SRLG Detection via One-Dimensional Backlight Power Analysis

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Solution Overview

Problem

Conventional methods for detecting shared risk link groups in optical networks face difficulties due to the complexity of analyzing three-dimensional polarization characteristics, making it challenging to determine whether links are in the same shared risk link group.

Innovation Solution

The method involves injecting a probe beam into test links, recording the power characteristics of the returned backlight, and calculating a resemblance value to determine if the links are in the same shared risk link group, using a one-dimensional power characteristic which is simpler and easier to apply compared to conventional three-dimensional approaches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional techniques using polarization characteristics are used to detect SRLGs, then the detection can identify links in the same shared risk link group, but the complexity of analyzing three-dimensional polarization characteristics makes the method difficult to implement

Engineering Contradiction:
Improvedetection accuracy of SRLGVSAvoidcomplexity of polarization characteristic analysis
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts only the necessary one-dimensional power characteristic information from the complex three-dimensional polarization characteristics. By using optical time domain reflectometry to measure only the power of backscattered light rather than analyzing full polarization states, the method obtains sufficient SRLG detection capability while dramatically reducing measurement and analysis complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms the detection from three-dimensional polarization space to one-dimensional power space. Instead of analyzing the complex three-dimensional polarization characteristics of optical links, the method projects the detection onto a single dimension by measuring only the power of backscattered light, thereby simplifying the detection process while maintaining effectiveness.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If three-dimensional polarization characteristics are analyzed to determine SRLG membership, then comprehensive link identification is achieved, but the difficulty of testing and analyzing the three-dimensional component increases implementation difficulty

Engineering Contradiction:
Improveprecision of SRLG identificationVSAvoiddifficulty of testing polarization characteristics
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent extracts only the necessary one-dimensional power characteristic information from the complex three-dimensional polarization characteristics. By using optical time domain reflectometry to measure only the power of backscattered light rather than analyzing full polarization states, the method obtains sufficient SRLG detection capability while dramatically reducing measurement and analysis complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses a simple, readily available optical time domain reflectometer to perform the measurement, replacing complex and expensive polarization analysis equipment. The method leverages the disposable nature of standard OTDR devices already present in optical networks, eliminating the need for specialized polarization measurement instruments.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If conventional polarization-based SRLG detection is implemented, then shared risk link groups can be identified, but the complexity and difficulty of application makes it less practical than simpler one-dimensional approaches

Engineering Contradiction:
Improvereliability of backup route allocationVSAvoidease of applying SRLG detection method
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent extracts only the necessary one-dimensional power characteristic information from the complex three-dimensional polarization characteristics. By using optical time domain reflectometry to measure only the power of backscattered light rather than analyzing full polarization states, the method obtains sufficient SRLG detection capability while dramatically reducing measurement and analysis complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the measurement parameter from three-dimensional polarization characteristics to one-dimensional power characteristics. This parameter transformation simplifies the detection method by replacing complex polarization state measurements with straightforward power measurements, making the system easier to operate and implement while maintaining reliability.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach allows for effective detection of shared risk link groups by analyzing the power characteristics of the backlight, enhancing the reliability of optical network services by ensuring main and backup routes are allocated to different shared risk link groups.

Implementation Method 1

Rayleigh backscattered light and Fresnel back-reflected light are collectively referred to as backlight

Methodology Applied
Scientific EffectRayleigh backscattering: Rayleigh Scattering

Implementation Method 2

Rayleigh backscattered light and Fresnel back-reflected light are collectively referred to as backlight

Methodology Applied
Scientific EffectFresnel back-reflection: Reflection

Data Source

PatentEP3259571B1Method and apparatus for detecting shared risk link groups
Publication Date: 2021.09.22 ALIBABA GROUP HOLDING LTD
  • EP3259571B1 patent drawingFigure 1~2
  • EP3259571B1 patent drawingFigure 3~4
  • EP3259571B1 patent drawingFigure 5~6

AI summary

A method and device for detecting shared risk link groups is disclosed. The method comprises injecting a probe beam, respectively, into a first test link and a second test link. The method further includes recording, respectively, a first curve of a time-varying first power corresponding to the first backlight and a second curve of a time-varying second power corresponding to the second backlight; calculating a resemblance value for the first curve and the second curve; and judging, based on the resemblance value, whether the first test link and the second test link are located in the same shared risk link group. The method and device for detecting shared risk link groups provided by embodiments of the present invention detect by testing a power characteristic of backlight of a probe beam in test links and, based on that one-dimensional power characteristic, judge whether the test links are in the same shared risk link group, which are simpler in application than those in the prior art.