Beaconless Dynamic Spectrum-Aware Routing Protocol for Cognitive Radio Ad hoc Networks

A beaconless dynamic spectrum-aware routing (DSAR) protocol for cognitive radio ad hoc networks is proposed. The protocol allows nodes to collect spectrum information and monitor spectrum mobility during a spectrum management interval which is followed by a transmission period. Channel selection and neighbor coordination are performed in the routing layer along with a restricted geographical routing to cover all spectrum opportunity regions. These remove any need to exchange spectrum status, while a requesting node requires introducing its location to its one-hop neighbors. In addition, cognitive users discover routes by joint spectrum and next-hop selection in the transmission intervals. By restricting forwarding nodes, DSAR covers a large area of spectrum opportunity while avoiding performance degradation, especially due to routing overhead. We also add spectrum mobility capabilities in our proposed method to investigate strong spectrum awareness in the routing process. DSAR protocol performance is investigated through simulation in different scenarios and is compared with the most similar work, SEARCH protocol. The results indicate that DSAR can significantly reduce the control overhead.