Cooperative MAC Protocol with Distributed Relay Actuation

Cooperative transmissions emulate multi-antenna systems utilizing merely nodes equipped with single-antenna and the degree of performance enhancement is dependent upon the relay selection and actuation mechanism employed. An essential part in the realization of cooperative wireless networks is the design of efficient adaptive MAC protocols that empower distributed selection and actuation of the best relays in the network. In this paper, we propose and analyze a distributed relay selection and actuation scheme based on random access. Our method relies on slotted ALOHA based relay advertisements, and unlike the other protocols in the literature, it supports cooperation with multiple relays. We provide the analysis of the throughput gain provided by the proposed scheme and obtain the optimum channel access probability for the relays to announce their availability for cooperation. The proposed scheme renders simple distributed operation, which makes it suitable especially for densely deployed wireless sensor networks. Via simulations, we verify the validity of optimum cooperation probability solution and we show that the proposed actuation scheme can provide significant throughput enhancements and energy savings over direct transmission.