5.30.2.3 UE configuration and subscription aspects

An SNPN-enabled UE is configured with the following information for each subscribed SNPN:

• PLMN ID and NID of the subscribed SNPN;
• Subscription identifier (SUPI) and credentials for the subscribed SNPN;
• Optionally, an N3IWF FQDN and the MCC of the country where the configured N3IWF is located;
• Optionally, if the UE supports access to an SNPN using credentials from a Credentials Holder:
• User controlled prioritized list of preferred SNPNs;
• Credentials Holder controlled prioritized list of preferred SNPNs;
• Credentials Holder controlled prioritized list of GINs;
• Optionally, if the UE supports access to an SNPN using credentials from a Credentials Holder and access to an SNPN providing access for Localized Services:
• User controlled prioritized list of preferred SNPNs;
• Credentials Holder controlled prioritized list of preferred SNPNs for accessing Localized Services, each entry of the list includes:
• an SNPN identifier;
• validity information; and
• optionally, location assistance information;
• Credentials Holder controlled prioritized list of GINs for accessing Localized Services, each entry of the list includes:
• a GIN;
• validity information; and
• optionally, location assistance information;
• Protection scheme for concealing the SUPI as defined in TS 33.501 [29].

NOTE 1: Additionally the UE can be configured with indication to use anonymous SUCI as defined in TS 24.501 [47].

Validity information consists of:

• Time validity information, i.e. time periods (defined by start and end times) when access to the SNPN for accessing Localized Services is allowed; and
• optionally, location validity information containing one or more location information as defined in TS 24.501 [47].

NOTE 2: Usage of the location validity information is further explained in TS 23.122 [17].

Location assistance information consisting of:

• Geolocation information and/or,
• Tracking Area information of serving networks, i.e. lists of TACs per PLMN ID or per PLMN ID and NID.

The UE may use the location assistance information to determine where to search for the SNPNs in the Credentials Holder controlled prioritized list of SNPNs and GINs for accessing Localized Services, i.e. the location assistance information is not used for any area restriction enforcement.

For an SNPN-enabled UE with SNPN subscription, the Credentials Holder controlled prioritized lists of preferred SNPNs and GINs, or Credentials Holder controlled prioritized lists of preferred SNPNs and GINs for accessing Localized Services may be updated by the Credentials Holder using the Steering of Roaming (SoR) procedure as defined in Annex C of TS 23.122 [17]. Updating Credentials Holder controlled prioritized lists of preferred SNPNs and GINs, or Credentials Holder controlled prioritized lists of preferred SNPNs and GINs for accessing Localized Services via the Steering of Roaming (SoR) procedure is not applicable for Credentials Holder with AAA Server.

A subscription of an SNPN is either:

• identified by a SUPI containing a network-specific identifier that takes the form of a Network Access Identifier (NAI) using the NAI RFC 7542 [20] based user identification as defined in clause 28.7.2 of TS 23.003 [19]. The realm part of the NAI may include the NID of the SNPN; or
• identified by a SUPI containing an IMSI.

NOTE 3: As to route network signalling to AUSF and UDM instances serving the SNPN-enabled UE, the UE can be configured with Routing Indicator locally or updated with Routing Indicator using the UE Parameters Update via UDM Control Plane procedure defined in clause 4.20 of TS 23.502 [3]. When the SNPN credential is stored in the USIM, the Routing Indicator is provisioned in the USIM, when the SNPN credential is stored in the ME, the Routing Indicator is provisioned in the ME.

In the case of access to an SNPN using credentials owned by a Credentials Holder as specified in clause 5.30.2.9.2 and clause 5.30.2.9.3, the SUPI shall also contain identification for the Credentials Holder (i.e. the realm in the case of Network Specific Identifier based SUPI or the MCC and MNC in the case of an IMSI based SUPI). In the case of access to an SNPN using credentials owned by a Credentials Holder using AAA-S as specified in clause 5.30.2.9.2, only Network Specific Identifier based SUPI is supported.

NOTE 4: When Credentials Holder is an SNPN and the MCC and MNC of the SNPN is not unique (e.g. MCC =999 is used and MNC is not coordinated amongst the SNPNs), then IMSI based SUPI is not supported as the MCC and MNC need not be globally unique always; instead USIM credentials are supported using Network Specific Identifier based SUPI.

NOTE 5: Network Specific Identifier are not supported for the case the Credentials Holder is provided by a PLMN.

NOTE 6: It is assumed that normally the SNPN and the Credentials Holder use different PLMN ID. If the SNPN and CHs (where CH can be another SNPN or a PLMN) share PLMN ID and IMSI based SUPI is used, then the Routing Indicator can be used for AUSF/UDM discovery and selection as long as the Routing Indicator values are coordinated among the involved SNPN and CHs. When the PLMN ID is not shared between SNPNs and CHs (where CH can be another SNPN or a PLMN) and IMSI based SUPI is used, then PLMN ID is sufficient to be used for AUSF/UDM discovery & selection unless the CHs deploys multiple AUSF/UDM in which case also the Routing Indicator can be used as long as the Routing Indicator values are coordinated within the CH.

An SNPN-enabled UE that supports access to an SNPN using credentials from a Credentials Holder and that is equipped with a PLMN subscription may additionally be configured with the following information for SNPN selection and registration using the PLMN subscription in SNPN access mode:

• User controlled prioritized list of preferred SNPNs;
• Credentials Holder controlled prioritized list of preferred SNPNs;
• Credentials Holder controlled prioritized list of preferred GINs.
• Optionally if the UE supports access to an SNPN providing access for Localized Services:
• Credentials Holder controlled prioritized list of preferred SNPNs for accessing Localized Services, each entry of the list includes:
• an SNPN identifier;
• validity information; and
• optionally, location assistance information;
• Credentials Holder controlled prioritized list of preferred GINs for accessing Localized Services, each entry of the list includes:
• a GIN;
• validity information; and
• optionally, location assistance information.

Validity information consists of:

• Time validity information, i.e. time periods (defined by start and end times) when access to the SNPN for accessing Localized Services is allowed; and
• optionally, location validity information containing one or more location information as defined in TS 24.501 [47].

NOTE 7: Usage of the location validity information is further explained in TS 23.122 [17].

Location assistance information consisting of:

• Geolocation information and/or,
• Tracking Area information of serving networks, i.e. lists of TACs per PLMN ID or per PLMN ID and NID.

The UE may use the location assistance information to determine where to search for the SNPNs in the Credentials Holder controlled prioritized list of SNPNs and GINs for accessing Localized Services, i.e. the location assistance information is not used for any area restriction enforcement.

For an SNPN-enabled UE with PLMN subscription, the Credentials Holder controlled prioritized lists of preferred SNPNs and GINs, or the Credentials Holder controlled prioritized lists of preferred SNPNs and GINs for accessing Localized Services may be updated by the Credentials Holder using the Steering of Roaming (SoR) procedure as defined in Annex C of TS 23.122 [17].

When the Credentials Holder updates a UE with the Credentials Holder controlled prioritized lists of preferred SNPNs and GINs and/or the Credentials Holder controlled prioritized lists of preferred SNPNs and GINs for accessing Localized Services, the UE may perform SNPN selection again, e.g. to potentially select a higher prioritized SNPN or to potentially select an SNPN that provides access for Localized Services.