Spectrum-aware Cluster-based Routing for Cognitive Radio Sensor Networks

In this paper, we propose a spectrum-aware cluster-based routing (SCR) protocol for cognitive radio sensor networks (CRSN) that jointly overcomes the formidable limitations of energy and spectrum. Clustering is exploited to provide energy efficient routing by limiting the nodes to participate in route establishment and also to ensure the smooth provision of data delivery to the sink in dynamic spectrum access. In SCR, the cluster-head selection is based on the energy and relative spectrum awareness such that non-contiguous available spectrum bands are clustered and scheduled to provide continuous transmission opportunity. For data routing, SCR employs the hybrid medium access by combining carrier sense multiple access (CSMA) and time division multiple access (TDMA) in which TDMA operates for intra-cluster transmission while CSMA is used for inter-cluster routing. Thus, a cross-layer design of routing, MAC and physical layer provides efficient routing in CRSN prevailing over the energy and spectrum issues, which is revealed through simulation experiments.