DIRECT RECIPROCITY-BASED COOPERATION IN MOBILE AD HOC NETWORKS
A distributed nature of a wireless mobile ad hoc network, lack of a single authority, and limited battery resources of participating devices may lead its users to be reluctant to packet relaying duties. This paper investigates potential networking conditions that could lead to a direct reciprocity-based cooperation on packet relaying. Simulation of behaviour of the network is carried out using an evolutionary game-theoretical approach. A game-based model of nodes' interactions coupled with a genetic algorithm is used to find successful relaying strategies for various networking conditions. Computational experiments demonstrate that the reciprocity-based packet relaying is an efficient way to overcome the social dilemma present in such a network. However, in the presence of a large number of unconditionally cooperatives nodes a selfish permanent defection strategy is more efficient than a reciprocal tit-for-tat strategy. Nevertheless the switch from cooperative to selfish behaviour among some users does not change significantly the overall performance of the network as the negative consequences of the switch are compensated by the generous packet relaying contribution of unconditionally cooperative nodes.