| 摘要 |
A two-way communication system that can improve the shorten the system recovery time by adjusting the transmission delay or transmission level before the operation of a subscriber station and shortening the system recovery time when a link switching operation between a center station and a relay station occurs, over two-way CATV networks, passive optical star networks and the like. A center station measures the round-trip propagation delay of a signal when a subscriber station starts its operation and then sets the transmission delay of the subscriber station so as to equalize the round-trip propagation delay measured for the subscriber station to a fixed system delay. When a link switching operation occurs from a working system to a stand-by system because of the occurrence of a failure in a relay transmission line, the center station measures the round-trip propagation delay of a signal for a subscriber station after the link switching operation and then resets transmission delays of all subscriber stations connected to the relay station at a time based on the difference between the measured delay and the round-trip propagation delay of a signal to the subscriber station before the link switching operation. |
