Inter-vehicle Geocast Protocol Supporting Non-equipped GPS Vehicles

IVG is a GPS-based Inter-Vehicle Communication protocol used for alarm message dissemination among vehicles in a highway in risk situations. It is based on the principle of wireless ad hoc networks. In this paper, we propose an improvement to IVG towards supporting its interoperability in environments where vehicles “GPS-U” without GPS devices are present. It is also the case, because of obstacles, where certain vehicles have GPS devices but cannot obtain their position via GPS. The proposed solution allows GPS-U vehicle to compute its position with the help of its neighbors that are equipped with GPS devices “GPS-E”. Analyses show that the optimal performances of IVG can be reached even when the rate of GPS-U vehicle is 40%.