James E. Marca

Autonet: Inter-vehicle Communication and Network Vehicular Traffic

With the proliferation of wireless communication technologies, inter-vehicle communication (IVC) could potentially be applied to solve ever-worsening transportation problems around the world. In this paper, we study impacts of network vehicular traffic on IVC, apply IVC to route-guidance and report preliminary field tests. These studies are intended to demonstrate the feasibility of IVC-based traveller information systems and the interaction between IVC and network vehicular traffic.

Design, Implementation and Test of a Wireless Peer-to-peer Network for Roadway Incident Exchange

The existing paradigms for vehicular traffic monitoring and control have a strong infrastructure bias. Data collection and processing typically require a support system that may be prohibitively expensive or suffer from scalability issues. Current research aims to solve these problems with local-area wireless technology, allowing the vehicles themselves to form an ad hoc network. Our vision of such a traveller-centric, zero-infrastructure system is called Autonet. In this paper, we present the key Autonet concepts, validated through a prototype implementation and field measurements. In the prototype, an in-vehicle client with an informative GUI continuously listens for other clients, exchanging knowledge about network state once contact is made. We show that knowledge about traffic conditions can be propagated successfully using this system. The prototype also enabled benchmarking of 802.11b wireless technology in a transportation environment. These measurements establish its maximum throughput at approximately 3,500 traffic incidents for two vehicles passing at highway speeds.

Design, Implementation, and Test of a Wireless Peer-to-Peer Network for Roadway Incident Exchange

Vehicular traffic monitoring and control has had a strong infrastructure bias—data is controlled centrally, processed, and the redistributed to travelers and other clients. There are several efforts to decentralize traffic monitoring by leveraging advanced local area wireless technology. This paper describes our implementation of such a traveler-centric system, called Autonet. Each Autonet client exchanges network knowledge wirelessly with other, nearby clients. It is demonstrated that knowledge about traffic state can be propagated using this system. The client programs were also used to test the actual throughput possible for messages sent from one vehicle to another using 802.11b wireless hardware. These measurements establish the maximum throughput at about 4,000 incidents for two vehicles moving in opposite directions at highway speeds.