Towards 6G Architecture: Key Concepts, Challenges, and Building Blocks

We are entering the standardization phase for the 6th generation (6G) of wireless technologies. While valuable lessons have been learned from the design, deployment, and operation of 5G and Beyond in Europe, new requirements, emerging technologies, and evolving business models must be natively integrated into the next-generation mobile network architecture.This white paper presents a comprehensive snapshot of the current architectural considerations explored by the Smart Networks and Services Joint Undertaking (SNS-JU) projects. It aims to discuss the rationale for novel architectural components, the ongoing design efforts, and the future outlook for 6G.We analyse the blueprint for next-generation mobile networks, building on past experiences while integrating cutting-edge advancements. The structure follows the IMT-2030 framework, categorizing insights into the key usage scenarios and overarching architectural aspects.- Usage Scenarios: We analyse the evolution of IMT-2030 paradigms, focusing on Immersive, Massive, and Hyper-Reliable Low-Latency Communications. We also explore novel 6G enablers, such as Ubiquitous Connectivity, AI-driven Communication, and Integrated Sensing & Communication.- Overarching Aspects: The next-generation architecture must natively embed Security, Privacy & Trustworthiness, Sustainability, and Network Exposure Capabilities—ensuring these critical aspects are foundationally considered rather than retroactively incorporated.Finally, we conclude by outlining the essential building blocks shaping the next-generation mobile network architecture, highlighting the most promising research paths identified in this white paper.