ata between RU and DU. The deployed security protocol was found to outperform the existing security protocols, such as IPsec, in terms of confidentiality, integrity, authenticity, and availability [90-93] CAPEX/ In [90], a hybrid fronthaul approach by using optical fibers and free-space optics has been proposed in order to minimize C-RAN deployment costs. The proposed approach was analyzed in dense urban area scenario where it was found to reduce the CAPEX/OPEX effectively. In [91], a cost-effective solution has been proposed for the resource allocation between C-RAN and mobile cloud computing (MCC). In [92], a low complexity and successive elimination algorithm has been proposed to reduce the number of RRHs in H-CRAN under a QoS constraint. In [93], a cost-effective scheme was proposed for C-RAN in order to minimize the scheduling cost subject to resource availability, application requirements, deadlines, and load balancing 1. Design flexibility to boost the network coverage and capacity. 2. Optimize the QoS, reliability, latency, and SO on. 3. High level of security and privacy because the data will be processed without interaction with the MNOs. 4. Enable customized and dedicated services. 1.3.1 5G Architecture for Private Networks The 5G communities and alliance permit the deployment of local 5G networks with dedicated equipment to support the various applications of private enterprises and vertical industries. In this regard, 3GPP studies broad initiatives to enable the deployment of 5G private networks, including non-public network (NPN) management, NR-U, NR industrial IoT, and SO on [47]. Moreover, the 5G alliance for connected industries and automation (ACIA) [48] and 5G-Smart [49] have con- sidered two main architectural options for the industrial and private 5G networks. 1 A Comprehensive Study on 5G The first option is the standalone NPN, while the second is NPN in conjunction with public network [48]. In the standalone NPN, all the enterprise functions related to user and control planes are processed 