uding V-CRAN, H- CRAN, and F-CRAN, have been compared in [3-6]. These 5G architectures have been compared, therein, in terms of energy consumption, latency, security, resource allocation, reliability, spectrum and interference management, and CAPEX/OPEX. In [3], the latency and CAPEX/OPEX of C-RAN and H-CRAN were concluded to be high to very high, while they found to be medium to low for F-CRAN and V- CRAN. In addition, H-CRAN was found to have higher level of energy consumption than F-CRAN and V-CRAN. In order to enhance the CAPEX/OPEX, security, energy efficiency, and SO on, several methods and strategies have been proposed for the 5G networks. Table 1.4 presents recent research works to tackle 5G network's challenges on energy efficiency, resource allocation, security, CAPEX/OPEX, and spectrum management. 1.3 Private 5G Networks Several wireless technologies have been deployed within the enterprise's networks to provide solutions for their industrial applications. These wireless technologies can be categorized into 3GPP technologies, e.g., LTE for machines (LTE-M) and narrow band-IoT (NB-IoT), and non-3GPP technologies. Non-3GPP technologies can be classified into long-range, e.g., LoRa and SigFox, and short-range, e.g., Wi- Fi and Bluetooth low energy (BLE). However, these wireless technologies cannot fulfill the diverse demands of the industrial IoT applications. For instance, the long- range wireless technologies, e.g., LoRa, SigFox, and NB-IoT, prolong the battery lifetime but provide low data rate and high latency that might reach to 7 s [12]. On the other hand, the short-range wireless technologies have limitations in terms of battery lifetime, capacity, and coverage. In addition, LTE-M faces limitation in terms of cost and geo-localization accuracy. Above all, none of these wireless technologies provide solutions for the delay-sensitive IoT applications. For the aforementioned reasons, 5G technology is foreseen as a promising technology to enable the various demands of the industrial IoT applications. I