A game theoretic approach to spectrum management in cognitive radio network

In this paper, we propose cognitive radio network models for providing spectrum management which includes spectrum trading and spectrum competition. The models described are with and without using the concepts of game theory. For both the models, the spectrum trading that occurs between the primary user and the secondary user is considered first, and then the spectrum competition among the primary users is considered. Our model includes multiple levels of QoS for different secondary users. In the first phase, the secondary user selects the spectrum by observing the changes in the price and the level of QoS offered by different primary users. In the second phase, the primary user controls its strategy in renting the spectrum to secondary users to achieve the highest utility. To model the dynamic behavior of spectrum competition among primary users, a Bertrand game is formulated where the Nash equilibrium is considered as the solution. Moreover, to model the spectrum trading between the primary user and the secondary user, a Stackelberg game is formulated where the Nash equilibrium is again considered as the solution. Basically the solution is in terms of the size of offered spectrum to the secondary users and the offered spectrum price.