KR20150064636A

KR20150064636A - Fault detection method in PON optical cable using the correction waveform and reference waveform

Info

Publication number: KR20150064636A
Application number: KR1020130149570A
Authority: KR
Inventors: 엄종훈; 정창수; 이남훈; 서주환
Original assignee: 주식회사 크레블
Priority date: 2013-12-03
Filing date: 2013-12-03
Publication date: 2015-06-11

Abstract

The present invention relates to an optical distributor for a PON optical cable line as a component of a PON communication line, a monitoring device for measuring a PON optical line according to a measurement scheduler using OTDR (Optical Time Domain Reflectometer) ; It is a PON surveillance system that includes a monitoring server that analyzes the measured waveform of the PON optical cable measured by the surveillance system, detects the line failure by analyzing the reference waveform and the corrected waveform, and confirms the fault location based on the GIS.

Description

[0001] The present invention relates to a fault detection method using a PON optical cable reference waveform and a correction waveform,

Optical cables are most likely to fail due to artificial disasters such as road construction, excavation works and vehicle accidents, and natural environments such as typhoons and floods. Environmental factors cause optical cable failures such as bending, cracking, wear and deterioration . The failure of the optical cable is measured by measuring the optical cable using the back scattering waveform of the OTDR of the monitoring device and analyzing the measured waveform to analyze the failure point of the PON cable. However, in the ONT subscribers, many OTT waveforms are lost in the ONT subscriber section, and the ONT waveforms are overlapped. Therefore, the conventional OTDR waveform analysis method can significantly reduce the failure analysis efficiency of the optical cable.

An object of the present invention is to provide a PON dedicated optical cable monitoring system capable of accurately and promptly grasping a failure of an ONT optical cable line of an optical distributor and a plurality of PON subscribers of a PON optical cable and recovering a faulty line.

According to an embodiment of the present invention, a surveillance system compares a waveform measured using an optical time domain reflectometer (OTDR) technique of a monitoring device with a reference waveform, Y-axis error correction function that corrects new measured waveform by error compared to basically set error range, X value is compared at peak of light distribution point, and new measurement waveform is corrected by error when out of the set error range Peak detection of the PON ONT subscriber measurement waveform using the X side correction function and the X and Y side correction waveforms.

According to an aspect of the present invention, there is provided a surveillance system, comprising: an OTDR measurement waveform of a monitoring device; A function of peak detection in information (within an error range); Finding a maximum value for each ONT subscriber section and determining whether a maximum value is an actual waveform peak; The peak value of the correction waveform for each ONT section can be stored and the fault detection section can be set.

According to an aspect of the present invention, there is provided a surveillance system comprising: a fault detection function for each PON ONT section by comparing a peak detection value of an OTDR measurement correction waveform of a monitoring apparatus with a reference waveform value for each fault detection interval; When the threshold value of the correction waveform is exceeded, ONT failure information such as bending or cutting can be expressed in the GIS.

According to the technical idea of the present invention, it is possible to accurately and quickly grasp the fault of the ONT optical cable line of the PON optical cable and the optical distributor of many PON subscribers, and to repair the faulty line.

1 is a configuration diagram showing a monitoring system according to the present invention.
2 is a functional block diagram showing the configuration of a monitoring apparatus and a monitoring server applied to the present invention.
3 is a flowchart illustrating a monitoring method according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a block diagram of a PON network monitoring system. The optical cable is composed of an OFD / FDF section, an OFD / FDF section and an ONT subscriber section in an OLT. The monitoring device consists of an OTDR and a monitoring device controller that can measure the optical cable. The monitoring server is composed of a monitoring system that corrects the wavelength measured by the monitoring device and detects the PON optical cable failure through peak detection of the waveform . The user can control the monitoring device via the web and measure the optical cable failure by measuring the PON optical cable.

2 is a functional block diagram of the monitoring apparatus and the monitoring server system. The monitoring device consists of a control part that can control the OTDR, transmit the measured waveform, and control the switch. The surveillance system consists of a measurement waveform analysis module measured by OTDR in the monitoring device, a waveform correction module for correcting the waveform based on the X / Y axis, a waveform peak detection module for detecting the optical distribution box and the optical distribution fringe waveform peak, detection data module, fault detection module that detects faults by comparison with reference waveforms and thresholds, GIS & Topology fault notification module that notifies users of alarm information based on GIS based on GIS, and external interlocking system module for data interworking service with other systems .

FIG. 3 is a failure logic of a surveillance system that detects a fault by detecting an optical cable failure section based on a correction waveform and a peak detection method, using a measurement waveform measured in an OTDR in a PON monitoring system. After comparing the measurement waveform measured by OTDR with the reference waveform, the correction waveform peak detection is performed after correcting the measurement waveform when the X, Y axis threshold is exceeded. PON ONT Find the maximum value for each subscriber section and determine whether the maximum value is actually the peak of the corrected waveform. If the correction waveform of each PON ONT section is peak, the peak value is stored and the fault detection section is set. The reference waveform and the correction waveform are compared to detect a fault for each section. When the corrected waveform and peak information exceed the threshold value, the optical cable is detected to be bent or cut, and the fault information is output to the GIS.

Claims

Compares the measured waveform with OTDR (Optical Time Domain Reflectometer) technology of the surveillance device and compares it with the reference waveform, compares the Y value with the set offset length, and corrects the newly measured waveform by an error Y-axis error correction function;
X-side correction function that compares new measured waveform with error by comparing the X value at the peak of peak of light distribution point, and detects peak detection of PON ONT subscriber measurement waveform with X and Y side correction waveform.

Based on the corrected waveforms corrected for OTDR measurement waveforms of the surveillance device, the optical splitting point has the function of detecting the peak at the first peak-up point and the optical distribution point distance (within the error range) after the Off Set distance; Finding a maximum value for each ONT subscriber section and determining whether a maximum value is an actual waveform peak; The monitoring system stores the peak value of the correction waveform for each ONT section and sets the fault detection interval.

OTDR measurement of the monitoring device After storing the peak detection value of the correction waveform, the fault detection function of each PON ONT section by comparing with the reference waveform value per fault detection section; A surveillance system that expresses ONT fault information such as bending, cutting, etc., in the GIS when the corrected waveform exceeds a threshold value.