Work on a free software GPRS/EDGE stack!
A project called OsmocomBB is underway to develop software that could be used in free mobile devices. Progress has been good, with regular telephone calls and text messages already working, but data connections are still not supported. This work is substantial and quite different from the work needed for voice calls.
OsmocomBB developers are looking for people with an interest in implementing data support.
The project is written in C and built using the GNU Compiler Collection and the GNU binutils for cross-compiling to the ARM7 chip used by many mobile devices.
Any developer working on this task should have a strong understanding of communications systems and be able to read and understand ETS/3GPP specifications. As a start, there should be a thorough understanding of GSM and GPRS network as well as protocol architecture - including but not limited to 3GPP specifications 02.60/22.060, 03.60/23.060, 03.64/43.064.