Optical Port Failure Protection in Aggregation Networks

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Solution Overview

Problem

Current optical transport networks face challenges in efficiently providing failure protection for faulty ports, particularly in aggregation networks, where existing solutions are either costly, resource-intensive, or require manual intervention, and do not effectively utilize the available spectrum for regular operations.

Innovation Solution

The system employs a WDM-device with N first ports and one additional second port at the core node, and each peripheral node has third and fourth ports that can be dynamically set to match wavelengths, allowing for automatic switching to a replacement port in case of a failure without the need for a technician, using simple splitters/couplers instead of FOADMs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a reserved replacement port is provided at each peripheral node for port failure protection, then network reliability is improved, but spectrum resources are wasted during normal operation

Engineering Contradiction:
Improveport failure protectionVSAvoidspectrum resource
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The system pre-configures replacement port relationships and wavelength mappings between core nodes and peripheral nodes before failures occur. When a port failure is detected, the pre-established replacement relationships enable immediate automatic switching without requiring real-time resource allocation or manual configuration, thus providing reliable protection while avoiding continuous reservation of spectrum resources.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention dynamically changes the operational state of ports based on failure conditions. During normal operation, all ports are active for regular services. Upon detecting a failure, the system changes the state by activating a replacement port with a different wavelength assignment, allowing the same physical infrastructure to serve both regular and protective functions at different times.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If manual intervention is required to switch to a replacement port upon failure, then switching precision is improved, but response time increases

Engineering Contradiction:
Improvefailure detection accuracyVSAvoidswitching response time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system implements automatic failure detection and self-healing capabilities through monitoring devices that continuously track port status and automated switching mechanisms that activate replacement ports without human intervention. The pre-configured replacement relationships enable the network to detect failures and execute recovery actions autonomously, eliminating manual intervention delays while maintaining accurate failure detection.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention incorporates monitoring devices that provide continuous feedback on port operational status to the control system. This feedback mechanism enables real-time detection of failures and triggers automated switching to replacement ports based on pre-established relationships, ensuring both accurate failure detection and rapid response without requiring manual assessment or decision-making.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If FOADMs are used at peripheral nodes for wavelength management, then wavelength assignment precision is improved, but device complexity increases

Engineering Contradiction:
Improvewavelength assignment accuracyVSAvoidoptical network element complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system uses simple optical couplers or splitters at peripheral nodes instead of complex FOADMs, copying the wavelength management function to the core node where full-capability WDM devices are deployed. This approach maintains wavelength assignment accuracy through centralized control while dramatically reducing the complexity of peripheral node equipment.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The invention consolidates wavelength management functionality into universal WDM devices at core nodes that can handle multiple wavelengths and ports. The simplified peripheral nodes use universal optical couplers that work with any wavelength, eliminating the need for wavelength-specific components at each peripheral location and reducing overall system complexity.

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

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 enables seamless port failure protection without manual intervention, optimizes spectrum usage, and increases network resilience by allowing the reserved wavelength to be used only during failures, while maintaining availability for regular services.

Implementation Method 1

the aggregation network is adapted for transmitting optical signals based on wavelength-division-multiplexing within a number of N transmission channels, each of which being differentiated by a different wavelength

Methodology Applied
Scientific EffectWavelength-division-multiplexing: Dispersion (of waves)

Data Source

PatentEP4009554A1System and method providing failure protection based on a faulty port in an aggregation network being an optical transport network
Publication Date: 2022.06.08 DEUTSCHE TELEKOM AG
  • EP4009554A1 patent drawingFigure 1
  • EP4009554A1 patent drawingFigure 2
  • EP4009554A1 patent drawingFigure 3

AI summary

The inventive solution suggests a system and a method of providing failure protection based on a faulty port in an aggregation network. A first optical network element (205), in particular a WDM-device, of a core node (200) includes a number of N first ports (210) and at least one second port (220). A second optical network element (105) of each of peripheral nodes (100) includes third ports (110), and at least one fourth port (120). Each of the third ports (120) is set to respectively match a wavelength of one of the first port (210) the first ports (210) and the thirds ports (110) are monitored concerning their respective port-behavior during transmitting optical signals, each of which having specific wavelength respectively assigned to one of the first ports. In case of detecting a faulty first port (210), one of the at least one second ports (220) is activated and the third port (110) which had matched the wavelength of the faulty port is set to match the wavelength of the activated second port. In case of detecting a faulty third port (110) of one of the second optical network elements, at this second optical network element it is switched from the faulty third port to one of the fourth ports (120) and this fourth port is set to match the wavelength formerly match by the faulty third port.