VALS: Vehicle-aided location service in urban environment

In Vehicular Ad-hoc Networks (VANETs), any vehicle uses a location service to get an up-to-date data of all vehicles' positions in its vicinity. Many location services rely on infrastructures to perform location update and location query tasks. However, the infrastructure penetration rate may differ from one region to another. We propose in this paper a new location service called Vehicle-Aided Location Service in urban environment (VALS) which resolves the problem of the shortage of infrastructure in some city districts. VALS replaces the missing Road-Side Units (RSU) with vehicles offering RSUs functionalities. It is based on a hierarchical and cluster-based design. Simulation results show that VALS achieves a high success ratio (86%), get most vehicles' data (82%) and a good position information level accuracy (less than 20 m) with a low RSU penetration rate (40%).