Abstract:
Emerging mobile applications involving distributed control and sensing call for accurate time synchronization over wireless links. This paper systematically studies the p...Show MoreMetadata
Abstract:
Emerging mobile applications involving distributed control and sensing call for accurate time synchronization over wireless links. This paper systematically studies the performance of Precision Time Protocol (PTP) in today’s Wi-Fi networks. We investigate both software and hardware PTP implementations. Our study uncovers the root causes of software PTP synchronization errors. We show that with fine-tuned system configurations and an online calibration procedure, software PTP can achieve reasonable accuracy with off-the-shelf Wi-Fi devices. Hardware PTP requires a PTP hardware timestamper clock not contained in Wi-Fi NICs. We propose a method to make use of the hardware TSF counter to emulate the PTP clock. Rigorous tests traversing various conditions show that both software and hardware PTP implementations can achieve 1- \mu s level accuracy on current ARM and x86 mobile platforms with practical Wi-Fi settings.
Published in: IEEE/ACM Transactions on Networking ( Volume: 31, Issue: 6, December 2023)