A Simulation Analysis of the Connectivity of Multi-hop Path between Two Arbitrary Nodes in Cognitive Radio Ad Hoc Networks

The connectivity of multi-hop path is one of the key factors that influence the performance of multi-hop wireless networks. In this paper, assuming that secondary users (SUs) and primary users (PUs), using same licensed frequency bands, are uniformly distributed in square network area, we investigate the connectivity of multi-hop path in cognitive radio ad-hoc networks (CRAHNs). Specifically, we propose an algorithm to find all available multi-hop paths between arbitrary source node and destination node in CRAHNs with random node distribution and PU activity. Then, we use statistical simulation method to intensively evaluate the connectivity of multi-hop path compared with that in conventional ad-hoc networks (AHNs) by using huge number of random network topologies with different network parameters such as the number of SUs and PUs, network size, network operating frequency, and the average active rates of PU. The simulation results reveal many interesting and distinguishing features of the connectivity of multi-hop path in CRAHNs. Moreover, from the simulation graphs in this paper, network designers can select optimal network parameters so that the reliability of network topology is high while saving network resources. Finally, the simulation results can be used to verify mathematical models of the connectivity of multi-hop path in CRAHNs in future research.