Power-Aware Cooperative Relay Selection Strategies in Wireless Ad Hoc Networks

Cooperative diversity is an effective technique to combat multipath fading. When this technique is applied to ad hoc networks, it is a key issue to design distributed and power-efficient relay selection strategies. In this paper, we propose the power-aware relay selection (PARS) strategies to maximize the network lifetime. The PARS strategies are composed of the optimal power allocation(OPA) and three power-aware selection criteria. The OPA aims at minimizing the overall transmit power, while the three criteria select the relay that best help extend the network lifetime, based on both the OPA results and the residual power levels of the nodes. We combine our strategies with the opportunistic relay model, which is based on a 802.11b-like media access control (MRC) protocol, so the selection process can be done in a totally distributed way. Simulation results show that the proposed strategies have great improvement in both network lifetime and power efficiency