CRBP: A broadcast protocol for Cognitive Radio ad hoc networks

Cognitive Radio (CR) technology enables unlicensed users to opportunistically use the vacant spectrum bands assigned to licensed users, thereby enhancing the spectrum utilization. In the last decade, Cognitive Radio Networks (CRNs) have been well studied and many important works have been proposed. However, the broadcast problem, which is one of the most fundamental operations in CRNs, has not been well studied. In this paper, a distributed reliable Cognitive Radio Broadcast Protocol (CRBP) for cognitive radio ad hoc networks is proposed that makes the following contributions: (i) reliable data dissemination, (ii) joint transmitter-receiver channel selection, (iii) protection of primary users´ communication and (iv) coordinating the broadcast process without the need for a common channel. A key novelty of the proposed CRBP is the formulation of the broadcast problem from the viewpoint of connecting different local topologies, which is a unique feature in cognitive radio networks. We jointly map the network topologies and the spectrum observations as a bipartite graph which allows the channel selection undertaken at each node to capture the spectrum information and the environmental topologies of all the neighbouring nodes.