What is Open RAN?
Open RAN is the movement to replace traditional closed, single-vendor RAN architectures with open, standardised interfaces between RAN components (RU, DU, CU), enabling multi-vendor interoperability and disaggregation. It is one of the most significant structural changes in the telecom industry, reducing operator dependence on a handful of dominant RAN suppliers.
How Does Open RAN Work?
Open RAN defines open interfaces at every internal RAN boundary: the F1 interface (between CU and DU, standardised by 3GPP), the E1 interface (between CU-CP and CU-UP), and the O-RAN Fronthaul (between O-DU and O-RU, specified by the O-RAN Alliance). The O-RAN Alliance additionally defines the RAN Intelligent Controller (Near-RT RIC and Non-RT RIC) for AI/ML-driven network optimisation via xApps and rApps.
Use Cases
Multi-vendor RAN deployments reducing vendor lock-in, AI/ML-driven RAN optimisation (interference management, energy saving, mobility optimisation), cloud-native RAN on commercial-off-the-shelf (COTS) servers.
3GPP / Standards Reference
O-RAN Alliance Specifications (WG1-WG11), 3GPP TS 38.401 (NG-RAN Architecture — CU/DU Split)
Related Terms
O-RAN | C-RAN | Fronthaul | gNB | RAN
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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.
