interface with VoIP backhaul could form the basis
of a new type of cellular network that could be deployed and operated
at substantially lower cost than existing technologies in greenfields
in the developing world.
In plain language, we are working on a new kind of cellular network
that can be installed and operated at about 1/10 the cost of current
technologies, but that will still be compatible with most of the
handsets that are already in the market."
I've got one USRP here that im using to track victorian age
satellites, if anyone else is working on radio related topics let me
know perhaps we could make some efforts and push the bricophone
project a bit since there are few developments out there on the
hardware side that are very likely the ways to go.
http://www.it46.se/entry/380 for one.
/a