PON Upstream Signal Recovery Pattern Identification

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Solution Overview

Problem

Current data recovery schemes for upstream PONs face challenges such as high complexity, power consumption, and inefficiency in adapting to dynamic signal impairments, particularly due to dispersion and bandwidth limitations, which hinder the transmission of high-speed data over long distances.

Innovation Solution

A system that embeds a received pattern in the header of upstream bursts, allowing for rapid signal recovery configuration determination using a look-up table that maps predefined patterns to corresponding signal recovery configurations, enabling efficient adaptation to impairments like fibre dispersion and bandwidth limitations without requiring MAC layer knowledge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If Digital Signal Processing is used to compensate for ISI, then signal recovery performance is improved, but system complexity and power consumption increase

Engineering Contradiction:
Improvesignal recovery performanceVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-calculating and storing equalizer parameters in a lookup table during system initialization or training phase. When an upstream burst is received, the system quickly retrieves pre-computed parameters based on detected signal characteristics rather than performing complex real-time calculations, thus maintaining high signal recovery performance while reducing operational complexity and power consumption.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If rapid adaptation of equalizer parameters is implemented for each ONU, then signal recovery performance is improved, but processing time and complexity increase

Engineering Contradiction:
Improvesignal recovery performanceVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary computation of equalizer parameters during a training phase or system initialization, storing optimal parameters in a lookup table. During actual upstream burst processing, the system quickly identifies the appropriate ONU and retrieves pre-computed parameters, avoiding time-consuming real-time calculations while maintaining adaptive performance for each ONU.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses copying by creating a lookup table that contains copies of pre-computed equalizer parameters for different ONU scenarios. Instead of recalculating parameters for each burst, the system copies and applies the appropriate pre-stored parameter set, dramatically reducing processing time while maintaining the ability to adapt to different ONU characteristics.

Inventive Principle:
Principle #26Copying

3Speed

If high bandwidth receivers are used to support 50 Gb/s transmission, then transmission rate is improved, but component cost and availability worsen

Engineering Contradiction:
Improvetransmission rateVSAvoidcomponent availability
Core Design Contradiction:
SpeedVSEase of manufacture

Solution Approach 1:

The patent applies this principle by using lower-cost, commercially available receiver components with moderate bandwidth (e.g., 35 GHz or less) instead of expensive high-bandwidth receivers. The system compensates for the limited hardware bandwidth through digital signal processing and adaptive equalization techniques, making the system more cost-effective while achieving the required 50 Gb/s transmission performance.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The system changes parameters by dynamically adjusting equalizer coefficients and signal processing parameters to optimize performance for different transmission conditions. This allows the use of lower-bandwidth hardware components while achieving high transmission rates through intelligent parameter adaptation rather than relying solely on high-bandwidth physical components.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If long training sequences are used for signal recovery adaptation, then signal recovery performance is improved, but upstream transmission efficiency decreases

Engineering Contradiction:
Improvesignal recovery performanceVSAvoidupstream transmission efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies partial action by using a shortened training sequence that contains only the essential information needed for rapid signal recovery adaptation. Instead of using complete training sequences from standard protocols, the system extracts and uses only the critical portions, achieving sufficient adaptation performance with reduced overhead and improved transmission efficiency.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3896871B1Pattern identification for signal recovery in PON up-stream
Publication Date: 2024.10.02 NOKIA SOLUTIONS & NETWORKS OY
  • EP3896871B1 patent drawingFigure 1A~1B
  • EP3896871B1 patent drawingFigure 2
  • EP3896871B1 patent drawingFigure 3

AI summary

A system (1) for determining a signal recovery configuration (100) for upstream transmission of bursts (10;11;12;13) from optical network units (2;3;4;5), abbreviated ONUs, to an optical line termination (6;7), abbreviated OLT, in a passive optical network (8), abbreviated PON, wherein said system (1) comprises: - means configured to receive an upstream burst (10) from one of said ONUs (2), wherein said upstream burst (10) is distorted by upstream transmission impairments; - means configured to detect a received pattern (110) in said upstream burst (110); - means configured to store a predetermined correspondence between predefined patterns and signal recovery configurations; and - means configured to determine a signal recovery configuration (100) corresponding to a predefined pattern (121) matching said received pattern (110) of said upstream burst (10).