Increasing energy efficiency in wireless sensor networks using cognitive radios

Abstract

Energy saving has been one of the major design criteria for wireless sensor networks. Cognitive radio is an enabling technology for dynamic spectrum access in opportunistic manner. In the present work, we assume that wireless sensor network consists of smart radios embedded with cognitive radio capability. These smart radio nodes can sense white space available and may decide the use of channels with the best propagation characteristics. In this paper, we investigate the use of cognitive radio in wireless sensor networks which can use the frequency from white space for their operation in opportunistic manner. Cognitive radio enabled sensor nodes can adapt their system parameters according to the propagation environment. Through numerical results, we have reported that communication range available to the cognitive radio enabled sensor nodes is significantly large as compared to that available to the conventional sensor nodes. This arises due to better radio propagation characteristics. Enhanced communication range can be traded off for energy saving for the given network coverage or communication range, which ultimately leads to higher energy efficiency. Numerical results show relative energy saving on the order of 0.0055 for given system parameters.