A new dynamic spectrum access scheme based on prioritized secondary data traffics for realistic networking scenarios with finite number of users

Abstract

This paper introduces a novel priority-based dynamic spectrum access (PB-DSA) scheme designed for centralized cognitive radio (CR) networking environments, where a finite number of secondary users (SUs) are categorized into two distinct groups based on their data traffic characteristics: high-priority and low-priority. High-priority SUs, such as those handling delay-sensitive applications like Voice over Internet Protocol (VoIP) and real-time health monitoring, are given high priority. On the other hand, low-priority SUs, which manage delay-tolerant data like e-mail and file transfers, are given low priority. The proposed PB-DSA scheme prioritizes channel allocation and spectrum handoff for high-priority SUs over low-priority ones. The study thoroughly investigates the effects of varying arrival rates of PUs and SUs on key performance metrics, including call blocking, call dropping, call completion, and call handoff probabilities. Analytical and simulation results of the proposed PB-DSA scheme are compared to those of a conventional DSA scheme that does not differentiate between SUs based on a predefined priority. The primary goals of this new PB-DSA scheme and its application are to reduce both call blocking and call dropping probabilities for high-priority SUs while maintaining them at acceptable levels for low-priority SUs. The proposed PB-DSA scheme is rigorously modeled by using three-dimensional continuous-time Markov chains, and the obtained analytical results are validated through a detailed discrete-event simulation study. The results clearly demonstrate that the PB-DSA scheme achieves a relatively high performance by reducing call blocking probability for high-priority SUs by up to \(98.78\%\) and call dropping probability by up to \(73.38\%\), compared to the traditional DSA scheme without a priority differentiation.