The FleetNet project develops a wireless multi-hop ad hoc network for inter-vehicle communication to improve the driver's and passenger's safety and comfort. Key design requirements for FleetNet are the capability to distribute locally relevant data where generated and needed and to satisfy the vehicle drivers' and passengers' needs for location-dependent information and services. Location awareness and position data play a crucial role not only for FleetNet applications but also for the communication protocols deployed.

NEC Network Labs Europe and University of Mannheim design and evaluate position-based routing and forwarding strategies for vehicular ad hoc networks within the framework of the FleetNet project. We follow a three-pronged approach looking at a) analytical investigations, b) performance evaluation via simulation, and c) implementation of a real-world vehicle test network.

Analysis and Simulation:
Based on highly accurate vehicle movement patterns provided by DaimlerChrysler AG we compared position-based routing strategies with 'traditional' topology-based ad hoc routing strategies for the case of highway and city scenarios.

We developed and evaluated a forwarding method called 'contention-based forwarding' (CBF) where the next hop in the forwarding process is selected through a distributed contention process based on the exact current positions of all neighbors. Our results show that CBF significantly reduces the load on the wireless channel required to achieve a specific delivery rate compared to standard beacon-based greedy forwarding strategies.

Real-world test network implementation:
Together with DaimlerChrysler AG, we implemented a position-based router for inter-vehicle communications. We have set up and evaluated a test network of 6 DaimlerChrysler Smart cars equipped with GPS receivers, IEEE 802.11 WLAN NICS with planar antennae and our router. The test network allows global monitoring of the ad hoc network via GPRS.

Book chapters:
Jörg Widmer, Martin Mauve, Hannes Hartenstein, Holger Füßler. Position-Based Routing in Ad-Hoc Wireless Networks. In Mohammad Ilyas (ed.): The Handbook of Ad Hoc Wireless Networks, CRC Press, 2002, Boca Raton, FL, U.S.A.

Journal articles:
Martin Mauve, Joerg Widmer, Hannes Hartenstein. A survey on position-based routing in mobile ad hoc networks, IEEE Network Magazine, pp. 30-39, November/December 2001.
Martin Mauve, Hannes Hartenstein, Holger Füßler, Jörg Widmer, Wolfgang Effelsberg. Positionsbasiertes Routing für die Kommunikation zwischen Fahrzeugen . it + ti 44 (5), pp. 278--286, October 2002.
Holger Füßler, Joerg Widmer, Michael Kaesemann, Martin Mauve, Hannes Hartenstein. Contention-based forwarding for mobile ad hoc networks. Accepted for publication in the Ad Hoc Networks Journal, Elsevier, pp. 351-369, Nov 2003.

Conference and workshop papers:
Michael Käsemann, Hannes Hartenstein, Holger Füßler, Martin Mauve. Analysis of a Location Service for Position-Based Routing in Mobile Ad Hoc Networks. Proc. of the 1st German Workshop on Mobile Ad-hoc Networking (WMAN 2002), pp. 121 -- 133, March 2002, Ulm, Germany.
Holger Füßler, Martin Mauve, Hannes Hartenstein, Michael Käsemann, Dieter Vollmer. Location-Based Routing for Vehicular Ad-Hoc Networks. Poster at ACM MobiCom '02, ACM MC2R, September 2002, Atlanta, GA.
Christian Lochert, Hannes Hartenstein, Jing Tian, Holger Füßler, Dagmar Herrmann, Martin Mauve. A Routing Strategy for Vehicular Ad Hoc Networks in City Environments . IEEE Intelligent Vehicles Symposium, June 2003, Columbus, Ohio.