Optical Network Unit Tunable Laser Wavelength Collision Avoidance

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Solution Overview

Problem

Existing optical network systems face challenges in efficiently interconnecting and transferring data between hierarchically deployed components of a network topology, particularly in data centers with high server interconnection demands and reliability requirements, where bandwidth decreases significantly per hierarchy level.

Innovation Solution

The optical network units (ONUs) can establish direct connections without an optical line termination (OLT), using tunable lasers for coherent heterodyne signals and a processing unit to detect and adjust wavelengths to avoid collisions, allowing for flexible point-to-point connections and efficient data transfer within a shared optical fiber, while a centralized component manages signaling and frequency allocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If direct ONU-ONU connections are established without OLT in the data transfer path, then bandwidth bottlenecks are reduced and data transfer efficiency is improved, but collision detection and wavelength coordination become more difficult

Engineering Contradiction:
Improvedata transfer efficiencyVSAvoidcollision detection difficulty
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent implements a feedback mechanism where ONUs transmit feedback signals to indicate their intended wavelengths for upstream channels. The processing unit detects these feedback signals and adjusts wavelengths accordingly to avoid collisions. This feedback loop enables collision detection and resolution in direct ONU-ONU connections without requiring OLT involvement in the data transfer path.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system enables ONUs to autonomously manage wavelength coordination by having each ONU transmit feedback signals containing their intended wavelengths. The processing unit automatically detects and processes these signals to adjust wavelengths, allowing the network to self-regulate without centralized OLT control for collision avoidance.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If wavelength tuning is implemented to avoid collisions in direct ONU connections, then connection flexibility is improved, but system complexity increases

Engineering Contradiction:
Improveconnection flexibilityVSAvoidwavelength coordination complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by having ONUs transmit feedback signals before actual data transmission begins. The processing unit detects these preliminary wavelength indications and adjusts wavelengths in advance to prevent collisions. This preliminary coordination enables flexible connection establishment while managing complexity through proactive wavelength allocation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system manages wavelength coordination complexity by dynamically changing the wavelength parameter based on feedback signals from ONUs. The processing unit adjusts wavelengths according to the feedback information, enabling flexible connection establishment while controlling complexity through parameter-based coordination rather than complex centralized control.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If centralized OLT components are removed from the data transfer path, then network simplicity and scalability are improved, but wavelength allocation and collision avoidance become more challenging

Engineering Contradiction:
Improvenetwork structure simplicityVSAvoidwavelength allocation ease
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent implements self-service by enabling ONUs to autonomously manage wavelength allocation through feedback signals. Each ONU transmits its intended wavelength information, and the processing unit automatically coordinates wavelengths to avoid collisions. This eliminates the need for centralized OLT control in the data transfer path, simplifying network structure while maintaining ease of operation through automated wavelength management.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The feedback mechanism enables wavelength allocation without centralized control. ONUs transmit feedback signals containing their intended wavelengths, and the processing unit uses this information to automatically allocate and adjust wavelengths. This feedback-based approach maintains ease of operation by automating the coordination process while removing OLT from the data transfer path.

Inventive Principle:
Principle #23Feedback

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 reduces bandwidth bottlenecks between racks or clusters by enabling flexible wavelength tuning and collision avoidance, allowing for efficient data transfer and interconnection within data centers without the need for centralized optical components in the data transfer path.

Implementation Method 1

The optical network unit comprises a tunable laser

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

using tunable lasers for coherent heterodyne signals

Methodology Applied
Scientific EffectCoherent light generation: Coherent Light

Implementation Method 3

a heterodyne receiver that is supplied by the tunable laser

Methodology Applied
Scientific EffectHeterodyne detection: Heterodyne

Implementation Method 4

Light incoming to the ONU is superimposed on a photodiode with a local oscillator laser. This produces on the photodiode a component which is proportional to the product of the incoming optical field and the local oscillator optical field

Methodology Applied
Scientific EffectOptical mixing: Interference

Implementation Method 5

Light incoming to the ONU is superimposed on a photodiode with a local oscillator laser. This produces on the photodiode a component which is proportional to the product of the incoming optical field and the local oscillator optical field

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 6

a processing unit that is arranged to detect a pending or an occurring collision

Methodology Applied
Scientific EffectSpectral detection: Absorption Spectroscopy

Data Source

PatentEP2572461B1Optical network unit, method for processing data in an optical network and communication system
Publication Date: 2019.01.30 XIEON NETWORKS SARL
  • EP2572461B1 patent drawingFigure 1
  • EP2572461B1 patent drawingFigure 2
  • EP2572461B1 patent drawingFigure 3

AI summary

An optical network unit is provided comprising a tunable laser, wherein the tunable laser is tunable such that a point-to-point connection to another optical network unit is established via an optical fiber. Also, a method for processing data in an optical network and an according communication system are suggested. The tunable laser can be adjusted based on a detected collision, and a frequency grid can be supplied from a centralized component.