Section: 4.5.2A Determination of the access identities and access category associated with a request for access for UEs operating in SNPN access operation mode over 3GPP access
Content: When the UE needs to initiate an access attempt in one of the events listed in subclause 4.5.1, the UE shall determine one or more access identities from the set of standardized access identities, and one access category from the set of standardized access categories and operator-defined access categories, to be associated with that access attempt. The set of the access identities applicable for the request is determined by the UE in the following way: a) for each of the access identities 1, 2, 11, 12, 13, 14 and 15 in table 4.5.2A.1, the UE shall check whether the access identity is applicable in the selected SNPN, if a new SNPN is selected, or otherwise if it is applicable in the RSNPN or equivalent SNPN; and b) if none of the above access identities is applicable, then access identity 0 is applicable. Table 4.5.2A.1: Access identities The contents of the unified access control configuration in the "list of subscriber data" stored in the ME (see 3GPP TS 23.122[ Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode ]  [5]), if an entry of "list of subscriber data" is selected, or in the USIM (see 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [22]), if the PLMN subscription is selected, and the rules specified in table 4.5.2A.1 are used to determine the applicability of access identity 1 in the SNPN. When the contents of the unified access control configuration in the "list of subscriber data" stored in the ME (see 3GPP TS 23.122[ Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode ]  [5]), if an entry of "list of subscriber data" is selected, or in the USIM (see 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [22]), if the PLMN subscription is selected, do not indicate the UE is configured for access identity 1 for the SNPN, the UE uses the MPS indicator bit of the 5GS network feature support IE in the REGISTRATION ACCEPT message and the MPS indicator bit of the Priority indicator IE in the CONFIGURATION UPDATE COMMAND message to determine if access identity 1 is valid. The contents of the unified access control configuration in the "list of subscriber data" stored in the ME (see 3GPP TS 23.122[ Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode ]  [5]), if an entry of "list of subscriber data" is selected, or in the USIM (see 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [22]), if the PLMN subscription is selected, and the rules specified in table 4.5.2A.1 are used to determine the applicability of access identity 2 in the SNPN. When the contents of the unified access control configuration in the "list of subscriber data" stored in the ME (see 3GPP TS 23.122[ Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode ]  [5]), if an entry of "list of subscriber data" is selected, or in the USIM (see 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [22]), if the PLMN subscription is selected, do not indicate the UE is configured for access identity 2 for the SNPN, the UE uses the MCS indicator bit of the 5GS network feature support IE in the REGISTRATION ACCEPT message to determine if access identity 2 is valid. The contents of the unified access control configuration in the "list of subscriber data" stored in the ME (see 3GPP TS 23.122[ Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode ]  [5]), if an entry of "list of subscriber data" is selected, or in the USIM (see 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [22]), if the PLMN subscription is selected, and the rules specified in table 4.5.2A.1 are used to determine the applicability of access classes 11 to 15 in the SNPN. In order to determine the access category applicable for the access attempt, the NAS shall check the rules in table 4.5.2A.2, and use the access category for which there is a match for barring check. If the access attempt matches more than one rule, the access category of the lowest rule number shall be selected. If the access attempt matches more than one operator-defined access category definition, the UE shall select the access category from the operator-defined access category definition with the lowest precedence value (see subclause 4.5.3). NOTE: The case when an access attempt matches more than one rule includes the case when multiple events trigger an access attempt at the same time. When multiple events trigger an access attempt at the same time, how the access attempt is checked for multiple events is up to UE implementation. Table 4.5.2A.2: Mapping table for access categories