Content for  TS 23.548  Word version:  18.1.1

The ECS Address Configuration Information consists of one or more ECS Configuration Information as defined in clause 8.3.2.1 of TS 23.558. The ECS Configuration Information may contain Spatial Validity Conditions, which includes one of the following alternatives:

• a Geographical Service Area (see TS 23.558);
• a list of TA(s); or
• a list of countries (list of MCC);
• a list of PLMN IDs (see Table 4.15.6.3d-1 of TS 23.502).

A UE may receive multiple instances of ECS Address Configuration Information e.g., corresponding to different ECSPs (e.g., the MNO or a 3rd party service provider). The ECS Address Configuration Information is sent to the UE on a per PDU Session basis. The same PDU session can be used by multiple ECS providers. The SMF does not need to be aware of the internal structure of the ECS Address Configuration Information.

If the UE hosts an EEC and supports transferring the ECS address received from the 5GC to the EEC, the UE indicates in the PCO at PDU Session establishment that it supports the ability to receive ECS address(es) via NAS and to transfer the ECS Address(es) to the EEC(s) (see TS 23.502). As described in TS 23.502, if the UE supports the ability to receive ECS Address Configuration Information via NAS and to transfer the ECS address(es) to the EEC(s), the UE may receive ECS Address Configuration Information from the SMF via PCO during PDU Session Establishment and/or during PDU Session Modification procedures. If Spatial Validity Condition of ECS is provided, the UE uses the appropriate ECS as defined in TS 23.558. The SMF may receive ECS Address Configuration Information and associated spatial validity conditions from the UDM together with SM subscription information. The UDM in the HPLMN may provide the SMF (in HPLMN in HR case, in VPLMN in LBO case) with ECS address configuration information that depends on the serving PLMN of the UE. The SMF determines the ECS Address Configuration Information to be sent to the UE based on UE subscription information received from UDM (as described in Table 4.15.6.3d-2 of TS 23.502). The SMF may decide to send updated ECS Address Configuration Information to the UE based on locally configured policy or updated UE subscription information. The PDU Session Modification procedure is used to send updated ECS Address Configuration Information to the UE as described in clause 4.3.3 of TS 23.502.

As described in TS 23.558, the Edge Configuration Server can be deployed in a 3rd party domain by a service provider. An AF in the MNO domain or, if the Edge Configuration Server is deployed in a 3rd party domain by a service provider, a 3rd party AF can use Nnef_ParameterProvision to provide, update, or delete AF provided ECS Address Configuration Information applying on a DNN and/or S-NSSAI for a group of UE, or any UE (See clause 4.15.6.2 of TS 23.502). When the AF uses Nnef_ParameterProvision to send a new AF provided ECS Address Configuration Information to the UDM (e.g. because on Application layer activity, etc.), the UDM may notify the impacted SMF(s) of the updated Subscription provided ECS Address Configuration Information and the new ECS Address Configuration Information will be sent to the UE(s) in a PDU Session Modification procedure.

The ECS Address Configuration Information can be provisioned by the MNO subscription provisioning in UDM.

In interworking scenarios, if the UE hosts an EEC and supports transferring the ECS address received from the 5GC to the EEC, the UE indicates in the PCO at PDN Connection establishment that it supports the ability to receive ECS address(es) via NAS and to transfer the ECS Address(es) to the EEC(s) (see TS 23.502) and the bearer modification procedure without bearer QoS update procedure is used to send updated ECS Address Configuration Information to the UE as described in clause 4.11.0a.5 of TS 23.502.

For both LBO and HR case, the subscription data of the ECS Address Configuration Information in UDM or UDR is stored per PLMN ID. For the LBO case, an AF in the visited PLMN may provide the EACI via External Parameter Provisioning procedure as described in clause 4.15.6.3d of TS 23.502 to UDM via H-NEF. This ECS Address Configuration Information is further provided to SMF as part of subscription information. For the HR case when access to EHE in VPLMN is allowed:

• The HPLMN has the knowledge of EACI in the VPLMN: For this scenario, the AF is able to interact with NEF in HPLMN. The AF may provide the VPLMN EACI to H-NEF via External Parameter Provisioning procedure as described in clause 4.15.6.3d in TS 23.502, and further to the UDM. During the HR PDU session establishment procedure, the H-SMF sends the VPLMN EACI to V-SMF and then to UE. The V-SMF does not modify, but just delivers the EACI provided by the H-SMF.
• HPLMN does not have the knowledge of EACI in VPLMN: For this scenario, the AF can't interact with NEF in HPLMN. The AF deployed in the VPLMN provides the VPLMN EACI to the V-SMF via the V-NEF as defined in clause 6.7.3.2. During the HR PDU Session establishment, the V-SMF sends the VPLMN EACI obtained from V-NEF to the H-SMF, and H-SMF decides the VPLMN ECS Address Configuration Information sent to V-SMF and then to UE according to the PLMN ID additionally.