on-premises without interaction with the MNOs or public networks. Nevertheless, in case some services demand an access to the public network, the NPN can access to the public network through a firewall [50]. An example of the standalone private architecture is the neutral-host network (NHN) proposed by muLTEfire alliance [51, 95]. In addition, Nokia [96] has proposed a standalone NPN defined as autonomous private wireless network. The second deployment option for the private 5G networks is dependent on the agreement with the MNOs and can be classified into shared-RAN, shared-RAN and core control plane, and also NPN hosted by the mobile operators [49]. In shared-RAN and control plane, some functions, e.g., data flow, might be executed on-premises, while other functions, e.g., control plane, can be transferred to be processed by the public network [50]. An example of the shared-RAN architecture has been investigated in [48, 49, 52] and [54]. Furthermore, Nokia [96] provided a shared-RAN solution that is defined as a private wireless as a service (PWaaS). On the other hand, the mobile operators provide solutions to host the NPN as third- party services via network slicing, access point name (APN), and NFV. Among the various architectures of the private 5G networks, the NHN has the highest security and cost than the shared-RAN and hosted-NPN. In [48], a comparison between the various private 5G architectures is drawn in terms of security, availability, connectivity, and latency. 1.3.2 Spectrum Options for the Private 5G Networks The UEs can communicate with the gNBs in the private 5G networks via licensed, shared, or unlicensed spectrum. The licensed spectrum can be dedicated for the private enterprises and third parties through agreement with the national regulator or the MNOs [47]. In this regard, the UK has licensed the spectrum 3.8-4.2 GHz for the private 5G networks, while Germany has dedicated a bandwidth of 100 MHz on bands 3.7-3.8 GHz for industry. Meanwhile, spectrum sharing enables multi-users to share a re