Data gathering in vehicular networks: The VESPA experience

The interest of intelligent transportation systems and vehicular networks is on the rise. In this paper, we present an overview of the development of VESPA, a system that we are developing for vehicles to share information (e.g., information about available parking spaces, accidents or obstacles in the road, emergency brakings, emergency vehicles asking the right of way, etc.) in inter-vehicle ad hoc networks. We summarize the research challenges that we have considered so far and the difficulties that still lie ahead. This includes the basic push-based approach used in VESPA, the resource allocation policy proposed to avoid competition in the access to scarce resources (such as parking spaces), and the development of data aggregation techniques for knowledge extraction. Besides, we also analyze our current and future work, which focuses on the exploitation of different data sources and pull-based query processing, the management of multimedia information, and the routing of query results.