摘要 |
In a signal transmission system having a number of routing nodes and in which traffic is carried by a number of optical carriers, an additional supervisory optical carrier carries node identifiers. A large transmission network contains many nodes, with several alternative routes between them, and a routing fault can be difficult to detect. The use of node identifiers on an optical carrier to identify those nodes at which it has been re-routed assists in the rapid identification of system errors. <IMAGE> |