gNB

gNodeB

Radio Access Network

Introduced in Rel-15

5G NR base station providing radio interface to UE and connecting to 5GC.

Description

The gNodeB (gNB) is the 5G NR base station that provides the radio interface to User Equipment (UE). It handles functions similar to eNodeB but enhanced for 5G requirements including mmWave, massive MIMO, and flexible numerology.

gNB can be deployed in Standalone (SA) mode with 5GC or Non-Standalone (NSA) mode with LTE EPC (EN-DC). It supports split architecture (CU-DU) for flexible deployment scenarios.

Purpose & Motivation

The gNB was designed to:

- Support wide range of frequencies (sub-6 GHz to mmWave) - Enable flexible numerology for diverse use cases - Provide massive MIMO and beamforming capabilities - Support network slicing at RAN level

Key Features

  • Support for FR1 (sub-6 GHz) and FR2 (mmWave)
  • Flexible numerology (15-240 kHz SCS)
  • CU-DU-RU split architecture
  • Massive MIMO support
  • Beamforming and beam management
  • Network slicing awareness

Evolution Across Releases

Rel-15Initial

Initial gNB for NSA and SA deployment, CU-DU split

IAB (Integrated Access and Backhaul), NR-U (unlicensed)

NTN support, 52.6 GHz support, reduced capability (RedCap)

Defining Specifications

SpecificationTitle
NR and NG-RAN Overall Description
NG-RAN Architecture Description
NR RRC Protocol