Traffic and Energy-Aware Access in Wireless Powered Cognitive Radio Networks

In wireless powered cognitive radio networks (WP-CRNs) where secondary users (SUs) access spectral white spaces left by primary users (PUs), there exists a trade-off between SU transmission and energy harvesting. However, the white spaces and the harvested energy depends on the PUs traffic applications, and this fact can be utilized to optimize SU transmissions based on the energy harvested from that traffic application. In this paper, we propose a threshold-based SU transmission strategy under the constraints that take into account the spectral access opportunities and the total energy harvested associated with each traffic application. Furthermore, we propose an algorithm which obtains an optimal threshold with respect to the available harvested energy. In the simulation results, we demonstrate the effectiveness of the proposed scheme in terms of throughput gains and show the transmission thresholds under various traffic applications (patterns). Moreover, we illustrate the effects of different collision costs on throughput for different traffic applications using real wireless traces.