Overview of Interfaces

This page describes all interfaces within an O-RAN environment.

Interface	Connected Components	Description
A1	Non-RT RIC ↔ Near-RT RIC	Provides policy-based guidance, AI/ML model updates, and enrichment information from Non-RT RIC to Near-RT RIC.
E2	Near-RT RIC ↔ O-CU / O-DU	Enables real-time control and monitoring of RAN functions via xApps, supporting RAN optimization.
F1	O-CU ↔ O-DU	Splits centralized and distributed units, carrying both control-plane (F1-C) and user-plane (F1-U) data.
E1	O-CU-CP ↔ O-CU-UP	Separates control-plane and user-plane within the O-CU for flexible deployment.
Open Fronthaul	O-DU ↔ O-RU	Transports digitized I/Q samples and control signaling, based on the 7-2x functional split.
N2	O-CU-CP ↔ 5G Core (AMF)	Handles control-plane signaling for mobility, session, and authentication management.
N3	O-CU-UP ↔ 5G Core (UPF)	Carries user-plane traffic between RAN and the 5G Core UPF.
O1	SMO ↔ All O-RAN Components	Used for management, configuration, and orchestration of O-RAN elements by the Service Management and Orchestration layer.
O2	SMO ↔ Cloud Infrastructure	Interface between SMO and cloud platforms for managing virtualized RAN functions and resources.