A multiple-recipient-based cooperative MAC protocol for wireless ad hoc networks

To further improve the cooperation efficiency and multiple access performance, we propose a novel multiple-recipient-based cooperative MAC protocol for wireless ad hoc networks. The sender selects a recipient among multiple candidate recipients. Candidate helpers employ a preliminary helper contention scheme and an optimal helper contention scheme to select the optimal helper according to their cooperation gain. Besides, the sender can send data packet at the highest data rate that it can support according to the busy tones in the preliminary helper contention process, guaranteeing both the channel utilization and the link reliability. Once the recipient receives the sender´s data packet through the optimal helper, it can also send its data packet to the sender through the same optimal helper. Furthermore, the optimal helper can piggyback its data packet to the sender or the recipient, reducing the reservation overhead and the possibility of collisions during channel reservation. Simulation results show that, in the ad hoc network environment, the proposed protocol has better performance than CoopMACA and 2rcMAC in terms of throughput and average packet delay.