Inducing Cooperation for Optimal Coexistence in Cognitive Radio Networks: A Game Theoretic Approach

Current coexistence protocols employed for contention by collocated Cognitive Radio Networks (CRN), such as the IEEE 802.22 WRAN, assume that the contending networks do not have any preference over the set of available channels. Having channels with different quality parameters can lead to an imbalance in contention for disparate channels, degraded quality of service and an overall inefficient utilization of spectrum resources. In this paper, we analyze this situation from a game theoretic perspective and model coexistence of CRNs as a non-cooperative, repeated general-sum game with perfect information. We demonstrate that due to the possibility of its centralized as well as a distributed implementation, the correlated equilibrium is a practical solution for the problems of inefficiency and unfairness of Nash Equilibria. It not only induces voluntary cooperation among non-cooperative CRNs and results in optimum spectrum utilization but also results in an egalitarian equilibrium which maximizes the minimum payoff for every CRN.