Marc Torrent-Moreno

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Direct radio-based vehicle-to-vehicle communication can help prevent accidents by providing accurate and up-to-date local status and hazard information to the driver. In this paper, we assume that two types of messages are used for traffic safetyrelated communication: 1) Periodic messages (“beacons”) that are sent by all vehicles to inform their neighbors(More)
NS-2, with its IEEE 802.11 support, is a widely utilized simulation tool for wireless communications researchers. However, the current NS-2 distribution code has some significant shortcomings both in the overall architecture and the modeling details of the IEEE 802.11 MAC and PHY modules. This paper presents a completely revised architecture and design for(More)
One key usage of VANET is to support vehicle safety applications. This use case is characterized by the prominence of broadcasts in scaled settings. In this context, we try to answer the following questions: <i>i)</i> what is the probability of reception of a broadcast message by another car depending on its distance to the sender, <i>ii)</i> how to give(More)
The main goal of inter-vehicle communication technologies is to provide each vehicle with the required information about its surrounding in order to assist the driver avoiding potential dangers. The required information level, or awareness, can be achieved by the exchange of periodic status messages (beacons) among neighboring vehicles together with the(More)
Improving the safety of drivers and passengers by wirelessly exchanging information between vehicles represents a major driving force for the design of vehicular ad hoc networks. In a heavy loaded 802.11-based network, however, safety-related packets might collide frequently and cannot be decoded by a receiver, thus they might not be effective in increasing(More)
We address the challenge of how to share the limited wireless channel capacity for the exchange of safety-related information in a fully deployed vehicular ad hoc network (VANET). In particular, we study the situation that arises when the number of nodes sending periodic safety messages is too high in a specific area. In order to achieve a good performance(More)
In wireless one-hop broadcast communications, each node broadcasts messages to inform all neighbors within an intended communication range. Clearly, the packet transmission of the various nodes might interfere with each other due to the overlapping communication ranges. IEEE 802.11 Distributed Coordination Function (DCF) provides some basic mechanisms for(More)
NoW – Network on Wheels is a German research project carried out by major car manufacturers, suppliers, research institutes and universities, and supported by the German government. The project develops a vehicular communication system for car-to-car and car-to-infrastructure communication based on ad hoc principles and wireless LAN technology for road(More)
Mobile IP, the current IETF proposal for IP mobility support, represents a key element for future <i>All-IP</i> wireless networks to provide service continuity while on the move within a multi-access environment. We conducted a performance evaluation of Mobile IPv6 and its proposed enhancements, i.e., Fast Handovers for Mobile IPv6, Hierarchical Mobile IPv6(More)
The discrepancy between real-world radio channel behavior and its standard modeling in simulations (unit disk graph) is a major reason for protocols to perform differently - often worse - than predicted when deployed in a real-world setup. As researchers having to deal with real ad hoc networks are aware of, assuming a fixed border for a node's(More)