The Emerging 3GPP 6G RAN Architecture An Overview

Jul 16, 2026

Upload by Miles

The emerging 3GPP 6G radio access network (RAN) architecture evolves 5G NG-RAN while preserving modular base station benefits and multi-vendor interoperability. The core study theme is boundary selection, covering CU-DU and CU-CP/CU-UP interfaces, recognition of the radio unit (RU) as a distinct logical unit, and the RAN-core network interface design. For connectivity services, it favors point-to-point signaling over service-based interfaces, and maps open research areas including non-connectivity RAN-core interfaces, data collection frameworks, and AI for 6G RAN.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages7

Reading Time18 min

Introduction

5G RAN as the Baseline for 6G

Boundary Selection in 6G RAN

CU-DU Split and CU Interfaces

RU as a Distinct Logical Unit

RAN-core Interface: P2P vs SBI

Overview and Open Research Areas

The Emerging 3GPP 6G RAN Architecture: An Overview Xingqin Lin NVIDIA [Email: xingqinl@nvidia.com](Email: xingqinl@nvidia.com) Abstract—The 6G radio access network (RAN) architecture is emerging as a disciplined evolution of 5G RAN. The 5G baseline introduced modular base station, providing a flexible framework for diverse deployment scenarios and multi-vendor interoperability. The key architectural challenge for 6G RAN is topreserve these benefits while adapting the RAN to new deployment and service requirements. This article reviews the emerging 3GPP 6G RAN architecture with emphasis on boundary selection. It discusses central unit and distributed unit split enhancements, recognition of radio unit as a distinct logical unit, and the RANcore network interface study, where point-to-point signaling is favored over service-based interface for connectivity services. It also highlights open areas including RAN-core network interface for non-connectivity services, data collection framework, and artificial intelligence for 6G RAN. I. INTRODUCTION The architecture of the sixth generation (6G) radio access network (RAN) is beginning to take shape, as the 3rd generation partnership project (3GPP) Release-20 6G study progresses [1] . While much public discussion of 6G focuses on radio performance, spectrum, artificial intelligence (AI), and sensing, the long-term success of the system will depend equally on the architecture that surrounds it [2][3] . Architecture determineshow functions are placed, how network nodes interact, where interoperability is expected, and where implementation freedom is preserved [4] . These choices shape network deployment, vendor integration, migration strategy, and the ability to introduce new capabilities without creating unnecessary complexity [5] . The immediate architectural baseline for 6G is 5G next-generation RAN (NG-RAN) [6] . The 5G node B (gNB) introduced a modular structure based on the separation of central unit (CU) and distributed unit (DU) functions. It also introduced a further separation between control plane (CP) and user plane (UP) functions inside the CU. NG-RAN provided a flexible framework for diverse deployment scenarios and multi-vendor interoperability. The emerging 6G RAN architecture is expected to refine the NGRAN framework where the existing design is insufficient and strengthen it where 5G experience has revealed areas for improvement [1] . A central theme of the 6G RAN architecture study is boundary selection. Some boundaries are system-level interoperability points and therefore need to be specified in 3GPP. The CU-DU interface, the CU-CP/CU-UP interface, the RAN-core network (CN) interface, and the interface between 6G node B’s (i.e., aNBs) belong to this category [7] . They define how independently implemented functions can interoperate and how the RAN behaves as part of the end-toend system. Other boundaries are closer to product implementation and deployment specific optimization. These boundaries still matter architecturally, yet they are not always suitable for 3GPP protocol specification. The treatment of the radio unit (RU) illustrates this distinction. In the 5G gNB architecture, the standardized logical decomposition stops at the DU. RU and fronthaul are not visible in the 3GPP logical architecture. In 6G, the RU will be recognized as a distinct logical unit inside the aNB [8] . The recognition is intentionally scoped: the RU functions and the interface between the RU and the rest of the aNB remain outside 3GPP specification. As a result, open RAN (O-RAN) fronthaul, enhanced common public radio interface (eCPRI) based solutions, and proprietary fronthaul can coexist under the same 6G RAN architecture. The CU-DU split represents a different kind of boundary. Unlike the RU fronthaul, the CU-DU interface is expected to bea 3GPP-defined interface in 6G RAN [7] . Its value comes from pooling, flexible placement, and multi-vendor interoperability [9] .

FAQs

What is the central theme of the emerging 3GPP 6G RAN architecture study?

Boundary selection is the central theme, identifying which interoperability points must be specified in 3GPP and which should remain implementation- or deployment-specific.

How does 6G treat the radio unit (RU) compared with 5G?

6G recognizes the RU as a distinct logical unit inside the aNB, while intentionally keeping RU functions and the RU-to-aNB interface outside 3GPP scope.

What are the proposed options for the RAN-core (CN) interface in 6G?

For connectivity services, the emerging direction favors point-to-point (P2P) signaling between the aNB and CN entity rather than a service-based interface (SBI); service-style mechanisms may still be useful for non-connectivity services.

Jul 16, 2026

Upload by Miles