5.33.3.1 General

QoS Monitoring for packet delay can be applied based on 3rd party application request or PCF policy control or both, e.g. to assist URLLC services. The packet delay between UE and PSA UPF is a combination of the RAN part of UL/DL packet delay as defined in TS 38.314 [120] and UL/DL packet delay between NG-RAN and PSA UPF. The NG-RAN is required to provide the QoS monitoring results on the RAN part of UL/DL packet delay measurement. The measurement of the UL/DL packet delay between NG-RAN and PSA UPF can be performed on different levels of granularities, i.e. per QoS Flow per UE level, or per GTP-U path level, subject to the operators' configuration.

The PCF generates the authorized QoS Monitoring policy for a service data flow based on the QoS Monitoring request received from the AF (as described in clause 6.1.3.21 of TS 23.503 [45]). The PCF includes the authorized QoS Monitoring policy in the PCC rule and provides it to the SMF.

When SMF receives the authorized QoS Monitoring policy for packet delay in a PCC rule from the PCF (as described in clause 6.1.3.21 of TS 23.503 [45]), SMF configures the UPF(s) and NG-RAN to perform delay measurements according to the method selected: per QoS Flow per UE QoS measurement (as described in clause 5.33.3.2) or per GTP-U Path measurement (as described in clause 5.33.3.3). The SMF configure the UPF to report the QoS monitoring results for the QoS Flow as described in clause 5.8.2.18 with parameters determined by the SMF based on the authorized QoS Monitoring policy received from the PCF and/or local configuration.

The UPF reporting behaviour for QoS Monitoring for packet delay of a QoS Flow is the same when per QoS Flow per UE level measurement (described further in clause 5.33.3.2) or when per GTP-U path level measurement (described further in clause 5.33.3.3) is used.