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).
An EEC Context shall be created for each registered EEC, after a successful registration, by the receiver EES, as follows:
If the EEC registration request does not include a previously assigned EEC Context ID value, the receiver EES creates an EEC Context as described in clause 8.2.8. The receiver EES shall assign an EEC context ID and set the source EES Endpoint to its own Endpoint. The EEC ID and UE Identifier shall be set based on the corresponding registration request parameters.
If the EEC registration request contains an EEC context ID and source EES Endpoint, the receiver (i.e., target) EES performs an EEC Context Pull relocation (clause 184.108.40.206). After a successful EEC Context relocation, the target EES updates the source EES Endpoint with its own Endpoint. The target EES may preserve the EEC Context ID received in the request or assign a new EEC Context ID, subject to EES implementation and local policies.
If the EEC Context relocation is not successful, the target EES creates an EEC Context as described in clause 8.2.8. The target EES shall assign an EEC context ID and set the source EES Endpoint to its own endpoint. The EEC ID and UE ID shall be set based on the corresponding registration request parameters.
After a successful EEC Context Relocation procedure is performed at EEC (re-)registration to a target EES, the source EES shall determine to be stale the EEC Context identified by the EEC Context ID included in the request (i.e., relocated) and the EEC to be de-registered.
The EEC Context provided to a target EES in an EEC Context Pull relocation or an EEC context Push relocation shall be stored at the target EES, as follows:
If an EEC context with the same EEC ID, EEC Context ID and source Endpoint already exists at the target EES, the EEC Context is updated.
If an EEC context with the same EEC ID, EEC Context ID and source Endpoint does not exist at the target EES, the EEC Context is stored.
After a successful EEC Context Relocation procedure is performed at ACR, the source EES shall determine to be stale the element(s) of the list of Service Session Context(s) information included in the request (i.e., relocated). If all Service Session Context(s) information in the EEC Context are stale, the EEC Context is determined to be stale and the EEC to be de-registered.
Elements of the list of Service Session Context(s) information shall be created by the EES when it determines that a registered EAS is providing services to an AC on the served EEC.
Elements of the list of Service Session Context(s) information shall be determined to be stale when the EES determines that a registered EAS is no longer providing services to an AC on the served EEC.
An EEC Context shall be updated as follows:
When EEC Context(s) are created, either after a registration request or based on EEC Context relocation procedure, the EES shall check whether the UE Identifier corresponds to an existing EEC Context and update the EEC Context accordingly.
When EEC subscription requests corresponding to the EEC ID are processed, the "List of EDGE-1 subscriptions" shall be updated accordingly
Upon receiving the request from the target EES, the source EES validates the request and verifies the security credentials of the requester. The source EES uses the EEC Context ID provided to identify and authorize the EEC Context to be relocated.
Upon receiving the request from the source EES, the target EES validates the request and verifies the security credentials. The target EES uses the EEC Context ID provided to authorize the EEC Context to be stored and managed. Then the target EES sends an EEC Context response indicating success. The T-EES performs implicit registration and creates the registration ID for the registration and includes it in the EEC context push response message for S-EAS decided ACR or S-EES executed ACR scenarios. The S-EES stores the registration details, and when required, notifes the EEC about registration details while sending ACR information notification.
The functional entities of the Edge Enabler Layer can utilize the 3GPP core network capabilities (i.e. 5GC, EPC) to fulfill the needs of the edge service operations. This clause specifies the details of the 3GPP core network capabilities consumed by each functional entity.
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.
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, UE mobility, upon receiving EEC Registration request containing AC profile.
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 220.127.116.11-2 due to no EAS is available or instantiated. The EES may trigger the EAS management system to instantiate the EAS serving the AC in the EDN before returning the EAS information to the EEC or S-EES, based on the pre-configured dynamic EAS instantiation information about which EAS can be dynamically instantiated at the associated EDN.