gNB
gNodeB: the 5G NR base station that provides the radio interface to UEs and connects to the 5G Core via the NG interface.
The gNB is where 3GPP started cleaning up the radio architecture. Unlike the LTE eNB, which was a single monolithic box, a gNB is usually split into functional units: a Central Unit (CU) running the higher layers, one or more Distributed Units (DU) handling the lower-layer real-time work, and Radio Units (RU) out at the antenna. That split is what lets operators centralise baseband in a regional hub while keeping radios close to subscribers.
The CU itself separates into CU-CP and CU-UP — control plane and user plane — so signalling and data can scale independently. Toward the core, the gNB speaks NG to the 5GC (NG-C to the AMF, NG-U to the UPF), and toward neighbouring gNBs it uses Xn for handover and dual connectivity. If you work O-RAN, this same gNB is what gets decomposed across the open fronthaul and the RIC.
Frequently asked questions
- What's the difference between a gNB and an eNB?
- An eNB is the LTE base station; a gNB is the 5G NR one. Beyond the radio technology, the gNB introduced the CU/DU/RU functional split, separate control- and user-plane CUs, and the NG interface to the 5G Core instead of the S1 interface to the EPC. In NSA deployments the two coexist — an eNB acts as master node and a gNB (called an en-gNB there) as the secondary node.
Related terms
Related comparisons
Want to truly understand gNB? Learn it in context.
A free account opens all 13 courses — 404 video lessons, labs and full practice exams — for 7 days, no card. Prime Membership keeps them and adds the certification exam and a verifiable certificate.
- 7 days of every course
- Then the first module, free
- No card needed
- TELCOMA since 2009
Get one 5G/LTE engineering deep-dive a fortnight
One thing explained properly every other Tuesday — a real failure, and the lab or trace where you work it yourself. No spam, no marketing, just engineering. Unsubscribe in one click.