| 摘要 |
PROBLEM TO BE SOLVED: To obtain a technical means utilizable technically and economically for preventing a portable terminal to perform radio transmission and reception from being carried into a facility or a location which is easy to receive failure caused by electromagnetic wave in a state of power source on. SOLUTION: An external control system is formed of a transmitter for control to send out an external control signal, and a portable terminal provided with a detecting means and processing means of the external control signal. The transmitter for control transmits the external control signal of a predetermined structure as a radio signal. The external control signal is the control signal including an operating state changeover command of the portable terminal, such as turn off, communication function stop and communication function recovery. An output antenna of the transmitter for control is installed in a passage of gateways, such as a hospital and an aircraft. The portable transmitter for control limits using of the portable terminal in the facility, when an attendant carries it and goes round.
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