Wireless Audio Clock Sync via Physical Transmission Rates

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Solution Overview

Problem

Existing wireless audio synchronization systems face disruptions due to variations in physical transmission rates on networks, leading to inconsistent clock synchronization among audio playback devices, especially when network access points go into non-communicative modes or experience sudden disturbances.

Innovation Solution

An audio distribution system that incorporates a clock synchronization algorithm considering physical transmission rates between audio playback devices and network access points, using a method that calculates adjusted transmission times to ensure consistent time updates across devices, even in varying network conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If standard clock synchronization protocols are used, then basic time synchronization is achieved, but synchronization accuracy deteriorates when physical transmission rates vary

Engineering Contradiction:
Improvetime synchronization accuracyVSAvoidsynchronization reliability under varying transmission rates
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent changes the parameters used in clock synchronization from standard NTP parameters to physical transmission rate parameters. The system measures actual transmission times and uses these measured parameters to calculate clock adjustments, rather than relying on standardized timing protocols that assume constant transmission rates.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system implements feedback by continuously measuring physical transmission rates between devices and using this feedback to adjust clock synchronization. The measured transmission times are fed back into the synchronization algorithm to compensate for rate variations, creating a closed-loop system that adapts to changing network conditions.

Inventive Principle:
Principle #23Feedback

2Use of energy by moving object

If network access points operate in non-communicative modes, then energy consumption is reduced, but transmission time variability increases

Engineering Contradiction:
Improveaccess point energy consumptionVSAvoidtransmission time variability
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

The system performs preliminary measurements of transmission rates during normal communication periods and stores these measurements. When the access point enters non-communicative mode, the system uses the pre-measured transmission rate data to predict and compensate for transmission time variations, rather than attempting real-time measurements during the non-communicative period.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If physical transmission rate variations are not compensated, then system complexity is reduced, but audio playback synchronization deteriorates

Engineering Contradiction:
Improvesynchronization system complexityVSAvoidaudio playback synchronization
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces an intermediary measurement and compensation layer between the physical network transmission and the audio playback system. This intermediary component measures actual transmission rates and calculates compensation values that are applied to the audio playback timing, isolating the playback system from direct exposure to transmission rate variations.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3868043B1Wireless audio synchronization
Publication Date: 2022.08.17 BOSE CORP
  • EP3868043B1 patent drawingFigure 1
  • EP3868043B1 patent drawingFigure 2
  • EP3868043B1 patent drawingFigure 3

AI summary

An audio distribution system includes a first playback device with a first clock time, and a second playback device with a second clock time. A wireless access point is wirelessly coupled to the first and second playback devices. The second playback device sends a time request to the first playback device via the wireless access point. The first playback device responds to the time request by sending a time response to the second playback device via the wireless access point. The second playback device calculates an update to the second clock time based on the time response, a first physical transmission rate between the second playback device and the wireless access point, and a second physical transmission rate between the first playback device and the wireless access point. The second playback device uses the update to the second clock time to playback audio in synchrony with the first playback device.