STC Counter Synchronization via TAI Time Conversion

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Solution Overview

Problem

In broadcasting and distribution systems, existing methods cannot synchronize STC counter values using IP-based interfaces, limiting seamless system switching and requiring coaxial cables for signal distribution.

Innovation Solution

A synchronization control apparatus and method that synchronizes STC counter values based on International Atomic Time (TAI) using a processor or dedicated arithmetic circuit, converting TAI time to STC counter values with high precision, allowing synchronization through IP packets over Ethernet cables.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If clocks are synchronized using PTP time information, then clock synchronization is achieved, but STC counter values cannot be synchronized

Engineering Contradiction:
Improveclock synchronization precisionVSAvoidSTC counter value synchronization
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces an STC counter value transmission path as an intermediary mechanism. While PTP provides clock synchronization, the STC counter values are transmitted separately through PCR packets in the transport stream, acting as a mediator that carries the precise timing information needed for seamless switching without relying solely on PTP

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the synchronization function into two independent parts: clock synchronization via PTP and STC counter value synchronization via transport stream packets. This segmentation allows each function to be optimized independently, with PTP handling time reference and transport packets handling precise counter values

Inventive Principle:
Principle #1Segmentation

2Reliability

If coaxial cables are used for signal distribution, then STC counter value transmission is reliable, but IP-based implementation cannot be achieved

Engineering Contradiction:
Improvesignal distribution reliabilityVSAvoidinterface implementation flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent makes the system universal by enabling STC counter value transmission through IP-based transport streams. The same transmission infrastructure can carry both video/audio data and synchronization information, allowing the system to function reliably over IP networks while maintaining compatibility with existing broadcasting standards

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

Solution Approach 2:

The patent substitutes the mechanical coaxial cable connection with an IP-based digital transmission system. Instead of requiring physical coaxial connections for STC value transmission, the system uses network packets over Ethernet, replacing the mechanical interface with a software-defined communication protocol

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

3Adaptability or versatility

If all interfaces are constructed by IP packets, then system adaptability is improved, but STC counter value synchronization cannot be achieved

Engineering Contradiction:
Improveinterface implementation flexibilityVSAvoidSTC counter value synchronization precision
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent implements feedback mechanisms through the transport stream structure, where PCR packets containing STC counter values are continuously transmitted and can be monitored for synchronization status. The system can detect and correct timing deviations by comparing received counter values with local clock information, ensuring precise synchronization over IP networks

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3554090B1Synchronization control apparatus and synchronization control method
Publication Date: 2022.03.02 KK TOSHIBA
  • EP3554090B1 patent drawingFigure 1
  • EP3554090B1 patent drawingFigure 2
  • EP3554090B1 patent drawingFigure 3

AI summary

According to one embodiment, there is provided a synchronization control apparatus which synchronizes an STC counter value, based on TAI (Temps Atomique International: international atomic time) time, in each of systems which constitute a transmission system in a broadcasting system or a distribution system, the apparatus includes a processor or a dedicated arithmetic circuit configured to determine a time length in which the STC counter value laps, to calculate a remainder of the time length relative to the TAI time, and to convert the remainder to the STC counter value, thereby determining the STC counter value.