Energy Efficient Routing in Cognitive Radio Networks: Challenges and Existing Solutions

Dynamic Spectrum Allocation using Cognitive Radio (CR) is a promising solution to the spectrum availability problem in wireless networks. Cognitive Radio, however, opens up certain new issues, mainly at the physical, medium access control and routing layer levels. Several solutions have been proposed to tackle these issues and use dynamic spectrum allocation to improve the performance of wireless networks. The focus of most of these has been to improve the throughput and other Quality of Service (QoS) metrics. However, energy spent by a node is also an important matter of concern in most wireless networks e.g. wireless sensor networks. In this paper, we focus on the challenges posed by CR in routing data in an energy efficient manner. We then study some existing solutions to route data energy efficiently in CR networks and suggest some directions for future research.