The OsmocomBB project provides an Open Source implementation of the higher layers of the mobile-side GSM protocol stack, which at the moment allows a end-user to make voice calls, and exchange SMS messages. But some important parts are still missing, so the aim of this task is to fill this gap:

• GAPK (GSM Audio Pocket Knife) audio front-end integration (see https://osmocom.org/versions/133)
• TDMA frame loss tracking (see https://gerrit.osmocom.org/10309/, TODO: create an issue)
• PDTCH channel coding for SDR based PHYs (see https://gerrit.osmocom.org/7023/)
• CBCH (Cell Broadcast Channel) implementation (see #3558)
• TCH/H channel coding for SDR based PHYs (see #3419)
• PHY info / capabilities exchange (see #1461)
• DTX (Discontinuous transmission) support
• AMR (Adaptive Multi-Rate) codec support