Has anyone put together all of the protocols, into a full simulation? I want to develop(play?) with the protocols, but not mess with RF. I was thinking of using IP/UDP to simulate all of the channels. A cell phone simulator could talk to a BTS simulator, that could talk to BSC, SGSN, etc. Automated testing then could verify protocols for regression testing.

Also what set of standards are being used in OpenBTS? I was looking at 3GPP and they talk about 04 and 4x series.

I don't want to do any work, unless it has never been done and there is a need.