Section: 5.37.8.2 Periodicity and N6 Jitter Information associated with Periodicity
Content: In the procedures for setting up or updating an AF session with QoS, the 5G System may be provided with UL/DL Periodicity information for NG-RAN to configure UE power management for connected mode DRX. The UL/DL Periodicity information is provided by the AF to the PCF via NEF or directly to the PCF when the AF is trusted. If UL/DL Periodicity information is available at the PCF, the PCF sends the Periodicity information received from the AF/NEF to the SMF. In accordance with the operator's local policies, the PCF may include an indication for SMF to request the UPF to perform N6 Traffic Parameter(s) measurement (i.e. N6 Jitter Information associated with the DL Periodicity and if not provided by the AF, UL/DL periodicity) within the PCC Rules. Upon reception of a PCC rule with Periodicity information, the SMF determines the TSCAI and forwards it to the NG-RAN. If the PCC rule indicates to perform N6 Traffic Parameter measurements, the SMF shall request the UPF to monitor and periodically report the N6 Traffic Parameters (i.e. the N6 Jitter Information associated with the DL Periodicity and, if not provided by the AF, UL/DL periodicity) using the N4 Session Modification procedure, see clause 5.8.5.11. If the measurement of N6 Jitter Information associated with the DL Periodicity is required and the DL Periodicity is available at the SMF, the SMF also sends the DL Periodicity to the UPF. The UPF reports the measured N6 Traffic Parameters to SMF via N4 interface. NOTE 1: How the UPF derives the N6 jitter and periodicity (i.e. when periodicity is not provided by the AF) is implementation dependent. At reception of measured N6 Traffic Parameter(s) from the UPF in the N4 Session Level Report, the SMF includes the N6 Jitter Information associated with the DL Periodicity together with the DL periodicity and the UL periodicity if not provided by the AF in the TSCAI and forwards it to the NG-RAN in an NGAP message, see clause 5.27.2. NOTE 2: In order to prevent frequent updates from the UPF, the UPF sends the N6 Jitter Measurement Report periodically or only when the N6 jitter is larger than a threshold. The N6 Jitter Information associated with the DL Periodicity indicates the range of the positive or negative deviation of the arrival time of first arrived packet of a Data Burst compared to the ideal Data Burst start time which is be determined based on the DL periodicity.