| 摘要 |
PURPOSE:To avoide the generation of a line disconnected state at the time of a fault generated in a signal distributing circuit. CONSTITUTION:A transmission terminal A is connected to a radio transmission system 11 and an optical transmission system 12 through the signal distributing circuit 13. The system 12 is directly connected to the transmission terminal A by the 1st and 2nd switching circuits 15, 16. When a fault such as the interruption of a power supply, etc., is generated in the circuit 13, the switching of the 1st and 2nd switching circuits 15, 16 is controlled by a control device (not shown) and the transmission terminal A is directly connected to the system 12. Consequently the generation of a line disconnected state is avoided even when a fault or the like is generated in the circuit 13. |
