In this paper, we develop the first comprehensive tutorial on designing future 6G networks that synergistically integrate notions of resilience and criticality from the ground up. While resilience refers to the ability to absorb, adapt to, and recover from adversarial or challenging conditions, criticality indicates the degree of importance or urgency assigned to a particular service or component. Despite a spiking interest in designing resilient wireless networks, most prior works do not provide a unified resilience definition, nor harness the intricate interplay between resilience and criticality. In order to fill this gap, in this paper, we highlight the importance of a criticality-aware approach as a key enabler for providing reliable and resilient service functionality. Moreover, we delve into the unique challenges and opportunities of the envisioned 6G features pertaining to resilience and (mixed) criticality. After reviewing resilience definitions, we present a core resilience strategy, a unified resilience metric, different criteria for service criticality, and prioritization frameworks, that augment the 6G resilience prospects. Afterwards, we explore the opportunities presented by promising technologies that enable a resilient 6G network design from a radio access network protocol stack perspective. We briefly revisit state-of-the-art network architectures, establish a rough connection to the Open-RAN Alliance vision, and discuss opportunities, existing techniques, and promising enabling mechanisms for 6G at each layer. Finally, the article discusses important research directions and open problems concerning resilience and criticality in 6G.

翻译：本文首次系统性地阐述了如何从底层设计出发，将弹性与关键性概念协同整合到未来6G网络中。弹性指网络在对抗性或挑战性条件下吸收冲击、适应变化并恢复服务的能力，而关键性则指赋予特定服务或组件的优先级或紧急性程度。尽管设计弹性无线网络的研究兴趣日益高涨，但现有工作大多既未提供统一的弹性定义，也未充分利用弹性与关键性之间复杂的相互作用。为填补这一空白，本文强调关键性感知方法作为提供可靠弹性服务功能的关键使能因素的重要性。此外，我们深入探讨了6G愿景中与弹性和（混合）关键性相关的独特挑战与机遇。在回顾弹性定义后，我们提出核心弹性策略、统一弹性度量指标、服务关键性的不同判据以及优先级框架，以增强6G的弹性前景。随后，我们从无线接入网络协议栈的视角，探讨了有望实现弹性6G网络设计的前沿技术所带来的机遇。我们简要回顾了现有网络架构，初步建立了与Open-RAN Alliance愿景的关联，并逐层讨论了6G各协议层的机遇、现有技术及潜在使能机制。最后，本文探讨了6G弹性与关键性领域的重要研究方向与开放性问题。