Behind the scenes, we've been working on preparing the experimental GSM/GPRS/EDGE network at the 27th Chaos Communication Congress. The regulatory authority was nice enough to grant us 6 ARFCN, which we will split to 3 BTS (2 TRX each), resulting in one BTS with 2 TRX on each of the 3 conference building floors.
I've started a page in the 27C3 conference wiki about the GSM network. Please notice that this information is still preliminary at this point.
The wiki page also contains detailed instructions on how you can participate in the test network. I'm hoping a lot of you will bring a dedicated cellphone that you can put the 27C3 SIM inside and participate in the network.
I'm particularly excited about GPRS/EDGE support. We will be handing out official, world-wide routed, unfiltered IPv4 addresses to each and every phone. This means you are free to run port scans or other attacks (please: No DoS) over an unfiltered IP network directly into your mobile phone.