Lifetime extended cooperative MAC protocol for wireless LANs

Cooperative communication techniques exploit diversity gain to improve the network throughput based on cooperation of multiple data transmissions. In wireless local area networks (WLAN), the whole network throughput can be increased by letting high-rate stations relay traffic from low-rate stations. However, such kind of strategy may lead to a shorter network lifetime due to additional energy consumption. In this paper, we propose a MAC protocol, namely Lifetime Extended Cooperative MAC protocol (LECMAC), to maximize both the network lifetime and throughput. In our MAC protocol, a dynamic score is assigned to each station for evaluating its availability and performance when acting as a relay station. Based on the score of each station, a scoring scheme is designed to determine whether a relay station is needed or not, and which station is the best choice for relaying traffic in the packet transmission. Extensive analysis and simulation results demonstrate that the throughput can be increased significantly with the extended network lifetime by the proposed LECMAC.