GNSS Synchronization in Vanets

The literature about GNSS in vehicular networks is usually restricted to the mutual interaction between positioning and routing (respectively with georouting and services of GNSS assistance). However, despite the apparent contradiction, also asynchronous vehicular ad-hoc networks (Vanets) built on the top of IEEE 802.11p require an absolute synchronization: this could be easily provided by the time information embedded in GNSS systems. This position paper analyses the issue of synchronization in Vanet both for the emerging asynchronous standard and for alternative synchronous solutions. The technical discussion adds also new elements useful for the comparative analysis among protocols for Vanets.