Channel Access Protocols for Multihop Opportunistic Networks: Challenges and Recent Developments.

The article presents a survey which examines the challenges and developments of channel access protocols proposed for multihop cognitive radio networks. It discusses key design issues in development of medium access control (MAC) protocols for such networks. It also explores the development in MAC protocol design for CRNs. It outlines several challenges including the provision of an effective distributed coordination among CR users and computation of neighborhood-dependent power mask.