| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the wrong number of wavelengths from being transferred to a downstream node even when an optical add/drop apparatus enters a failure mode or when an erroneous signal is inserted to an inserting port because of a connection error or the like of an optical fiber by an optical add/drop part. <P>SOLUTION: A shut-down control part 607 is provided which monitors the temperature of an optical multiplexer 208 and, when a temperature monitor result indicates abnormality, brings an optical attenuator 210 to loss maximization. Further, in an optical add/drop part 202, an optical level change detecting circuit part 603 is provided for optical level monitors of individual channels. Furthermore, an optical level monitor 602 for all main signals is provided at the back of the optical multiplexer 208 and after mismatching in the number of wavelengths is detected by comparison with a total sum of optical level monitors 214 of individual channels, shut-down control is implemented to maximize a loss of the optical attenuator 210 only for the channel wherein an optical level change is detected by the optical level change detecting circuit part 603. <P>COPYRIGHT: (C)2011,JPO&INPIT |
