A simulation-based comparison of IEEE 802.11's timing advertisement and SyncTSF for clock synchronization

Abstract

The absence of built-in clock synchronization support for IEEE 802.11 networks has been a concern for industrial applications which are seeking to use wireless networking on the factory floor. In IEEE 802.11-2012, the timing advertisement (TA) mechanism is proposed which provides guidelines for the application synchronization. It involves calculating and maintaining the time offset with respect to the timing synchronization function (TSF) timer of the access point. In the wireless stations, the TSF-based synchronization mechanism and the offset are combined to establish synchronization to an external timebase. With respect to the lack of implementation guidelines and support for the TA scheme, this paper compares and discusses the TA scheme and the software-based SyncTSF scheme previously proposed by the authors, which employs the TSF timer as the timing source in the network. The initial simulation results show that both schemes can provide similar performance, depending upon the controller design and the timestamping technique.