Data aggregation in VANETs: the VESPA approach

VESPA (Vehicular Event Sharing with a mobile P2P Architecture) 1 is a system for enabling vehicles to share information in vehicular ad-hoc networks (VANETs). The originality of VESPA is to process and disseminate any type of event (e.g., available parking spaces, accidents, emergency braking, information relative to the coordination of vehicles in emergency situations, etc.). The basic functions of VESPA are both disseminating events to potentially interested vehicles and evaluating their relevance once received in order to determine, for instance, whether the driver should be warned or not. This paper concentrates on knowledge extraction in VESPA. In particular, it focuses on how to exploit data exchanged among vehicles to produce knowledge to be used later on by drivers. Existing systems only use exchanged data to produce warnings for drivers when needed. Then, data is considered obsolete and is deleted. In contrast, we propose to aggregate data once it becomes “obsolete”. Our objective is to produce additional knowledge to be used by drivers when no relevant data has been communicated by neighboring vehicles. For example, by aggregating events it is possible to dynamically detect potentially dangerous road segments or to determine the areas where the probability to find an available parking space is high.