CLA-MAC: A cooperative extension of load adaptive MAC protocol

The use of cooperative communications techniques has proven to significantly improve network performance. In this paper, we propose a cooperative extension of load adaptive MAC (LA-MAC) protocol proposed earlier by us as a hybrid CSMA-TDMA protocol for MANETs. We describe the design and GNU radio implementation of our protocol to which we refer as cooperative LA-MAC (CLA-MAC). Our protocol design takes into account frame structure, message exchange, multiple relay selection policies, and contention avoidance. The relay selection policies of the protocol include two practically viable alternatives, namely, the nearest neighbor and largest harmonic mean channel. Experiments confirm that both relay selection policies proposed by CLA-MAC protocol can achieve lower packet error rates and smaller packet delays compared to the original LA-MAC in the cases of poor signal quality reception at a destination.