A group based MAC protocol for QoS provisioning in cognitive radio networks

With the deployment of more wireless applications, spectrum scarcity becomes an issue in many countries. Recent reports show that the reason for this spectrum shortage is the underutilization of some spectrum resources. Fortunately, the emergence of open spectrum and dynamic spectrum assess technology in cognitive radio networks relieves this problem. In this paper, we propose a novel cognitive MAC protocol to achieve highly efficient spectrum usage and QoS provisioning. In the proposed protocol, secondary users are divided into several non-overlapping groups, and all leftover channels are allocated among groups taking the groups¿ bandwidth requirements into consideration. Moreover, the allocation of vacant channels can be adjusted dynamically when members join/leave groups or primary users return/leave the current network. Simulations show that the proposed MAC protocol greatly improves the quality of service for secondary users and utilizes spectrum resources to the superior.