Ethernet Cascading Conference Phone Clock Offset Compensation
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Solution Overview
Problem
Existing Ethernet-based cascading conference phone systems rely on dedicated hardware for clock synchronization, limiting universality and chip selection, and are prone to clock offsets, network jitter, and asynchronous playback issues.
Innovation Solution
The system employs a master and slave conference phone configuration where the master phone sends synchronized broadcast packets, and the slave phone calculates and compensates for clock offsets by linearly adjusting the real-time stream signal, eliminating the need for hardware-based synchronization and enabling signal compensation across different chip solutions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dedicated hardware is used for clock synchronization, then clock synchronization is achieved, but chip selection is limited and universality is reduced
Solution Approach 1:
The patent replaces the hardware-based clock synchronization mechanism with a software-based solution. The slave device calculates clock offset by comparing timestamps from synchronized broadcast packets and compensates for the offset through software processing of audio data, eliminating the need for dedicated hardware synchronization chips and enabling universal application across different chip solutions.
Solution Approach 2:
The patent introduces synchronized broadcast packets as an intermediary mechanism to transmit timing information between master and slave devices. These packets serve as a mediator that enables the slave device to calculate clock offset without requiring direct hardware synchronization, thereby achieving both reliability and versatility.
2Reliability
If hardware-based clock synchronization is implemented, then clock offset is compensated, but device complexity increases due to dedicated chips
Solution Approach 1:
The patent substitutes complex hardware synchronization circuits with simple software algorithms. The slave device uses basic timestamp comparison and linear interpolation calculations to achieve clock offset compensation, significantly reducing device complexity while maintaining compensation effectiveness.
Solution Approach 2:
The slave device performs self-calibration by autonomously calculating its own clock offset based on received synchronized broadcast packets and automatically compensating for the offset in its audio processing, eliminating the need for external hardware synchronization components.
3Area of stationary object
If multiple conference phones are cascaded, then coverage range is extended, but clock asynchronization and network jitter affect speech quality
Solution Approach 1:
The patent implements a feedback mechanism where the slave device continuously monitors clock offset by comparing timestamps in synchronized broadcast packets and dynamically adjusts its audio processing parameters to compensate for the offset, thereby maintaining speech quality despite cascading and network jitter.
Solution Approach 2:
The master device pre-calculates and embeds timing information in synchronized broadcast packets before transmission. The slave device uses this preliminary timing data to proactively compensate for clock offset in incoming audio streams, preventing speech quality degradation before it occurs.
Data Source
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AI summary
The present invention discloses an Ethernet-based cascading conference phone device, which includes a master conference phone and a slave conference phone. The master conference phone receives at least one network data packet through an Ethernet, obtains a real-time stream signal according to the at least one network data packet, plays the real-time stream signal after a delay, sends the real-time stream signal to the slave conference phone, periodically sends at least one synchronized broadcast packet to the slave conference phone. The slave conference phone receives the at least one synchronized broadcast packet, receives the real-time stream signal, calculates a master-slave clock offset according to the at least one synchronized broadcast packet, performs linear compensation on the real-time stream signal according to the master-slave clock offset to obtain a compensation real-time stream signal, plays the compensation real-time stream signal and sends the real-time stream signal to the master conference phone.