TLST: Time of Arrival Based Localization and Smart Tunnel concept in VANETs

The working of the GPS requires a clear line of sight for accurate services. However this is a drawback when the vehicle is stuck in a long tunnel or a place where the GPS data is unavailable. In this paper we propose the TLST: Time of Arrival Based Localization and Smart Tunnels in VANETs. The paper focuses on the time of arrival and time difference of arrival based localization in the vehicular ad hoc networks. We propose a scenario, where we have a vehicular cloud, roadside cloud and the central cloud server for managing the real time on road safety applications. The vehicle that is stuck in a tunnel or a place where the GPS data is unavailable, we propose to serve that particular vehicle with resources in a shared network with the help of the vehicular cloud network. An on board unit is installed in the vehicles moving in the vehicular cloud such that the data exchange takes place and then the computation of the algorithm proposed takes place in this on board unit. The location of the stuck vehicle can be calculated with the help of the time of arrival and the time difference of arrival based approach as shown in the algorithm. The direction estimation based on the cardinal points is then calculated for the nearest reference vehicle to track down the target vehicle. The other vehicles moving in that vehicular cloud network, will also take pictures and video of the stuck vehicle with the help of a camera enabled in the on board unit and share it in the network in order to avoid any collision and maintain a safe on road environment. The proposed algorithm has been simulated with the help of SUMO (traffic simulator) and NS2 (network simulator) and then crosschecked with the help of PERL scripts for the proof of concept and theory. All this activity in the vehicular cloud and the roadside cloud will further be monitored by the traffic official with the help of a smart app that accesses the data from the central cloud server.