Communication Link SNR-Based BER Reporting Beyond FEC Thresholds

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Solution Overview

Problem

Conventional BER measurement techniques become inaccurate and fail to provide pre-FEC BER estimates beyond the FEC threshold, limiting the ability to assess link viability and make necessary adjustments.

Innovation Solution

Utilizing signal-to-noise ratio (SNR)-based methods to extrapolate BER calculations, enabling accurate determination and reporting of pre-FEC BER even when operating above the FEC threshold.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional BER measurement techniques are used, then BER can be accurately measured below the FEC threshold, but BER measurement becomes inaccurate and fails beyond the FEC threshold

Engineering Contradiction:

ImproveBER measurement accuracyVSAvoidBER measurement range

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent changes the measurement parameter from direct BER counting to SNR-based estimation. By measuring SNR (signal-to-noise ratio) and using it to calculate BER through mathematical relationships, the system can accurately determine BER even beyond the FEC threshold where conventional error counting fails. This parameter transformation enables extended measurement range while maintaining accuracy.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If FEC is used to enable operation at lower SNR values, then high data rates can be achieved, but the ability to monitor and assess link viability beyond the FEC threshold is lost

Engineering Contradiction:

Improvedata rateVSAvoidlink viability information

Core Design Contradiction:

ProductivityVSLoss of information

Solution Approach 1:

The patent implements a feedback mechanism by continuously measuring SNR and calculating BER to provide real-time information about link quality. This feedback enables system operators to monitor link viability, assess performance, and make necessary adjustments even when operating beyond the FEC threshold, thus preventing information loss about link status.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent introduces SNR measurement as an intermediary parameter that bridges the gap between FEC operation and BER monitoring. By using SNR as a mediator that can be measured regardless of FEC threshold crossing, the system maintains the ability to assess link viability and guide operational decisions without being limited by FEC correction capabilities.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If SNR-based BER calculation is used, then BER can be reported beyond the FEC threshold, but additional complexity is introduced in the measurement and calculation process

Engineering Contradiction:

ImproveBER reporting rangeVSAvoidmeasurement and calculation complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical/error-counting-based BER measurement system with an SNR-based calculation system. Instead of physically counting bit errors (which requires direct BER measurement), the system uses electrical/signal-based SNR measurement and mathematical calculation to derive BER, thereby extending reporting capability while managing complexity through different physical domain measurement.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP4508776B1Signal-to-noise ratio-based bit error ratio calculation for reporting beyond a forward error correction threshold

Publication Date: 2025.09.03 CIENA CORP

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AI summary

Signal-to-noise ratio (SNR)-based bit error ratio (BER) calculations for reporting beyond a forward error correction (FEC) threshold include measuring (32, 102) signal-to-noise ratio, SNR, of a first signal; extrapolating (34, 104) the SNR of the first signal to determine an SNR of a second signal; and determining (36, 104) a pre-forward error correction, FEC, bit error ratio, BER, for the second signal based on the determined SNR of the second signal.