| 摘要 |
PCT No. PCT/JP93/00013 Sec. 371 Date Sep. 2, 1993 Sec. 102(e) Date Sep. 2, 1993 PCT Filed Jan. 8, 1993 PCT Pub. No. WO93/14574 PCT Pub. Date Jul. 22, 1993.An optical transmission system allows quick switching to protection side transmitting and receiving circuits by providing sub optical or subsidiary transmitting and receiving circuits for each current side transmission unit and each protection side transmission unit. A controller or exerciser successively starts the sub optical transmitting circuits of the current side transmission units for a predetermined time when no fault is detected. When a fault is detected, the defective portion of the system is bypassed using the protection side transmission units and the sub optical transmitting and receiving circuits of the affected current side transmission units. In this manner, the time required for the received signal to stabilize is reduced to about 10 msec.
|
