unctional splitting NG-RAN protocol architecture Interface protocols (Xn, NG, F1) NG-AP and Xn procedure NG-RAN and 5G-NR Chapter Designation Content Search cell Access procedure Data transmission procedure Radio access procedure Session management Secondary node establishment Beam management Attachment Frequency band Multiplexing structure Reference signals: PSS, SSS, CSI-RS, Physical layer of the 5G-NR PT-RS, RIM-RS interface Physical signals: PSS, SSS Physical channels: PBCH, PDCCH, PDSCH, PMCH, PUSCH, PUCCH, PRACH Carrier aggregation Operations on frequency bands SUL mode Dual connectivity SU-MIMO MU-MIMO Beamforming Multi-antenna structure Massive-MIMO Antenna port Channel measurement reports Beam management BWP initial Bandwidth partition CORESET#0 BWP switching SDAP protocol PDCP protocol Data link layer RLC protocol MAC protocol Structure protocol NG-RAN procedure Information systems RRC protocol Connection control Measurements Broadcasting control April 2021 NG-RAN Network - Functional Architecture 1.1. Functional architecture NSA/SA Unlike previous generations of mobile networks, the deployment of 5G does not require the simultaneous implementation of the 5G core network (5GC) and the NG-RAN (Next-Generation Radio Access Network). NSA (Non-Standalone Access) and SA (Standalone Access) are two 5G network models: - SA is a completely new core service-based architecture: each radio node is autonomously controlled by the 5G core network. A service-based architecture delivers services as a set of NFs (Network Functions). NFs in the 5G core network are cloud native; - NSA relies either on the 4G core network or on the 5G core network. NSA anchors the control signaling to the core network through a radio MN (Master Node). The MN is either a 4G radio node or a 5G radio node. The MN controls an SN (Secondary Node) (4G radio node or 5G radio node) according to the DC (Dual Connectivity) mechanism. The 5G-SA architecture requires the deployment of a 5G core network connected to the NG-RAN. The 5G-NSA architecture 