An Optical Communication Approach for Ultra-High-Speed Train Running in Evacuated Tube: Potentials and Challenges

Modern society demands a new kind of ultra-high-speed ground transportation, which can be achieved by evacuated tube transportation (ETT). However, conventional radio frequency communication is faced with serious Doppler spread and frequent handovers in such ultra-high-speed environments. Thus, in this article, a novel wireless communication system suitable for ETT is proposed, which is based on optical wireless communication (OWC). This system meets the requirements of ultra-high speed, high reliability, and low latency, while the OWC can effectively avoid Doppler spread in metal tubes by nature. In addition, a system structure with seamless connection is designed to improve system reliability by providing communication redundancy. Furthermore, a vehicle-centric handover-free method is proposed, which can effectively reduce the number of handovers, thereby decreasing system latency. Finally, the challenges and future research trends for ultra-high-speed trains are highlighted to provide insights on the potential future work for researchers in this field.