Distributed-System Clock Synchronization With Global Offset Equalization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current clock synchronization methods in distributed systems suffer from low precision due to variations in clock crystal oscillators caused by factors like temperature and voltage, leading to inaccurate time synchronization across different servers.

Innovation Solution

A method where a master node determines global clock offsets by performing error equalization on local clock offsets between nodes with directional relationships, using probe and response packets to improve synchronization precision, and implementing a linearly independent loop topology for continuous data collection and filtering to enhance accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a master clock source provides clock source to each server, then clock synchronization is achieved, but time delay occurs during network transmission reducing precision

Engineering Contradiction:
Improveclock synchronizationVSAvoidsynchronization precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent introduces timing packets as intermediaries that carry timestamp information between master and slave nodes. These packets enable precise measurement of transmission delays and clock offsets without requiring direct clock source transmission, thus resolving the contradiction between achieving synchronization and maintaining precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the traditional mechanical clock source transmission with an electronic timestamp-based measurement system. By using software-based timing packets and algorithmic offset calculation, the system achieves higher precision than physical clock transmission while eliminating network transmission delays.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If servers perform local clock synchronization based on local clock offsets, then each server can maintain independent synchronization, but synchronization precision is low due to oscillator variations

Engineering Contradiction:
Improveindependent synchronizationVSAvoidsynchronization precision
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where slave nodes send timing packets to the master node, which then calculates round-trip delays and clock offsets. This closed-loop feedback enables continuous refinement of synchronization precision while maintaining independent operation of each server's clock oscillator.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent segments the synchronization problem into measurable components: transmission delay, clock offset, and frequency drift. By measuring and correcting each component separately through timing packets and algorithms, the system achieves high precision while allowing independent server operation.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If multiple local clock offsets are measured between nodes, then comprehensive synchronization data is obtained, but calculation complexity increases

Engineering Contradiction:
Improveclock offset measurementVSAvoidcalculation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses timing packets with embedded timestamps as intermediaries to simplify complex multi-node offset measurements. Each packet carries precise timing information that enables the master node to calculate all necessary offsets through a standardized process, reducing calculation complexity despite comprehensive measurements.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4199385B1Clock synchronization method and device in distributed system, and system
Publication Date: 2025.10.29 HUAWEI TECH CO LTD
  • EP4199385B1 patent drawingFigure 1
  • EP4199385B1 patent drawingFigure 2~3
  • EP4199385B1 patent drawingFigure 4

AI summary

This application discloses a clock synchronization method and a related apparatus in a distributed system. The distributed system includes a plurality of nodes, and the plurality of nodes include a master node and a plurality of slave nodes. The master node obtains a plurality of local clock offsets, where each of the plurality of local clock offsets indicates a clock offset between two nodes in the distributed system. The master node determines a global clock offset of a target slave node relative to the master node based on the plurality of local clock offsets, and sends the global clock offset to the target slave node. The target slave node obtains a clock reference value of a local clock, and then performs clock synchronization based on the clock reference value and the global clock offset. According to the solution provided in embodiments of this application, global error equalization can be implemented by determining the global clock offset by the master node. This helps improve clock synchronization precision of each node. Clock synchronization precision in this application can reach 1 microsecond.