MAC protocols in cognitive radio ad hoc networks

As the issue of scarcity of wireless spectrum resources emerges, the cognitive radio networks have gained extensive attention and investigation. In these networks, the medium access control (MAC) protocol is one of the key technologies. Particularly in the cognitive radio ad hoc networks, the design of MAC protocols confronts with great challenges because of the lack of infrastructures. Besides the traditional issues such as the medium access control, these challenges include how to guarantee the service quality of primary users, how to efficiently sense and manage the spectrum resources and so on. This paper surveys the up-to-date advances in the field of MAC protocols in cognitive radio ad hoc networks. It first introduces some recent MAC protocols in cognitive radio ad hoc networks, then compares existing works, and finally analyzes and discusses the future research directions.