Dual-Connectivity Clock Synchronization Using a Specific Cell Reference

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Solution Overview

Problem

In 5G IIoT networks, achieving accurate clock synchronization is challenging due to inconsistent frame boundaries between master and secondary nodes in Dual Connectivity scenarios, leading to inaccuracies in clock synchronization between terminals and network devices.

Innovation Solution

A method where terminals determine a specific cell as a clock reference point by analyzing first and second clock information received from master and secondary nodes, ensuring consistent understanding of frame boundaries through predefined or updated clock information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If GPS-based clock synchronization is used, then time synchronization can be achieved across distributed devices, but security vulnerabilities arise due to potential GPS signal spoofing or jamming

Engineering Contradiction:
Improvetime synchronization reliabilityVSAvoidGPS signal spoofing and jamming
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a dual-path synchronization mechanism where PTP packets serve as an intermediary to establish time synchronization through a secure network path, while NTP packets provide an alternative routing path for verification. This intermediary approach allows the system to bypass direct GPS dependency and use multiple communication paths to verify time synchronization, thereby mitigating GPS spoofing and jamming attacks.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically changes synchronization parameters by switching between different protocol modes (PTP and NTP) and adjusting synchronization source priorities based on detected attack conditions. When GPS anomalies are detected, the system changes the time synchronization parameter source from GPS-primary to network-primary, and adjusts the weighting of different synchronization packets to maintain reliable timing despite GPS interference.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If multiple time synchronization sources are integrated, then synchronization reliability improves, but system complexity increases

Engineering Contradiction:
Improvetime synchronization reliabilityVSAvoidsynchronization system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a universal time synchronization device that can perform multiple functions: receiving and processing both PTP and NTP packets, integrating GPS, PPS, and network time sources, and providing time synchronization services to multiple protocol stacks simultaneously. This multi-functional design consolidates what would otherwise require separate specialized systems into a single integrated device, managing complexity through functional consolidation rather than proliferation of separate components.

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

Solution Approach 2:

The system employs feedback mechanisms where the time synchronization device continuously monitors the quality and reliability of multiple time sources (GPS, PTP, NTP), compares their outputs, and automatically adjusts the selected synchronization source based on detected anomalies or attack conditions. This feedback loop enables automatic adaptation to changing conditions without requiring complex manual configuration or intervention, managing system complexity through intelligent automation.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If PTP protocol is used for high-precision synchronization, then synchronization precision improves, but vulnerability to network attacks increases

Engineering Contradiction:
Improvetime synchronization precisionVSAvoidnetwork-based time synchronization attacks
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent implements preliminary verification actions where NTP packets are received and processed in advance of PTP packets, establishing a baseline time reference through the more robust NTP protocol before attempting high-precision PTP synchronization. This preliminary action creates a safety net that can detect anomalies in PTP packets before they compromise the system, allowing the device to reject malicious PTP synchronization attempts while maintaining precision when conditions are safe.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts its synchronization strategy based on real-time network conditions and security assessments. When PTP precision is needed, the system activates enhanced verification routines that dynamically analyze packet authenticity, source reliability, and timing consistency. This dynamic approach allows the system to maintain high precision when safe while automatically increasing security scrutiny when potential attacks are detected, rather than using a static high-security mode that would always reduce precision.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4044697B1Clock synchronization method and related apparatus
Publication Date: 2026.04.29 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD
  • EP4044697B1 patent drawingFigure 1A~1B
  • EP4044697B1 patent drawingFigure 2A~2B
  • EP4044697B1 patent drawingFigure 2C~2D

AI summary

Disclosed are a clock synchronization method and a related apparatus. The method comprises: a terminal receiving first clock information; determining a specific cell according to the first clock information; and taking the specific cell as a clock reference point, and performing clock synchronization according to the first clock information. It can be seen that in the embodiments of the present application, a specific cell, which serves as a clock reference point, of a terminal is determined, then the specific cell is taken as the clock reference point, and clock synchronization is performed according to first clock information related to the specific cell, such that a synchronization error caused by inconsistent understandings with regard to the specific cell that serves as the clock reference point by the terminal and a network device can be avoided, and clock synchronization of the terminal and the network device is ensured.