Section: 8.13.2.3 Management based MDT Activation in gNB-DU
Content: The signalling flow for Management based MDT Activation in gNB-DU is shown in Figure 8.13.2.3-1. Figure 8.13.2.3-1 Management based MDT Activation in gNB-DU 1. The gNB-CU-CP sends UE CONTEXT SETUP REQUEST message to the gNB-DU, including Management based MDT PLMN List. The message may include the Polluted Measurement Indicator IE. If the gNB-DU has received the Polluted Measurement Indicator IE, the gNB-DU includes the information contained in such indicator 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. 2. The gNB-DU sends UE CONTEXT SETUP RESPONSE message to the gNB-CU-CP. 3. The EM sends a Trace Session activation request to the gNB-DU. This request includes the parameters for configuring UE measurements. 4. The gNB-DU 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-DU 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, the gNB-DU may send CELL TRAFFIC TRACE message to the gNB-CU-CP in the F1 UE associated signalling, including Trace ID for MDT. 5. Upon reception of a CELL TRAFFIC TRACE message from F1, the gNB-CU-CP shall send CELL TRAFFIC TRACE message to the AMF for this 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].