Hybrid Network Scheduling for Time-Triggered Ethernet

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Solution Overview

Problem

Conventional network scheduling tools do not adequately leverage the capabilities of underlying hardware to improve performance metrics such as end-to-end delay and jitter in Time-Triggered Ethernet networks.

Innovation Solution

A hybrid network scheduling method that coordinates transmission of virtual links across end stations using global and local schedules, allowing for efficient allocation of slot times and buffer management, thereby optimizing network performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional scheduling tools are used for Time-Triggered Ethernet networks, then the network can operate with basic scheduling functionality, but performance metrics such as end-to-end delay and jitter are not optimized

Engineering Contradiction:
Improvenetwork performanceVSAvoidscheduling complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the network into multiple domains, each with its own scheduler that operates semi-autonomously. This segmentation allows local optimization within domains while maintaining global coordination, improving performance without requiring a single complex centralized scheduler.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different schedulers are deployed at different network locations (end stations and switches) with specialized functions. Each scheduler is optimized for its specific role, creating local quality variations that collectively improve overall network performance while keeping individual scheduler complexities manageable.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If centralized global scheduling is implemented across all end stations, then coordination of transmission is achieved, but the complexity of managing global schedules across all nodes increases significantly

Engineering Contradiction:
Improvetransmission coordinationVSAvoidglobal schedule management
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The centralized scheduling function is segmented into distributed schedulers located at end stations and switches. Each scheduler manages a portion of the global schedule locally, maintaining transmission coordination while reducing the complexity burden on any single node.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a hierarchical scheduling structure where local schedules at end stations are nested within domain-level schedules, which are in turn nested within the global network schedule. This nested arrangement maintains global coordination while allowing local autonomy, reducing overall management complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Stability of the object's composition

If all virtual links are scheduled on a global schedule, then network-wide coordination is achieved, but flexibility in local transmission optimization is reduced

Engineering Contradiction:
Improvenetwork coordinationVSAvoidlocal optimization capability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The scheduling system is segmented into multiple levels: global schedule for network-wide coordination, domain schedules for regional optimization, and local schedules for individual end station flexibility. This segmentation allows virtual links to be coordinated globally while enabling local optimization where appropriate.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic scheduling where the degree of global versus local scheduling control can be adjusted based on traffic requirements. Some virtual links use strict global scheduling for high coordination needs, while others allow more local flexibility, creating a dynamic adaptive system.

Inventive Principle:
Principle #15Dynamics

4Productivity

If hierarchical scheduling with multiple levels is implemented, then local and global optimization are balanced, but the complexity of managing multiple scheduling levels increases

Engineering Contradiction:
Improvenetwork efficiencyVSAvoidmulti-level schedule management
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent designs schedulers with multi-functionality that can operate at different hierarchical levels. A single scheduler architecture can function as a global scheduler, domain scheduler, or local scheduler depending on configuration, reducing the need for completely separate systems at each level and managing complexity through universality.

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

Data Source

PatentEP3076620B1Scheduling of different traffic classes
Publication Date: 2018.10.10 HONEYWELL INTERNATIONAL INC
  • EP3076620B1 patent drawingFigure 1~2
  • EP3076620B1 patent drawingFigure 3
  • EP3076620B1 patent drawingFigure 4A

AI summary

Systems and methods for systematic hybrid network scheduling for multiple traffic classes with host timing and phase constraints are provided. In certain embodiments, a method of scheduling communications in a network comprises scheduling transmission of virtual links pertaining to a first traffic class on a global schedule to coordinate transmission of the virtual links pertaining to the first traffic class across all transmitting end stations on the global schedule; and scheduling transmission of each virtual link pertaining to a second traffic class on a local schedule of the respective transmitting end station from which each respective virtual link pertaining to the second traffic class is transmitted such that transmission of each virtual link pertaining to the second traffic class is coordinated only at the respective end station from which each respective virtual link pertaining to the second traffic class is transmitted.