DEC-MAC: delay- and energy-aware cooperative medium access control protocol for wireless sensor networks

This paper deals with two critical issues in wireless sensor networks: reducing the end-to-end packet delivery delay and increasing the network lifetime through the use of cooperative communications. Here, we propose a delay- and energy-aware cooperative medium access control (DEC-MAC) protocol, which trades off between the packet delivery delay and a node’s energy consumption while selecting a cooperative relay node. DEC-MAC attempts to balance the energy consumption of the sensor nodes by taking into account a node’s residual energy as part of the relay selection metric, thus increasing the network’s lifetime. The relay selection algorithm exploits the process of elimination and the complementary cumulative distribution function for determining the most optimal relay within the shortest time period. Our numerical analysis demonstrates that the DEC-MAC protocol is able to determine the optimal relay in no more than three mini slots. Our simulation results show that the DEC-MAC protocol improves the end-to-end packet delivery latency and the network lifetime significantly compared to the state-of-the-art protocols, LC-MAC and CoopMAC.