On prioritised opportunistic spectrum access in cognitive radio cellular networks

Cognitive radio CR networks allow secondary users SUs to opportunistically access licensed spectrum, thus providing efficient use of radio resources. Different studies carried out on CR networks have focused on the procedure of spectrum handoff of SUs such as the data transmission in a communication that can be carried out in different channels. In this paper, we consider cellular networks enhanced with facilities for CR communication where a user with a call in progress moves across neighbouring cells, that is, the so-called inter-cell handoff. Our model assumes that the cell gives priority to inter-cell handoff calls over the calls originating within it. A finite queue is used in every cell for SUs, and a fixed number of buffer slots are reserved for the inter-handoff SU calls. With these considerations, we study the transmission performance of SUs by using Markov chains-based modelling approach. The numerical analysis is validated by simulation experiments. We also suggest a fuzzy logic-based hybrid decision-making algorithm to select the best solution for inter-handoff prioritisation. The goal is to optimise the transmission performance of SUs by leveraging their requirements on service completion throughput and waiting time in each cell. Copyright © 2014 John Wiley & Sons, Ltd.