Dynamic Channel Access for Energy Efficient Data Gathering in Cognitive Radio Sensor Networks

TL;DR

This paper proposes dynamic channel access schemes for cognitive radio sensor networks to enhance energy efficiency by optimizing sensing, switching, and resource allocation under primary user protection constraints.

Contribution

It introduces novel schemes for dynamic channel sensing and switching that consider energy costs and primary user protection, improving energy efficiency in CRSNs.

Findings

Significant reduction in energy consumption with proposed schemes

Effective resource allocation for intra- and inter-cluster transmission

Enhanced energy efficiency under primary user protection constraints

Abstract

Wireless sensor networks (WSNs) operating in the license-free spectrum suffer from uncontrolled interference as those spectrum bands become increasingly crowded. The emerging cognitive radio sensor networks (CRSNs) provide a promising solution to address this challenge by enabling sensor nodes to opportunistically access licensed channels. However, since sensor nodes have to consume considerable energy to support CR functionalities, such as channel sensing and switching, the opportunistic channel accessing should be carefully devised for improving the energy efficiency in CRSN. To this end, we investigate the dynamic channel accessing problem to improve the energy efficiency for a clustered CRSN. Under the primary users' protection requirement, we study the resource allocation issues to maximize the energy efficiency of utilizing a licensed channel for intra-cluster and inter-cluster data transmission, respectively. With the consideration of the energy consumption in channel sensing and switching, we further determine the condition when sensor nodes should sense and switch to a licensed channel for improving the energy efficiency, according to the packet loss rate of the license-free channel. In addition, two dynamic channel accessing schemes are proposed to identify the channel sensing and switching sequences for intra-cluster and inter-cluster data transmission, respectively. Extensive simulation results demonstrate that the proposed channel accessing schemes can significantly reduce the energy consumption in CRSNs.