Network Terminal Clock Synchronization via Round Trip Delay Offset
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Solution Overview
Problem
In data networks, independent receiver and transmitter clocks can lead to data starvation or overflow conditions due to random time delays, known as 'jitter', which affect the synchronization of audio-video data transmission and playback.
Innovation Solution
A method and system for synchronizing terminal clocks in a data network by determining the round trip delay time and offsetting slave terminal clocks to match a master terminal clock, ensuring a common time reference and adjusting for phase and frequency offsets to maintain synchronized playback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If independent clocks are used at transmitter and receiver, then device complexity is reduced, but synchronization reliability deteriorates due to jitter causing data starvation or overflow
Solution Approach 1:
A clock synchronization message is introduced as an intermediary carrier to transmit timing information from transmitter to receiver. The message includes timestamp data that enables the receiver to calculate network delay and adjust its clock accordingly, resolving the synchronization reliability issue while maintaining independent clock hardware
Solution Approach 2:
The receiver calculates the round-trip delay by comparing the received timestamp with its local clock time, then uses this feedback information to adjust its clock offset. This closed-loop feedback mechanism continuously compensates for jitter and maintains synchronization reliability
2Measurement precision
If clock synchronization messages are transmitted frequently, then synchronization precision is improved, but network bandwidth consumption increases
Solution Approach 1:
The system transmits clock synchronization messages at optimized intervals rather than continuously, using just enough synchronization updates to maintain acceptable precision while avoiding excessive bandwidth consumption. The synchronization period is tuned to balance precision requirements with network resource conservation
Data Source
AI summary
A method and system for network terminal clock synchronization includes determining a respective round trip delay time from a master terminal to each slave terminal and offsetting the clock of each slave terminal by an amount proportional to the respective determined round trip delay time such that the master terminal and each of the slave terminals have substantially the same point of reference in time. The method and system further include, in response to a trigger signal, determining a respective offset between the master clock of the master terminal and the clocks of each of the slave terminals and offsetting the clocks of each of the slave terminals by an amount proportional to the determined respective offset to synchronize the clocks of each of the slave terminals to the master clock of the master terminal.