L2CAP Enhanced Retransmission Support

by Gustavo F. Padovan for BlueZ

L2CAP lies above the Link Manager and Baseband and interfaces with higher layer protocols. It passes the packet from the Link Manager to the higher layer protocols or vice-versa. L2CAP operates in five modes but BlueZ supports only L2CAP Basic Mode. My idea is to implement L2CAP Enhanced Retransmission Mode, which is an improved version of retransmission & flow control modes ( Not yet implemented on Linux) The Basic Mode doesn't support either Retransmission or Flow Control of packets. Those features will make bluetooth transfers more reliable and for the first time we will be able to retransmit corrupted packets making the bluetooth experience better on Linux. Bluetooth protocols like AVRCP will take advantages of L2CAP Enhanced Retransmission.