Vehicular traffic monitoring in V2I systems using a wireless sensor network

In the near future the majority of the automotive systems will strongly rely on the exchange of information among vehicles or infrastructure to improve the driving conditions, increment security or simply have access to internet and entertainment services. This is the reason why the research and development of Vehicular Ad-Hoc Networks is very important nowadays. In this paper, a design and analysis of a Vehicular Ad-Hoc Network (VANET) assisted by an event driven Wireless Sensor Network (WSN) for traffic monitoring in a highway is presented. The aforementioned WSN is based on the wellknown LEACH protocol. However, a key modification is proposed in order to increase the network lifetime for applications on VANETs. The basic idea is to minimize the overlapping areas among neighboring clusters in order to reduce redundancy and to have a better coverage of the supervised highway with a lower transmission cost. Additionally, two different methods for the event reporting are proposed. In the first one, the traffic information is transmitted exclusively among the WSN nodes, while the second method makes use of the vehicles in order to relay the information to the sink. The proposed methods are analyzed in terms of energy consumption and average report delay.