IVI and Mobile Playback Latency Alignment for Synchronized Audio

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Solution Overview

Problem

Modern vehicles with in-vehicle infotainment systems face synchronization issues with mobile devices due to varying capabilities and performance, leading to out-of-sync multimedia playback.

Innovation Solution

A method to determine playback latency between a primary device (e.g., IVI system) and secondary devices (e.g., mobile devices) by sending messages and detecting responses, adjusting playback delays to synchronize multimedia content across devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If mobile devices are used for multimedia playback in the vehicle, then user preference and flexibility are improved, but playback synchronization with the IVI system deteriorates due to varying device capabilities and processing speeds

Engineering Contradiction:

Improveuser preferenceVSAvoidplayback synchronization

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The system implements a feedback mechanism where the IVI system sends a trigger message to the mobile device, which then plays back audio and returns a response message. The IVI system measures the round-trip time to calculate playback latency, continuously monitoring and adjusting for synchronization issues across different mobile devices

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the playback delay parameter of the mobile device based on measured latency. By changing the timing parameters and compensating for device-specific processing speeds, the system achieves synchronized playback across devices with varying capabilities

Inventive Principle:

Principle #35Parameter changes

2Reliability

If playback delay is adjusted to synchronize mobile device with IVI system, then playback synchronization is improved, but system complexity increases due to latency measurement and delay adjustment mechanisms

Engineering Contradiction:

Improveplayback synchronizationVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The mobile device autonomously measures its own playback latency by receiving a trigger message, playing back audio, and returning a response message. The device self-adjusts its playback timing based on the measured delay, reducing the need for complex external control mechanisms

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system uses an intermediary audio signal (such as a chirp or tone) as a timing reference. This intermediary signal serves as a common reference point between the IVI system and mobile device, simplifying the synchronization process by providing a measurable event to track latency

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12587699B2Synchronizing playback of multimedia between in-vehicle and mobile devices

Publication Date: 2026.03.24 NISSAN MOTOR CO LTD

AI summary

Synchronizing playback of multimedia content between playback devices integrated into a primary device, such as an in-vehicle infotainment (IVI) system and one or more nearby secondary devices, such as mobile devices, being served multimedia content by the IVI system. The IVI system determines a playback latency of each mobile device and serves the multimedia content to each primary and secondary playback device with a respective delay based on a difference between a maximum playback latency across all playback devices and the respective determined playback latency. In some implementations, playback latencies may be determined using an audio signal. In other implementations, playback latencies may be determined using satellite-synchronized timestamps.