Section: 5.12.2 Usage Data Reporting for Secondary RAT
Content: When NG-RAN is deployed in dual connectivity configuration, the HPLMN or VPLMN operator may wish to record the data volume sent and received on the Secondary RAT. In order to reduce the complexity of this procedure, the following principles are used in this release: a) The PLMN locally activates the Secondary RAT Usage Data Reporting by NG-RAN OAM. The activation is based on configuration in NG-RAN and NG-RAN determines whether the data volume report will contain data volumes consumed for the whole PDU Session or for selected QoS Flows or both as described in TS 38.413[ NG-RAN; NG Application Protocol (NGAP) ]  [34]. The activation can happen separately for Data Volume Reporting of NR in licensed or unlicensed spectrum and E-UTRA in licensed or unlicensed spectrum. If the PLMN uses this feature, it should ensure that this functionality is supported by all NG-RAN nodes that support NR or E-UTRA as a Secondary RAT. b) Depending on its configuration the NG-RAN reports uplink and downlink data volumes to the 5GC for the Secondary RAT (including the using of unlicensed spectrum for NR or E-UTRA) for the PDU Session or for selected QoS Flows or both and per time interval. c) During Xn handover and N2 handover, the source NG-RAN node reports the data volume to the 5GC. The reported data volume excludes data forwarded to the target RAN node. d) At the time of NG connection release, Secondary RAN Node change/release, deactivation of UP connection for a PDU Session, the NG-RAN node reports the data volumes to the 5GC. e) To assist "partial CDR" generation, NG-RAN OAM can instruct the NG-RAN to also make periodic reports (as described in clause 5.12.3) if no event has triggered a report before the period expires. NOTE 2: The timing of these periodic NG-RAN reports is not expected to align with the timing of partial CDR generation. Hence the frequency of NG-RAN reports might be greater than that of partial CDR generation. NOTE 3: RAN needs to be able to partition the measurements in a report to indicate usage that occurred before and after an absolute time. An example of the absolute time is that RAN is configured to partition data usage reports that occurred before and after midnight.