Great little article: “How to shrink a 30ft base-station into a three-inch Raspberry Pi” here:
Not quite sure a Raspberry Pi can be used to shrink a 30ft base-station without the additional costs of a duplexer and some power amplification! Also I have concerns that the Pi doesn’t have enough physical RAM. But hats off – it shows the art of the possible.
From my own experiences and like the folks at PA Consulting Group say “Overcoming some seriously complex obstacles along the way, we successfully managed to route voice and SMS traffic through the computer”. For me the biggest obstacle to date on Centos 5 / RHEL 5 has been sorting out all the package version dependencies.
For my project I’m planning to use a Fairwaves (http://fairwaves.ru/) UmTRX (http://code.google.com/p/umtrx/) as the GSM transceiver rather than an Ettus USRP (http://www.ettus.com/). This will give me a bit more flexibility to use the same hardware for other projects in the future.
Also rather than having my own screened-room facility my research suggests that an old Microwave oven with some copper mesh should make a cheaper Faraday cage (although the UmTRXv2 is pretty low-power at 50-100mW anyway)!