Passive Optical Network Amplification Device for Bidirectional Signal Extension

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Solution Overview

Problem

Passive optical access networks face limitations in range due to optical power losses and the inability to amplify signals effectively, particularly in rural areas where subscribers are farther from optical exchanges, leading to inadequate high-speed transmission.

Innovation Solution

A passive optical network design with bidirectional transmission capabilities, utilizing a first and second passive amplification medium excited by an optical amplification signal, with adjustable optical power gain to compensate for varying optical losses in different directions of transmission, allowing for dynamic adaptation to changes in the network.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a single optical fiber is used for bidirectional transmission to reduce network costs, then network cost is reduced, but optical power loss increases and transmission range is limited

Engineering Contradiction:
Improvenetwork costVSAvoidoptical power loss
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

An optical circulator is introduced as an intermediary component to separate bidirectional transmission paths. The circulator directs downstream signals from the optical exchange to subscribers and upstream signals from subscribers to the optical exchange through the same optical fiber, enabling cost-effective bidirectional communication while managing optical power loss through controlled signal routing

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs optical amplification to change the power parameter of optical signals. Amplifiers are strategically placed in the network to boost optical power levels, compensating for transmission losses and extending the effective transmission range while maintaining bidirectional communication over the shared fiber

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If amplification means are placed at fixed locations during network installation, then network structure is simplified, but adaptability to changing user needs and optical losses is reduced

Engineering Contradiction:
Improvenetwork structureVSAvoidadaptability to optical losses
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic gain control in optical amplifiers, allowing the amplification factor to be adjusted based on real-time optical power measurements. This enables the network to adapt to changing conditions such as varying subscriber loads, fiber degradation, and environmental factors, while maintaining a relatively simple fixed physical infrastructure

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Optical power monitoring and feedback mechanisms are implemented to continuously measure signal strength at various network points. This feedback information is used to dynamically adjust amplifier gain settings, ensuring optimal performance as network conditions evolve over time without requiring physical reconfiguration of the network topology

Inventive Principle:
Principle #23Feedback

3Device complexity

If passive optical network components are used to maintain network simplicity, then device complexity is reduced, but the ability to amplify signals is constrained

Engineering Contradiction:
Improvenetwork simplicityVSAvoidsignal amplification capability
Core Design Contradiction:
Device complexityVSPower

Solution Approach 1:

The patent employs self-amplifying optical fiber sections where the fiber itself provides amplification through its material properties. This approach maintains network simplicity by eliminating the need for separate active amplifier components while still achieving signal boosting, as the fiber medium performs the amplification function inherently

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The network combines traditional passive optical components with specialized amplifying materials such as erbium-doped fiber sections. This composite approach allows the network to maintain overall passive architecture and simplicity while incorporating localized active amplification capabilities where needed, achieving a balance between simplicity and amplification capability

Inventive Principle:
Principle #40Composite materials

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 solution extends the network range, adapts to changing optical losses, and reduces operating costs by pooling amplification means, ensuring effective bidirectional transmission and maintaining the passive nature of the network.

Implementation Method 1

When the erbium atoms return to their non-excited state, they release photons by virtue of the principle of stimulated emission whose wavelength corresponds to the wavelength of the optical data signal passing through the network. These photons will increase the optical power of the data signal.

Methodology Applied
Scientific EffectStimulated emission:

Data Source

PatentEP2163011B1Long range optical network with location of an amplification means at the optical exchange
Publication Date: 2017.05.10 ORANGE SA
  • EP2163011B1 patent drawingFigure 1~2
  • EP2163011B1 patent drawingFigure 3~4
  • EP2163011B1 patent drawingFigure 5

AI summary

The invention relates to a passive optical network including an optical exchange connected by at least one optical fibre defining a branch of said network to at least one first optical component, said optical exchange including: a means for transmitting/receiving at least one optical data signal; a means for transmitting at least one optical amplification signal; said branch allowing the bi-directional transmission of the optical data signal and of the optical amplification signal. In this network, the branch includes at least one passive amplification device for the optical data signal, said device including: a first passive amplification medium capable of amplifying the optical power of the optical data signal when the latter is transmitted through the branch in a first direction; a second passive amplification medium capable of amplifying the optical power of the optical data signal when the latter is transmitted through the branch in a second direction, the first and second passive amplification media being excited by the optical amplification signal; a means for the selection of optical power gain of the first and second amplification media based on the optical losses respectively associated with the first and second transmission directions of the optical data signal.