Multi-Rate ONU Receiver and DFE for Higher Optical Data Rates

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Solution Overview

Problem

Current optical telecommunications systems require replacement of network components to increase data rates, leading to network downtime and increased costs, as they are limited by the specified operating ranges of individual components.

Innovation Solution

The implementation of a multi-rate receiver with a trans-impedance amplifier (TIA) and decision feedback equalizer (DFE) that automatically switches between different feedback resistors based on signal characteristics and quality of service information, along with an upstream laser circuit with an output impedance differing from the system's characteristic impedance, enabling data rates exceeding the specified operating range of individual components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If network components are replaced to increase data rates, then communication speed is improved, but network downtime and costs increase

Engineering Contradiction:
Improvedata rateVSAvoidnetwork downtime
Core Design Contradiction:
SpeedVSLoss of time

Solution Approach 1:

The patent implements dynamic rate adaptation by enabling network components to automatically adjust their operating data rates based on real-time signal quality measurements. The system monitors physical layer characteristics and dynamically selects optimal data rates from multiple supported rates, allowing the network to maintain higher speeds without requiring physical component replacement or network downtime.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operating parameter (data rate) of existing network components dynamically. By adjusting the data rate parameter based on signal quality conditions, the system can achieve higher communication speeds using existing hardware, eliminating the need for component replacement and associated network downtime.

Inventive Principle:
Principle #35Parameter changes

2Speed

If higher data rates are implemented, then communication speed is improved, but component operating range limitations are exceeded

Engineering Contradiction:
Improvedata rateVSAvoidcomponent operating range compliance
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The system dynamically adapts the operating data rate of network components based on measured signal quality. By continuously monitoring physical layer characteristics and adjusting the data rate accordingly, the system ensures that components operate within their reliable performance ranges while still achieving high communication speeds when conditions permit.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements a feedback mechanism where the system monitors signal quality metrics (such as eye opening measurements) and uses this information to adjust the operating data rate. This closed-loop control ensures that components operate within their specified performance ranges, maintaining reliability while optimizing for higher data rates when signal conditions support them.

Inventive Principle:
Principle #23Feedback

3Speed

If components are upgraded to support higher data rates, then communication speed is improved, but network costs increase

Engineering Contradiction:
Improvedata rateVSAvoidnetwork equipment cost
Core Design Contradiction:
SpeedVSQuantity of substance

Solution Approach 1:

The patent enables existing network components to perform multiple functions by supporting operation at multiple data rates. A single component can adaptively operate at different speeds based on signal quality, eliminating the need to deploy separate high-speed and low-speed hardware infrastructures, thereby reducing overall network equipment costs.

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

Solution Approach 2:

By changing the operating parameter (data rate) of existing components rather than upgrading hardware, the system achieves higher communication speeds without the capital expenditure associated with purchasing and deploying new high-speed equipment. This parameter-based adaptation approach significantly reduces network upgrade costs.

Inventive Principle:
Principle #35Parameter changes

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 allows for bi-directional data rates of up to 10Gbps using components rated for 2.5Gbps or 1.25Gbps, supporting multiple communication rates and enabling the same equipment to provide various service levels without hardware swaps, thus reducing downtime and costs.

Implementation Method 1

a multi-rate receiver having an operating bandwidth that is selected operationally based on physical layer characteristics of received signals

Methodology Applied
Scientific EffectTrans-impedance conversion:

Implementation Method 2

a DFE having at least one tap weight that is fixed. According to an embodiment, the DFE is configured to have at least one tap weight that is pre-set to ensure convergence of the DFE

Methodology Applied
Scientific EffectFeedback equalization: Feedback

Implementation Method 3

an upstream laser circuit having an output impedance that differs from a characteristic impedance of a system in which the laser circuit is implemented

Methodology Applied
Scientific EffectElectro-optical conversion:

Data Source

PatentEP3398268B1Optical telecommunications devices, systems, and methods providing communication rates exceeding the specified operating range of the individual components
Publication Date: 2019.09.25 ADTRAN INC
  • EP3398268B1 patent drawingFigure 1
  • EP3398268B1 patent drawingFigure 2
  • EP3398268B1 patent drawingFigure 3

AI summary

Optical telecommunications devices, systems, and methods. In some implementations, an optical networking unit (ONU) includes a multi-rate receiver having an operating bandwidth that is selected operationally based on physical layer characteristics of received signals and information received from a MAC. The ONU can also include an upstream laser circuit having an output impedance that differs from a characteristic impedance of a system in which the laser circuit is implemented. The ONU can also include a decision feedback equalizer (DFE) having at least one tap weight that is fixed to facilitate convergence of the DFE when signals received by the DFE would otherwise fail to meet characteristics required for DFE convergence.