Showing papers on "Vehicular communication systems published in 2004"

Vehicle-to-vehicle safety messaging in DSRC

Abstract: This paper studies the design of layer-2 protocols for a vehicle to send safety messages to other vehicles. The target is to send vehicle safety messages with high reliability and low delay. The communication is one-to-many, local, and geo-significant. The vehicular communication network is ad-hoc, highly mobile, and with large numbers of contending nodes. The messages are very short, have a brief useful lifetime, but must be received with high probability. For this environment, this paper explores the efficacy of rapid repetition of broadcast messages. This paper proposes several random access protocols for medium access control. The protocols are compatible with the Dedicated Short Range Communications (DSRC) multi-channel architecture. Analytical bounds on performance of the proposed protocols are derived. Simulations are conducted to assess the reception reliability and channel usage of the protocols. The sensitivity of the protocol performance is evaluated under various offered traffic and vehicular traffic flows. The results show our approach is feasible for vehicle safety messages in DSRC.

A vehicle-to-vehicle communication protocol for cooperative collision warning

Abstract: This paper proposes a vehicle-to-vehicle communication protocol for cooperative collision warning Emerging wireless technologies for vehicle-to-vehicle (V2V) and vehicle-to-roadside (V2R) communications such as DSRC are promising to dramatically reduce the number of fatal roadway accidents by providing early warnings One major technical challenge addressed in this paper is to achieve low-latency in delivering emergency warnings in various road situations Based on a careful analysis of application requirements, we design an effective protocol, comprising congestion control policies, service differentiation mechanisms and methods for emergency warning dissemination Simulation results demonstrate that the proposed protocol achieves low latency in delivering emergency warnings and efficient bandwidth usage in stressful road scenarios

MDDV: a mobility-centric data dissemination algorithm for vehicular networks

Abstract: There has been increasing interest in the exploitation of advances in information technology in surface transportation systems. One trend is to exploit on-board sensing, computing and communication capabilities in vehicles, e.g., to augment and enhance existing intelligent transportation systems. A natural approach is to use vehicle-to-vehicle communications to disseminate information. In this paper, we propose MDDV, a mobility-centric approach for data dissemination in vehicular networks designed to operate efficiently and reliably despite the highly mobile, partitioned nature of these networks. MDDV is designed to exploit vehicle mobility for data dissemination, and combines the idea of opportunistic forwarding, trajectory based forwarding and geographical forwarding. We develop a generic mobile computing approach for designing localized algorithms in vehicular networks. Vehicles perform local operations based on their own knowledge while they collectively achieve a global behavior. We evaluate the performance of the MDDV algorithm using realistic simulation of the vehicle traffic in Atlanta area.

TrafficView: traffic data dissemination using car-to-car communication

Abstract: Vehicles are part of people's life in modern society, into which more and more high-tech devices are integrated, and a common platform for inter-vehicle communication is necessary to realize an intelligent transportation system supporting safe driving, dynamic route scheduling, emergency message dissemination, and traffic condition monitoring. TrafficView, which is a part of the e-Road project, defines a framework to disseminate and gather information about the vehicles on the road. With such a system, vehicle's driver will be provided with road traffic information that helps driving in situations as foggy weather, or finding an optimal route in a trip several miles long. This paper describes the design and implementation of TrafficView and the different mechanisms used in the system.

Security in Automotive Bus Systems

Abstract: This work presents a study of current and future bus systems with respect to their security against various malicious attacks. After a brief description of the most well-known and established vehicular communication systems, we present feasible attacks and potential exposures for these automotive networks. We also provide an approach for secured automotive communication based on modern cryptographic mechanisms that provide secrecy, manipulation prevention and authentication to solve most of the vehicular bus security issues.

Empirical determination of channel characteristics for DSRC vehicle-to-vehicle communication

Abstract: Dedicated Short Range Communication (DSRC) wireless band, allocated by the FCC for vehicular communication, constitutes the basis for one of the first vehicular ad-hoc networks/systems that is likely to be deployed. Therefore, it is important to characterize the physical properties of the DSRC channel.In this work we propose that due to the complexity, unpredictability and wide variety of road environments a statistical parametric model should be used to describe the physical channel behavior, and its parameters should be inferred from empirical data.Based on this methodological approach we construct channel gain models for two different environments: an open space and a typical highway with moderate traffic. To model the distribution of channel gain amplitude we choose the well-known two-parameter Nakagami model and estimate the distance dependency of its parameters from empirical road data. Spatial correlation of the channel strength is also estimated for a few separation distances.The results obtained show that in both environments the Nakagami average power parameter O falls off as the inverse-square of the sender-receiver separation distance up to a crossover distance of about 160m and as the inverse-fourth of the distance thereafter. The Nakagami fading parameter m lies between 1 and 4 for the open area and between 0.5 and 1 for the highway. The spatial correlation coefficients lie between 0.4 and 0.75 for the open environment, but between 0.9 and 1 for the highway. These results provide valuable input to support the design of optimal modulation, coding, diversity and protocol schemes for vehicle-to-vehicle and vehicle-to-infrastructure communication.

FleetNet: Bringing Car-to-Car Communication into the Real World

Abstract: Car-to-car communication by means of wireless technology shows a strong potential to enhance both safety and comfort of road users. The necessity to reach cars beyond the transmission range of the own radio creates the challenge to find algorithms to efficiently forward packets. In these so-called vehicular ad hoc networks, position information has been identified as a crucial component that alleviates some of the limitations of existing topology-based protocols. Thus, we see the use of positional information at the core of a car-to-car communication system that provides advanced applications for active safety, distributed floating car data, as well as user communication and information. A major thrust to leverage a car-to-car communication platform was provided by the FleetNet project, partly funded by the German Ministry of Education and Research BMB+F and led by DaimlerChrysler AG. Based on ad hoc networking principles and the availability of position information, the project developed suitable communication concepts. In addition to simulation studies, a prototype communication and application system was implemented and deployed, embedding safety and convenience applications. With car-based real world field trials successfully conducted, first results and experiences look promising.

TrafficView: a driver assistant device for traffic monitoring based on car-to-car communication

Abstract: TrafficView is a device that can be embedded in the next generation of vehicles to provide drivers with a real-time view of the road traffic far beyond what they can physically see. Vehicles equipped with TrafficView devices disseminate traffic information using short-range wireless communication. The main benefits of disseminating traffic information in a vehicle-to-vehicle fashion are scalability and ease of deployment. The paper describes the TrafficView prototype and presents preliminary experimental results for this prototype.

SPAWN: a swarming protocol for vehicular ad-hoc wireless networks

Abstract: Future vehicular networks are expected to deploy short-range communication technology for inter-vehicle communication In addition to vehicle-to-vehicle communication, users will be interested in accessing the multimedia-rich Internet from within the vehicular network This motivates a compelling application of Co-operative Networking in the Vehicular Ad-Hoc network where the Ad Hoc network extends and complements the Internet The broadcast nature of the wireless medium drives us to explore different design paradigms from the ones used in typical wired settingsA new paradigm in content delivery on the Internet using peer-peer swarming protocols is emerging [1,2] We propose SPAWN, a simple cooperative strategy for content delivery in future vehicular networks We study the issues involved in using such a strategy from the standpoint of Vehicular Ad-Hoc networks Several enhancements to a popular swarming protocol (BitTorrent) are discussed including a gossip mechanism that leverages the inherent broadcast nature of the wireless medium, and a piece-selection strategy that uses proximity to exchange pieces quicker Preliminary results show that SPAWN increases the perceived performance of the network, resulting in faster downloads for popular files

Toward intelligent driver-assistance and safety warning system

Abstract: A major problem associated with the rapid growth in automotive production is an increase in traffic congestion and accidents, especially in big cities of China. To solve the problem, the government has been increasing funds for improving the traffic infrastructure, enforcing traffic laws, and educating drivers about traffic regulations. In addition, research institutes have launched R&D projects in driver assistance and safety warning systems. In particular, in 1999, the Chinese Academy of Sciences' Intelligent Control and Systems Engineering Center started the Intelligent Vehicle Platforms project. The project aims to promote the use of intelligent technology for safe, efficient, and smart vehicles and to prototype vehicular electronic and sensory products and systems for the Chinese automotive industry. One of the project's key objectives is to develop a vehicular application-specific operating system (vASOS). The National Science Foundation of China and the CAS Knowledge Innovation Program support the project. Supported by the Vehicular Embedded Computing Platform project, the Xi'an Jiaotong University (XJTU-"Jiao Tong" means transportation in Chinese) Institute of Artificial Intelligence and Robotics and the CAS have collaborated to develop intelligent driver-assistance and safety warning systems for passenger vehicles, particularly GPS-and vision-based systems.

Safety-oriented communication in mobile networks for vehicles

Abstract: Accident statistics indicate that every year a large number of casualties and extensive property losses are recorded due to traffic accidents. Consequently, efforts are directed towards developing passive and active safety systems that help reducing the severity of crashes or prevent vehicles to collide with each other. Within the development of these systems, technologies such as sensor systems, computer vision and vehicular communication are considered of importance. Vehicular communication is defined as the exchange of data between vehicles, and is considered a key technology for traffic safety due to its ability to provide the vehicles with information that cannot be acquired using other means (e.g. radar and video systems). However, due to the current early stage in the development of in-vehicle safety systems, the applicability of communication for improving traffic safety is still an open issue. Furthermore, due to the specificity of the environment in which vehicles travel, the design of communication systems that provide an efficient exchange of safety-related data between vehicles poses a series of major technical challenges.In this thesis we focus on the development of a communication system that provides support for in-vehicle active safety systems such as collision warning and collision avoidance.We begin by studying the applicability of communication for supporting the development of effective active safety systems. Within our study, we investigate different safety aspects of traffic situations. For performing such investigations we develop ECAM, a temporal reasoning system for modeling and analyzing accident scenarios. This system gives us the possibility of analyzing relations between events that occur in traffic and their possible consequences. We use ECAM for analyzing the degree of accident prevention that can be achieved by applying crash countermeasures based on communication in specific traffic scenarios.By acknowledging the potential of communication for traffic safety, we further focus in the thesis on the design of a safety-oriented vehicular communication system. We propose a new solution for vehicular communication in the form of a distributed communication protocol that allows the vehicles to organize the network in an ad-hoc decentralized manner. For disseminating information, we develop an anonymous context-based broadcast protocol that requires the receivers to determine whether they are the intended destination of sent messages based on knowledge about their momentary situation in traffic. We further design a vehicular communication platform that provides an implementation framework for the communication system, and integrates it within a vehicle. Investigations of the communication performances, which evaluate metrics such as transmission delay, send errors, packet collisions and information filtering, indicate that the proposed vehicular communication system is able to provide a reliable and timely exchange of data between vehicles.

Self-Organizing Traffic Information System based on Car-to -Car Communication: Prototype Implementation

Abstract: Car-to-Car Communication (C2CC) is an important research and future application topic which is getting increasing attention from all major car man- ufacturers. Direct communication between individual vehicles can significantly increase passenger safety and comfort. An example is the exchange of traffic infor- mation, as in the novel Self-Organizing Traffic Infor- mation System (SOTIS), which has been proposed in the FLEETNET project. SOTIS is a decentralized information system which uses a technique called Segment-Oriented Data Ab- straction and Dissemination (SODAD) to solve two of the most pressing challenges for C2CC: required pen- etration and scalability. While most of the envisioned applications for C2CC require a relatively large ratio of equipped vehicles, SOTIS provides significant benefit even if only a small fraction of all vehicles is equipped, e.g. as in the phase of market introduction. In order to demonstrate the SOTIS idea and as a proof-of-concept, a SOTIS prototype has been im- plemented based on commercially available standard hard- and software. This article describes the design and implementation of the prototype and outlines first experimental results.

Layer-2 protocol design for vehicle safety communications in dedicated short range communications spectrum

Abstract: This paper studies the design of layer-2 protocols for a vehicle or the roadside to send safety messages to other vehicles. The target is to meet vehicle safety applications' requirements of high reliability and low delay in reception. The communication is one-to-many, local, and geo-significant. The vehicular communication network is ad-hoc and highly dynamic, with potentially large number of contending nodes. We design several random access protocols residing in MAC and MAC extension layers. The protocols fit the DSRC multichannel architecture. Analytical bounds of the protocols' performance are derived. Simulations are conducted to compare the performance of the protocols in terms of reception reliability and channel usage efficiency. The sensitivity of the protocol performance is tested under various communication conditions as well as vehicle traffic conditions. The results show that our approach is a feasible solution to the MAC design problem to support vehicle safety communications.

Vehicular communication - a candidate technology for traffic safety

Abstract: Research in traffic safety has indicated that in-vehicle safety systems provide a better service to drivers when they use data about nearby vehicles. For supplying such information, vehicular communication can be employed. However, the development of in-vehicle safety systems is currently at an early stage, and the applicability of the communication between vehicles for improving traffic safety is still under investigation. This paper provides an analysis of the role of communication for implementing traffic safety services. We survey approaches to vehicular communication and identify the most appropriate alternative for developing active safety systems that implement safety functions such as collision warning and collision avoidance.

Vehicular optical communications system

Abstract: Described are a vehicle optical communications system and network to exchange high bandwidth optical data between vehicles or between a vehicle and a stationary host. The vehicle optical communications system includes a communications module and a sensor having pixels for detecting an image in a field of view. Each pixel can generate a pixel data signal responsive to an incident optical data signal that includes vehicle data transmitted from a remote optical transmitter. The communications module provides remote data in response to the pixel data signals. The vehicular communications system optionally includes an optical transmitter to enable bi-directional communication. Data can be transmitted through a multi-node network of vehicular communication systems deployed in vehicles or on stationary hosts located between or around the data transmitter and intended data receiver. Simultaneous data from multiple optical transmitters within the sensor field of view are processed concurrently and maintained as separate communication channels.

Intelligent highway safety markers

Abstract: Intelligent highway safety markers are only the beginning for truly intelligent highway systems and for applications of robotics in transportation. Our research has demonstrated a robot's ability to act as a smart safety barrel guiding traffic and serving as a visible barrier between traffic and work crews. Through GPS, geographic information systems, wireless communication, and advanced vehicular electronic systems, we drive with greater safety along with various smart mobile robotic devices that warn us about safety hazards and even clean road debris.

Direct vehicle to vehicle communication network procedure for traffic, route and incident data receives or updates confidence information and tests it for further use

Abstract: A direct vehicle (F1-3) to vehicle communication network procedure receives or updates confidence information contained separately or within the communication signal and tests it for further use and distribution within the network Independent claims are included for equipment using the procedure

The planning and design of taxipooling on feeder system

Abstract: Intelligent transportation system technology applied to public transportation can provide useful information to systems operators and users, and increase the use and productivity of high occupancy vehicles. Especially the integration of the MRT, feeder buses and taxipool can attract more potential public transportation users. Advanced taxipooling transfer assignment systems, one of the advanced public transportation systems (APTS) program, aims at applying advanced technologies to taxi operations including dynamic taxi fleet management, taxipool strategies and safety monitoring systems. This research first discusses the general planning rules of advanced transfer systems at transfer terminals. Secondly a dynamic taxipool dispatch model with stochastic demand is developed and a case study analysis with GIS is done to show the feasibility of the proposed methods. Finally, the proposed system with real-time and door-to-door taxipooling service can significantly increase the riderships on public transportation modes in urban areas.

Simulation of information propagation for vehicles in physical communication network models

Abstract: It is important to propagate information about software update to vehicle users. We present a computer simulation of information propagation in physical communication network models to broadcast information rapidly. In this simulation we measure the rate of information propagation of vehicles per unit-time in physical communication network models. The characteristic obtained by the simulation is as follows; a) the vehicle operation rate has a large influence on the rapidity of information propagation, b) the vehicle mobility rate and c) the vehicle density rate has influence on the rapidity of information propagation of vehicle to vehicle communication network model, d) in the information environment of vehicles of urban area, the complex communication network model can propagate information rapidly. We grasped the communication network models to propagate information rapidly.

Wireless LAN extensions for vehicular environments and the control channel capacity

Abstract: In this paper, extensions of wireless LAN technology needed to support transportation safety applications and general multimedia to the car are introduced Based on the collection of IEEE 80211 protocols, the proposed standard specifies additional requirements associated with the vehicular environment Through simulations, the capacity of roadside to vehicle communications and vehicle to vehicle communications is examined

Design and test of a communication based advanced driver assistance system

Abstract: An advanced driver assistance system has been developed, based on a vehicle-to-vehicle communication system. It is able to control the longitudinal movement in a stop-and-go traffic situation and its purpose is to improve traffic safety, traffic flow and driver comfort. A concept architecture has been developed that uses a world-model to make the system highly extendible, like for the extension with lateral control in the future. 3D visualisation software shows a clear picture of the current perceived state of the world. Tests with three vehicles have proven the potential of such a system. Later tests with partners in the project showed that it can interact with third-party systems, based on the same communication protocol.

GPS and Vehicular Travel

Abstract: This chapter reviews the range of applications where global positioning systems (GPS) is currently having, or will have, an impact on vehicular travel. The chapter starts by introducing a framework that identifies the key technology links that are needed to build applications around the availability of the location information provided by the GPS. The compatibility between those applications and various vehicular travel sectors, specifically private motorists, freight, and public transport, are then identified. Individual applications are then considered in more detail and the final section explores a number of critical and unresolved issues that will be influential in determining the future impact of GPS-based systems on vehicular travel.