eDSA: Energy-Efficient Dynamic Spectrum Access Protocols for Cognitive Radio Networks

In this paper, we propose a class of energy-efficient dynamic spectrum access (DSA) protocols for secondary user (SU) communication over a single primary user (PU) channel. The proposed variants of DSA can be optimized with respect to different back-off strategies and SU packet lengths. Via Markov chain models and numerical analysis, we derive the optimal SU packet length and inter-sensing time for optimal SU performance in the DSA variants. We evaluate the protocol performance in terms of SU goodput, SU energy efficiency, and PU collision ratio. Adaptability of the proposed SU operation protocol in practical scenarios is tested over cellular GSM band as well as under real-time video over IP based PU traffic in ISM band. Our performance studies demonstrate that the proposed protocols offer significantly high channel utilization while keeping the PU collisions below an acceptable threshold. The proposed protocol operation is also outlined, where the protocol adapts to the changing PU traffic load for optimized performance.