Quorum-based location service in Vehicular Sensor Networks

Geographic routing in Vehicular Sensor Networks (VSNs) has been considered as an efficient and scalable approach since it exploits location information instead of topology information to route data packets. Geographic routing requires sources to be aware of the location information of destinations. Many solutions have been proposed to provide the location information of destinations in ad hoc and sensor networks. However, they are not suitable and energy-efficient for VSNs because the field property of VSNs is very different from that of ad hoc and sensor networks. In VSNs, sensor nodes are deployed on roads and vehicles also moves on the roads. Thus, we propose a quorum-based location service scheme to provide source nodes with the location information of the vehicles in VSNs. The proposed scheme exploits the property of the road map in VSNs. For providing location service, a location query makes a quadrangular path quorum and a location update makes a line path quorum. Then, the proposed scheme guarantees a crossing point between the quadrangular path quorum and the line path quorum. A sensor node on the crossing point sends a location reply to source nodes. The source nodes deliver their data to the vehicle via geographic routing. For data delivery to the moving vehicles, we also propose a mobility supporting scheme. Simulation results shows that the proposed scheme has better performance than the existing scheme in terms of the number of transmitted and received packets and the location service delay.