| 摘要 |
PURPOSE:To attain the connection or disconnection with an optical transmission line only with an optical signal by detecting the presence of a change in an optical signal outputted from a terminal equipment, deciding whether or not the connection with an optical network is implemented and applying the connection control between the terminal equipment and the optical network. CONSTITUTION:When terminal equipments 3a, 3b fitted to an optical transmission line 5 are operated, optical signals 7a, 7b are outputted respectively and inputted to optical switches 11a, 11b and detection instruction sections 9a, 9b. The detection instruction sections 9a, 9b detect the presence of a change in the optical signal and when there is any change in the optical signal, the terminal equipments 3a, 3b are regarded to be in normal operation and the instruction is issued to the optical switches 11a, 11b so as to be connected to an optical transmission line 5. When no change exists in the optical signal, it is discriminated that a fault takes place in the terminal equipments 3a, 3b and the instruction is issued to be disconnected from the optical transmission line 5 and optical signals 7a, 7b are looped back to the terminal equipments 3a, 3b. Thus, the connection or disconnection between the optical transmission line 5 and the terminal equipments 3a, 3b with the optical signal only is implemented. |
