CU/DU/RU Split

In telecommunications, the CU/DU/RU split refers to the disaggregation of the gNB into a Central Unit (CU) hosting higher-layer protocols, a Distributed Unit (DU) hosting lower-layer real-time processing, and a Radio Unit (RU) handling RF. The split is connected by the F1 interface (CU-DU) and the fronthaul interface (DU-RU), and it underpins virtualized and Open RAN deployments.

Categories: Radio Access NetworkProtocols and StandardsCloud and Virtualization

CU/DU/RU Split in context

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

Telecom security is written into standards from 3GPP, GSMA, ETSI, IETF and ITU-T. Understanding which body owns which specification, and how they interlock, is essential for both design and audit work.

To place CU/DU/RU Split in the wider telecom-security picture, review O-RAN Alliance, Cloud RAN, RRH, ETSI ISG MEC, RIC and Open Fronthaul: each entry cross-references back to this page so you can walk the topic in either direction.

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