5.37.10.2 Time to Next Burst marking

The time to next data burst, which is the interval between the transmission of the last PDU in the current data burst and the first PDU of the next data burst, may be provided to the NG-RAN by the UPF to assist NG-RAN's behaviour in downlink. As described in clause 6.1.3.27.5 of TS 23.503 [45] the PCF may include a Time to Next Burst Marking Indication within a PCC Rule to request the UPF to identify and mark the time to next data burst for the corresponding QoS Flow. The PCF also includes the DL Protocol Description received from AF.

Based on the Time to Next Burst indication in a PCC Rule, the SMF instructs the UPF to identify and mark the time interval to next data burst in downlink. The SMF may provide the UPF the Protocol Description used by the service data flow received in the PCC Rule.

According to the Time to Next Burst indication and DL Protocol Description from the SMF, the UPF identifies the time interval to next data burst carried in an N6 RTP Header Extension/transport protocol header as defined in TS 26.522 [179] and sends the identified time interval to next data burst to NG-RAN in a downlink GTP-U header.

Time to next data burst marking is only used when the deployment is such that the time to next data burst is sufficiently accurate i.e. the jitter (e.g. the N6 jitter) is sufficiently limited without impact to the accuracy of the time to next data burst.