Method for monitoring failure

Abstract

Abstract PURPOSE:To adopt a failure monitoring method specified to an optical communication system, by retrieving an intermediate repeater having a failure, depending on the difference of optical characteristics between a failure monitor light transmitted from a master station and a reflexed receiving light. CONSTITUTION:If a failure takes place in intermediate repeaters 14-1-14-n and an optical signal is reflexed at any of optical changeover switches 15-1-15-n corresponding to the repeaters, a receiving level at an optical receiver 22 is any of P1-Pn and the level difference is decreased as (Pr-P1),...(Pr-Pn). Since the receiving levels are proportional to the length of fiber, the relation of P1> P2>...>Pn is established. A decision circuit 23 recognizes the generation of failure at first since each level difference of the reflexed optical signal received and that transmitted is not (Pr-P0), and then detects the actual level difference, from the level of which the failure of the intermediate repeater is retrieved.

Inventors

• 👤 Shinji Kiyota
• 👤 清田　眞司

Bibliographic Details