Section: 8.13.2.2 Management based MDT Activation in gNB-CU-CP
Content: The signalling flow for Management based MDT Activation in gNB-CU-CP is shown in Figure 8.13.2.2-1. Figure 8.13.2.2-1 Management based MDT Activation in gNB-CU-CP 1. The EM sends a Trace Session activation request to the gNB-CU-CP. This request includes the parameters for configuring UE measurements. 2. The gNB-CU-CP shall select the suitable UEs for MDT data collection. If the UE is not in the specified area or if the serving PLMN is not within the Management Based MDT PLMN List the UE shall not be selected by the gNB-CU-CP for MDT data collection as defined in TS 32.422[ Telecommunication management; Subscriber and equipment trace; Trace control and configuration management ]  [20]. For each selected UE, if the gNB-CU-UP should perform MDT measurement, the gNB-CU-CP sends TRACE START message to the gNB-CU-UP, including MDT configuration parameters. 3. For each selected UE, if the gNB-DU should perform MDT measurement, the gNB-CU-CP sends TRACE START message to the gNB-DU, including MDT configuration parameters. 4. The gNB-CU-CP may send CELL TRAFFIC TRACE message to the AMF for the selected UE, including Trace ID for MDT. The AMF forwards Trace ID and other information to the TCE as specified in TS 32.422[ Telecommunication management; Subscriber and equipment trace; Trace control and configuration management ]  [20]. If the UE reports an indication of measurement pollution, the gNB-CU-CP shall, if supported, include such indication as part of the measurement report to be sent to the TCE so that the TCE is able to correlate and filter the affected measurements.