An adaptive tit-for-tat strategy for IEEE 802.11 CSMA/CA protocol

In non-cooperative environments, selfish nodes can take advantage of the mechanisms in place to obtain unfair shares of the network resources. Unfortunately, they may impact the performance of the other nodes. Our objective is to propose a novel IEEE 802.11 medium access control protocol, which can fairly share the resources among cooperative nodes but can retaliate if some selfish ones are present. We first show that the classical jamming method is inappropriate. We then present a novel game theoretical strategy designed to cope with the shortterm unfairness of resource sharing. Our reputation-based tit-for-tat mechanism is immune to infrequent misclassification errors and motivates rational selfish nodes to cooperate. It depends on the observation of the nodes' behaviour. If any node misbehaves, the monitoring nodes should adapt and behave themselves selfishly. Thus, rational nodes should not have any other choice than to follow the legitimate behaviour in order to maximise their payoff.