5.8.2.6.2 Activation of Usage Reporting in UPF

Triggered by the PCC rules received from the PCF or preconfigured information available at SMF, as well as from the CHF for online charging method via quota management mechanisms, the SMF shall provide Usage Reporting Rules to the UPF for controlling how usage reporting is performed.

The SMF shall request the report of the relevant usage information for Usage Monitoring, based on Monitoring Keys and triggers which are specified in TS 23.503 [45]. Each Usage Reporting Rule requested for usage monitoring control is associated with the PDR(s) whose traffic is to be accounted under this rule. The SMF shall generate the Usage Reporting Rule for each Monitoring-key within the active PCC Rule(s), either preconfigured or received from the PCF and also shall keep the mapping between them. Multiple Usage Reporting Rules may be associated with the same PDR.

The SMF shall request the report of the relevant usage information for offline and online charging, based on Charging keys and additional triggers which are specified in TS 32.255 [68]. Each Usage Reporting Rule requested for offline or online charging is associated with the PDR(s) whose traffic is to be accounted under this rule. The SMF shall generate the Usage Reporting Rule for each Charging key and Sponsor Identity (if applicable) within the active PCC Rule(s), either preconfigured or received from the PCF and also shall keep the mapping between them. Multiple Usage Reporting Rules may be associated with the same PDR.

The SMF function shall also provide reporting trigger events to the UPF for when to report usage information. The reporting trigger events (e.g. triggers, threshold information etc.) shall be supported for the PDU Session level reporting as well as on Rule level basis as determined by the SMF. The triggers may be provided as a volume, time or event to cater for the different charging/usage monitoring models supported by the TS 23.503 [45] for usage monitoring and by TS 32.255 [68] for converged offline and online charging. The SMF shall decide on the thresholds value(s) based on allowance received from PCF, CHF or based on local configuration. Other parameters for instructing the UPF to report usage information are defined in TS 29.244 [65].

When the PCC Rule attribute Service Data flow handling while requesting credit (specified in TS 23.503 [45]) indicates "non-blocking", the SMF shall request the report of the relevant usage information for the Charging key and Sponsor Identity (if applicable) and provide a default threshold value to the UPF while waiting for the quota from the CHF.

In some cases, the same Usage Reporting Rule can be used for different purposes (for both usage monitoring and charging), e.g. in the case that the same set of PDR(s), measurement method, trigger event, threshold, etc. apply. Similarly a reported measurement can be used for different purposes by the SMF.