Section: 4.5.2 Determination of the access identities and access category associated with a request for access for UEs not 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, 3, 11, 12, 13, 14 and 15 in table 4.5.2.1, the UE shall check whether the access identity is applicable in the selected PLMN, if a new PLMN is selected, or otherwise if it is applicable in the RPLMN or equivalent PLMN; and b) if none of the above access identities is applicable, then access identity 0 is applicable. Table 4.5.2.1: Access identities The UE uses the MPS indicator bit of the 5GS network feature support IE or the Priority indicator IE to determine if access identity 1 is valid. Processing of the MPS indicator bit of the 5GS network feature support IE in the REGISTRATION ACCEPT message is described in subclause 5.5.1.2.4 and subclause 5.5.1.3.4. Processing of the MPS indicator bit of the Priority indicator IE in the CONFIGURATION UPDATE COMMAND message is described in subclause 5.4.4.3. The UE shall not consider access identity 1 to be valid when the UE is neither in the country of its HPLMN nor in an EHPLMN (if the EHPLMN list is present), until the UE receives the MPS indicator bit of the 5GS network feature support IE in the REGISTRATION ACCEPT message or of the Priority indicator IE in the CONFIGURATION UPDATE COMMAND message being set to "Access identity 1 valid" from the RPLMN or from an equivalent PLMN. When the UE is in the country of its HPLMN or in an EHPLMN (if the EHPLMN list is present), the contents of the USIM file EFUAC_AIC as specified in 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [22] and the rules specified in table 4.5.2.1 are used to determine the applicability of access identity 1. When the UE is in the country of its HPLMN or in an EHPLMN (if the EHPLMN list is present), and the USIM file EFUAC_AIC does not indicate the UE is configured for access identity 1, the UE uses the MPS indicator bit of the 5GS network feature support IE in the REGISTRATION ACCEPT message or of the Priority indicator IE in the CONFIGURATION UPDATE COMMAND message to determine if access identity 1 is valid. When the UE is in the country of its HPLMN or in an EHPLMN (if the EHPLMN list is present), and the USIM file EFUAC_AIC indicates the UE is configured for access identity 1, the MPS indicator bit of the 5GS network feature support IE and the Priority indicator IE are not applicable. When the UE is not in the country of its HPLMN or in an EHPLMN (if the EHPLMN list is present), the contents of the USIM file EFUAC_AIC are not applicable. The UE uses the MCS indicator bit of the 5GS network feature support IE to determine if access identity 2 is valid. Processing of the MCS indicator bit of the 5GS network feature support IE in the REGISTRATION ACCEPT message is described in subclause 5.5.1.2.4 and subclause 5.5.1.3.4. The UE shall not consider access identity 2 to be valid when the UE is not in the country of its HPLMN or in an EHPLMN (if the EHPLMN list is present) prior to receiving the MCS indicator bit of the 5GS network feature support IE in the REGISTRATION ACCEPT message being set to "Access identity 2 valid". When the UE is in the country of its HPLMN or in an EHPLMN (if the EHPLMN list is present), the contents of the USIM file EFUAC_AIC as specified in 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [22] and the rules specified in table 4.5.2.1 are used to determine the applicability of access identity 2. When the UE is in the country of its HPLMN or in an EHPLMN (if the EHPLMN list is present), and the USIM file EFUAC_AIC does not indicate the UE is configured for access identity 2, 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. When the UE is in the country of its HPLMN or in an EHPLMN (if the EHPLMN list is present), and the USIM file EFUAC_AIC indicates the UE is configured for access identity 2, the MCS indicator bit of the 5GS network feature support IE is not applicable. When the UE is not in the country of its HPLMN or in an EHPLMN (if the EHPLMN list is present), the contents of the USIM file EFUAC_AIC are not applicable. The UE checks the conditions specified in subclause 4.4.3.1.1 of 3GPP TS 23.122[ Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode ]  [5] to determine if access identity 3 is valid, and the applicability of access identity 3. When the UE is in its HPLMN (if the EHPLMN list is not present or is empty) or in an EHPLMN (if the EHPLMN list is present), the contents of the USIM file EFACC as specified in 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [22] and the rules specified in table 4.5.2.1 are used to determine the applicability of access classes 11 and 15. When the UE is not in its HPLMN (if the EHPLMN list is not present or is empty) or in an EHPLMN (if the EHPLMN list is present), access classes 11 and 15 are not applicable. When the UE is in the country of its HPLMN, the contents of the USIM file EFACC as specified in 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [22] and the rules specified in table 4.5.2.1 are used to determine the applicability of access classes 12 - 14. When the UE is not in the country of its HPLMN, access classes 12-14 are not applicable. In order to determine the access category applicable for the access attempt, the NAS shall check the rules in table 4.5.2.2, 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 4.5.2.2: Mapping table for access categories