Connectivity of two nodes in cognitive radio ad hoc networks

This paper analyzes the connectivity of cognitive radio networks. The connectivity of cognitive network which is more consistent with reality is redefined in our article and the closed-form formula of relation between connectivity and density of PUs, density of SUs, and transmission radius of SU is given. Specifically, the impact of correlation of adjacent nodes for connectivity of cognitive radio ad hoc network is illustrated. On the basis of Random geometric graph and probability theory, a novel method that divides connectivity of cognitive radio ad hoc network into topological connectivity and physical connectivity is proposed to derive the close-form formula. We prove theoretically that once the density of secondary users is large enough and the transmission radius is appropriate, the probability of cognitive network connectivity tends to a stable non-zero value under the condition that density of primary users is small.