With the large-scale deployment and commercialization of the fifth-generation (5G) wireless communication system, the sixth-generation (6G) wireless communication system has gradually become a new focus in the field of wireless communication. In June 2023, the International Telecommunication Union (ITU) defined the new application scenarios of 6G, including the integrated AI and communications, the integrated sensing and communications, and the ubiquitous connectivity, delving deeper into intelligent perception, seamless connectivity, and profound integration with other domains. Anticipated for full commercialization by 2030, the ongoing standardization efforts for 6G-related technologies urgently require breakthroughs in foundational 6G theories to guide the standardization process of 6G channel models.

Wireless channel modeling is the foundation for the design, theoretical analysis, performance evaluation, optimization, deployment, and standardization of wireless communication systems. The standardization of each generation of wireless communication technology has always started with the standardization of channel models. Future wireless communication will aim for global coverage in space, air, ground, and sea, with base stations and users tending to move in three-dimensional (3D) continuous-space, and antennas deeply coupled with the propagation environment. The future wireless channels are evolving from discrete local space wireless propagation channels to 3D continuous-space radio channels. This trend presents challenges in channel modeling, capacity analysis, antenna design, channel map construction, and transmission system optimization. To address these challenges, it is necessary to introduce new channel modeling theories and methods. These new theories will be grounded in traditional methods such as geometry-based stochastic channel modeling, ray tracing channel modeling, and beam domain channel modeling, while integrating AI-based predictive channel modeling, digital twin channel modeling, channel map construction and communication system optimization, and electromagnetic information theory-enabled 3D continuous-space radio channel modeling. These studies will contribute to the standardization of 6G channel models, the research of 6G common theoretical technologies, and the system fusion construction. Through these efforts, we will promote the continuous advancement of wireless communication technology, providing more stable, efficient, and intelligent solutions for future global communication networks.