Spatially Constrained Dissemination of Traffic Information in Vehicular Ad Hoc Networks

Distributed traffic information systems apply inter-vehicular ad hoc communication to disseminate information on the current state of road traffic. The high amount of traffic information carried and flooded along the road network leads to frequent appearance of broadcast storms and superfluous forwarding. These negative effects are usually reduced by using rate adaptivity in the dissemination mechanisms. This paper takes a further step by proposing a dissemination strategy with spatial context-awareness, as well. An algorithm is presented to calculate the areas of interest on a digital map, where vehicles should be informed in case of an incident. Based on this information, the dissemination protocol is able to reduce the flooding not only temporally, but also spatially. The behavior of a dissemination protocol with spatial-awareness is explored through simulations. Our approach performs better than the previous solutions in terms of channel utilization, while the travel time of vehicles remained unaffected.