Cable Modem Echo Channel Fault Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing cable network monitoring systems face challenges in accurately and efficiently detecting and locating faults in cable networks, particularly in full duplex (FDX) operations where echoes and interference complicate fault identification.

Innovation Solution

A method and apparatus utilizing echo channel estimation by a cable modem to detect and locate faults in a cable network. The cable modem performs echo cancellation and channel estimation to identify changes in the echo channel response, which indicates potential faults, and calculates the distance to these faults based on the time domain channel response.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional network monitoring methods are used, then fault detection capability is limited, but operating expenses increase due to manual identification and fixing of network faults

Engineering Contradiction:

Improvefault detection capabilityVSAvoidoperating expenses

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The cable modem performs self-diagnosis by analyzing echo channel responses to detect and locate faults in the cable network. The system uses its own transmitted signals and analyzes the reflected echoes to identify faults, eliminating the need for external monitoring equipment or manual inspection. This self-service approach reduces operating expenses while maintaining reliable fault detection.

Inventive Principle:

Principle #25Self-service

2Measurement precision

If manual fault identification methods are used, then fault location accuracy is limited, but time and resources are consumed for identifying and fixing faults

Engineering Contradiction:

Improvefault location accuracyVSAvoidtime for identifying and fixing faults

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The system continuously monitors the echo channel response during normal cable modem operation, performing fault detection and location proactively before faults affect service. By analyzing echoes in real-time during regular operations, the system identifies faults early and provides precise location information, reducing the time required for fault identification and repair.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces manual fault identification methods with automated electronic analysis of echo channel responses. The cable modem uses signal processing techniques to analyze reflected signals and calculate fault locations based on time-domain responses, substituting mechanical/manual inspection with automated electronic measurement for higher precision and faster results.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If dedicated fault detection hardware is deployed, then fault detection accuracy improves, but device complexity and cost increase

Engineering Contradiction:

Improvefault detection accuracyVSAvoidhardware requirements

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The cable modem performs multiple functions including data communication and fault detection using the same hardware components. The existing transmitter and receiver used for data communication are also utilized for fault detection by analyzing echo channel responses. This multi-functionality approach maintains high fault detection accuracy without adding dedicated fault detection hardware, thereby reducing device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines fault detection functionality with the cable modem's data communication operations. The echo analysis for fault detection is integrated into the existing uplink transmission and downlink reception processes, merging what would traditionally be separate functions into a unified system that uses shared hardware resources.

Inventive Principle:

Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables proactive and accurate detection and location of faults in the cable network, reducing service disruptions and truck rolls, and improving overall network reliability without requiring additional dedicated hardware.

Implementation Method 1

performing channel estimation to obtain a time domain channel response on an echo channel

Methodology Applied

Scientific EffectEcho: Echo

Data Source

PatentUS12328152B2Method and apparatus for detecting and locating a fault in a cable network

Publication Date: 2025.06.10 MAXLINEAR INC

AI summary

A method and apparatus for detecting and locating a fault in a cable network. A cable modem may perform channel estimation to obtain a time domain channel response on an echo channel in a cable network. The cable modem then analyzes the time domain channel response to determine whether there is any change from a previously obtained time domain channel response on the echo channel. If there is a change from the previously obtained time domain channel response, the cable modem may generate an alert for a fault in the cable network and estimate a location of the fault based on the time domain channel response. Calibration may be performed to determine a reference latency for a reflection occurred inside the cable modem, and the location of the fault may be estimated based on the reference latency.