introduced the network ID (NID), which is broadcast by NG-RAN cells in addition to the PLMN ID as depicted in Figure 3.2.13. 3.2 5G Core Network Figure 3.2.13 Stand-alone non-public network (SNPN). SNPN services NG-RAN System Information Broadcast (SIB) PLMN ID = (e.g.) 999 01 Network ID (NID) = X (subscribed for (PLMN 999 01, NID X) The NID supports two assignment models: Locally managed NIDs can be chosen by SNPNs at deployment time and may therefore not be unique. Universally managed NIDs refer to scenarios where the NID is assigned by a legal entity, e.g. by regulators. The key idea is that Release-16 UEs in SNPN access mode only select networks broadcast- ing both PLMN ID and NID. In other words, Release-16 UEs in SNPN access mode ignore PLMNs and only register with SNPNs. Legacy and non-supporting UEs are prevented from accessing SNPN cells. In contrast to PLMNs there is no support for emergency calls in limited service state in SNPNs. Furthermore, there is no notion of home SNPNs and therefore also no support for roaming between SNPNs. 3.2.7.3 Public-Network-Integrated Non-public Network The challenge for PNI-NPNs applies to deployment scenarios where dedicated NG-RAN cells serve the NPN, for example, dedicated small cells in a factory. Given that the PLMN and the NPN share the PLMN ID of the PLMN, PLMN UEs would also be able to access the small cells that are supposed to be dedicated to the factory. In other words, the question is how to ensure that only NPN UEs can access the dedicated NPN cells. The key idea to limit cell access to a group of devices is the notion of Closed Access Groups (CAGs). In addition to the PLMN ID of the public network, the dedicated cells broadcast a CAG ID. The CAG IDs are managed by the PLMN operator as a result of which they can be assumed to be unique in combination with the PLMN ID. 3 5G System Overview Both the UE and the UE's subscription in the network are configured with the list of allowed CAG IDs that a UE is entitled to access. Based on this, UEs only select CAG cel