The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 25, 2022
Filed:
Apr. 25, 2019
Nec Corporation, Tokyo, JP;
NEC CORPORATION, Tokyo, JP;
Abstract
An optical detection unit detects a return light and outputs a detection signal. An optical multiplexer/demultiplexer outputs the monitoring light to the optical transmission line, and outputs the return light to the optical detection unit. A processing unit detects a first timing at which the detection signal becomes less than a first threshold value, detects a second timing at which the detection signal becomes less than a second threshold value, and calculates a first change rate of the detection signal in a period between the first and second timings. The processing unit changes the first and second threshold values to calculate the first change rate for a plurality of periods, and, when a second change rate between the first change rates in two adjacent periods is greater than a threshold value, either of the first and second timings in one period is detected as the breakage position.