Innovation and standardization in 5G have brought advancements to every facet of the cellular architecture. This ranges from the introduction of new frequency bands and signaling technologies for the radio access network (RAN), to a core network underpinned by micro-services and network function virtualization (NFV). However, like any emerging technology, the pace of real-world deployments does not instantly match the pace of innovation. To address this discrepancy, one of the key aspects under continuous development is the RAN with the aim of making it more open, adaptive, functional, and easy to manage. In this paper, we highlight the transformative potential of embracing novel cellular architectures by transitioning from conventional systems to the progressive principles of Open RAN. This promises to make 6G networks more agile, cost-effective, energy-efficient, and resilient. It opens up a plethora of novel use cases, ranging from ubiquitous support for autonomous devices to cost-effective expansions in regions previously underserved. The principles of Open RAN encompass: (i) a disaggregated architecture with modular and standardized interfaces; (ii) cloudification, programmability and orchestration; and (iii) AI-enabled data-centric closed-loop control and automation. We first discuss the transformative role Open RAN principles have played in the 5G era. Then, we adopt a system-level approach and describe how these Open RAN principles will support 6G RAN and architecture innovation. We qualitatively discuss potential performance gains that Open RAN principles yield for specific 6G use cases. For each principle, we outline the steps that research, development and standardization communities ought to take to make Open RAN principles central to next-generation cellular network designs.

翻译：5G的创新与标准化推动了蜂窝架构各个层面的进步，涵盖从引入新频段和无线接入网信令技术，到以微服务与网络功能虚拟化为核心的下一代核心网。然而，如同任何新兴技术，实际部署的节奏往往无法即时匹配创新的步伐。为弥合这一差距，持续演进的关键环节之一便是无线接入网，其目标是使其更加开放、自适应、功能化且易于管理。本文重点阐述了通过从传统系统向渐进式开放的开放无线接入网原则转型，从而拥抱新型蜂窝架构的变革潜力。这一转型有望使6G网络更具敏捷性、成本效益、能效与韧性，并催生大量新型应用场景，从对自主设备的泛在支持到在以往服务不足区域实现经济高效的扩展。开放无线接入网的原则涵盖：（i）采用模块化与标准化接口的分解架构；（ii）云化、可编程与编排能力；（iii）基于人工智能的数据驱动闭环控制与自动化。本文首先讨论开放无线接入网原则在5G时代所发挥的变革作用，随后采用系统级方法，阐述这些原则将如何助力6G无线接入网与架构创新。我们定性分析开放无线接入网原则为特定6G用例带来的潜在性能提升，并针对每条原则，概述研究、开发与标准化社区应采取的步骤，以使开放无线接入网原则成为下一代蜂窝网络设计的核心。