Upstream Channel Bonding Segmentation for DOCSIS Modems

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Solution Overview

Problem

The complexity of upstream channel bonding in DOCSIS cable systems increases exponentially with the number of channels, requiring significant hardware and software complexity for monitoring and tracking bandwidth requests, making it difficult to scale beyond a few channels.

Innovation Solution

Implementing limited contention-based requesting and stateless requesting mechanisms, where bandwidth requests are limited to a subset of channels for contention-based operations and no state cycle is maintained for stateless flows, reducing the complexity and overhead of tracking requests and grants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the number of upstream channels is increased, then the upstream bandwidth capacity is improved, but the hardware and software complexity for monitoring and tracking bandwidth requests increases exponentially

Engineering Contradiction:
Improvenumber of upstream channelsVSAvoidhardware and software complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent segments upstream channels into two distinct subsets: a first subset for contention-based bandwidth requests and a second subset for unicast polling. This segmentation allows the cable modem to apply different monitoring and tracking mechanisms to different channel groups, reducing the exponential complexity growth that would occur if all channels required full contention-based monitoring.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different quality levels of monitoring and tracking to different channel subsets. The first subset channels receive full contention-based monitoring with state cycle tracking, while the second subset channels use simpler unicast polling mechanisms. This local differentiation allows selective complexity application based on channel type and usage requirements.

Inventive Principle:
Principle #3Local quality

2Reliability

If contention-based requesting is implemented on all upstream channels, then bandwidth allocation control is improved, but memory requirements for storing and monitoring bandwidth request data increase significantly

Engineering Contradiction:
Improvebandwidth allocation controlVSAvoidmemory requirements
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent divides upstream channels into a first subset for contention-based requesting and a second subset for unicast polling. This segmentation limits contention-based memory-intensive tracking to only the first subset channels, reducing overall memory requirements while maintaining reliable bandwidth control where needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies contention-based requesting with full monitoring and tracking (excessive action) only to the first subset of channels, while using simplified unicast polling (partial action) for the second subset. This partial application of complex monitoring mechanisms reduces total memory requirements while maintaining adequate bandwidth control for each channel type.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If state cycle tracking is maintained for all upstream channels, then bandwidth request monitoring accuracy is improved, but processing overhead increases exponentially

Engineering Contradiction:
Improvebandwidth request monitoring accuracyVSAvoidprocessing overhead
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent segments upstream channels into a first subset for contention-based requesting with state cycle tracking and a second subset for unicast polling without state cycle tracking. This segmentation maintains measurement precision for bandwidth request monitoring on the first subset while significantly reducing processing overhead by eliminating state cycle tracking on the second subset channels.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies state cycle tracking (high measurement precision) locally to the first subset of channels where contention-based requesting is used, while using simpler monitoring approaches for the second subset. This local quality differentiation maintains monitoring accuracy where necessary while reducing overall processing overhead.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2670086B1Solutions for Upstream Channel Bonding
Publication Date: 2019.01.23 AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LTD
  • EP2670086B1 patent drawingFigure 1A
  • EP2670086B1 patent drawingFigure 1B
  • EP2670086B1 patent drawingFigure 2A

AI summary

A cable modem that supports stateless requesting and/or limited contention-based requesting is provided herein. In an example, a physical layer (PHY) configured to communicate over a plurality of upstream channels is provided. A bandwidth requestor is provided to request bandwidth using contention-based requesting over a first subset of the upstream channels for contention-based flows and request bandwidth using stateless requesting over a second subset of the upstream channels for stateless flows.