Age of Information Minimization for Energy Harvesting Overlay/Underlay Cognitive Radio Networks

Cognitive radio networks (CRNs) having energy harvesting capability have been an encouraging technology to solve the spectrum deficiency problem in wireless networks. Nevertheless, the wireless spectrum must be correctly administered to achieve the strict needs on integrity and transmission of information with minimum delay. Influenced by this, this paper takes into account the measure of the Age of information (AoI) to serve as the newness of data in the multi-channel (m-channel) allocation problem of hybrid CRNs. Here, energy can be harvested by secondary transmitters (STs) to improve channel distribution performance. Two new mechanisms have been proposed to limit average AoI values whilst assigning channels to STs by satisfying energy and collusion constraints. A new measure is proposed to assign precedence to STs, and they are permitted to utilize channels only if the resultant AoI value fulfills presented conditions. AoI levels are computed based on cochannel interference between STs and minimized by reducing interference levels. For comparison, three algorithms were studied: a greedy mechanism for m-channel allocation of hybrid CRNs without AoI control, and the presented m-channel distribution schemes based on ranking STs according to the presented measure and limiting AoI levels based on cochannel interference. The simulations highlight that the performance of the presented m-channel allocation schemes outweighs the greedy scheme in terms of both AoI minimization and maximization of channel allocation performance which demonstrates the primacy of the proposed algorithms.