High-Speed Train System
Trains that have wireless communication capabilities, either for on-board customer use or transport communication services, typically operate in RF bands. With the emergence of FSO technologies, researchers modeled and simulated various broadband FSO wireless communication systems to replace the current RF bands. Most models are designed for both above-ground and underground applications. The base stations typically interface with the fiber-optic backbone network of the city or area at 1550nm and are predicted to reach link speeds of 155 Mbps or more. 
For above-ground applications, transceivers are mounted on the roof of trains and mobile base stations are positioned on the track. The transceivers are pointed opposite the direction of travel of the train. The base stations are pointed in the direction of travel of the train and are stationed at regular intervals. For underground applications, base stations are mounted on the roof of the tunnel at regular intervals. Transceivers are mounted to the roof of trains and are angled up at the ceiling to transmit and receive data.