Cross-layer Packet Scheduling Framework with QoS Mapping for Real-time Video in CSMA/CABased Networks

This paper proposes a cross-layer packetscheduling framework with QoS (Quality of service) mapping to provide UEP (Unequal error protection) at bothapplication and MAC (Medium access control) layers byinvestigating the CSMA/CA (Carrier sense multiple access with Collision avoidance) protocol from the queuetheory. We take full advantage of the rate-adjustabilityof shortened-and-punctured RS (ReedSolomon) codes, anddiscuss three essential aspects of the framework: the packetloss probability under both FEC (Forward error correction) and delay constraint, the mapping mechanism frompackets loss distortion to retransmission limit, and thecongestion-aware scheduling algorithm. Besides, a reservation factor for queue space is introduced to restrain thenegative effect of burst behavior of the parity packets. Simulation results indicate that the performance of our schemeis superior to the conventional methods.