Node Selection Score based Clustering scheme for Cognitive Radio Networks

Cognitive radio means a radio system whose parameters is changing dynamically according to the external environment. By using the several cognitive radios’ in the network they built Cognitive Radio Networks (CRNs). CRNs has the capability to deal with the exact requirement of the radio spectrum as well as take care of its shortage .Cognitive Radio Networks plays an important role to solve the problem of insufficient amount of radio spectrum for use. In cognitive radio ad hoc networks (CRAHNs) , due to the absence of network infrastructure and heterogeneous spectrum availability , there is a need of the self-organization of cognitive radio users (CRs) , for efficient spectrum coordination . In case of CRAHNs ,the channel availability among cognitive radio nodes is varying in nature , hence connectivity and durability are the challenging issues . To address this challenge , clustering of neighboring cognitive radio nodes is the suitable approach. Clustering supports a coordinated channel switching and simplifies routing in CRAHNs. In this paper a node selection score based clustering scheme is introduced , which considers spectrum heterogeneity, node degree, intra cluster delay and stability of the topology.