A distributed energy-efficient cooperative routing algorithm based on optimal power allocation

Abstract

Power consumption is a key issue for wireless network design. Cooperative routing, an efficient scheme for saving transmission power in wireless networks, combines the advantage of the cooperative communication in the physical layer and the routing technology in the network layer. In this paper, we propose a distributed minimum power cooperative routing algorithm based on optimal power allocation, namely the OPAMPCR algorithm that realizes minimum total transmission power for each source-destination pair. Each cooperative route from a source to a destination is a concatenation of cooperative transmission links and direct transmission links. For each type of link mode, the minimum transmission power required for a target BER is calculated. Especially, the proposed algorithm first finds the relay node which consumes the minimum total transmission power for assisting the data transmission. If such a relay does not exist, the direct transmission mode is applied in current link; Otherwise, we adopt the cooperative transmission mode. Then, the proposed OPAMPCR algorithm applies the distributed Bellman-Ford shortest-path routing algorithm to find the route with least transmission power required. Simulation results reveal that the OPAMPCR algorithm outperforms the SNCP algorithm, the CASNCP algorithm and the MPCR algorithm with respect to the average total transmission power per route and the power saving. Moreover, the proposed OPAMPCR algorithm achieve less hops per route than the MPCR algorithm.