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Secondary Network Connectivity of Ad Hoc Cognitive Radio Networks

This letter investigates the connectivity of large-scale ad hoc cognitive radio networks (CRNs). Considering correct detection and false alarm probabilities ( Pd and Pf, we derive in closed-form the thinned density of active secondary users (SUs) in a secondary network. We show the active-probability and detectable radius of primary users (PUs) have a significant impact on the density of active SUs. Moreover, we find that increasing Pf of SUs considerably decreases the node density of active SUs. The connectivity of the secondary network is further analysed with the continuum percolation theory. Given the critical density of the secondary network without the impact of PUs, the critical density of the secondary network coexisting with PUs is estimated analytically. Simulations confirm our analysis.