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Inquiring traffic information is an important issue in vehicular ad hoc networks. This paper proposes an aggregating data dissemination algorithm in vehicular ad hoc networks. This algorithm can offer the various degrees of traffic information when users propose inquiry for different regional ranges. The user often needs to obtain the detailed data from the small area or the summary data for the large...
In this paper we investigate physical layer requirements for the NOTICE system proposed for notification of traffic incidents. The system uses short-range wireless communication between vehicles and sensor belts embedded in the roadway which impose constraints on time available for connection and data exchange, and we study the probabilities of establishing the wireless link and of successfully exchanging...
Vehicular communications provide new convergence applications by combining vehicles and communication technologies. In this paper, we consider the anti-collision warning application using vehicle-to-vehicle (V2V) communication. First, we introduce the general and special features of the overall system and specifications of the communication prototype. Then, we investigate the application scenarios...
The state of the art of vehicular communications includes extensive investigations on distributed-contention approaches (mostly focused on WiFi CSMA/CA optimal and/or custom configurations), while scalable solutions for a distributed but contention-free wireless architecture remain unexplored. In this paper, starting from an existing protocol called RR-Aloha, we propose some novel extensions to it,...
In vehicular communications, safety applications are the most challenging and they have become a main target in the research activity. Comprehensive testing and validation of such applications is very complex, but it is absolutely necessary if the applications are going to be widely used in vehicles all over the world. In this scope, simulation is an indispensable tool for leading the way to new test...
A novel design solution for a low-profile full-duplex satellite-on-the-move communications hybrid scanned phased array antenna for low elevation angle coverage (down to 10??) is described. The antenna is operated at Ku-Band. The unique louvered array element geometry in combination with a spatial filter/ ??ray bending?? lens facilitates the shaping of the element pattern to increase gain at low elevation...
In this paper we present an advanced method to offer differentiated Internet access to users of public transportation systems. On one hand, enterprise VPN access is offered to employees of the public transportation agency; on another hand, straight access to Internet is offered to passengers - both passengers and employees are part of same vehicular moving network. The double addressing scheme is...
Vehicular networks (VANET) attract a lot of attention in the research world. Novel vehicular applications need suitable communication mechanisms to extend in-vehicle capabilities and, be aware about surrounding events. However, these networks present some characteristics, such as high mobility or specific topologies. These properties affect the performances of applications and more effort should be...
The availability of efficient location system receivers, numerous calculation techniques of the relative coordinates and the need to design an efficient and a scalable network are the main reasons for geographical information usage in vehicular networks (VANET). IPv6 is considered as the most appropriate technologies to support communication in VANET thanks to its extended address space, enhanced...
Non wide-sense stationary (WSS) uncorrelated-scatterering (US) fading processes are observed in vehicular communications. To estimate such a process under additive white Gaussian noise we use the local scattering function (LSF). In this paper we present an optimal parametrization of the multitaper-based LSF estimator. We do this by quantizing the mean square error (MSE). For that purpose we use the...
One of the fundamental requirements of a traffic management system is the ability to determine when an incident has occurred so that proper responses can be initiated. Most of the existing automatic incident detection techniques suffer from many limitations including their inability to detect incidents under non dense traffic conditions and generation of many false positive alarms. In this paper,...
Idea of accessing broadband services from already deployed WiFi APs while travelling at vehicular speed has gained considerable popularity among the researchers. Random location of APs makes it difficult to get continuous Internet connection. As a result, a mobile node moving at vehicular speed faces periods of connections and disconnections; this intermittence is termed as "disruption"...
In this paper, we propose a location-release signature scheme based on bilinear pairings for vehicular ad hoc networks (VANETs). Location-release signature is a capsule signature signed by a source location server that becomes valid after the signature arrives at a specific destination location, where a location server publishes some trapdoor information associated with such a destination location...
This work presents the performance analysis and optimization of the IEEE 802.11p Physical layer and the implementation of the forward error correction (FEC) coding chain on Xilinx FPGA hardware. A MATLAB simulation is carried out in order to analyze baseband processing of the transceiver. IEEE 802.11p wireless access in the vehicular environment defines modifications to IEEE 802.11 to support intelligent...
Vehicular networking (VN) has reached a high level of maturity, but security mechanisms have only recently been explored. The nature of VNs requires that nodes not behaving as expected should be detected without delay and eliminated to avoid possibly fatal traffic accidents. This paper redefines and explores the problem of estimating the vulnerability window as the time it takes to detect and eliminate...
In vehicular communications, the channel estimation is critical to compensate signal distortion due to wireless channel in high mobility scenario. To improve the error performance of vehicular communications, we proposed the midamble-based channel estimation scheme. Based on the proposed scheme, we investigate the effect of midamble insertion on the system performance. With various midamble insertion...
The rapid deployment of wireless networks has radically changed the development methods of applications and solutions. Nevertheless, there are still poorly served areas with network infrastructures, especially the road systems when considering the intelligent transportation systems and on-the-road Internet and entertainment services. While the most known solutions of vehicular communications network...
Cooperative collision warning, based on vehicle-to-vehicle radio communications and GPS systems, is one of the promising active safety applications that have attracted considerable research interest. In this paper, we address one of the functional key points of the cooperative collision warning application, which is an accurate estimation of the range data of neighboring vehicles during persistent...
Vehicular communications attract the attention of many people in the networking research world. These networks present some special features, such as high mobility or specific topologies, which affect the performance of applications. In order to select the appropriate technologies, more effort should be directed to identify the final necessities of the network. Few works identify possible applications...
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