Green opportunistic access for CRN with selfish users using coalitional game approach in partition form

We study energy conservation and system performance of decentralized cognitive radio network with cognitive users. Every cognitive radio (CR) user needs to sense the channel to send data, if the channel is unoccupied by a licensed user only one winner transmits its data. Hence, all other users waste their energy in sensing the licensed bands and in negotiating the resource access without managing to transmit data packets. We formulate the sensing-energy tradeoff problem for distributed cognitive radio network as a coalition formation game. Our contribution is to apply the coalitional game design to the most important phases of cognitive radio network (CRN): sensing and data transmission. The concept of coalitional game may enforce the cooperative behavior of CR users in order to improve the system performance (energy and delay.). The network is modeled using a coalitional game in partition form with non transferable utility (NTU). After forming coalitions, no CR user in those coalitions aim to change its position. Indeed, the members of this coalition will cooperate both in sensing and access phases to improve system performance. The selfish behavior becomes evident when the cognitive users are constrained to send their data in a short delay and with a minimum of energy consumption. Our proposed algorithm explains how the selfish atittude of the cognitive user leds to join the coalition that increases its individual gain, and tacitly to improve the performance of the entire system.