DSL Line RF Interference Detection via SNR Margin Analysis

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Identifying and distinguishing between metallic path faults and radio frequency (RF) interference issues in digital subscriber lines (DSL) is challenging, especially when RF interference sources are intermittent or unwilling to be addressed, and existing methods do not effectively differentiate between line imbalances and interference susceptibility.

Innovation Solution

A method that measures the signal-to-noise ratio (SNR) margin over time and compares it to a diurnal reference function to determine the degree of similarity, indicating interference susceptibility, using a line analysis unit to assess the DSL line's susceptibility to RF interference by modeling the expected SNR margin variations due to broadcast radio transmissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If RF interference sources are identified and removed, then RF interference issues are resolved, but the process becomes complex and time-consuming requiring advanced diagnostic skills

Engineering Contradiction:
ImproveRF interference resolutionVSAvoiddiagnostic complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex manual diagnostic procedures with an automated electronic system that uses signal analysis and pattern recognition algorithms to identify RF interference sources and line imbalances, substituting human expert analysis with computational methods

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an intermediary diagnostic system that acts as a mediator between the DSL line and the engineer, providing automated analysis and identification of interference sources before engineer dispatch, thereby reducing the need for advanced diagnostic skills during field visits

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If line inspection is performed to remove imbalances, then susceptibility to RF interference is reduced, but the process requires engineer dispatch and manual testing

Engineering Contradiction:
Improveline balanceVSAvoidtime to identify imbalance
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent performs preliminary automated analysis of SNR margin variations to identify line imbalances before engineer dispatch, allowing proactive identification and scheduling of line repairs without waiting for customer complaints or manual field testing

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system enables the DSL line to effectively diagnose its own issues by continuously monitoring SNR margin variations and automatically comparing them against reference patterns, allowing the line to identify its own imbalances and interference susceptibility without external intervention

Inventive Principle:
Principle #25Self-service

3Measurement precision

If continuous SNR margin monitoring is implemented, then interference susceptibility is accurately determined, but the system complexity increases

Engineering Contradiction:
Improveinterference identification accuracyVSAvoidmonitoring system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a universal monitoring system that serves multiple functions: continuously monitoring SNR margin, comparing against reference patterns, identifying RF interference sources, detecting line imbalances, and prioritizing engineer dispatch, thereby achieving high measurement precision through a multi-functional rather than specialized system

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

Data Source

PatentEP3949133B1DSL line interference susceptibility
Publication Date: 2024.04.10 BRITISH TELECOM PLC
  • EP3949133B1 patent drawingFigure 1
  • EP3949133B1 patent drawingFigure 2
  • EP3949133B1 patent drawingFigure 3

AI summary

A method is presented of determining whether a digital subscriber line is susceptible to radio frequency interference. The method measures the signal to noise ratio (SNR) margin on the digital subscriber line over a number of 24 hour periods. The measured SNR margin over a given 24 hour period is then compared to a reference function of SNR margin over time (24 hours), where the SNR margin of the reference function is higher during the day and lower during the night, and also repeats daily. A measure of the interference susceptibility is generated based on the degree of similarity between the measured SNR margin and the reference function.