| 摘要 |
<p>Provided is a switching device which achieves switching of an active signal line when unusable as a transmission line to a switching destination which is a definitely usable backup signal line. Also provided is a transmission system that utilizes the switching device. When at least one active signal line for transmitting a main signal has become unusable as a transmission line, multiple backup signal lines transmit multiple forms of monitor signals not only in the forward direction but also in the reverse direction relative to the transmission direction of the main signal to monitor the states of the multiple backup signal lines in advance, and the monitoring results are shared by respective devices via a control signal line. This ensures that only a definitely usable backup signal line can be selected from among the multiple backup signal lines as the switching destination, leading to reliable securing of a transmission line in the event of a failure, thus improving the reliability of the transmission system.</p> |
