Distance-aware reliable relay selection provisioning in wireless cooperative MAC protocol

Over the years, the Medium Access Control (MAC) protocols for wireless networks have considered direct-communication between source and destination. Although direct communication-oriented protocols have proven their efficiency, most of the cases suffer from unsuccessful communication. Therefore, Wireless Cooperative MAC concept has been evolved, where relay node(s) in between the source and destination take(s) the responsibility of making successful communication. As of now, different types of relay selection mechanism have been proposed for cooperative MAC considering the metrics like - node´s residual energy, delay, Signal to Noise Ratio (SNR) etc.; whereas rarely the distance metric is used and the unsuccessful communication problem still exists. In this paper we have designed a Distance-Aware Reliable Relay Selection (DRRS) mechanism for wireless cooperative MAC protocol. To ensure reliable communication, the proposed work emphasizes mostly for selecting the best relay node from the midst-location in between the source and destination. The source maintains a relay selection distance window that adaptively used for finding a prospective relay node having optimal residual energy and delay. Furthermore, adaptation is made in our MAC design where possible direct transmission between source and destination takes place first; and on its failure, the relay selection and cooperative MAC concepts are applied. Finally, the simulation results have demonstrated the efficiency of our work in terms of success rate and energy in compare to the existing works.