gNodeBs

gNodeB, commonly abbreviated as gNB, is the 5G NR radio access network node that terminates the air interface and provides the radio link between user equipment and the core network. It is the successor to the LTE eNodeB (eNB) and is defined by 3GPP in the 5G NR specifications. A gNB can be deployed as a single unit or in a distributed configuration that splits radio functions across units such as a centralized unit (gNB-CU) and distributed units (gNB-DU). This split supports edge deployment and scalable performance.

The primary role of a gNB is to manage radio resources, perform scheduling, modulation, coding, beamforming, and multiple-input multiple-output operations, and handle radio protocol functions across the NR stack. It interfaces with the core network via NG interfaces, with NG-C handling control plane signaling and NG-U carrying user plane traffic. In standalone (SA) deployments, the gNB connects directly to a 5G Core (5GC). In non-standalone (NSA) deployments, the gNB can operate with an existing LTE network to provide NR access while control and user plane traffic may traverse an evolved core or a converged core solution.

gNBs are deployed across a range of cell sizes, from macro to small cells, and are often part of ultra-dense networks in urban areas. They support features such as carrier aggregation, beamforming, dynamic spectrum sharing, and, in some architectures, network slicing. Overall, the gNB forms the radio access portion of the 5G system, enabling high data rates, low latency, and flexible connectivity.