An Energy-Aware Cross-Layer Cooperative MAC Protocol for Wireless Ad Hoc Networks

• An adaptive cross-layer cooperative MAC protocol called EAP-CMAC was proposed.
• EAP-CMAC integrates the PNC characteristics into cooperative communication.
• A new relay selection algorithm was suggested for improving the network lifetime.

Cooperative communication (CC) has recently emerged as an effective technique to combat the channel impairment, energy limitation and radio spectrum constraints. Physical-layer Network Coding (PNC) is an alternative applied in wireless networks to reduce transmission time slots and deliver higher throughput while also being energy-efficient. In order to benefits from both CC and PNC characteristics an efficient Medium Access Control (MAC) protocol is required. This study introduces a new cooperative MAC protocol called EAP-CMAC (Energy Aware Physical-layer Network Coding Cooperative MAC) that integrates cooperative communication into PNC in wireless ad-hoc networks. In EAP-CMAC, the best transmission mode is selected among direct transmission, traditional cooperation and PNC-based transmission by considering the destination queue and source-destination link quality. Moreover, a joint relay selection and power allocation algorithm is proposed based on location information and the nodes residual energy that significantly improves the network lifetime and energy saving in wireless networks. The simulation results indicate that EAP-CMAC outperforms IEEE 802.11 and CoopMAC in terms of network lifetime by 50% and 140% respectively. Furthermore, the proposed optimal power allocation enhances EAP-CMAC performance in terms of network lifetime by 7% compared to equal power allocation.