| 摘要 |
PROBLEM TO BE SOLVED: To judge and inform the propriety of communication inside an area before a slave station originates a call, to eliminate a useless operation and to effectively utilize radio waves by judging the propriety of connection by free line signals and squelch signals. SOLUTION: A part between a master station l and the slave station A2 and the slave station B3 is composed of the MCA system of two or more channels and the slave station A2 and the slave station B3 receive the free line signals and the squelch signals transmitted from the master station 1. In the control parts 4 and 8 of the respective slave stations 2 and 3, the signals are judged and the propriety of the communication inside the area is judged. The result is informed to the display devices 6 and 10 of the telephone sets 5 and 9 of the respective slave stations 2 and 3. Also, calling sound 7 to be listened to at the time of picking up a handset is provided for two kinds and discrimination is performed by that as well. When the slave station A2 originates the call to the slave station B3 inside the same area, the propriety is judged by the display device 6 of the telephone set 5, and when negative, a connection operation is not performed to save dead time. Even when the display device 6 is overlooked, confirmation is attained by the calling sound 7. |
