5G • RAN
gNodeB (gNB)
Next Generation NodeB
The 5G NR base station that connects 5G devices to the 5G Core network over the air interface (Uu) and backhaul (NG).
Technical Explanation
The gNodeB is the 3GPP 5G New Radio (NR) radio access base station node. It terminates the 5G NR air interface protocols (SDAP, PDCP, RLC, MAC, PHY) toward User Equipment (UE) and provides connectivity to the 5G Core Network via the NG interface (NG-C / N2 to AMF, NG-U / N3 to UPF). A gNodeB can be deployed as a monolithic unit or split into disaggregated components: Centralized Unit (CU-CP, CU-UP) and Distributed Unit (DU) communicating over the F1 interface, connected to Radio Units (RU) over open fronthaul.
Key Functions
- Radio Resource Management (radio bearer control, admission control, scheduling)
- Advanced Multi-Antenna processing (Beamforming, Massive MIMO, Spatial Multiplexing)
- Dynamic allocation of resources in uplink and downlink (scheduling)
- Header compression, user data encryption, and SDAP-based QoS mapping
- Inter-cell mobility and dual connectivity coordination via Xn interface
Specifications
3GPP TS 38.300, TS 38.401
Interfaces
Uu (Air Interface to UE)N2 (Control to AMF)N3 (User plane to UPF)Xn (Inter-gNB)F1 (CU-DU)
Related 5G Concepts
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