Node of an optical transmission network and transmission maintenance procedure after a network failure

摘要

The optical node comprises two working directional switches (22,27) connected serially in a primary ring line (2), respectively ahead of and after an extracting and/or inserting unit (11), and further connected serially in a secondary ring line (3), which are adapted to controllably switch the optical signal path between the primary ring line (2) and the secondary ring line (3), and to the extracting and/or inserting unit (11). The node further comprises two backup directional switches associated with the working directional switches and connected operatively in the primary (2) and secondary (3) ring lines to restore the optical node (10) to proper operation on the occurrence of a failure at the working directional switches. IMAGE