| 摘要 |
PROBLEM TO BE SOLVED: To realize a system that can effectively limit the use of a portable telephone at a specific place at a low cost by a method of high versatility. SOLUTION: The portable telephone control system consists of portable telephones 2 and a controller 3 that is installed at a place such as a train body at which use of the portable telephone 2 is limited, in which the telephones 2 and the controller 3 make wireless communication in compliance with the Bluetooth standards. When any of the telephones 2 approaches the controller 3, the controller 3 transmits an instruction signal denoting power-off to the telephone 2. The telephone 2 transmits a confirmation signal to the controller 3 by each prescribed time after turning off its power supply and the controller 3 transmits a control signal in response to the confirmation signal. When the telephone 2 cannot receive the control signal from the controller 3, the telephone 2 switches its power supply to an ON state. |
