Cable Modem Mode Selection via Frequency Band Analysis

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Solution Overview

Problem

The transition to DOCSIS 3.1 requires network compatibility with both DOCSIS 3.0 and DOCSIS 3.1 standards, necessitating accurate mapping of existing signals on coaxial cable television networks, which is challenging due to differences in frequency plans and the presence of out-of-band signals.

Innovation Solution

A method and device for a cable modem to select operating modes based on signal analysis, switching between DOCSIS 3.0 and DOCSIS 3.1 standards by analyzing frequency bands and adjusting transmission and reception modes accordingly, ensuring compatibility with various signals present on the network.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the cable modem operates in DOCSIS 3.1 mode with expanded frequency bands, then transmission speed and bandwidth are improved, but compatibility with existing DOCSIS 3.0 networks and out-of-band signals deteriorates

Engineering Contradiction:
Improvetransmission speedVSAvoidcompatibility with existing networks
Core Design Contradiction:
SpeedVSAdaptability or versatility

Solution Approach 1:

The cable modem dynamically switches between DOCSIS 3.0 and DOCSIS 3.1 operating modes based on real-time signal analysis. The system monitors the frequency spectrum, detects out-of-band signals, and automatically adjusts its operational parameters to match the detected standard, enabling adaptive operation across different network configurations without manual intervention.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes critical operational parameters including frequency band allocation, modulation mode, and signal detection thresholds based on the detected network standard. When DOCSIS 3.0 signals are detected, the modem adjusts its parameters to conform to the 3.0 frequency plan; when DOCSIS 3.1 signals are detected, it switches to 3.1 parameters, thereby maintaining compatibility across different standards.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the cable modem analyzes signals in the fifth frequency band to detect out-of-band signals, then signal mapping accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvesignal mapping accuracyVSAvoidsignal analysis complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The frequency spectrum is divided into distinct bands (first, second, third, fourth, and fifth frequency bands) with specific functional assignments. The fifth frequency band is specifically allocated for out-of-band signal detection, while other bands handle data transmission. This segmentation allows targeted analysis of specific frequency regions for signal mapping without requiring comprehensive analysis of the entire spectrum, thereby reducing overall system complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary signal analysis in the fifth frequency band before initiating data transmission. By detecting out-of-band signals and mapping them in advance, the system prepares the frequency spectrum allocation before actual communication begins, preventing interference and ensuring accurate signal mapping without requiring complex real-time adjustments during data transmission.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3556057B1Method and device for selecting a mode of operation of a cable modem
Publication Date: 2020.11.04 SAGEMCOM BROADBAND SAS
  • EP3556057B1 patent drawingFigure 1~2
  • EP3556057B1 patent drawingFigure 3a~3c
  • EP3556057B1 patent drawingFigure 4

AI summary

The invention relates to a method for selecting a mode of operation of a cable modem between a first and a second mode of operation, the first mode of operation using a first standard and a first and a second frequency band separated by a third frequency band, the second mode of operation using a fifth frequency band according to a second standard. The cable modem: - places itself in the second mode of operation, - analyses signals included in at least the part of the fifth frequency band comprising the third frequency band, - determines (E500) whether analysed signals are not signals in accordance with the first or with the second standard, - places itself (E508) in a mode of transmission and reception of data according to the second standard if analysed signals are not signals in accordance with the first and with the second standards and are not included in the third frequency band.