Spatial Context-Awareness in Vehicular Ad Hoc Networks

Distributed traffic information systems apply inter-vehicular ad hoc communication to disseminate road traffic information. The high amount of traffic information carried and flooded along the road network leads to superfluous forwarding, which is usually reduced by using rate- or spatial- adaptivity in the dissemination mechanisms. However, in certain cases due to the lack of context-aware information, the current protocols employing distributed spatial adaptivity will fail to achieve the desired performance. Therefore, an off-line heuristic algorithm (SPACE) was proposed to calculate on a digital map the Domain of Interest (DoI) of traffic jams. Based on this information, the dissemination protocol will be able to reduce more efficiently the superfluous forwarding. This paper takes a further step by proposing an Integer Linear Programming (ILP) formulation for DoI optimizations, and analytically investigating the effect of spatial context-awareness on traffic information dissemination. The behavior of such a dissemination protocol is also explored through extensive simulations. Important characteristics on spatial adaptivity regarding the information dissemination strategies are concluded from the analytical and simulation results.