Section: 8.14.1.2 Signalling of RACH information from gNB-CU to gNB-DU
Content: The signalling flow for signalling of RACH information from gNB-CU to gNB-DU is shown in Figure 8.14.1.2-1, where the example where NG-RAN nodes exchange the RACH Report via the Xn: ACCESS AND MOBILITY INDICATION message has been considered. Figure 8.14.1.2-1 Example of signalling of RACH information from gNB-CU to gNB-DU in NG-RAN 1. A UE with a RACH Report concerning cells of gNB1 connects to a cell in gNB2 and it signals the RACH Report to gNB2 by means of the RRC UE Information Request/Response procedures. 2. GNB2 sends an Xn: Access and Mobility Indication message to gNB1-CU where the UE may have previously been connected. This includes also the RACH Report. 3. GNB1-CU sends the F1: Access and Mobility Indication message to the gNB1-DU, including the RACH Report. It is also possible for the gNB-CU receiving the RACH Report from the UE to signal it directly to the gNB-DU by means of the F1: Access and Mobility Indication procedure.