RAILWAY COMMUNICATION SYSTEM, ON-VEHICLE DEVICE, GROUND DEVICE AND COMMUNICATION CONTROL METHOD

摘要

PROBLEM TO BE SOLVED: To actualize low-cost communication means having secured reliability in a railway radio communication system.SOLUTION: A railway communication system 1 includes an on-vehicle device 20 and a ground device 30 that are communication connected by a communication channel N using a public radio communication service such as a mobile telephone network. Each of the on-vehicle device 20 and the ground device 30 transmits a message having an added transmission time by an internal clock, and on receiving a communication message, transmits (returns) a corresponding response message. From the relationship of the time series in regard to the transmission/reception time of the messages and a time difference thereof, a communication defect such as a communication delay and a communication interception and synchronization/asynchronization of the internal clocks are determined.