Optical Link Anomaly Localization from Power Difference Profiles

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Solution Overview

Problem

Existing optical time-domain reflectometers (OTDRs) for monitoring optical links are costly, require special hardware configurations, and lack real-time capability for ultra-long haul links, necessitating lengthy averaging times for complete information.

Innovation Solution

A method and apparatus using signal and reference power profiles to determine power loss and location of anomalies in optical links by calculating difference and derivative profiles, enabling real-time monitoring with improved accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If OTDR is used for monitoring optical links, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improveanomaly detection precisionVSAvoidhardware configuration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a virtual copy of the OTDR functionality by using digital signal processing on existing optical power monitoring data. Instead of requiring physical OTDR hardware, the system processes power profile data through algorithms that simulate OTDR anomaly detection, thereby achieving similar measurement precision without the complex hardware configuration

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical/optical hardware system (OTDR with filters and couplers) with a digital signal processing system. By substituting physical measurement hardware with computational algorithms that process existing power monitoring data, the system achieves anomaly detection precision comparable to OTDR while eliminating the need for complex hardware configurations

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If OTDR averaging is performed for ultra-long haul links, then measurement precision is improved, but productivity deteriorates

Engineering Contradiction:
Improveoptical loss measurement precisionVSAvoidreal-time monitoring capability
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent performs preliminary action by continuously collecting and storing optical power profile data in the background without interruption. This pre-collected data is then processed by algorithms that can quickly identify anomalies and calculate optical losses, providing real-time monitoring results without requiring hours of averaging time

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent transforms the static, time-consuming OTDR averaging process into a dynamic real-time monitoring system. By continuously updating power profiles and applying differential algorithms, the system adapts to changing network conditions and provides immediate anomaly detection and optical loss calculation, enabling real-time monitoring for ultra-long haul links

Inventive Principle:
Principle #15Dynamics

3Reliability

If OTDR works on out-of-band channel, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvenetwork amplifier disruption avoidanceVSAvoidspecial hardware configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the existing optical power monitoring system multi-functional by enabling it to perform both its original function (power monitoring) and OTDR-like anomaly detection using the same hardware infrastructure. The digital signal processing algorithms analyze existing power profile data to identify anomalies and calculate losses, eliminating the need for separate OTDR hardware while maintaining reliability

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3982559B1Method and apparatus for estimating the location and power loss of anomalies along an optical link
Publication Date: 2026.05.20 NOKIA SOLUTIONS & NETWORKS OY
  • EP3982559B1 patent drawingFigure 1
  • EP3982559B1 patent drawingFigure 2~3
  • EP3982559B1 patent drawingFigure 4~5

AI summary

The location and power loss of anomalies along an optical link are determined from a distance-wise signal power profile along the optical link and a reference signal power profile. A distance-wise power difference profile between the reference signal power profile and the signal power profile is calculated. A derivative of the power difference profile is calculated. An anomaly indicating a power loss in the optical link is identified from the difference profile. The estimated location of the anomaly is determined from the derivative. An estimated power loss of the anomaly is determined from the difference profile and the estimated location.