Foreword1 Scope2 References3 Definitions and abbreviations4 General principles5 General architecture6 NG-RAN architecture7 NG-RAN functions description8 Overall procedures in gNB-CU/gNB-DU Architecture8.1 UE Initial Access8.2 Intra-gNB-CU Mobility8.2.1 Intra-NR Mobility8.2.2 EN-DC Mobility8.2.3 Intra-CU topology adaptation procedure8.2.4 Intra-CU topological redundancy procedure8.2.5 Intra-CU Backhaul RLF recovery for IAB-nodes in SA mode8.3 Mechanism of centralized retransmission of lost PDUs8.4 Multi-Connectivity operation8.4.1 Secondary Node Addition8.4.2 Secondary Node Release (MN/SN initiated)8.4.3 SCG suspend/resume in RRC_INACTIVE8.4.4 SCG Deactivation and Activation8.5 F1 Startup and cells activation8.6 RRC state transition8.7 RRC connection reestablishment8.8 Multiple TNLAs for F1-C8.9 Overall procedures involving E1 and F18.9 Overall procedures involving E1 and F18.9.1 UE Initial Access8.9.2 Bearer context setup over F1-U8.9.3 Bearer context release over F1-U8.9.4 Inter-gNB handover involving gNB-CU-UP change8.9.5 Change of gNB-CU-UP8.9.6 RRC State transition8.9.7 Trace activation/deactivation over F1 and E18.9.8 BH RLC channel establishment procedure8.9.9 Traffic Mapping8.9.10 IAB-node release8.9.11 IAB-node OAM8.9.12 Handling of IAB-MTs in INACTIVE State8.9.13 IP Address Allocation for IAB-nodes8.10 Multiple TNLAs for E18.11 Support of Network Sharing with multiple cell-ID broadcast8.12 IAB-node Integration Procedure8.13 Overall procedures for MDT8.14 Self-optimisation8.15 Overall procedures for NR MBS8.16 Overall procedures for CPAC8.17 IAB Inter-CU Topology Management8.17.1 IAB Inter-donor-DU Re-routing8.17.2 IAB Inter-CU Topology Redundancy8.17.3 IAB Inter-CU Topology Adaptation8.17.4 IAB Inter-CU Backhaul RLF recovery for single connected IAB-node8.18 Overall procedure for Small Data Transmission during RRC Inactive8.19.1 Remote UE initial access8.19.2 Remote UE RRC Reestablishment8.19.3 Remote UE RRC Inactive to other states8.19.4 Service Continuity for L2 U2N relay8.20 Void8.19 Overall procedures for L2 UE-to-Network Relay9 Synchronization10 NG-RAN interfaces11 Overall procedures in NG-RAN Architecure 8.20 Void 38.4013GPPArchitecture descriptionNG-RANRelease 17TS Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM