Today I finally received PDF's of the Siemens BS-11 GSM BTS. This means that I'll now be able to actually connect the device to power, E1 and RS232.
Unfortunately I'm still lacking the configuration software for the device, and a corresponding E1 card for the Abis interface. Anyway, seems like we're slowly getting there. Maybe during Q1/Q2 2006 I can spend some time actually implementing code for that beast.