Content for  TS 23.288  Word version:  18.4.0

The consumer of QoS Sustainability analytics may request the NWDAF analytics information regarding the QoS change statistics for an Analytics target period in the past in a certain area or the likelihood of a QoS change for an Analytics target period in the future in a certain area. The consumer can request either to subscribe to notifications (i.e. a Subscribe-Notify model) or to a single notification (i.e. a Request-Response model). The service consumer may be a NF (e.g. AF). The request includes the following parameters:

• Analytics ID = "QoS Sustainability";
• Target of Analytics Reporting: any UE;
• Analytics Filter Information:
  • QoS requirements (mandatory):
    • 5QI (standardized or pre-configured) and applicable additional QoS parameters and the corresponding values (conditional, i.e. it is needed for GBR 5QIs to know the GFBR); or
    • the QoS Characteristics attributes including Resource Type, PDB, PER and their values;
  • Location information (mandatory): an Area Of Interest or a path of interest. The location information could reflect a list of waypoints:
    • if the location information is an Area Of Interest, the area can be either described in a coarse granularity as list of TAIs or Cell IDs, or in a fine granularity as geographical area (that can be smaller than a cell), or both (coarse and fine granularity); if both granularities are provided, the NWDAF understands that the area of interest is the intersection between the fine granularity location and the list of TAIs or Cell IDs.
    • if the location information is a path of interest, the area can be either described in a coarse granularity as list of TAIs or Cell IDs, or in a fine granularity as a list of waypoints (expressed as longitude and latitude in geographical coordinates) and combined with a radius value, or both (coarse and fine granularity); if both granularities are provided, the NWDAF understands that the path of interest is the intersection between the fine granularity location and the list of TAIs or Cell IDs.
    • Threshold linear distance: The distance travelled by the UE before reporting subsequent location as described in TS 23.273.
  • S-NSSAI (optional);
• Optional maximum number of objects;
• Optional UE Device and Context Information: which may contain one or more of the following:
  • Speed range, which is a range of UE speeds for which analytics is requested, where the speed range is indicated as a range of Velocity Estimate, as in clause 6.1.6.2.17 of TS 29.572;
  • Device information, which may contain one of the following:
    • List of equipment types, according to clause 8.0 of GSMA TS.06 [38].
• Analytics target period: relative time interval, either in the past or in the future, that indicates the time period for which the QoS Sustainability analytics is requested;
• Optionally, Spatial granularity size and Temporal granularity size;
• Reporting Threshold(s), which apply only for subscriptions and indicate conditions on the level to be reached for the reporting of the analytics, i.e. to discretize the output analytics and to trigger the notification when the threshold(s) provided in the analytics subscription are crossed by the expected QoS KPIs.
  • A matching direction may be provided such as crossed (default value), below, or above.
  • An acceptable deviation from the threshold level in the non-critical direction (i.e. in which the QoS is improving) may be set to limit the amount of signalling.
    The level(s) relate to value(s) of the QoS KPIs defined in TS 28.554, for the relevant 5QI:
    • for a 5QI of GBR resource type, the Reporting Threshold(s) refer to the QoS flow Retainability KPI;
    • for a 5QI of non-GBR resource type, the Reporting Threshold(s) refer to the RAN UE Throughput KPI and/or delay in RAN KPI as defined in TS 28.554.
• In a subscription, the Notification Correlation Id and the Notification Target Address.

To derive the QoS Sustainability analytics when the location information is an area of interest with coarse granularity (i.e. TAIs or Cell IDs):

• The NWDAF collects the corresponding statistics information on the QoS KPI for the relevant 5QI of interests from the OAM, i.e. the QoS flow Retainability or the RAN UE Throughput or delay in RAN as defined in TS 28.554 and average GTP metrics as defined in TS 28.552.

To derive the QoS Sustainability analytics when the location information is an area of interest with fine granularity (i.e. geographical area that can be smaller than a cell):

• The NWDAF derives the UE list for the area of interest with fine granularity by two steps, firstly based on an initial selection of the UE list in the corresponding coarse area from AMF, secondly based on finer granularity location data using LCS as described in clause 6.2.12, e.g. NWDAF can collect finer granularity location data of a UE using LCS and identify whether this UE is inside of the area of interest with fine granularity area, input data as defined in Table 6.9.2-2.
• The NWDAF can then collect the corresponding UE level information on the QoS KPI for the relevant 5QI of interests from the 5GC NF/OAM, i.e. input data as defined in Table 6.9.2-2.
• NWDAF derives QoS sustainability statistics or predictions for the area of interest with fine granularity by averaging these input data for all the UEs that are in the UE list.

To improve QoS Sustainability analytics, the NWDAF may additionally collect GTP metrics defined in Table 6.9.2-3. If the Analytics target period refers to the past:

• The NWDAF verifies whether the triggering conditions for the notification of QoS change statistics are met and if so, generates for the consumer one or more notifications.
• The analytics feedback contains the information on the location and the time for the QoS change statistics and the Reporting Threshold(s) that were crossed.

If the Analytics target period is in the future:

• The NWDAF detects the need for notification about a potential QoS change based on comparing the expected values for the KPI of the target 5QI against the Reporting Threshold(s) provided by the consumer in any cell in the requested area for the requested Analytics target period. The expected KPI values are derived from the statistics for the 5QI obtained from OAM. OAM information may also include planned or unplanned outages detection and other information that is not in scope for 3GPP to discuss in detail.
• The analytics feedback contains the information on the location and the time when a potential QoS change may occur and what Reporting Threshold(s) may be crossed.

To derive the QoS Sustainability analytics for a path of interest or for an area of interest with coarse granularity (i.e. TAIs or Cell IDs), the input data is listed in Table 6.9.2-1.

To derive the QoS Sustainability analytics for an area of interest with fine granularity (i.e. geographical area that can be smaller than a cell), additional input data is listed in Table 6.9.2-2.

Additionally, the NWDAF collects the following input (Table 6.9.2-3) according to measurements defined in clause 5.33.3 QoS Monitoring to Assist URLLC Service of TS 23.501 and IP-layer clause capacity and IP-layer available clause capacity definition from ITU-T Y.1540 [40] between UE, NG-RAN and UPF at GTP level.

The NWDAF outputs the QoS Sustainability analytics. Depending on the Analytics target period, the output consists of statistics or predictions. The detailed information provided by the NWDAF is defined in Table 6.9.3-1 for statistics and Table 6.9.3-2 for predictions.

The number of QoS sustainability analytics entries is limited by the maximum number of objects provided as part of Analytics Reporting Information.