On the delay and data rate performance of throughput-efficient multi-channel access algorithms in cognitive radio networks

Cognitive Radio Networks (CRNs) are designed to increase spectrum utilization by allowing unlicensed secondary users (SUs) to operate over existing wireless channels where primary users (PUs) have license to transmit. An SU searches for channels not currently occupied by PUs, it estimates their link quality and it aggregates the resources found available for transmission, by means of multi-channel access. Typically, optimal stopping algorithms decide when to interrupt the exploration phase and start exploiting the channels for transmission, with the goal of throughput maximization. In this paper we recognize the importance of evaluating the performance of throughput-efficient multi-channel access algorithms in terms of delay and data rate, which constitute fundamental traffic requirements for mobile applications. Through extensive simulations, we have derived guidelines for supporting SUs with stringent traffic requirements of delay, jitter and guaranteed data rate in the current multi-channel algorithms under multiple CRN scenarios. The encouraging results of the conducted performance evaluation motivate our interest in further researching multi-channel access algorithms for the optimization of application-specific requirements.