Servo design for improved performance in software timestamping-assisted WLAN synchronization using IEEE 1588

Abstract

The clock servo is an essential constituent of distributed clock synchronization systems and a determining factor for the synchronization performance. This paper focuses on the clock servo design for better accuracy and precision in software-based clock synchronization over WLAN. The behaviour of the clock servo is analysed in this work and errors arising from software timestamps and the oscillator are evaluated. These errors are then used to investigate the operating conditions of the servo loop which results in the least synchronization offset and jitter. Results are obtained through simulations and then verified experimentally by a prototypical implementation. The results indicate that the synchronization performance is optimal when the servo relies more on the oscillator and less on the software timestamps.