A distributed routing and time-slot assignment algorithm for cognitive radio ad hoc networks with primary-user protection

Cognitive Radio (CR) technology enables Secondary Users (SUs) to transparently utilize the licensed spectrum bands while causing limited interference to Primary Users (PUs). In this paper, a distributed routing and time-slot assignment (DRTSA) algorithm is proposed to addess the PU protection issue. Specifically, we first design a proper routing metric for distributed path selection and then we propose a time-slot assignment algorithm to improve SUs' capacity and reduce the interference to PU as well. Theoretical analysis shows that the complexity of DRTSA is no more than O(NTlogN), where N and T denote the number of nodes and the time-slot period in the network respectively. Simulation results show that, under various network scenarios, the performance of the proposed distributed algorithm can approach that of the centralized alternatives.