Submarine Optical Communication Control Device for Signal Intensity Distribution

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Solution Overview

Problem

In submarine optical communication systems, the fixed gain equalizers cannot set the signal light intensity of added signal light to an optimum value, leading to transmission characteristic degradation and suppressed frequency utilization efficiency due to uneven light intensity distribution after amplification.

Innovation Solution

A control device that determines the optimum signal light intensity distribution based on transmission characteristics, frequency utilization efficiency, and power spectral density, and adjusts the gain equalizer to compensate for measured light intensity deviations, ensuring optimal signal light intensity across the submarine cable transmission line.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If fixed gain equalizers are used to amplify signal light, then signal light intensity is amplified, but the light intensity distribution becomes uneven due to device variation

Engineering Contradiction:
Improvesignal light intensityVSAvoidlight intensity distribution
Core Design Contradiction:
PowerVSStability of the object's composition

Solution Approach 1:

The patent implements a feedback control mechanism where the control device measures the actual light intensity distribution of the optical path and uses this measurement to calculate appropriate gain equalization settings. The measured values are fed back to adjust the variable gain equalizer, creating a closed-loop system that compensates for device variation and maintains even light intensity distribution across different wavelengths.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent transitions from static fixed gain equalizers to dynamic variable gain equalizers that can adjust their characteristics based on measured conditions. The gain equalization settings are not fixed but are calculated and updated based on actual measurements of the light intensity distribution, allowing the system to adapt to variations and maintain optimal performance.

Inventive Principle:
Principle #15Dynamics

2Productivity

If wavelength addition is performed to increase communication capacity, then frequency utilization efficiency improves, but transmission characteristics degrade due to inability to set optimum signal light intensity

Engineering Contradiction:
Improvecommunication capacityVSAvoidtransmission characteristic
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the operating parameters of the variable gain equalizer based on measured light intensity distributions. By calculating gain equalization settings from measurements and applying these settings, the system optimizes the signal light intensity for each wavelength channel, ensuring that added wavelengths achieve their optimum input light intensity to the submarine cable and maintain reliable transmission characteristics.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If fixed gain equalizers are used, then device complexity is reduced, but frequency utilization efficiency is suppressed due to uneven light intensity distribution

Engineering Contradiction:
Improveequalizer structureVSAvoidfrequency utilization efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The system performs self-diagnosis and self-adjustment by measuring its own light intensity distribution and automatically calculating the appropriate gain equalization settings. The control device measures the actual performance, identifies deviations from optimal distribution, and adjusts the variable gain equalizer accordingly, enabling the system to maintain high frequency utilization efficiency without requiring complex manual configuration.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3780420B1Submarine optical communication control device, control method, and non-transitory computer-readable medium
Publication Date: 2023.08.09 NEC CORP
  • EP3780420B1 patent drawingFigure 1
  • EP3780420B1 patent drawingFigure 2
  • EP3780420B1 patent drawingFigure 3~4A

AI summary

A submarine optical communication system control device (1) according to the present invention includes: a light intensity distribution determination device (2) configured to determine an optimum distribution of signal light intensity of each optical path for each allocated frequency from a value of one of a transmission characteristic of the optical path, frequency utilization efficiency, a signal light power spectral density, and a waveform distortion compensation setting, or a combination of values thereof; a light intensity distribution measuring device (3) configured to measure a light intensity distribution of an optical path after transmission through a submarine cable transmission line; an equalization setting calculation unit (4) configured to calculate a gain equalization setting for compensating for the difference between an optimum distribution in the light intensity distribution determination device and a measured distribution in the light intensity distribution measuring device; and a variable gain equalizer (5) configured to compensate for a light intensity distribution of an optical path to the optimum distribution, based on a gain equalization setting in the equalization setting calculation unit.