Time synchronization method of IEEE 802.1AS through automatic optimal sync message period adjustment for in-car network

We investigated the performance of the IEEE 802.1AS time synchronization protocol and its usage in in-vehicle networks by assessing the precise time synchronization mechanisms, such as offset correction, rate correction and the automatic optimal sync message period. In particular, this paper presents a method for adjusting the optimal synchronization message period to achieve high-precision time synchronization for the in-car network. Since the in-vehicle network is a static network, and performs synchronization when the ignition is turned on, the synchronization algorithm is not required for a certain period of time. Performing the synchronization algorithm too frequently can lead to vehicle malfunction and an increase in the network traffic load. Thus, according to current in-vehicle network circumstances, the best synchronization performance of the in-vehicle network is proposed by determining an optimum synchronization message period.