On the energy efficiency of dynamic spectrum access under dynamic channel conditions

The Cognitive Radio (CR) technique has mainly dealt with how spectrum can be sensed, the co-existence of primary and secondary users, and the channel access aspect. A key aspect of these radios is the `cognition´ gained through a spectrum scanning process. The benefit of this cognition is apparent and well-studied in terms of achieving better communication performance on selected spectrum. The benefits in terms of reduced energy consumption, however, due to easier channel access and less contention have been rarely quantified in prior work. This work defines and studies the impact of important parameters on the energy consumption of a CR node under dynamic channel conditions. Results obtained include the range of parameter values under which a CR node is more energy-efficient than a conventional non-CR node, and a comparison of the effectiveness of different spectrum scanning algorithms.