SSPV: Self-time Synchronization Protocol for Vehicular Networks

Time synchronization is fundamental for vehicular communications (V2X). In practical, V2X requires tight time synchronization for TDMA Medium Access Control (MAC) protocol and safety applications. Mostly, V2X devices are equipped with a Global Positioning System (GPS) receiver, which guarantees tight time synchronization for connected vehicles. However, vehicles might be subject to some GPS outages, especially inside tunnels. To address this issue, we introduce this paper. It proposes an efficient time synchronization technique called Self-time Synchronization Protocol for V2X (SSPV). It fixes the clock drift resulted from the GPS connectivity loss using a history of experienced time offsets. This paper shows that SSPV achieves significantly less synchronization error compared to the case of not applying any correction method. Simulation results show that our approach only incurs a maximum time offset of 80 microseconds for a time period of 30 minutes.