Dynamic spectrum access with traffic prioritization in Cognitive Radio networks

Cognitive Radio networks (CRN) enable cognitive users to use portions of the licensed spectrum of the primary users (PU). Dynamic spectrum access (DSA) is a design aspect that facilitates the transmission of cognitive radio (CR) users over idle channels. In many cases, it is not preferable that CR users to be treated equally. Provisioning quality of service (QoS) to some CR users is a challenge in DSA design. In this situation, The CR user traffic is divided into high and low priority classes. Sub-channel reservation (SCR) scheme is the most traditional scheme to provide priority to CR users in admission. In this paper, a new scheme named “low priority bounding” (LPB) scheme is used to provide QoS for CR users. The LPB scheme provides priority by restricting the number of low priority CR users by a threshold. This scheme maintains a suitable level of service to high priority users (as provided by SCR scheme) while improve the level of service for low priority ones. So the revenue gained from LPB scheme is optimized in comparison with SCR scheme. The impact of LPB scheme in the provided QoS is evaluated in terms of blocking probability, service termination rate, and service completion rate. Simulation results are compared with SCR scheme and it shows that the LPB scheme can significantly improve the revenue gained over the traditional SCR scheme.