| 摘要 |
PURPOSE:To eliminate the waiting time between master equipment and a ground base station and to prevent a battery from being out by interrupting the reception between the master equipment mounted on an automobile and the ground base station when wireless child equipment is detected to be out of a usable range based on the intensity of a radio wave from the child equipment. CONSTITUTION:An electric field intensity measuring part 15 is connected through a sharing equipment 13 and a change-over switch 16 to an antenna 14, and measures the radio wave intensity from the child equipment. When the measured intensity is smaller than a received electric field corresponding value, that 'the child equipment moves out of the service area of the master equipment' is decided, and a transmission power source at the section of the NTT(Nippon Telegraph and Telephone Corporation) automobile telephone base station of the master equipment is turned off. Thus, the waiting time between the master equipment and the base station can be eliminated, and the battery can be prevented from being out. |
