Inter Vehicular Communication Systems

Research Abstract

Our vision is focused on utilizing the intrinsic properties of vehicular traffic, coupled with modern communication, computing and information management technologies, in order to facilitate increased safety and situational awareness on high-speed highways. We anticipate an environment where traveling vehicles communicate among themselves, forming rapidly changing ad hoc network topologies. Several cars travel on a highway while communicating locally via an ad hoc wireless network Each car is equipped with a laptop or PDA equipped with a wireless LAN card (e.g., 802.11) for local communication and forms, around itself, a local area of communication. Cars that are further away, although they may constitute part of a neighbor's local area, are not part of that particular car's communication network. All cars broadcast information omni-directionally and receive data from any and every direction. There is no point-to-point communication link. The purpose of the ad hoc network is to impart information, i.e., the car's vital signs, to vehicles in close proximity and to receive the same data from them. The information is processed locally to provide the driver with a map indicating the status of each car in the immediate vicinity, e.g., acceleration, turning signal status, braking, etc.

We are faced with a very dynamic environment composed of fast-moving vehicles, which, from the communication perspective, translates into rapidly changing network topologies. In addition, the data that is exchanged between the vehicles is time sensitive. Since the communication devices are mounted in vehicles, power supply is practically unlimited thus making it possible to use fairly large antennas and on-board GPS devices. Also, the data is really of interest only to a small circle of neighboring vehicles.

Although the problem is simplified by the single-hop nature of the network and the consequent lack of routing, it also raises some concerns, primarily, the throughput of the system and the delays involved. Since data is time-sensitive, and in many cases, urgent in nature (e.g., speeding vehicle approaching in left lane), the system must be robust and capable to support the traffic load and its time critical needs. Tradeoffs to be investigated involve the type of data, its urgency and the practical limits of the system before it degenerates into chaos and data flow comes to a halt. More complex, multi-channel systems capable of coping with the traffic load and its delay constraints, pose a different set of problems associated with the speed with which vehicles can associate themselves to the different channels and maintain an up-to-date picture of their surroundings.