Full Duplex CATV Interference Grouping via Graph Clustering

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Solution Overview

Problem

Full duplex CATV transmission architectures face interference issues between upstream and downstream signals, particularly in point-to-multi-point systems where multiple cable modems share the same network resources, making it difficult to mitigate interference effectively.

Innovation Solution

Organizing cable modems into Interference Groups (IGs) using a graph-based connected components technique, where modems are sorted based on interference metrics measured by a sounding procedure, allowing for efficient scheduling of transmissions to minimize interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If full duplex transmission is implemented in CATV systems, then downstream bandwidth is improved, but interference from upstream transmissions deteriorates signal quality

Engineering Contradiction:

Improvedownstream bandwidthVSAvoidinterference from upstream transmissions

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent segments cable modems into different Interference Groups based on their upstream transmission characteristics. By dividing the modem population into groups where modems within each group have similar interference profiles, the system can schedule downstream transmissions to avoid interference from specific upstream groups, thus maintaining high downstream bandwidth while managing interference through structured segmentation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic interference group assignment and scheduling based on real-time sounding measurements. The system continuously monitors upstream transmissions and dynamically adjusts which downstream modems are affected by which upstream groups, allowing flexible resource allocation that adapts to changing interference conditions while maintaining optimal downstream throughput.

Inventive Principle:

Principle #15Dynamics

2Object-affected harmful factors

If cable modems are organized into Interference Groups, then interference mitigation is improved, but system complexity increases

Engineering Contradiction:

Improveinterference mitigationVSAvoidsystem complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent implements self-service through automated sounding procedures where cable modems autonomously measure their own upstream transmission characteristics and report back to the CMTS. The CMTS automatically performs graph-based clustering to form interference groups without manual intervention, and dynamically schedules transmissions based on real-time interference conditions, reducing the need for complex manual configuration while achieving effective interference mitigation.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent employs continuous feedback loops where cable modems perform sounding measurements of upstream transmissions and report interference levels back to the CMTS. The CMTS uses this feedback to dynamically adjust interference group assignments and scheduling decisions, creating a closed-loop system that automatically adapts to changing interference conditions without requiring complex manual intervention.

Inventive Principle:

Principle #23Feedback

3Measurement precision

If graph-based connected components technique is used to organize modems, then interference group formation accuracy is improved, but processing time increases

Engineering Contradiction:

Improveinterference group formation accuracyVSAvoidprocessing time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-computing interference metrics during scheduled sounding intervals and pre-forming interference groups based on graph-based connected components analysis. By performing these computationally intensive operations in advance rather than in real-time, the system achieves accurate interference group formation while minimizing the processing time impact on actual data transmissions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements partial action by performing graph-based clustering only on subsets of modems that require reassignment based on changing interference conditions, rather than re-processing all modems continuously. This selective approach maintains high accuracy in interference group formation while significantly reducing overall processing time by focusing computational resources only where needed.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS11757673B2Systems and methods for sounding in a full duplex CATV architecture

Publication Date: 2023.09.12 ARRIS ENTERPRISES LLC

AI summary

Systems and methods for managing interference groups in a full duplex transmission network.