Content for  TS 23.288  Word version:  18.4.0

The clause 6.5 describes how NWDAF can provide NF load analytics, in the form of statistics or predictions or both, to another NF. The service consumer may be an NF, or the OAM. The consumer of these analytics shall indicate in the request:

• Analytics ID = "NF load information";
• Target of Analytics Reporting: an optional SUPI or any UE;
• Analytics Filter Information:
  • optional S-NSSAI;
  • an optional list of NF Instance IDs, NF Set IDs, or NF types;
  • optional area of interest;
  • an optional list of analytics subsets that are requested (see clause 6.5.3);
• Optional preferred level of accuracy of the analytics;
• Optional preferred level of accuracy per analytics subset (see clause 6.5.3);
• Optional preferred order of results for the list of resource status: ascending or descending NF load;
• Optional Reporting Threshold; the Reporting Threshold is unique for all NFs matching the above Analytics Filter and the reporting applies when the conditions are met for at least one of these NFs;
• An Analytics target period indicates the time period over which the statistics or predictions are requested;
• In a subscription, the Notification Correlation Id and the Notification Target Address are included.

The NWDAF shall notify the result of the analytics to the consumer as indicated in clause 6.5.3. If a list of the NF Instance IDs (or respectively of NF Set IDs) is provided, the NWDAF shall provide the analytics for each designated NF instance (or respectively for each NF instance belonging to each designated NF Set). In such case the Target of Analytics Reporting should be ignored. Otherwise, if a SUPI is provided, the NWDAF shall use the SUPI to determine which NF instances (AMF and SMF) are serving this specific UE, filter them according to the provided S-NSSAI and NF types using data collected from NRF or OAM and provide analytics for these NF instances.

For the purpose of NF load analytics, the NWDAF may collect the information as listed in Table 6.5.2-1 for the relevant NF instance(s).

If target NF type is UPF, the NWDAF may collect the information as listed in Table 6.5.2-2, in addition to information listed in Table 6.5.2-1.

For the purpose of NF load analytics, the NWDAF may collect the information as listed in Table 6.5.2-3 (from OAM via MDT) and Table 6.5.2-5 via the AF (for trusted AF) or NEF (for untrusted AF) in addition to other information described above.

Based on network configuration, NWDAF may discover the AF from the NRF as defined in clause 6.2.8.2.2 (based on Collective Behaviour as Event ID or a corresponding Application ID). For AF in trusted domain, the NWDAF invokes step 3a in clause 6.2.8.2.3 by using Naf_EventExposure_Subscribe service (Event ID = Collective Behaviour, Event Filter information, Target of Event Reporting). The collective attribute (see Table 6.5.2-5) can be indicated as part of event filter information as defined in TS 23.502. Otherwise, the AF notifies for all collective attributes within the area of interest. For AF in untrusted domain, the NWDAF invokes step 3b in clause 6.2.8.2.3 by using Nnef_EventExposure_Subscribe (Event ID = Collective Behaviour, Event Filter information, Target of Event Reporting). The collective attribute (see Table 6.5.2-5) can be indicated as part of event filter information as defined in TS 23.502. Otherwise, the AF via NEF notifies for all collective attributes within the area of interest. For Collective Behaviour of multiple UEs, NWDAF based on the configuration by MNO may request certain type of data processing from the AF as part of event filter information (e.g. for anonymisation, normalisation, aggregation). The data processing requested by NWDAF is used to anonymise, normalise or aggregate the same UE attribute from multiple UEs at the AF before notifying to the NWDAF. For each UE attribute of a specific UE, whether and how AF is processing the data that is received from the UE depends on the SLA configured in AF (defined in clause 6.2.8.1) and is not known by the NWDAF. To determine NF load (per area of interest), NWDAF may collect and take into account UE trajectory input data from the AF, defined in clause 6.7.2.2, Table 6.7.2.2-2 for UE mobility analytics in addition to MDT input data and /or collective behaviour input data, defined in clause 6.5.2, Table 6.5.2-3 and Table 6.5.2-5, respectively.

The NWDAF services as defined in the clause 7.2 and clause 7.3 are used to expose the analytics. NF load statistics information are defined in Table 6.5.3-1. NF load predictions information are defined in Table 6.5.3-2.

The predictions are provided with a Validity Period, as defined in clause 6.1.3. The number of resource status is limited by the maximum number of objects provided as part of Analytics Reporting Information.

The procedure depicted in Figure 6.5.4-1 allows a consumer NF to request analytics to NWDAF for NF load of various NF instances as defined in clause 6.5.1.