# Managing Emergency Situations in VANET Through Heterogeneous Technologies Cooperation
## 1 Introduction  
In the first half of 2017, more than 80,000 road accidents with injuries to people happened only in Italy, causing more than 110,000 injuries, and 1600 deaths [1]. Every year in the world 1.25 million people die for road accidents an in one third of the cases the fault is the excessive speed. This is stated in a report published by the _World Health Organization_ (WHO) [2]. Clearly, road accidents represent a big issue for the entire planet, due to people that lose their life on the roads. Given such dramatic numbers, from several years, the whole scientific community is continuously researching about new possibilities offered by the new technologies in vehicular environments. _Car-to-Car_ (C2C) communication paradigm allows the development of many new applications in vehicular environment, especially related to the road safety. The increasing research and development activity in the _Intelligent Transportation System_ (ITS) [3] environment is due to the huge diffusion of transport vehicles and, proportionally, to the number of accidents that happen. Generally, the main reason for these dramatic events is related to the violation of the traffic rules and to the bad driving styles: a solution that provides the cooperation of heterogeneous technologies (such as IEEE802.11p, GPS and Radar) could be helpful in preventing critical situations. The use of these standards and the related road infrastructures could help drivers to avoid accidents, introducing into the driving system a new set of information (_in fortainment_)about road conditions, enhancing drivers' sight along the road [4; 5]. Recent researches try to exploit IEEE802.11p to allow multi-hop communications [6] and to make an efficient data dissemination [7; 8], exploiting ad-hoc connections that could be created on the IEEE802.11p-based network. To prevent accidents when driving, current systems make use of vehicle detection through active (e.g., laser) or passive (e.g., camera) sensors. The laser allows to calculate the distance from other cars that come across during the trip. Passive sensors permit to acquire data in a non-intrusive way [9]. In [10] the authors show the importance of the beacon messages for exchanging vehicles information between them in order to create cooperative awareness and understanding the right frequency interval. In this paper, in order manage in a scalable way car traffic, we propose a full integration framework between vehicle sensors and IEEE802.11p-based _On-Board Unit_ (OBU) technology. Clearly, a communication protocol should be also properly designed, in order to deal with the data dissemination, maintaining the overhead under acceptable levels. The possibility to integrate the _Vehicular Ad-hoc Network_ (VANET) components with vehicular equipments can improve safety and road management by collecting and analyzing data properly. In this work, the concept of OBU is extended in order to have the possibility to acquire data from vehicle's sensors, to have a deeper knowledge of the surrounding environment. In this way, it is possible to act in a better way on protocol management by avoiding to flood unnecessary messages in the network. _Extended On-Board Units_ (E-OBUs) can exploit acquired data from sensors to know their neighbors and monitor them and, in case of strange behavior, it can act on the vehicle behavior to reduce damages or avoid collisions.