Section: 5.30.2.4 Network selection in SNPN access mode 5.30.2.4.1 General
Content: An SNPN-enabled UE supports the SNPN access mode. When the UE is set to operate in SNPN access mode the UE selects and registers with SNPNs over Uu as described in clause 5.30.2.4. Network selection in SNPN access mode for access to SNPN services via Untrusted non-3GPP access, Trusted non-3GPP access and Wireline access is specified in clause 5.30.2.12, clause 5.30.2.13 and clause 5.30.2.14 respectively. Access network selection in SNPN access mode for 5G NSWO is specified in clause 6.3.12b. Emergency services are supported in SNPN access mode over Uu as defined in clause 5.16.4.1. Support for Emergency in SNPN access mode via Untrusted non-3GPP access is specified in clause 5.30.2.12. If a UE is not set to operate in SNPN access mode, even if it is SNPN-enabled, the UE does not select and register with SNPNs. A UE not set to operate in SNPN access mode performs PLMN selection procedures as defined in clause 4.4 of TS 23.122[ Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode ]  [17]. For a UE capable of simultaneously connecting to an SNPN and a PLMN, the setting for operation in SNPN access mode is applied to each of the Uu/Yt/NWu interfaces independently. Clause D.4 provides more details. An SNPN-enabled UE that supports access to an SNPN using credentials from a Credentials Holder and that is equipped with a PLMN subscription needs to first enter SNPN access mode to be able to select SNPNs. Once the UE has entered SNPN access mode, SNPN selection is performed as described in clause 5.30.2.4. Once an SNPN has been selected the UE attempts registration in the SNPN using the PLMN credentials. NOTE 1: Details of activation and deactivation of SNPN access mode are up to UE implementation. When a UE is set to operate in SNPN access mode the UE does not perform normal PLMN selection procedures as defined in clause 4.4 of TS 23.122[ Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode ]  [17]. UEs operating in SNPN access mode read the information described in clause 5.30.2.2 from the broadcast system information and take them into account during network selection. Furthermore, if the UE supports access to an SNPN providing access for Localized Services, and the end user enables to access the Localized Services the UE may select an SNPN providing access for Localized Services. NOTE 2: Details of how the user enables/disables access to Localized Services are up to UE implementation.