PURPOSE: To perform a shift to loop back and one-way loop conditions with high reliability in a loop network composed of two one-way circuits when a fault occurs in the transmission system.
CONSTITUTION: An input signal level detecting circuit and frame synchronism detecting circuit are provided in each node 1∼4 and, when these detecting circuits detect a fault in circuits, the signal of a normal loop is turned back while supplying signals to the loop, in which the fault is detected. When, for example, the clockwise loop between the nodes 2 and 3 is faulty, the turned- back signal from the node 3 is received at the node 4 and the synchronism of the clockwise loop is established. Then inputs of the clockwise loop are outputted to the clockwise loop and inputs of the counterclockwise loop are outputted to the counterclockwise loop. Thereafter, the synchronism between the node 4 and center node 1 is established in the same way and two transmission systems in which the sections between the remote node 4 and remote node 3 are set to turning-back modes are established.
OIKAWA YOSHINORI
MASUDA MICHINORI
ONO KENZO
FUKUCHI YOSHIRO
OKAMOTO HIROSHI
MATSUSHITA ELECTRIC IND CO LTD
MATSUSHITA COMMUNICATION IND
| JPS58114644A | 1983-07-08 | |||
| JPS5957544A | 1984-04-03 | |||
| JPS58111545A | 1983-07-02 | |||
| JPS57109439A | 1982-07-07 |