Usage Reporting

UPF measures the volume and the time usage of all traffic for the PDU session or the corresponding service data flows. UPF sends the accumulated usage report in either the PFCP Session Report Request or the PFCP Session Modification Response to SMF. Then, SMF includes one or multiple accumulated usage reports in the "accuUsageReports" attribute in one of the following messages towards PCF.

  • HTTP POST message

    Note

    This message also includes the "US_RE" value in the "repPolicyCtrlReqTriggers" attribute.

  • Message to include the SM Policy Delete Data data structure during the terminate procedure.

Each AccuUsageReport data structure includes the accumulated usage within one or two usage report information elements. These elements are corresponding to a usage monitoring control instance that PCF requested. If the PCF provides both volume and time thresholds and the threshold for one of the measurements reaches, then the UPF communicates this event to the SMF along with the accumulated volume and time measurements. Then, SMF sends the accumulated usage since the last report to PCF for both the measurements.

The SMF receives the accumulated usage report from UPF in the PFCP Session Report Request. After receiving this report, the SMF identifies the list of usage report corresponding to the usage monitoring control instance. Then, SMF posts a PDU Modify or PDU Dedicated bearer procedure. This procedure includes new event type, list of usage reports, and the list of URRs to process them.