Minimizing Nested Interrupts of Secondary Users in Multi-Priority Cognitive Radio Networks

Abstract

In cognitive radio networks (CRNs), unpredictable communication interruptions increase data communication delay of secondary users. The QoS of CRNs will dramatically decrease when interruptions are nested. In this paper, we propose a general multiple priority cognitive radio networks (MP-CRNs) model for both single-channel and multi-channel communications. In our MP-CRNs, SUs are divided into multiple categories of different priorities; users with higher priority preemptively interrupt lower ones; interruptions can be nested and all interrupted tasks are resumable. By introducing some extra concepts and terminologies, we first define and model the nested interrupts, we then derive and prove the formulas of nested interrupts. We also validate these formulas through mathematical experiments. Using Queuing Theory, we design a Mutual Minimizing Algorithm to minimize average nested interrupts. We also propose a novel Turnaround Time Control Algorithm to minimize SU’s turnaround time when considering nested interrupts. Simulations and experiments demonstrate the efficiency and effectiveness of the proposed algorithms.