5.7.2.4.1 General

The QoS Parameter Notification control indicates to the NG-RAN that notifications of "GFBR can no longer (or can again) be guaranteed" are requested when the NG-RAN determines that the GFBR, the PDB or the PER of the QoS profile cannot be fulfilled (or can be fulfilled again) for a QoS Flow (during the lifetime of the QoS Flow) and that the QoS Flow should be kept while the NG-RAN is not fulfilling the requested QoS profile. Notification control may be used for a GBR QoS Flow if the application traffic is able to adapt to the change in the QoS (e.g. if the AF is capable to trigger rate adaptation).

The NG-RAN determination whether the GFBR, the PDB and the PER can be fulfilled or not, is done under consideration of the QoS parameters Averaging Window and MDBV (for a GBR QoS Flow using the Delay-critical resource type), which are either provided explicitly as part of the QoS profile or implicitly via the standardized 5QI QoS characteristics defined in clause 5.7.4.

The SMF shall only enable Notification control when the QoS Notification Control parameter is set in the PCC rule (received from the PCF) that is bound to the QoS Flow. The Notification control parameter is signalled to the NG-RAN as part of the QoS profile.

If the NG-RAN has received the PDU Set QoS parameters PSDB and PSER for UL and/or DL (as described in clause 5.7.7) and PDU Set based QoS Handling is applied in the respective direction(s), the NG-RAN uses the PSDB and PSER instead of the PDB and PER in the respective direction(s) for the actions described in all (sub) clauses of clause 5.7.2.4. If the PDU Set based QoS Handling, PSER and PSDB are applied in one direction only, the NG-RAN still uses the PDB and PER in the other direction for the actions described in all (sub) clauses of clause 5.7.2.4 and clause 5.7.1.2a.