High Velocity Aware Clocks Synchronization Approach in Vehicular Ad Hoc Networks

Clock synchronization plays an important role in communications organization between applications in Vehicular Ad hoc NETworks (VANETs) requiring a strong need for coordination. Having a global time reference or knowing the value of a physical clock (indeed with an acceptable approximation) of cooperative process involved in the provision of a service by distributed applications, takes on a fundamental importance in decentralized systems, particularly in VANETs. The intrinsic and constraining features of VANETs, especially the high mobility of vehicles make the clock synchronization mechanisms more complex and require a concise and a specific adequacy. The aim of the work reported in this paper is to propose a new protocol for clocks synchronization for VANETs, sufficiently robust, with a good precision, and convenient to the main constraint such high nodes mobility. Our proposed protocol, named Time Table Diffusion (TTD), was simulated using a combination of two simulators: VanetMobiSim and NS2 to evaluate its performance in terms of convergence time and number of messages generated. The obtained results were conclusive.