gNodeB (Next Generation Node B)

Also known as: gNB, Next Generation NodeB

The gNodeB is the 5G NR base station, the radio node that terminates the 5G air interface to the UE. It connects to the 5G core over the NG interface (N2 to the AMF, N3 to the UPF), with Xn between neighbouring gNodeBs. In a disaggregated Open RAN deployment it splits into O-CU, O-DU and O-RU. As the entry point to the 5G network, its fronthaul, management plane and NGAP/NAS handling are core to RAN security.

Categories: Radio Access NetworkCore NetworkSignaling

gNodeB in context

The radio access network is the layer where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations, downgrade attacks and jamming, and defenses hinge on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

The mobile core is where subscriber sessions, mobility and policy live. In 4G it is the EPC (MME, HSS, S/PGW); in 5G it is the Service-Based Architecture with AMF, SMF, UPF, AUSF, UDM and the NRF. Core exposure is the difference between a single-subscriber leak and a fleet-wide breach.

To place gNodeB in the wider telecom-security picture, review eNodeB, AMF, UPF, NGAP, Xn Interface and O-CU.

Related terms

Equipment

Base stations (BTS, NodeB, eNodeB, gNodeB)

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