What is gNB?
The gNB (gNodeB) is the 5G NR base station — the radio access node that provides the wireless interface between the 5G network and User Equipment (UE). It is the 5G equivalent of the 4G eNB and is the central element of the NG-RAN (Next Generation Radio Access Network).
How Does gNB Work?
The gNB is logically split into three units: the gNB-CU (Central Unit) handling SDAP, PDCP, and RRC protocols; the gNB-DU (Distributed Unit) handling RLC, MAC, and PHY-High; and the Radio Unit (RU) handling PHY-Low and RF. The gNB connects to the 5GC via the NG interface (N2 control, N3 user plane) and to other gNBs/ng-eNBs via the Xn interface. In Open RAN, the CU/DU/RU are from different vendors.
Use Cases
All 5G SA deployments connected to the 5GC, all 5G NSA deployments as the Secondary Node in EN-DC, private 5G campus networks.
3GPP / Standards Reference
3GPP TS 38.300 (NR Overall Description), TS 38.401 (gNB-CU/DU Split Architecture)
Related Terms
eNB | 5G | NR | AMF | Xn Interface | Open RAN | SA | NSA
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This glossary entry is part of the 5GWorldPro Complete 5G Glossary. To go deeper into 5G architecture and technology, explore our 5G Training courses.
