A.15 Use case for QoS flow retainability-related KPI

28.5543GPP5G end to end Key Performance Indicators (KPI)Management and orchestrationRelease 18TS

QoS Flow is the key and limited resource for 5GS to deliver services. The release of the QoS flow needs to be monitored. QoS Flow drop ratio is a key performance indicator of how often an end-user is abnormally losing a bearer. This key performance indicator is of great importance to estimate the end users’ experiences.

The KPI shall be available per QoS group.

From QoS perspective it is important to focus also on call duration as in some cases wrong quality perceived by the end user is not fully reflected by drop ratio nor retainability KPI. Typical case is when due to poor radio conditions the end user redials (the call was terminated normally) to the same party to secure the quality. But in this case the drop ratio KPI will not show any degradation. Secondly, although the call is dropped the end user may or may not redial depending on dropped call duration compared to the case when the call would be normally released. It is therefore highly recommended to monitor distribution of duration of normally and abnormally released calls.