Channel switching system for use in a digital communication system

Abstract

A channel switching method and system for a digital communication system including a repeater station linked with first and second stations and including first and second regular channels and a standby channel in each direction between the repeater station the first and second stations, one of the regular channels being a regenerative relay channel and the other being a dropping/insertion channel. A first control signal is generated upon the detections of a fault on the first regular channel and a non-fault on the standby channel at the second station. A first control signal is then transmitted from the second station to the first station through the repeater station. The second station is then informed of the presence or absence of a fault on the standby channel between the first station and the repeater station by at least the first control signal. A digital signal is transmitted over the first regular channel and the standby channel simultaneously in response to the first control signal at the first station. The standby channel between the first station and the repeater station is then connected by the repeater station to the standby channel between the repeater station and the second station in response to a third control signal produced in response to the second control signal at the repeater station. After the connection is made, a fourth control signal is transmitted to the second station, whereupon the first regular channel is switched over the standby channel.