User-Centric Access Network (UCAN) for 6G: Motivation, Concept, Challenges and Key Technologies

A universal and flexible network architecture is required to meet the demands for optimal user experience and all coverage types including wide area coverage and ultra-dense coverage in 6G. In this paper, a powerful network architecture, the user-centric access network (UCAN), is proposed to meet the multi-dimensional demands of 6G. After analyzing the motivations and requirements, we introduce the concept, architecture, and networking scenarios of UCAN. UCAN has four distinct features including deeply customized network, elastic reconfigurable network, open and compatible network, and intelligent adaptive network for user services. In deployment, flexible cell can be constructed and updated for a user with the suitable surrounding access points. The challenges and corresponding key technologies to achieve UCAN are then illustrated to include user-centric access and connection management, dynamic AP management, unified management of interference and resource, and lightweight security. Then a simulation result is given to verify the effectiveness of UCAN. Finally, future works are discussed to indicate the research directions for academia and industry.