An Energy-Efficient and Reliable Routing Protocol for Cognitive Radio Sensor Networks

Abstract

With rapid advances in wireless communications and networking technologies, the demand for high speed, wireless and ubiquitous connectivity continues to increase in order to cope with new services and applications. Increasing demand for spectral resources has introduced the problem of spectrum scarcity. Moreover, the static spectrum allocation policy for wireless communications can cause the issue of spectrum underutilization. Cognitive Radio (CR) offers promising solution for spectrum shortage and underutilization problem by means of dynamic spectrum management. Routing in Cognitive Radio Sensor Networks (CRSNs) is a very challenging task due to energy constraints, opportunistic spectrum access, dynamic topology changes as well as intermittent connectivity caused by activities of Primary Users (PUs). This paper proposes the Energy-efficient and Reliable Cognitive Ad-hoc Routing Protocol (ERCARP) with an aim to provide reliable transmission path and prolong network lifetime in CRSNs. The protocol takes account of packet loss probability, link latency and residual energy for path establishment. Furthermore, by utilizing the joint path and spectrum diversity in routing, the multi-path multi-channel routes are given for fast route recovery. The protocol performance is compared with that of the Dual Diversity Cognitive Ad-hoc Routing Protocol (D2CARP) through simulations using NS-2 simulator. The simulation results obviously prove that ERCARP outperforms D2CARP in terms of packet loss, energy efficiency, end-to-end delay and jitter.