| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a fault detection system capable of avoiding repetition of occurrence of a fault and restoration thereof due to an ALS function. <P>SOLUTION: An optical transmitter 1 wherein a fault takes place uses a non use byte of an overhead to transmit apparatus fault information to an opposite optical transmission apparatus 2 before stop of an optical output, and the opposite optical transmission apparatus 2 transfers the apparatus fault information by return to the faulty apparatus 1 by using the non use byte of the overhead before stop of the optical output. When the transferred apparatus fault information does not reach the faulty apparatus 1 within a prescribed time, the faulty apparatus 1 discriminates it to be the faulty apparatus, and masks detection of input interruption so as to maintain interruption of the optical output. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
