Inter Vehicular Communication For Collision Avoidance Using Wi Fi Direct

"Inter vehicular collision avoidance systems warn vehicle drivers of potential collisions. The U.S Department of Transportation (USDOT) National Highway Traffic Safety Administration, in February 2014 has decided to enable vehicular communication among lightweight vehicles to exchange warning messages to prevent accidents. Dedicated Short Range Communications (DSRC) is a communication standard that allows short-range communication between vehicles and infrastructure, exchanging critical safety information to avoid collision. DSRC safety applications include forward collision warning, sudden brake warning and blind spot warning among many other warnings. It is also important to exchange location information between vehicles and pedestrians to avoid accidents. To exchange safety messages using DSRC, dedicated equipment is required. Pedestrians may not benefit from DSRC, as they may not carry dedicated DSRC safety equipment with them. Wi-Fi Direct technology can be used as an alternate to DSRC to exchange safety messages. Wi-Fi Direct enabled smartphones can exchange important safety information without the need of additional equipment. Peer-to-Peer (P2P) connections are formed between Wi-Fi Direct devices to exchange safety information. The Group Owner acts as the access point through which all clients communicate. This work examines how Wi-Fi Direct can be used in vehicular environment to exchange basic safety information between smartphones of vehicle drivers. Wi-Fi Direct and DSRC transmission delays are calculated are calculated. The results show, with more devices in a Wi-Fi Direct group the congestion in the network increases due to unnecessary retransmissions through the group owner. As mitigation, a broadcast method is proposed to reduce the delay. The results illustrate that the P2P group can now accommodate more vehicles and the delay is lesser. The calculations are extended to compute the transmission delay when P2P groups of same size exchange safety messages. The results help analyse the limitations of the system."--Abstract.