| 摘要 |
PURPOSE:To improve the utilizing efficiency of a communication line and to decrease the number of communication lines, by installing plural unit lines in the unit of bidirectional communication lines and managing the lines in the unit of the bidirectional communication lines and in the unit of the unidirectional communication lines. CONSTITUTION:When a transmission communication terminal 1 makes a call and requests a communication to a receiving communication terminal 4, an exchange controller 22 checks an idle transmission unidirectional relay communication line data, catches an idle unidirectional relay communication line 10A and connects the communication lines 1A, 10A and 10A, 4A. When there exists no idle unidirectional relay communication line, an idle bidirectional relay communication line data is checked, a receiving unidirectional relay line 11B of an idle bidirectional relay communication circuit 11 is caught, and communication lines 2A, 11B and 11B, 5B are connected. When a transmission and receiving terminal 3 makes a call and requests a communication to a transmission and receiving communication terminal 6, the exchange controller 22 checks the idle bidirectional relay communication line data, catches the idle bidirectional relay line 11 and connects communication lines 7, 11 and 11, 8. |
