ONU Activation Preamble Scheme for OLT Equalizer Training

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Solution Overview

Problem

The challenge in high-speed Passive Optical Networks (PON) is the increased possibility of ONU activation failures due to collision during the initial equalizer training procedure, which is exacerbated by longer preamble sequences, leading to inefficient system throughput and bandwidth waste.

Innovation Solution

Configuring a common preamble sequence for upstream transmission by the ONU and using it for initial equalizer training at the OLT, allowing efficient training and eliminating the need for a quiet window, thereby reducing collisions and optimizing bandwidth utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If longer preamble sequences are used for initial equalizer training, then training accuracy is improved, but collision possibility increases and system throughput decreases

Engineering Contradiction:
Improveequalizer training accuracyVSAvoidsystem throughput
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent segments the upstream transmission into two distinct phases: a training phase using a first wavelength with longer preamble sequences for accurate equalizer training, and a data transmission phase using a second wavelength with shorter preamble sequences for efficient throughput. This segmentation allows each phase to optimize its parameters independently, resolving the contradiction between training accuracy and system throughput.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a wavelength dimension to separate training and data transmission functions. By using different wavelengths (first wavelength for training, second wavelength for data), the system can simultaneously perform equalizer training with long preambles and maintain high throughput with short preambles, effectively resolving the contradiction through dimensional separation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If longer preamble sequences are used for initial equalizer training, then training accuracy is improved, but bandwidth utilization decreases

Engineering Contradiction:
Improveequalizer training accuracyVSAvoidbandwidth waste
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The patent segments the transmission bandwidth into two wavelength channels, allocating the first wavelength specifically for training purposes where long preambles are necessary, and the second wavelength for data transmission where bandwidth efficiency is critical. This segmentation eliminates bandwidth waste by ensuring long preambles are only used where absolutely necessary for training accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By introducing wavelength as an additional dimension for resource allocation, the patent enables simultaneous use of different preamble lengths on different wavelengths. The first wavelength carries training signals with long preambles when needed, while the second wavelength maintains high bandwidth utilization with short preambles, thus resolving the contradiction between training accuracy and bandwidth efficiency.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If quiet window is extended for ONU activation, then collision possibility is reduced, but system throughput decreases

Engineering Contradiction:
ImproveONU activation reliabilityVSAvoidsystem throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent segments the activation and data transmission processes into separate wavelength channels. The first wavelength handles ONU activation and training with extended quiet windows when necessary, while the second wavelength maintains continuous data transmission without quiet windows, thereby maintaining high system throughput while ensuring reliable ONU activation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By using wavelength separation, the patent eliminates the need to choose between activation reliability and throughput. The first wavelength provides a protected environment for ONU activation with quiet windows when needed, while the second wavelength ensures continuous high-speed data transmission, effectively resolving the contradiction through dimensional separation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3979523B1Devices, methods, apparatuses and computer readable storage media for optical communication
Publication Date: 2025.12.03 NOKIA SOLUTIONS & NETWORKS OY
  • EP3979523B1 patent drawingFigure 1
  • EP3979523B1 patent drawingFigure 2
  • EP3979523B1 patent drawingFigure 3

AI summary

Embodiments of the present disclosure relate to devices, methods, apparatuses and computer readable storage media of ONU activation for OLT Equalizer training. The method comprises determining, at OLT, configuration information indicating a bandwidth allocation dedicated for an ONU and a first target preamble sequence associated with the bandwidth allocation, the first target preamble sequence being to be used by the ONU for a transmission from the ONU to the OLT on a first wavelength; transmitting the configuration information to the ONU; and receiving the transmission from the ONU from the ONU on the first wavelength, the transmission is performed by the ONU based on the first target preamble sequence. In this way, an efficient training at the OLT side and ONU activation quiet window elimination can be achieved at the same time.