| 摘要 |
PURPOSE:To make it possible to use the same transmission frequency by each base station, by making odd- and even-number base stations alternately send out a free line signal and a selective calling signal from the control station to plural base stations communicating with the mobile station. CONSTITUTION:When the circuit is disengaged, a free line signal VC is sent out to the mobile station 1 alternately from the odd- and even-number base stations 2-n (n: 1, 2...) under the control of the control device 4 of the control station 3. At the same time, a zone discriminating signal ZS which is different in each base station is also sent out. In case when the control station calls the mobile station 1, the signal VC is stopped, and a selective calling signal SL corresponding to the mobile station 1 is sent out alternately from the odd- and even-number base stations. When the mobile station has received the signal SL, it sends out a base station designating signal SD corresponding to the signal ZS, and a monitor signal SV showing whether it is up or down. The control station fixes the circuit by receiving the signal SD, and stops a transmitting radio wave from the base stations in the zones before and after the base station which is in the course of communication. When the mobile station has moved, the control staion cuts off the radio wave in the previous zone by changing it to the zone which is strong in the receiving electric field intensity. |
