Springer Science+Business Media
A challenging problem in Cognitive Radio Networks (CRNs) is to design a throughput efficient routing and scheduling algorithm for end-to-end communications between Secondary Users (SUs) in a distributed manner. Due to the opportunistic nature of CRN routing, they consider a framework with randomized path selection in this paper. Motivated by the back-pressure scheduling policy, they adopt the differential queue backlog as the routing metric to achieve throughput efficiency. Moreover, they demonstrate the sufficient condition for their framework to achieve throughput optimality by analyzing the drift. They further propose a distributed medium access control algorithm that can approximately satisfy the required condition when the transmission attempt probability is low. The performance of their proposed scheme is evaluated in a simulation platform and the evaluation results verify the effectiveness of their distributed scheme.