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.

认知无线电使能的协作通信被认为是基于5G的物联网（IoT）的重要组成部分。由于物联网包含数十亿个资源受限的设备，因此频谱利用效率（SUE）成为一个重大问题，以便在稀缺的频谱中容纳如此多的设备。因此，在本文中，从信道可用性和服务完成概率的角度研究了认知无线电网络（CRN）的SUE。我们提出了一种频谱有效的CRN（SE-CRN），它在协作通信下为次要用户（SU）采用了CRN的混合底层交织（UI）模式。考虑了两种类型的SU，具有低优先级和高优先级。此外，提出了一种基于多属性的低优先级用户中断服务确定方法，该方法可确保高优先级用户的最佳信道可用性。SE-CRN由两种算法组成，即频谱有效动态频谱访问（SE-DSA）和频谱有效动态信道预留（SE-DCR）。SE-DSA根据优先级和优先级将可用通道动态分配给主要和次要用户。SE-DCR动态保留多个通道，以支持正在进行的服务中断。我们利用连续时间马尔可夫链（CTMC）进行建模，并为许多QoS参数形成数学表达式。在不同级别的网络流量负载和多种信道故障率下评估该方案。