TSN CU-DU Handover Time Reference Conversion

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Solution Overview

Problem

In wireless communications, especially in TSN networks with CU-DU architecture, accurately determining time information during handover processes is challenging due to differences in timing between source and target network devices, leading to complexities in data unit ordering and latency measurement.

Innovation Solution

A method and apparatus that enable the transmission of time information using the timing of the source network device as a reference, which is then converted to align with the timing of the target network device, allowing for unified timing usage by the receive end device, thereby simplifying the handover process and ensuring data unit order and latency measurement accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If time information is transmitted using source network device timing during handover, then data unit ordering accuracy is improved, but processing complexity increases due to timing conversion requirements

Engineering Contradiction:
Improvetime information accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The source network device acts as an intermediary by embedding its timing information into the forwarded data units. This mediator approach allows the target network device to receive pre-synchronized time stamps without needing to perform complex timing conversions itself, thus improving measurement precision while managing processing complexity through architectural design

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The source network device performs preliminary timing alignment by converting and embedding target network device timing references into the time information field before forwarding data units. This preliminary action ensures that time information is already aligned with the target device's clock when received, eliminating the need for the target device to perform complex real-time timing conversions

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If timing conversion from source to target network device is performed, then unified timing usage is improved, but latency measurement complexity increases

Engineering Contradiction:
Improveunified timing usageVSAvoidlatency measurement complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent changes the time information parameter from source network device timing to target network device timing through conversion. By modifying this parameter at the source device before transmission, the target device receives already-converted timing data that aligns with its own clock, achieving unified timing usage while the source device absorbs the conversion complexity

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If time information is embedded in data units for latency measurement, then latency measurement capability is improved, but data unit structure complexity increases

Engineering Contradiction:
Improvelatency measurement capabilityVSAvoiddata unit structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The time information field in the data unit structure serves multiple functions: it carries timing stamps for latency measurement, enables synchronization between network devices, and provides reference information for ordering data units. This multi-functionality approach improves latency measurement capability while avoiding the need for separate dedicated timing structures

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

Data Source

PatentEP3886497B1Synchronization of a TSN network comprising a CU-du architecture
Publication Date: 2024.12.18 HUAWEI TECH CO LTD
  • EP3886497B1 patent drawingFigure 1-1
  • EP3886497B1 patent drawingFigure 1-2
  • EP3886497B1 patent drawingFigure 2

AI summary

This application discloses a communications method and apparatus. The method includes: obtaining, by a transmit end device, information that is about a first time and that corresponds to a data unit, where the first time uses timing of a source network device as a reference; determining, by the transmit end device, information that is about a second time and that corresponds to the data unit, where the second time uses timing of the target network device as a reference; and sending, by the transmit end device, the information about the second time to a receive end device. A corresponding apparatus is further disclosed. According to the solutions of this application, in a handover transmission process, the information about the first time is information about a time that uses the timing of the source network device as a reference, and the transmit end device converts the information about the first time into the information about the second time that uses the timing of the target network device as a reference. Therefore, the receive end device may use timing of a current serving cell in a unified manner. This reduces processing complexity of the receive end device.