A power control mechanism for non-cooperative packet forwarding in ad hoc networks

Based on energy consumption considerations, an ad hoc network node may reject other nodes´ forwarding requests to save the limited battery power for its own data transmission. Therefore, a lot of incentive schemes have been proposed to promote the cooperation of the nodes. The utilization of the incentive schemes makes the nodes willing to cooperate with each other, because their non-cooperation can be punished in the future. However, the activities of the nodes in ad hoc networks have some inherent uncertainty. For example, the batteries of some nodes are exhausted or some nodes move to other regions. Under these situations, the existing incentive schemes are no longer effective and the nodes have to terminate their cooperation and stop forwarding packets for others. In this paper, we propose a power control mechanism in ad hoc networks under a dynamic repeated game-theoretic framework. A notion of nodes´ evaluation levels for the future experiences is defined to take account of the non-cooperation due to the inherent uncertainty in the ad hoc network nodes´ activities. The nodes achieve their optimal transmission efficiency by using a two-step power control mechanism. The simulation results show that compared with the existing schemes our power control mechanism considering non cooperative packet forwarding improves the average transmission efficiency by approximately 25%.