| 摘要 |
PROBLEM TO BE SOLVED: To prevent wasteful traffic (packet) from flowing into a ring network at execution of squelching. SOLUTION: The network is provided with a plurality of transmitters connected to enable to transmit both in the incoming and outgoing directions in a ring shape, and work band and protection band are allocated in each direction. When there is a fault in a transmission line, a transmission signal is relieved by looping back using the protection band in the network. The transmitter monitors the fault in the transmission lien between an insert transmitter and a drop transmitter. The insert transmitter inserts the packet, inputted from the lower-order group side into the higher-order group signal and delivers it to the transmission line, and the drop transmitter extracts the packet from the higher-order signal and delivers it to the lower-order group side. When the communication is unrelievable due to the faults in the transmission line, the insert transmitter stops transmitting of the packet to the transmission line. |
