A Network Lifetime Extension-Aware Cooperative MAC Protocol for MANETs With Optimized Power Control

In this paper, a cooperative medium access control (CMAC) protocol, termed network lifetime extension-aware CMAC (LEA-CMAC) for mobile ad-hoc networks (MANETs) is proposed. The main feature of the LEA-CMAC protocol is to enhance the network performance through the cooperative transmission to achieve a multi-objective target orientation. The unpredictable nature of wireless communication links results in the degradation of network performance in terms of throughput, end-to-end delay, energy efficiency, and network lifetime of MANETs. Through cooperative transmission, the network performance of MANETs can be improved, provided a beneficial cooperation is satisfied and design parameters are carefully selected at the MAC layer. To achieve a multi-objective target-oriented CMAC protocol, we formulated an optimization problem to extend the network lifetime of MANETs. The optimization solution led to the investigation of symmetric and asymmetric transmit power policies. We then proposed a distributed relay selection process to select the best retransmitting node among the qualified relays, with consideration on a transmit power, a sufficient residual energy after cooperation, and a high cooperative gain. The simulation results show that the LEA-CMAC protocol can achieve a multi-objective target orientation by exploiting an asymmetric transmit power policy to improve the network performance.