An implementation of IEEE 1588 protocol for IEEE 802.11 WLAN
Clock synchronization is one of the enabling technologies for Wireless Local Area Networks (WLAN). It is crucial to perform applications such as data fusion, location detection and energy conservation. IEEE 1588 Precision Time Protocol (PTP) is a widely used clock synchronization protocol, but its accuracy is affected by bidirectional asymmetric delays in WLAN. A detailed analysis of the generation mechanism and statistical properties of the bidirectional asymmetric delays in IEEE 802.11 WLAN is conducted firstly. Then, a Kalman filter is designed for delay filtering. And based on the Kalman filter, a clock servo system is proposed using pure software-based implementation of PTP for IEEE 802.11 WLAN. Finally, the effectiveness of the implementation is verified by experiments. Experimental results show that the implementation has the virtues of high synchronization accuracy, short convergence time and small deviation error.
ieee 1588 wlan synchronization bidirectional asymmetric delays kalman filter clock servo