5.6 ML Model provisioning procedures

29.5523GPP5G SystemNetwork Data Analytics signalling flowsRelease 17Stage 3TS

5.6.1 General

The ML Model provisioning procedures allow the NF service consumers (i.e. NWDAF (MTLF+AnLF), NWDAF (AnLF)) to obtain the ML model information on the related Analytics from another NWDAF (i.e. an NWDAF containing MTLF).

5.6.2 ML Model Subscribe/Unsubscribe/Notify procedure

The procedure is used by an NF service consumer to subscribe to/unsubscribe from the ML model information on the related Analytics on NWDAF containing MTLF, and also used by the NWDAF containing MTLF to notify the ML model information to the NF service consumer if it subscribed to the ML model information previously.

Figure 5.6.2-1: ML Model Subscribe/Unsubscribe/Notify procedure

1. In order to subscribe to ML model information, the NF service consumer invokes Nnwdaf_MLModelProvision_Subscribe service operation by sending an HTTP POST request targeting the resource "NWDAF ML Model Provision Subscriptions". The request shall include the event ID(s) and the notification URI, and may include the event filter information, the target UE information, the expected time interval during which the ML model shall be reported and the expiry time.

In order to modify the existing subscription, the NF service consumer invokes Nnwdaf_MLModelProvision_Subscribe service operation by sending an HTTP PUT request with Resource URI of the resource "Individual NWDAF ML Model Provision Subscription".

2. The NWDAF containing MTLF responds to the Nnwdaf_MLModelProvision_Subscribe service operation. Upon receipt of the HTTP POST request, if the subscription is accepted to be created, the NWDAF containing MTLF responds to the NF service consumer with "201 Created", and the URI of the created subscription is included in the Location header field.

Upon receipt of the HTTP PUT request, if the subscription is accepted to be updated, the NWDAF containing MTLF responds to the NF service consumer an HTTP "200 OK" with a response body containing a representation of the updated subscription or "204 No Content".

3. If the NWDAF containing MTLF determines that the subscribed ML model information is available, the NWDAF containing MTLF invokes MLModelProvision_Notify service operation to report the ML model information by sending an HTTP POST request to the NF service consumer identified by the notification URI received during the creation/modification of the subscriptions. The request shall include the event ID, the subscriptionId and the address (e.g. URL or FQDN) of ML Model file, and may include the period of validity that indicates the time period when the provided ML model applies and spatial validity that indicates the area where the provided ML model applies.

4. The NF service consumer responds to the NWDAF containing MTLF with an HTTP "204 No Content" message.

5. In order to unsubscribe from the notification(s) of the ML model information, the NF service consumer invokes Nnwdaf_MLModelProvision_Unsubscribe service operation by sending an HTTP DELETE request, which targets the resource "Individual NWDAF ML Model Provision Subscription", to the NWDAF containing MTLF.

6. If the request is accepted, the NWDAF containing MTLF deletes the subscription and responds to the NF service consumer with an HTTP "204 No Content" message.

NOTE: For details of Nnwdaf_MLModelProvision_Subscribe /Unsubscribe/Notify service operations refer to 3GPP TS 29.520 [5].