Distance-aware data rate adaptive cooperative MAC protocol for wireless networks

Abstract

Over the years, different types of relay selection mechanism in wireless networks have been proposed for Cooperative Medium Access Control (MAC) protocols considering the metrics like — residual energy, delay, signal to noise ratio (SNR) etc. In recent days, distance metric is added to the list for optimal relay selection. However, protocols those use distance metric are found to be suffered from higher delay in relay selection process. Hence, it is important to design a relay selection based cooperative MAC protocol that would ensure higher reliability and data rate as well as lower delay. In this paper we have designed an adaptive relay selection mechanism for wireless cooperative networks named as Distance-Aware Data Rate Adaptive Cooperative (D2RAC) MAC protocol. To ensure reliable data transmission, the proposed method emphasizes selection of the best/optimal relay node within two distance thresholds. Furthermore, using node's residual energy a balancing between energy consumption of the nodes is guaranteed. To ascertain selection of an optimal relay having high data rate, the data rates of IEEE 802.11b are assigned in a Relay Response (RR) frame. The simulation result shows that the proposed D2RAC MAC protocol significantly outperforms the existing work 2rcMAC MAC protocols in terms of delay and throughput.