Impact of Spectrum Allocation on Connectivity of Cognitive Radio Ad-Hoc Networks

The essence of spectrum allocation is to find an appropriate distribution of spectrum bands among users so that they can coexist. Thus, spectrum allocation can avoid interference that caused by two interference SUs using the same channel. Different spectrum allocation can lead to different network topologies and consequently have effect on the network connectivity. The aim of this paper is twofold: 1) based on the Laplacian spectrum of graphs, we represent the cognitive radio Ad-Hoc network connectivity with knowledge of the effects of the different labeling rules of spectrum allocation; 2) we give a deep analysis of the network connectivity and the impact that different parameters have on it. The results show that the different labeling rules of Color-Sensitive Graph Coloring have different influence on the network connectivity. For the different labeling rules of Color-Sensitive Graph Coloring, we can obtain the different relationship between the probability of primary users' activity and the network connectivity.