Free Space Optics Communication for Ultra-High-Speed Train Running in Evacuated Tube

This paper develops a novel communication method for an ultra-high-speed train that runs in an evacuated tube. The proposed method significantly reduces the number of needed base stations to provide adequate coverage and data rates. Moreover, the time connectivity for each base station was enhanced considerably. The proposed method can provide improvements in terms of transmitted power and received power, either fixed or variable; this method offers a fixed or variant data rate. Moreover, the paper studies the effects of the divergence angle on transmitted and received power. Additionally, the proposed communication procedure might produce a system with a fixed data rate, such as 1.25 Gbps. It can also create a design with adaptive divergence angles (that can be altered dynamically) depending on the train distance to the base station. The results show that this method is promising for working for an ultra-high-speed train that runs in an evacuated tube. It can reduce the base stations number from 500 to less than 10 base stations with respect to the data rate and power consumption. Furthermore, a new handover method is proposed and addressed in this work.