6.9 QoS Sustainability Analytics

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

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

6.9.1 General

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 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);

NOTE 1: In this Release, the consumer of the "QoS Sustainability" Analytics ID will provide location information in the area of interest format (TAIs or Cell IDs or geographical area) which is understandable by NWDAF.

NOTE 2: When location information is described as an area of interest in a fine granularity (i.e. as geographical area that can be smaller than a cell) the Cell ID(s) can already be determined by the NEF based on its local configuration and provided to the NWDAF in addition. This addresses the scenario when Cell ID(s) cannot be determined by the NWDAF based on its local configuration. Alternatively, the NWDAF can also be configured with the Cell ID(s) corresponding to an area of interest in a fine granularity.

– S-NSSAI (optional);

– Optional maximum number of objects;

– 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;

– 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 [10], 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.

– 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 as defined in TS 28.554 [10].

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 based on finer granularity location data from LCS, e.g. NWDAF can collect finer granularity location data of a UE from LCS and identifies whether this UE is inside of the area of interest with fine granularity area.

– 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.

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.

6.9.2 Input data

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.

Table 6.9.2-1: Data collection for "QoS Sustainability" analytics

Information	Source	Description
RAN UE Throughput	OAM TS 28.554 [10]	Average UE bitrate in the cell (Payload data volume on RLC level per elapsed time unit on the air interface, for transfers restricted by the air interface), per timeslot, per cell, per 5QI and per S-NSSAI.
QoS flow Retainability	OAM TS 28.554 [10]	Number of abnormally released QoS flows during the time the QoS Flows were used per timeslot, per cell, per 5QI and per S-NSSAI.

NOTE: The timeslot is the time interval split according to the time unit of the OAM statistics defined by operator.

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.

Table 6.9.2-2: UE level data collection for "QoS Sustainability" analytics with fine granularity

Information	Source	Description
Timestamp	LCS	A time stamp associated with the collected information.
UE ID	LCS	SUPI.
Finer granularity location data	LCS	UE position in the area of interest.

Editor’s note: Other input data is FFS.

6.9.3 Output analytics

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.

Table 6.9.3-1: "QoS Sustainability" statistics

Information	Description
List of QoS sustainability Analytics (1..max)
>Applicable Area	A list of TAIs or Cell IDs within the Location information that the analytics applies to.
>Applicable Time Period	The time period within the Analytics target period that the analytics applies to.
>Crossed Reporting Threshold(s)	The Reporting Threshold(s) that are met or exceeded or crossed by the statistics value or the expected value of the QoS KPI.

Table 6.9.3-2: "QoS Sustainability" predictions

Information	Description
List of QoS sustainability Analytics (1..max)
>Applicable Area	A list of TAIs or Cell IDs within the Location information that the analytics applies to.
>Applicable Time Period	The time period within the Analytics target period that the analytics applies to.
>Crossed Reporting Threshold(s)	The Reporting Threshold(s) that are met or exceeded or crossed by the statistics value or the expected value of the QoS KPI.
>Confidence	Confidence of the prediction.

NOTE 1: The meaning of Confidence is based on the SLA, i.e. the consumer has to understand the meaning of the different values of Confidence.

NOTE 2: The Analytics can contain multiple sets of the above information if the location information reflected a list of waypoints.

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

6.9.4 Procedures

Figure 6.9.4-1 depicts a procedure for "QoS Sustainability" analytics provided by NWDAF.

Figure 6.9.4-1: "QoS Sustainability" analytics provided by NWDAF

1. The consumer requests or subscribes to analytics information on "QoS Sustainability" provided by NWDAF. The parameters included in the request are described in clause 6.9.1.

The consumer may include multiple sets of parameters in order to provide different combinations of "Location information" and "Analytics target period" when requesting QoS Sustainability analytics.

2. The NWDAF collects the data specified in clause 6.9.2 from the OAM, following the procedure captured in clause 6.2.3.2.

3. The NWDAF verifies whether the triggering conditions are met and derives the requested analytics. The NWDAF can detect the need for notification based on comparing the requested analytics of the target 5QI against the Reporting Threshold(s) provided by consumer in any cell over the requested Analytics target period.

4. The NWDAF provides response or notification on "QoS Sustainability" to the consumer.