Content for  TS 23.558  Word version:  19.3.0

EEC Context contains information related to an EEC which is used by EESs to provide the Edge Enabler Layer services. The EEC Context may include information about the EEC-hosting UE and the ACs to which the EEC provides services. The EEC Context information may be collected and maintained at the EES in an EDN while the respective ACs are connected to EASs in that EDN. EEC Context relocation procedures allow the EEC Context information to be shared between EESs (via EDGE-9 interactions). The EEC Context information may contain List of EDGE-1 subscriptions (i.e., list of subscription IDs for an EEC). The corresponding EDGE-1 subscription information includes EEC ID, Event ID, subscription ID, 3GPP CN subscription information (optional), notification target address (optional) and filter information (optional).

The functional entities of the Edge Enabler Layer can utilize the 3GPP core network capabilities (i.e. 5GC, EPC) to fulfil the needs of the edge service operations. This clause specifies the details of the 3GPP core network capabilities consumed by each functional entity.

When required, the ECS may utilize:

• user plane path management events by subscribing with the 3GPP core network for the user plane path management event notifications of the UE as described in TS 23.501 and TS 23.502; and
• the location information from the API exposed by 3GPP core network, e.g. SCEF/NEF/SCEF+NEF or LCS (Location Service) as specified in TS 23.682, TS 23.502, TS 23.271, TS 36.305, TS 23.273 and TS 38.305 to obtain the UE's location from the 3GPP Core Network.
• application triggering service as specified for Nnef_Trigger_Delivery service in clause 4.13.2 of TS 23.502 or the device triggering procedure via T8 in clause 5.17 of TS 23.682 for the EEC Triggering service described in clause 8.16.

When required, the EES and CES may utilize:

• AF traffic influence functionality, including the user plane path management event notifications of the UE, from the 3GPP core network either directly (e.g. via PCF) as described in TS 23.501, TS 23.502; or indirectly (i.e. NEF/SCEF+NEF) as described in TS 23.501, TS 23.502, TS 29.522.
• the location information from the API exposed by 3GPP core network, e.g. SCEF/NEF/SCEF+NEF or LCS (Location Service) as specified in TS 23.682, TS 23.502, TS 23.271, TS 36.305, TS 23.273 and TS 38.305 to obtain the UE's location from the 3GPP Core Network;
• capabilities exposed by the 3GPP core network, e.g. NEF or PCF, to establish an AF session with QoS, and QoS related event notifications subscribed with the 3GPP core network as specified in TS 23.501, TS 23.502 and TS 23.503;
• capabilities exposed by the 3GPP core network, e.g. NEF or NWDAF, to analyse UE expected behaviour as specified in TS 23.288; and
• the monitoring capability exposed by the 3GPP core network as specified in TS 23.501 and TS 23.502.
• application triggering service as specified for Nnef_Trigger_Delivery service in clause 4.13.2 of TS 23.502 or the device triggering procedure via T8 in clause 5.17 of TS 23.682 for the EEC Triggering service described in clause 8.16.
• AF specific UE ID retrieval as specified in clause 4.15.10 of TS 23.502 to obtain an identifier that can be used when invoking further NEF provided services (e.g., location monitoring).

The architecture for enabling edge applications supports EEC authentication/authorization. After the successful EEC authentication/authorization, the EEC acquires a valid security credential for EEC related procedures including service provisioning procedure, EEC registration procedure, EAS discovery procedure and ACR procedure. Detailed procedures are specified in TS 33.558.

The EES may trigger the EAS instantiation dynamically due to e.g., EAS discovery request, EAS discovery subscription request, UE mobility, upon receiving EEC Registration request containing AC profile or upon receiving an EAS information provisioning request. Upon receiving the EAS discovery request with EAS discovery filter from the EEC or the S-EES during the procedures for EAS discovery or ACR, the EES may fail to discover and select the EAS that matches the UE location and the requesting application characteristics specified in Table 8.5.3.2-2 due to no EAS is available or instantiated. The EES may determine the required computing ability based on the AC service KPI (i.e. the E2E KPI requirements), the available transmission capability (e.g. DN performance analytic from NWDAF) for the requested EAS. The EES may trigger the ECSP management system with the required EAS ID, and the required computing ability with the required computing resource or the required computing KPI (which is specified in TS 28.538) to instantiate the EAS serving the AC in the EDN corresponding to the EAS that can be instantiable before returning the EAS information to the EEC or S-EES, based on the information about instantiable EASs which can be dynamically instantiated at the associated EDN. If EAS selection is performed by the EES, the selected EAS is dynamically instantiated if applicable. Based on the information about instantiable EASs, the EES may maintain the EAS instantiation status transition (e.g., among instantiated, instantiable but not instantiated yet, or instantiation in progress) via the EAS (de-)registration procedure or the dynamic EAS instantiation triggering procedure. The EAS instantiation status can be provided to the EEC using the Instantiable EAS Information IE of EAS discovery response and EAS discovery notification for the use of EAS selection by the EEC. If the EEC indicates EAS Instantiation Triggering Suppress in EAS discovery request and EAS discovery subscription request, then the EES does not trigger EAS instantiation. Upon receiving EEC Registration request with bundle EAS information the EES may determine that only a subset of the EAS(s) in the bundle are registered and instantiated. If only a subset of bundle EASs is determined, the EES may trigger the ECSP management system to instantiate the subset of remaining EASs corresponding to the bundle that can be instantiable before responding to the registration request. Upon receiving one or more EAS discovery subscription request(s) for the availability of an EAS, EES may determine if there is a need for EAS instantiation based on the information about instantiable EASs. If such a need for EAS instantiation determined, EES may send a report for a need of the EAS instantiation to the ECSP management system to consider instantiating the requested EAS by invoking an MnS API of the ECSP management system. When the requested EAS has been instantiated, the EES may obtain the EAS profile during the EAS registration procedure and notify the availability change event of the requested EAS with the EAS profile to the corresponding EECs via the EAS discovery notification procedure as specified in the clause 8.5.2.3. Upon receiving the EAS information provisioning request, the EES may trigger the ECSP management system to instantiate the EAS in the EDN before returning the EAS information to the EEC.