Patent ID: 7409155
Filing Date: 2008-08-05
Classification: H04B,H04J,H04L

Abstract:
1. An optical transmission system for performing WDM optical transmission, comprising an optical transmission device and an optical reception device; wherein said optical transmission device includes, said optical reception device includes, wherein said first optical supervisory signal generated by said optical-supervisory-signal generation unit contains clock information as said information for use in determination of continuity of said optical transmission line, and said optical-supervisory-signal reception unit activates an APSD (Auto Power Shut Down) function based on the clock information, wherein, even when the level of the second optical-supervisory-signal varies and an error occurs in the second optical-supervisory-signal, the APSD function is not activated as long as the clock information can be extracted from the first optical-supervisory-signal, and wherein, only when said optical-supervisory-signal reception unit cannot extract the clock information from the first optical-supervisory-signal, said optical-supervisory-signal reception unit determines that a fiber failure has occurred, and activates the APSD function.