Interference avoidance among IEEE 802.22 networks: A Game Theoretic Approach

In this paper, we use game theory to mitigate selfinterference among cognitive radio based IEEE 802.22 networks such that these networks can efficiently co-exist. When a network experiences interference, it can adopt either one of two choices- switch to a new band hoping to find a non-interfering one, or stay with its current band hoping that the interfering network(s) will move away to a new band. We model the spectrum band switching process as an infinite horizon repeated game where the aim of each network (player) is to find a channel void of interference from it's neighboring networks incurring minimal cost. We investigate both pure and mixed strategy solution space of the game and show that pure strategy solution of the game is infeasible. Thus a mixed strategy is proposed which achieves subgame-perfect Nash equilibrium. Until now we have investigated the case where each network is within the interference range of all other networks. We seek to generalize it to the case where networks can have an arbitrary number of potential interferers. Simulation results reveal that using the proposed strategies, each network can find a clear channel quickly and at the same time incur a low cost.