PON Test Instrument ONU ID Capture via Downstream Signals

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Solution Overview

Problem

Technicians face challenges in accurately measuring and capturing upstream optical signals in passive optical networks due to their bursty nature, making it difficult to determine ONU identifiers and diagnose transmission issues effectively.

Innovation Solution

A test instrument connected to the optical network captures information from downstream signals, using a capture circuit to identify ONU identifiers during activation processes, and measures power levels, which can be used to determine connected ONUs and diagnose issues without directly capturing bursty upstream signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If technicians directly capture upstream optical signals to identify ONU identifiers, then identification accuracy may be improved, but the bursty nature of upstream signals makes measurement and capture difficult

Engineering Contradiction:

ImproveONU identifier identification accuracyVSAvoidupstream signal capture difficulty

Core Design Contradiction:

Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

Instead of capturing upstream signals from ONU to OLT, the patent inverts the approach by capturing downstream signals from OLT to ONU. The test instrument positioned at the ODN receives downstream signals containing ONU identifiers broadcast by the OLT, thereby identifying ONUs through the reverse signal direction that is continuous and easier to measure.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces downstream signals as an intermediary medium. Rather than directly capturing the problematic upstream signals, the system uses downstream signals as a mediator that carries ONU identifier information from the OLT to the test instrument, enabling indirect but reliable ONU identification.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If technicians use traditional methods to measure optical power levels at various ODN locations, then power level data can be obtained, but it is difficult to correlate power levels with specific ONU identifiers

Engineering Contradiction:

Improveoptical power level measurementVSAvoidONU identifier correlation information

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The patent merges two previously separate measurement functions into one unified process. The test instrument simultaneously captures both optical power level data and ONU identifier information from the same downstream signal, thereby combining power measurement with device identification in a single operation.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent applies preliminary action by capturing ONU identifiers from downstream signals before performing power level measurements. The test instrument first receives and processes downstream signals containing both identifier and power information, establishing the correlation between specific ONUs and their corresponding power levels prior to analysis.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP3112838B1Optical network test instrument including optical network unit identifier capture capability from downstream signals

Publication Date: 2022.08.10 VIAVI SOLUTIONS DEUT

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AI summary

A test instrument can be coupled to a test point in a passive optical network to measure optical signals transmitted between an optical line terminal and an optical network unit in the optical network. The test instrument can capture an identifier of the ONU from downstream signals sent from the OLT to the ONU.