gNodeB

gNodeB, abbreviated as gNB, is the 5G NR base station in the next-generation radio access network (NG-RAN). It serves as the radio access point that links user equipment (UE) to the 5G core network (5GC) and supports the higher data rates, lower latency, and advanced features of 5G. The term mirrors the evolution from the LTE era, where eNodeB was the base station, to 5G where gNB is used for New Radio.

A gNB provides the radio interface, performs radio resource management, scheduling, modulation, coding, and beamforming, and interfaces with the core network to carry both control and user plane data. In modern deployments, a gNB can be implemented as a multi-part entity consisting of a central unit (gNB-CU) and one or more distributed units (gNB-DU), with possible further partitioning. This split architecture enables flexible deployment across centralized data centers and local radio sites while supporting advanced features like massive MIMO and multi-band operation.

Interfaces and deployment modes define how a gNB connects to other network elements. The gNB connects to UEs via the NR air interface. It communicates with the 5G Core through NG interfaces, specifically NG-C for control plane signaling and NG-U for user plane traffic. For inter-gNB coordination, the Xn interface is used. In standalone (SA) deployments, the gNB connects directly to the 5GC. In non-standalone (NSA) deployments, NR radios may operate with an existing 4G core (EPC) while relying on supplementary control-plane or user-plane paths as defined by the operator’s architecture.

gNBs are central to 5G networks, enabling high-speed, low-latency connectivity and network slicing through the flexible radio access and core integration enabled by 5G standards.