Sub-Microsecond Network Synchronization for Distributed Wireless PHY Protocols

Abstract

We present a hybrid wired-wireless time synchronization method targeting enterprise WLAN networks to enable future deployments of distributed wireless PHY protocols. Our method synchronizes all network APs on the Ethernet backhaul using the IEEE 1588 Precise Time Protocol, while all clients are synchronized to their home AP via reference broadcast synchronization. We implement this synchronization primitive on WARP software-defined radios and evaluate through a microbenchmark involving four network links. The results verify that our method achieves sub-microsecond synchronization accuracy among all network nodes and therefore serves as an effective building block for protocol development.