Unified Clock Source Selection Across SDH and PTP Protocols

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Solution Overview

Problem

Existing network equipment cannot effectively compare and select a higher-quality clock source when clocks are transmitted based on different protocols, such as SDH and IEEE 1588 PTP, leading to the selection of a lower-class clock instead of a higher-class clock during network convergence.

Innovation Solution

A method and apparatus for clock transmission between networks that acquire and convert information from different protocols, allowing for unified source selection and transmission of clock quality class information using a precision time protocol (PTP), enabling the selection of a higher-class clock across different protocols.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If network equipment uses different protocol-specific methods to handle clocks from different protocols, then each protocol can be processed according to its own rules, but the equipment cannot compare and select the higher-quality clock source across protocols

Engineering Contradiction:
ImproveProtocol compatibilityVSAvoidClock quality comparison capability
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent converts clock quality indicators from different protocols (SDH SSM and IEEE 1588 PTP Clock Class) into a unified quality parameter scale. By mapping SSM values (QL-PRC, QL-SSU-A, QL-SSU-B, etc.) and PTP Clock Class values (0-7) to a common quality metric, the system enables direct comparison and selection of the higher-quality clock source across protocol boundaries.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If the equipment selects clock sources based on protocol-specific information only, then the selection process is simple within each protocol, but the equipment may select a lower-class clock instead of a higher-class clock during protocol convergence

Engineering Contradiction:
ImproveClock source selection simplicityVSAvoidClock source quality
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces a protocol-independent clock quality conversion mechanism as an intermediary layer. This converter translates protocol-specific clock quality information (SSM for SDH, Clock Class for PTP) into a unified quality representation, allowing the clock selection function to compare clocks from different protocols on an equal basis and reliably select the higher-quality source.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3849111B1Method and apparatus of clock transmission between networks
Publication Date: 2023.05.03 HUAWEI TECH CO LTD
  • EP3849111B1 patent drawingFigure 1~2
  • EP3849111B1 patent drawingFigure 3
  • EP3849111B1 patent drawingFigure 4~5

AI summary

A method of clock transmission between networks and an apparatus of clock transmission are disclosed, in which a second information corresponding to a clock transferred by a first network equipment based on a first protocol, and the second information corresponding to a clock transferred by a second network equipment based on a second protocol are acquired, and a source selection is performed in a united way by adopting a source selection manner based on the second protocol according to the second information. Therefore, the equipment in different types of networks can conveniently select a clock with a higher class from clocks transferred based on different protocols, so as to realize a normalization management on the clocks transferred based on different protocols.