Patent ID: 6041216
Filing Date: 2000-03-21
Classification: H04B

Abstract:
A radio communications system for use by trains in a tunnel, comprising:an antenna subsystem for receiving and sending RF signals, including:a surface antenna located beyond the tunnel portals thereof at either end thereof;a radiating coaxial cable located in and along the length of the tunnel;plural bi-directional, in-line amplifiers disposed along the length of said Radiating coaxial cable at predetermined intervals for amplifying RF signals therein;a monitoring repeater and a control repeater, and an interface for joining said monitoring repeater and said control repeater to said Radiating coaxial cable, wherein said interface corrects RF levels as said RF signals are received by said Radiating coaxial cable;a monitoring subsystem, including:an EOT device for sending a first status signal at a first predetermined interval and for receiving a second status signal;a HOT device for sending said second status signal at a second predetermined interval and for receiving said first status signal, wherein said antenna subsystem receives and transmits said first and second status signals when the train is at least partially in the tunnel; anda control subsystem, including:a control encoder located in a control train engine for encoding control input signals for said engine;a control transmitter for transmitting a control signal generated from the encoded control input signal;a control receiver located in a controlled train engine for receiving said control signal; anda control decoder for decoding said control signal into a control input signal for controlling said controlled engine.