|License||GPL (Free software)|
OsmocomBB implements the GSM protocol stack's three lowest OSI Layers of the client side GSM protocol and device drivers. The protocol layers forming the kernel exists on the baseband processor, typically consisting of an ARM processor and a digital signal processor.
After developing OpenBSC, a Base Station Controller side implementation of the A-bis protocol, the authors wanted to create a free client-side implementation of the GSM protocol in January 2010. GSM has been in use since 1991, but OsmocomBB is still the only free implementation, excluding failed projects like TSM30 from THC and MadOS.
The developers work with "Calypso" chipset produced by Texas Instruments, because of the amount of information (e.g. datasheet availability) which makes hacking easy. After rolling out the libosmocore library from OpenBSC, it was possible to reuse a lot of code in OsmocomBB.