| 摘要 |
PURPOSE:To return a mobile equipment in a speech zone by attenuating or stopping the radiation of a radio wave once when a fixed station discriminates the mobile equipment to be at the outside of the speech zone and activating a circuit identifying the electric field strength of the mobile equipment forcedly, thereby informing the presence of outside of the speech zone to the user. CONSTITUTION:When an arrived radio wave from a mobile equipment 2 inputted from the reception antenna 12 of a stationary station 1 to a radio reception circuit 10 reaches the setting level of an electric field strength identification circuit 11 or below, a control circuit 7 interrupts a switching circuit 14, interrupts the power supply of a transmission circuit 18 to bring the state into the stop state, the radiation of a radio wave is stopped and a call circuit 5 keeps the speech state. Since the radio wave from the stationary station 1 is interrupted in the mobile equipment 2, a carrier detection circuit 23 identifying the electric field strength outputs a signal being outside of the speech zone to the control circuit 16 and the control circuit 16 activates a buzzer 26 and an LED 27 to apply visual and audible announcement to the user for the presence at the outside of the speech zone. Thus, the return into the speech zone is urged and the interruption of the speech is avoided. |
