Signal quality monitoring system and method

摘要

A signal quality monitoring method which can rapidly identify the location of a failure is disclosed. In a WDM network composed of a plurality of elements, each of the repeaters detects signal transmission quality for a corresponding transmission line based on a section quality check information included in a transmission signal received from the preceding element. After replacing the section quality check information with a new computed section quality check information, the repeater transmits a second transmission signal to a following element. When receiving a quality request from another element, the repeater transmits the signal transmission quality to the element originating the request.