Cooperative relaying has been developed for wireless communications to mitigate the negative effects of small-scale fading caused by multipath propagation. A huge amount of research has been done in the past ten years to assess benefits and drawbacks of such techniques by simulations and analytical means. It is surprising, however, that only few studies with real-world measurements in realistic environments were published so far. The goal of a research team led by Christian Bettstetter at Klagenfurt’s NES institute is to contribute toward closing this research gap. Based on an implementation of a simple cooperative relaying protocol on the programmable radio platform WARP, measurements were conducted to evaluate the packet delivery performance in a car-to-car communications scenario. The results will be published in IEEE Wireless Communications Letters. “We studied the ratio and temporal correlation of packet delivery for suburban and highway environments using three cars serving as sender, relay, and destination,” Günther Brandner, a researcher in the project team, explains.
Freezing rain causes an accident on a highway. Sensors attached to cars detect this event and communicate it via WLAN to other cars to inform oncoming drivers. The implementation of new WLAN technologies for car-to-car communication is running at full speed. Bettstetter and his team have also been tackling this problem. Their key ideas lead to filing two patent applications. Esther Farys reports. Download article:
Technologies for ad hoc networking will enable car companies to include new safety and communication features into their cars. For example, efficient accident warnings are possible: Cars involved in an accident can send warning messages back over a number of other vehicles, thus avoiding motorway pileups. We could also envision person-to-person applications using ad hoc communication between vehicles (e.g., simple text messaging, game communities, or even hop-by-hop telephony). The goal of a panel at the 2005 MINEMA Summer School in Klagenfurt, Austria (July 11-15), was to discuss potential and feasible applications, technology and research challenges, visions, roadmaps, and risks of such scenarios. Each of the panelists gave a 5-10 minute statement, followed by a 20-minute discussion with questions from the audience. Panelists Moderator and Organizer: Christian Bettstetter (DoCoMo Euro-Labs, Munich, Germany) Hannes Hartenstein (University of Karlsruhe, Germany) Jean-Pierre Hubaux (EPFL, Lausanne, Switzerland) Timo Kosch (BMW Research and Technology, Munich, Germany) Kirsten Matheus (CarMeq, Berlin, Germany) Charles E. Perkins (Nokia Research, Mountain View, USA)