Spectrum utilization efficiency in the cognitive radio enabled 5G-based IoT

Abstract

The cognitive radio enabled cooperative communication is envisioned to be a vital part of the 5G-based Internet of Things (IoT). Since IoT contains billions of resource constrained devices, spectrum utilization efficiency (SUE) becomes a significant problem in order to accommodate such a large number of devices within the scarce spectrum. Therefore, in this paper, SUE of cognitive radio networks (CRNs) is investigated in terms of channel availability and service completion probability. We propose a spectrum efficient CRN (SE-CRN) that employs a hybrid underlay-interweave (UI) mode of CRNs for secondary users (SUs) under cooperative communication. Two types of SUs, with low and high priority levels, are considered. Moreover, a multi-attribute based approach for service determination for low priority users’ interruption is proposed that ensures the optimal channel availability for high priority users. SE-CRN is composed of two algorithms, namely, spectrum efficient dynamic spectrum access (SE-DSA) and spectrum efficient dynamic channel reservation (SE-DCR). SE-DSA dynamically assigns available channels to primary and secondary users based on their priority levels. SE-DCR dynamically keeps a number of channels reserved to support interruption of ongoing services. We utilize continuous time Markov chain (CTMC) for modeling and also form mathematical expressions for a number of QoS parameters. The scheme is evaluated under varying levels of network traffic loads and multiple rates of channel failure. We show through numerical results that SUE can be reasonably enhanced by SE-CRN.