Game-Theoretic Analysis of Selfish Secondary Users in Cognitive Radio Networks

In this paper, we study the problem of selfish behavior of secondary users (SUs) based on cognitive radio (CR) in the presence of primary users (PUs). We assume that SUs contend on a channel using the Carrier Sense Multiple with Collision Avoidance (CSMA/CA) and PUs do not consider transmission of SUs. CSMA/CA protocols rely on the random deferment of packets. SUs are vulnerable to selfish attacks by which selfish users could obtain a much larger share of the available bandwidth at the expense of other SUs. Game theory is used to study the systematic cheating of SUs in the presence of PUs in multiband CR networks. We study two cases: a single cheater and several cheaters acting without any restraint. We identify the Pareto-optimal point of operation of a network with multiple cheaters. We also derive the Nash equilibrium of the network.