7 Nnwdaf Services Description

23.2883GPPArchitecture enhancements for 5G System (5GS) to support network data analytics servicesRelease 18TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

7.1 General

Table 7.1-1 illustrates the NWDAF Services.

Table 7.1-1: NF services provided by NWDAF

Service Name	Service Operations	Operation Semantics	Example Consumer(s)
Nnwdaf_AnalyticsSubscription	Subscribe	Subscribe / Notify	PCF, NSSF, AMF, SMF, NEF, AF, OAM, CEF, NWDAF, DCCF
	Unsubscribe		PCF, NSSF, AMF, SMF, NEF, AF, OAM, CEF, NWDAF, DCCF
	Notify		PCF, NSSF, AMF, SMF, NEF, AF, OAM, CEF, NWDAF, DCCF, MFAF
	Transfer	Request / Response	NWDAF
Nnwdaf_AnalyticsInfo	Request	Request / Response	PCF, NSSF, AMF, SMF, NEF, AF, OAM, CEF, NWDAF, DCCF
	ContextTransfer	Request / Response	NWDAF
Nnwdaf_DataManagement	Subscribe	Subscribe / Notify	NWDAF, DCCF
	Notify		NWDAF, DCCF, MFAF, ADRF
	Fetch	Request / Response	NWDAF, DCCF, MFAF, ADRF
Nnwdaf_MLModelProvision	Subscribe	Subscribe / Notify	NWDAF
	Unsubscribe		NWDAF
	Notify		NWDAF
Nnwdaf_MLModelInfo	Request	Request / Response	NWDAF
NOTE 1: How OAM consumes Nnwdaf services and which Analytics information is relevant is defined in TS 28.550 [7] Annex H and out of the scope of this TS. NOTE 2: How CEF consumes Nnwdaf services and which Analytics information is relevant is defined in TS 28.201 [21] and out of the scope of this TS. NOTE 3: The Nnwdaf_MLModelProvision service and the Nnwdaf_MLModelInfo service are provided by an NWDAF containing MTLF and consumed by an NWDAF containing AnLF.

Table 7.1-2 shows the analytics information provided by NWDAF service.

Table 7.1-2: Analytics information provided by NWDAF

Analytics Information	Request Description	Response Description
Slice Load level information	Analytics ID: load level information	Load level provided as number of UE registrations and number of PDU sessions for a Network Slice and Network Slice instances as well as resource utilization for Network Slice instances.
Observed Service experience information	Analytics ID: Service Experience	Observed Service experience statistics or predictions may be provided for a Network Slice or an Application. They may be derived from an individual UE, a group of UEs or any UE. For slice service experience, they may be derived from an Application, a set of Applications or all Applications on the Network Slice.
NF Load information	Analytics ID: NF load information	Load statistics or predictions information for specific NF(s).
Network Performance information	Analytics ID: Network Performance	Statistics or predictions on the load in an Area of Interest; in addition, statistics or predictions on the number of UEs that are located in that Area of Interest.
UE mobility information	Analytics ID: UE Mobility	Statistics or predictions on UE mobility. When visited AOI(s) is included in the Analytics Filter information, only statistics on UE mobility can be provided.
UE Communication information	Analytics ID: UE Communication	Statistics or predictions on UE communication.
Expected UE behavioural parameters	Analytics ID: UE Mobility and/or UE Communication	Analytics on UE Mobility and/or UE Communication.
UE Abnormal behaviour information	Analytics ID: Abnormal behaviour	List of observed or expected exceptions, with Exception ID, Exception Level and other information, depending on the observed or expected exceptions.
User Data Congestion information	Analytics ID: User Data Congestion	Statistics or predictions on the user data congestion for transfer over the user plane, for transfer over the control plane, or for both.
QoS Sustainability	Analytics ID: QoS Sustainability	For statistics, the information on the location and the time for the QoS change and the threshold(s) that were crossed; or, for predictions, the information on the location and the time when a potential QoS change may occur and what threshold(s) may be crossed.
Session Management Congestion Control Experience	Analytics ID: Session Management Congestion Control Experience	Statistics on session management congestion control experience for specific DNN and/or S-NSSAI.
Redundant Transmission Experience	Analytics ID: Redundant Transmission Experience	Statistics or predictions aimed at supporting redundant transmission decisions for URLLC services.
WLAN performance	Analytics ID: WLAN performance	Statistics or predictions on WLAN performance of UE.
Dispersion	Analytics ID: UE Dispersion	Statistics or predictions that identify the location (i.e. areas of interest) or network slice(s) where a UE, or a group of UEs disperse their data volume, or disperse mobility or session management transactions or both.
DN Performance	Analytics ID: DN Performance	Statistics or predictions on user plane performance for a specific Edge Computing application.

7.2 Nnwdaf_AnalyticsSubscription Service

7.2.1 General

Service Description: This service enables the consumer to subscribe/unsubscribe for network data analytics.

When the subscription for network data analytics is accepted by the analytics NWDAF, the consumer receives from the NWDAF an identifier (Subscription Correlation ID) allowing to further manage (modify, delete) this subscription. The modification of Analytics subscription can be enforced by NWDAF based on operator policy and configuration.

This service also enables the consumer to transfer analytics subscriptions to another NWDAF using the Nnwdaf_AnalyticsSubscription_Transfer service operation. Using this service operation, a consumer can request to the NWDAF to prepare for or take over analytics subscription(s), indicating also if and where analytics context is available.

7.2.2 Nnwdaf_AnalyticsSubscription_Subscribe service operation

Service operation name: Nnwdaf_AnalyticsSubscription_Subscribe.

Description: Subscribes to NWDAF analytics with specific parameters.

Inputs, Required:

– (Set of) Analytics ID(s) as defined in Table 7.1-2;

– Target of Analytics Reporting;

– Notification Target Address (+ Notification Correlation ID);

– Analytics Reporting Parameters (including Analytics target period, etc.).

NOTE 1: Target of Analytics Reporting can be provided per individual Analytics ID.

Inputs, Optional:

– Analytics Filter Information;

– Subscription Correlation ID (in the case of modification of the analytics subscription);

– preferred level of accuracy of the analytics;

– preferred level of accuracy per analytics subset;

– Reporting Thresholds;

– maximum number of objects requested (max);

– preferred order of results, maximum number of SUPIs requested (SUPImax);

– time when analytics information is needed;

– Analytics Metadata Request;

– (Set of) NWDAF identifiers used by the NWDAF service consumer when aggregating multiple analytic subscriptions;

– Dataset Statistical Properties;

– Output strategy;

– Data time window;

– consumer NF’s serving area or NF ID;

– information of previous analytics subscription, i.e. NWDAF identifier (i.e. Instance ID or Set ID), Analytics ID(s) (including SUPIs and Analytics Filter Information for UE-related Analytics) and Subscription Correlation ID;

– Use case context.

NOTE 2: Analytics Filter Information, Reporting Thresholds, maximum number of objects requested (max), maximum number of SUPIs requested (SUPImax), Analytics Metadata Request, Dataset Statistical Properties, Output strategy, Data time window and time when analytics information is needed can be provided per individual Analytics ID.

Outputs Required: When the subscription is accepted: Subscription Correlation ID (required for management of this subscription). When the subscription is not accepted, an error response.

Outputs, Optional: None.

NOTE 3: When the Target of Analytics Reporting is a SUPI or a GPSI then the subscription may not be accepted, e.g. user consent is not granted and an error is sent to the consumer. When the Target of Analytics Reporting is an Internal Group Id, or a list of SUPIs/GPSI(s) or any UE, no error is sent, but a SUPI or GPSI is skipped if user consent is not granted.

7.2.3 Nnwdaf_AnalyticsSubscription_Unsubscribe service operation

Service operation name: Nnwdaf_AnalyticsSubscription_Unsubscribe.

Description: Unsubscribe to NWDAF analytics.

Inputs, Required: Subscription Correlation ID.

Inputs, Optional: None.

Outputs, Required: Operation execution result indication.

Outputs, Optional: None.

7.2.4 Nnwdaf_AnalyticsSubscription_Notify service operation

Service operation name: Nnwdaf_AnalyticsSubscription_Notify.

Description: NWDAF notifies the consumer instance of the analytics that has subscribed to the specific NWDAF service. See also clause 6.1.3 for contents of the Analytics Exposure.

Inputs, Required: Notification Correlation Information: this parameter indicates the Notification Correlation Id that has been assigned by the consumer during analytics subscription.

Inputs, Optional:

– Set of the tuple (Analytics ID, Analytics specific parameters): this parameter shall be present if output analytics are reported.

– Timestamp of analytics generation (required when ADRF is deployed).

– Validity period.

– Confidence

– Revised waiting time.

– Analytics Metadata Information.

– Termination Request: this parameter indicates that NWDAF requests to terminate the analytics subscription, i.e. NWDAF will not provide further notifications related to this subscription, with cause value (e.g. user consent revoked, NWDAF overload, UE moved out of NWDAF serving area, etc.).

NOTE: Validity period can also be provided as part of Analytics specific parameters for some NWDAF output analytics.

– Subscription Change Notification Correlation ID: this parameter shall be present if the notification is for informing the assignment of a new Subscription Correlation Id by the NWDAF. It is set to the old Subscription Correlation ID.

– Subscription Correlation ID: this parameter shall be present if the notification is for informing the assignment of a new Subscription Correlation Id by the NWDAF. It is set to a new Subscription Correlation ID assigned by the NWDAF.

Outputs, Required: Operation execution result indication.

Outputs, Optional: None.

7.2.5 Nnwdaf_AnalyticsSubscription_Transfer service operation

Service operation name: Nnwdaf_AnalyticsSubscription_Transfer.

Description: Requests to NWDAF for transferring analytics subscription(s) from the consumer NWDAF.

Inputs, Required:

– Transfer type: indicates the type of the transfer request. The following values are supported:

– Analytics subscription transfer preparation: requests the NWDAF to prepare for taking over the analytics subscription(s) and/or prepare for collecting Analytics Context(s).

– Analytics subscription transfer: requests the NWDAF to take over the analytics subscription(s).

– Analytics subscription transfer cancel: cancels a prepared analytics subscription request.

Inputs, Optional:

– If this service operation is for "analytics subscription transfer preparation", the following parameter shall be provided:

– (Set of) analytics subscription information with the following parameters:

– All input parameters for the analytics exposure as specified in clause 6.1.3.

– [OPTIONAL] Active data source ID(s): Instance ID or Set ID of the active data source(s) the consumer NWDAF is currently using for the analytics of this analytics subscription.

– [OPTIONAL] ML Model related information, i.e. information related to the ML model(s) that the NWDAF is currently using for the analytics:

– ID(s) of NWDAF(s) containing MTLF: Instance ID(s) of the NWDAF(s) containing MTLF from which the consumer NWDAF currently subscribes to the ML model information used for the analytics.

– [OPTIONAL] File address of the ML model(s).

– ID of the analytics consumer, e.g. NF, AF or OAM, that is subscribed to receive analytics.

– (Set of) analytics context identifier(s): identifies analytics context available at the consumer NWDAF as defined in clause 6.1B.4.

– If this service operation is to request analytics subscriptions transfer and if analytics subscription transfer preparation is not performed, the same parameters as those for transfer type "Analytics subscription transfer preparation" shall be provided.

– If this service operation is to request analytics subscriptions transfer and if analytics subscription transfer preparation is performed, the same parameters as those for transfer type "Analytics subscription transfer preparation" can be provided with updated parameter values.

– If this service operation is to request analytics subscriptions transfer cancel, the following parameter shall be provided:

– Subscription Correlation ID.

Outputs Required: Operation execution result indication.

Outputs, Optional: None.

7.3 Nnwdaf_AnalyticsInfo service

7.3.1 General

Service description: this service enables the consumer to request and get from NWDAF network data analytics or enables NWDAF to request transfer of analytics context from another NWDAF.

7.3.2 Nnwdaf_AnalyticsInfo_Request service operation

Service operation name: Nnwdaf_AnalyticsInfo_Request.

Description: The consumer requests NWDAF operator specific analytics.

Inputs, Required: (Set of) Analytics ID(s) as defined in Table 7.1-2, Target of Analytics Reporting, Analytics Reporting Parameters (including Analytics target period, etc.).

NOTE 1: Target of Analytics Reporting can be provided per individual Analytics ID.

Inputs, Optional: Analytics Filter Information, preferred level of accuracy of the analytics, preferred level of accuracy per analytics subset, time when analytics information is needed, maximum number of objects requested (max), preferred order of results, maximum number of SUPIs requested (SUPImax), Analytics Metadata Request, Dataset Statistical Properties, Output strategy, Data time window, Use case context.

NOTE 2: Analytics Filter Information, Maximum number of objects requested (max), Maximum number of SUPIs requested (SUPImax), Analytics Metadata Request, Dataset Statistical Properties, Output strategy, Data time window and time when analytics information is needed can be provided per individual Analytics ID.

Outputs, Required: If the request is accepted, then set of the tuple (Analytics ID, Analytics specific parameters). When the request is not accepted, an error response.

Outputs, Optional: Timestamp of analytics generation (required when ADRF is deployed), validity period, confidence, revised waiting time, Analytics Metadata Information. See clause 6.1.3.

NOTE 3: Validity period can also be provided as part of Analytics specific parameters for some NWDAF output analytics.

NOTE 4: When the Target of Analytics Reporting is a SUPI or a GPSI then the request may not be accepted, e.g. user consent is not granted and an error is sent to the consumer. When the Target of Analytics Reporting is an Internal Group Id, or a list of SUPIs/GPSI(s) or any UE, no error is sent, but a SUPI or GPSI is skipped if user consent is not granted.

7.3.3 Nnwdaf_AnalyticsInfo_ContextTransfer service operation

Service operation name: Nnwdaf_AnalyticsInfo_ContextTransfer.

Description: Requests to NWDAF to transfer context information related to analytics subscriptions.

Inputs, Required: (Set of) Analytics context identifier(s).

Inputs, Optional: Requested Analytics Context per analytics context identifier.

Outputs Required: (Set of) Analytics Context as specified in clause 6.1B.4.

Outputs, Optional: ADRF ID with Analytics Context Type stored in the ADRF (i.e. Historical output Analytics and/or Data related to Analytics).

NOTE: For the Requested Analytics Context, the NWDAF can return a combination of Analytics Context and reference to ADRF ID from where Historical output Analytics and/or Data related to Analytics can be retrieved.

7.4 Nnwdaf_DataManagement Service

7.4.1 General

Service Description: This service enables the consumer to subscribe/unsubscribe for data exposed by an NWDAF, fetch the subscribed data. Historical data or runtime data may be obtained using this service.

7.4.2 Nnwdaf_DataManagement_Subscribe service operation

Service operation name: Nnwdaf_DataManagement_Subscribe.

Description: The consumer subscribes to receive data, or if the data is already requested from the NWDAF, then the subscription is updated. The subscription includes service operation specific parameters that identify the data to be provided and may include formatting and processing instructions that specify how the data is to be delivered to the consumer. The consumer may request bulked data related to Analytics, as an alternative to asking individual events (i.e. subscription to multiple event IDs to obtain the data required for an analytics generation). The consumer may also request that data be stored in an ADRF. When historical data is being obtained, the consumer may specify the ID of the ADRF or NWDAF containing the data.

Inputs, Required: Data Specification or Analytics Specification, Notification Target Address(es) (+ Notification Correlation ID(s)).

When the required data is data for Event IDs received from NFs, the Data Specification includes set of Event IDs, Event Filter Information, Target of Event Reporting.

When the required data is a bulked data for an Analytics ID, the Data Specification includes Target of Reporting with the Analytics ID to generate bulked data, Target of Analytics reporting and Analytics Filter.

Inputs, Optional: Service Operation, Time Window, NF (or NF-Set) ID, ADRF or NWDAF hosting ADRF information where data are to be stored, ADRF ID where historical data are stored, Formatting Instructions, Processing Instructions, user consent check information (i.e. an indication that the data consumer has checked user consent), purpose for data collection.

NOTE 1: See clause 8.2.2 for further description of the Input Parameters.

Outputs Required: When the subscription is accepted: Subscription Correlation ID (required for management of the requested subscription). When the subscription is not accepted, an error response.

Outputs, Optional: First corresponding event report is included, if available (see clause 4.15.1 of TS 23.502 [3]), Requested data.

NOTE 2: When the Target of Event Reporting or Target of Reporting is a SUPI or a GPSI then the subscription may not be accepted, e.g. for user consent is not granted and an error is sent to the consumer. When the Target of Event Reporting or Target of Reporting is an Internal Group Id, or a list of SUPIs/GPSI(s) or any UE, no error is sent, but a SUPI or GPSI is skipped if user consent is not granted.

7.4.3 Nnwdaf_DataManagement_Unsubscribe service operation

Service operation name: Nnwdaf_DataManagement_Unsubscribe.

Description: The NF consumer unsubscribes to the NWDAF for data.

Inputs, Required: Subscription Correlation ID.

Outputs, Required: Operation execution result indication.

Outputs, Optional: None.

7.4.4 Nnwdaf_DataManagement_Notify service operation

Service operation name: Nnwdaf_DataManagement_Notify.

Description: NWDAF notifies the consumer instance of the requested data, or notifies of the availability of previously subscribed Data or Analytics when delivery is via an NWDAF.

Inputs, Required: Notification Correlation ID, time stamp representing time when NWDAF completed preparation of the requested data.

Inputs, Optional:

– Requested Data with timestamp;

– Fetch Instructions;

– Termination Request.

NOTE 1: If the NWDAF has received the notifications from another source without a timestamp, then the NWDAF adds itself a timestamp based on the time it received the notification.

Fetch Instructions indicate whether the data are to be fetched by the Consumer. If the data are to be fetched, the fetch instructions include an address from which the data may be fetched, one or more Fetch Correlation IDs and a deadline to fetch the data (Fetch Deadline).

Termination Request indicates that NWDAF requests to terminate the data management subscription, i.e. NWDAF will not provide further notifications related to this subscription.

NOTE 2: Data provided in notifications are processed and formatted according to the Processing and Formatting Instructions provided by the Consumer in Nnwdaf_DataManagement_Subscribe.

Outputs, Required: Operation execution result indication.

Outputs, Optional: None.

7.4.5 Nnwdaf_DataManagement_Fetch service operation

Service operation name: Nnwdaf_DataManagement_Fetch.

Description: Consumer retrieves from the NWDAF subscribed data (which is regarded as a kind of data), as indicated by Fetch Instructions from Nnwdaf_DataManagement_Notify.

Inputs, Required: Set of Fetch Correlation ID(s).

Inputs, Optional: None.

Outputs, Required: Operation execution result indication.

Outputs, Optional: Requested data.

7.5 Nnwdaf_MLModelProvision services

7.5.1 General

Service Description: This service enables the consumer to receive a notification when an ML model matching the subscription parameters becomes available.

When the subscription is accepted by the NWDAF containing MTLF, the consumer NF, i.e. the NWDAF containing Analytics Logical Function, receives from the NWDAF an identifier (Subscription Correlation ID) allowing to further manage (modify, delete) this subscription. The modification of ML model subscription can be enforced by NWDAF based on operator policy and configuration.

7.5.2 Nnwdaf_MLModelProvision_Subscribe service operation

Service operation name: Nnwdaf_MLModelProvision_Subscribe.

Description: Subscribes to NWDAF ML model provision with specific parameters.

Inputs, Required: (set of) Analytics ID(s) defined in Table 7.1-2, Notification Target Address (+ Notification Correlation ID).

Inputs, Optional: Subscription Correlation ID (in the case of modification of the ML model subscription), ML Model Filter Information to indicate the conditions for which ML model for the analytics is requested and Target of ML Model Reporting to indicate the object(s) for which ML model is requested (e.g. specific UEs, a group of UE(s) or any UE (i.e. all UEs)), ML Model Reporting Information (including e.g. ML Model Target Period), Expiry time, Use case context, indication of support for multiple ML models, multiple ML models Filter Information to indicate the conditions for which multiple ML models are requested.

Outputs Required: When the subscription is accepted: Subscription Correlation ID (required for management of this subscription), Expiry time (required if the subscription can be expired based on the operator’s policy).

Outputs, Optional: None.

7.5.3 Nnwdaf_MLModelProvision_Unsubscribe service operation

Service operation name: Nnwdaf_MLModelProvision_Unsubscribe.

Description: unsubscribe to NWDAF ML model provision.

Inputs, Required: Subscription Correlation ID.

Inputs, Optional: None.

Outputs, Required: Operation execution result indication.

Outputs, Optional: None.

7.5.4 Nnwdaf_MLModelProvision_Notify service operation

Service operation name: Nnwdaf_MLModelProvision_Notify.

Description: NWDAF notifies the ML model information to the consumer instance which has subscribed to the specific NWDAF service.

Inputs, Required: Notification Correlation Information, Set of:

– the tuple (Analytics ID, address (e.g. URL or FQDN) of Model file), when multiple ML models is not supported; or

– the tuple (Analytics ID, one or more tuples of unique ML Model identifier and address (e.g. URL or FQDN) of Model file).

Inputs, Optional: Validity period, Spatial validity.

Outputs, Required: Operation execution result indication.

Outputs, Optional: None.

7.6 Nnwdaf_MLModelInfo service

7.6.1 General

Service description: this service enables the consumer to request and get from NWDAF containing MTLF ML Model Information.

7.6.2 Nnwdaf_MLModelInfo_Request service operation

Service operation name: Nnwdaf_MLModelInfo_Request

Description: The consumer requests NWDAF ML Model Information.

Inputs, Required: (Set of) Analytics ID(s) defined in Table 7.1-2.

Inputs, Optional: ML Model Filter Information to indicate the conditions for which ML model for the analytics is requested and Target of ML Model Reporting to indicate the object(s) for which ML model is requested (e.g. specific UEs, a group of UE(s) or any UE (i.e. all UEs)), ML Model Reporting Information (including e.g. ML Model Target Period), Use case context, indication of support for multiple ML models, multiple ML models Filter Information to indicate the conditions for which multiple ML models are requested.

Outputs, Required: Set of:

– the tuple (Analytics ID, address (e.g. URL or FQDN) of Model file), when multiple ML models is not supported; or

– the tuple (Analytics ID, one or more tuples of unique ML Model identifier and address (e.g. URL or FQDN) of Model file).

Outputs, Optional: Validity period, Spatial validity.