| 摘要 |
The network includes several nodes connected by first communication links to transfer information. The nodes and the first link are arranged in an annular configuration. Each node is connected to only two neighbouring nodes through a counterclockwise first link and a clockwise first link. One of several second links is provided parallel to each first link. The nodes include switches which are arranged so that in the case where all first nodes are correct and transmit information, the switch has such positions that the second links between the nodes all are connected to form a closed loop. - The switch is also arranged so that in the case of a failure of a first link between two nodes the information to be transferred is transferred through all second links except the second link parallel to the first link that has a failure. The information will have to travel through all nodes and all second links. In the case where all first links are correct and transmit information light propagates along the closed loop. The light along the closed loop has an intensity or a power different from the intensity or power respectively of light which carries information on the first links. |
