Performance Analysis of the Spectrum Access Strategies in Cognitive Radio Networks

Abstract

The world has seen revolutionary changes in the area of communication. Nowadays, communication is the very important part of everyone’s life. It has changes the way we live, talk, move, think, commerce, study and so on. Wireless radio spectrum is the backbone of this entire scintillating structure. Static allocation of radio spectrum has resulted not only in the scarcity of the availability of spectrum bands, but also the under utilization of the available bandwidth as well. Cognitive radio is envisioned as the panacea for this scarcity. The protection of primary users is vital when secondary users use the licensed spectrum bands. Overlay and underlay are the two main approaches being used in the area of cognitive radio networks. Modern research has proven that none of them alone is good enough for achieving the purpose of desirable spectral efficiency. A hybrid approach is required for taking the full benefit of the opportunities generated, due to the behavioural pattern of the primary users. In this article, we use a Markov based model for maximum utilization of available spectrum bands. This article provides a performance analysis of three different access strategies namely Overlay, Underlay, and Hybrid access methods on several network parameters including the primary user (PU) arrival rate, achieved throughput for secondary users, sensing time (sensing interval), and the consumption of energy by the secondary users during the process of data transmission. OMNeT++ simulator is used for the analysis purpose. Our analysis reveals that adopting a hybrid access strategy is more preferable for better spectrum utilization.