6G-Enabled Smart Railways
Bo Ai, Yunlong Lu, Yuguang Fang, Dusit Niyato, Ruisi He, Wei Chen, Jiayi Zhang, Guoyu Ma, Yong Niu, Zhangdui Zhong
TL;DR
This paper surveys the limitations of 5G in meeting the demands of future smart railways and articulates a vision for 6G-enabled, green, secure, and fully connected operations. It proposes an integrated 6G network architecture that fuses communications, computing, edge intelligence, sensing, and security across space–air–ground networks, with cross-domain channel modeling and advanced coverage strategies. Key contributions include detailed discussions of OTFS-based reliability in high-speed scenarios, RIS-assisted coverage, cell-free MIMO, THz/ISAC approaches, and endogenous security leveraging blockchain and digital twins. The work further outlines an array of security, privacy, edge intelligence, and digital twin innovations, along with future research directions and deployment considerations for robust, scalable, and secure 6G railways with real-world impact for autonomous operation, predictive maintenance, and passenger services.
Abstract
Smart railways integrate advanced information technologies into railway operating systems to improve efficiency and reliability. Although the development of 5G has enhanced railway services, future smart railways require ultra-high speeds, ultra-low latency, ultra-high security, full coverage, and ultra-high positioning accuracy, which 5G cannot fully meet. Therefore, 6G is envisioned to provide green and efficient all-day operations, strong information security, fully automatic driving, and low-cost intelligent maintenance. To achieve these requirements, we propose an integrated network architecture leveraging communications, computing, edge intelligence, and caching in railway systems. We have conducted in-depth investigations on key enabling technologies for reliable transmissions and wireless coverage. For high-speed mobile scenarios, we propose an AI-enabled cross-domain channel modeling and orthogonal time-frequency space-time spread multiple access mechanism to alleviate the conflict between limited spectrum availability and massive user access. The roles of blockchain, edge intelligence, and privacy technologies in endogenously secure rail communications are also evaluated. We further explore the application of emerging paradigms such as integrated sensing and communications, AI-assisted Internet of Things, semantic communications, and digital twin networks for railway maintenance, monitoring, prediction, and accident warning. Finally, possible future research and development directions are discussed.
