Proactive Cooperation Mechanism based on Cooperation Records for Mobile Ad hoc Networks

The emergence of mobile ad hoc networks changes the form of communications in a public network from the one through trusted carrier networks, involving only a single hop of a wireless link, to the one among a number of un-trusted third parties, involving multiple wireless hops. In such an ad hoc network, the cooperation among the third parties is essential to successful communication. However, some third parties may not want to cooperate because, for example, battery limitation. They may not be interested in forwarding packets for others but nonetheless hope that others will cooperate to assist their communication. To ensure fairness in communications, it is necessary to eliminate the influence of such selfish third parties, and to seek cooperation from as many third parties as possible. Many researchers have been studying these issues. However, their studies assume that selfish behavior involves the malicious falsification of program codes or routing information even though not all selfish behaviors involve such falsification. In addition, the solutions they propose cannot completely eliminate the influence of selfish behavior. This paper defines the selfish behavior which ordinary third party entities are likely to exhibit and proposes a solution, called proactive cooperation mechanism (PCOM), which completely solves the problem caused by selfish behavior. In PCOM, each node keeps records of the cooperation of its adjacent nodes, and forwards only those packets that are generated by the adjacent nodes with a good cooperation record. Consequently, PCOM prevents selfish entities from joining the network.