An improved map-based location service for vehicular ad hoc networks

Routing remains one of the key challenges in vehicular networks due to their special properties such as the high mobility and the intermittent connectivity. Almost all the efficient routing solutions proposed for VANETs are based on geographic information provided by the navigation systems widely deployed in the new generation of vehicles. Typically, in these position-based protocols, a source node has to discover the location of destination node before sending the data. In this paper, we propose a distributed hierarchical location service called Density aware Map-Based Location Service (DMBLS) for Vehicular Ad-hoc Networks. DMBLS makes use of the street digital maps and the traffic density information to define a three level-hierarchy of locations servers. This infrastructure-less scheme has proven to be robust to node mobility and well suited to dynamic networks. Simulations results obtained with different scenarios demonstrate that DMBLS achieves promising performances in terms of location query success ratio as well as the query and update delays with a good accuracy.