Showing papers on "Vehicular communication systems published in 2012"

A Review of Information Dissemination Protocols for Vehicular Ad Hoc Networks

Abstract: With the fast development in ad hoc wireless communications and vehicular technology, it is foreseeable that, in the near future, traffic information will be collected and disseminated in real-time by mobile sensors instead of fixed sensors used in the current infrastructure-based traffic information systems. A distributed network of vehicles such as a vehicular ad hoc network (VANET) can easily turn into an infrastructure-less self-organizing traffic information system, where any vehicle can participate in collecting and reporting useful traffic information such as section travel time, flow rate, and density. Disseminating traffic information relies on broadcasting protocols. Recently, there have been a significant number of broadcasting protocols for VANETs reported in the literature. In this paper, we classify and provide an in-depth review of these protocols.

3GPP LTE Versus IEEE 802.11p/WAVE: Which Technology is Able to Support Cooperative Vehicular Safety Applications?

Abstract: The concept of vehicular ad-hoc networks enables the design of emergent automotive safety applications, which are based on the awareness among vehicles. Recently, a suite of 802.11p/WAVE protocols aimed at supporting car-to-car communications was approved by IEEE. Existing cellular infrastructure and, above all 3GPP LTE, is being considered as another communication technology appropriate for vehicular applications. This letter provides a theoretical framework which compares the basic patterns of both the technologies in the context of safety-of-life vehicular scenarios. We present mathematical models for the evaluation of the considered protocols in terms of successful beacon delivery probability.

From Delay-Tolerant Networks to Vehicular Delay-Tolerant Networks

Abstract: This paper provides an introductory overview of Vehicular Delay-Tolerant Networks. First, an introduction to Delay-Tolerant Networks and Vehicular Delay-Tolerant Networks is given. Delay-Tolerant schemes and protocols can help in situations where network connectivity is sparse or with large variations in density, or even when there is no end-to-end connectivity by providing a communications solution for non real-time applications. Some special issues like routing are addressed in the paper and an introductory description of applications and the most important projects is given. Finally, some research challenges are discussed and conclusions are detailed.

Data naming in Vehicle-to-Vehicle communications

Abstract: Vehicular networking is becoming reality. Today vehicles use TCP/IP to communicate with centralized servers through cellular networks. However many vehicular applications, such as information sharing for safety and real time traffic purposes, desire direct V2V communications which is difficult to achieve using the existing solutions. This paper explores the named-data approach to address this challenge. We use case studies to identify the design requirements and put forth a strawman proposal for the data name design to understand its advantages and limitations.

Smart city for VANETs using warning messages, traffic statistics and intelligent traffic lights

Abstract: Road safety has become a main issue for governments and car manufacturers in the last twenty years. The development of new vehicular technologies has favoured companies, researchers and institutions to focus their efforts on improving road safety. During the last decades, the evolution of wireless technologies has allowed researchers to design communication systems where vehicles participate in the communication networks. Thus, new types of networks, such as Vehicular Ad Hoc Networks (VANETs), have been created to facilitate communication between vehicles themselves and between vehicles and infrastructure. New concepts where vehicular networks play an important role have appeared the last years, such as smart cities and living labs [1]. Smart cities include intelligent traffic management in which data from the TIC (Traffic Information Centre) infrastructures could be reachable at any point. To test the possibilities of these future cities, living labs (cities in which new designed systems can be tested in real conditions) have been created all over Europe. The goal of our framework is to transmit information about the traffic conditions to help the driver (or the vehicle itself) take adequate decisions. In this work, the development of a warning system composed of Intelligent Traffic Lights (ITLs) that provides information to drivers about traffic density and weather conditions in the streets of a city is proposed and evaluated through simulations.

Improving QoS in High-Speed Mobility Using Bandwidth Maps

Abstract: It is widely evidenced that location has a significant influence on the actual bandwidth that can be expected from Wireless Wide Area Networks (WWANs), e.g., 3G. Because a fast-moving vehicle continuously changes its location, vehicular mobile computing is confronted with the possibility of significant variations in available network bandwidth. While it is difficult for providers to eliminate bandwidth disparity over a large service area, it may be possible to map network bandwidth to the road network through repeated measurements. In this paper, we report results of an extensive measurement campaign to demonstrate the viability of such bandwidth maps. We show how bandwidth maps can be interfaced with adaptive multimedia servers and the emerging vehicular communication systems that use on-board mobile routers to deliver Internet services to the passengers. Using simulation experiments driven by our measurement data, we quantify the improvement in Quality of Service (QoS) that can be achieved by taking advantage of the geographical knowledge of bandwidth provided by the bandwidth maps. We find that our approach reduces the frequency of disruptions in perceived QoS for both audio and video applications in high-speed vehicular mobility by several orders of magnitude.

A Simple Free-Flow Traffic Model for Vehicular Intermittently Connected Networks

Abstract: The performance of vehicular data networks (VDNs) is highly dependent on vehicular traffic. Existing studies on VDNs consider custom-developed traffic models that mimic real-life vehicular traffic behavior and prepare the ground for accurate VDN performance evaluation. Traffic evolution is affected by numerous random events. Some developed models are microscopic. They independently consider some possible factors (e.g., weather, road geometry, and drivers' skills). These microscopic models are complex, and their implementations may be costly. Other models are macroscopic. They revolve around only the following three major traffic parameters: 1) density; 2) flow; and 3) speed. The majority of such existing models are unrealistic, because they are based on restrictive assumptions tailored to their enclosing study. Comparing the performance of VDN protocols becomes adequate if and only if these protocols are all developed on top of the same traffic model. Unfortunately, the opposite is true. Hence, the design of a generic traffic model that serves as a basis for future studies on VDNs is equally urgent and important. This paper presents a comprehensive and traffic-theory-inspired macroscopic description of vehicular traffic behavior over roadway facilities that operate under free-flow traffic conditions. Accordingly, a simple and tractable macroscopic traffic model is proposed. Extensive simulations are conducted to verify the validity of the proposed model and its high accuracy.

Impact of the radio channel modelling on the performance of VANET communication protocols

Abstract: The expected traffic safety and efficiency benefits that can be achieved through the development and deployment of vehicular ad-hoc networks has attracted a significant interest from the networking research community that is currently working on novel vehicular communication protocols. The time-critical nature of vehicular applications and their reliability constraints require a careful protocol design and dimensioning. To this aim, adequate and accurate models should be employed in any research study. One of the critical aspects of any wireless communications system is the radio channel propagation. This is particularly the case in vehicular networks due to their low antenna heights, the fast topology changes and the reliability and latency constraints of traffic safety applications. Despite the research efforts to model the vehicle-to-vehicle communications channel, many networking studies are currently simplifying and even neglecting the radio channel effects on the performance and operation of their protocols. As this work demonstrates, it is critical that realistic and accurate channel models are employed to adequately understand, design and optimize novel vehicular communications and networking protocols.

Trust Management for VANETs: Challenges, Desired Properties and Future Directions

Abstract: An increasingly large number of cars are being equipped with GPS and Wi-Fi devices, forming vehicular ad-hoc networks VANETs and enabling vehicle to vehicle communication with the goal of providing increased passenger and road safety. However, dishonest peers vehicles in a VANET may send out false information to maximize their own utility. Given the dire consequences of acting on false information in this context, there is a serious need to establish trust among peers. This article first discusses the challenges for trust management caused by the important characteristics of VANET environments, and identifies desired properties that effective trust management should incorporate in order to address the challenges. The author then surveys and evaluates existing trust models in VANETs, and points out that none of the trust models has achieved all the properties. Finally, the author proposes some important future directions for research towards effective trust management for VANETs.

Intelligent traffic management at intersections supported by V2V and V2I communications

Abstract: This paper describes an intelligent traffic management system applied to road intersections, namely round-about and crossroads. A microscopic traffic simulator was developed to study intelligent traffic management techniques and evaluate their performance. The intelligent management techniques are aimed to minimize accidents, traffic congestion and consequently the environmental costs of road traffic. Each vehicle is modeled by an agent and each agent provides information depending on its vehicle sensors. Two intersection types, roundabout and crossroads, were simulated each using its intelligent traffic management system. Both intersections use an algorithm based on a spatio-temporal reservation scheme. The envisioned intelligent traffic management algorithm is supported by vehicle-to-vehicle and vehicle-to-infrastructure communications, allowing the exchange of information between vehicles and the intersection intelligent traffic management system. The developed intelligent traffic management system is very well suited for autonomous vehicles, it can also be used by human drivers if they follow accurately the proposed speed profile along the path.

Cellular-network based control of vehicle-to-vehicle communication

Abstract: A vehicle-to-vehicle communication device (100; 100') is provided with access to a cellular network (200, 210). The cellular network (200, 210) implements at least a first radio technology. The vehicle-to-vehicle communication device (100, 100') further supports a second radio technology for vehicle-to-vehicle communication. For controlling vehicle-to- vehicle communication by the second radio technology, data from the cellular network (200, 210) are provided to the vehicle-to-vehicle communication device (100, 100'). For example, such data may be derived from presence or mobility information available in the cellular network (200, 210). On the basis of the data from the cellular network (200, 210), the vehicle- to-vehicle communication device (100, 100') sets at least one control parameter of vehicle-to- vehicle communication by the second radio technology, e.g., a rate of sending a message or a transmission power utilized by the second radio technology.

Machine-to-Machine (M2M) Communications in Vehicular Networks

Abstract: To address the need for autonomous control of remote and distributed mobile systems, Machine-to-Machine (M2M) communications are rapidly gaining attention from both academia and industry. M2M communications have recently been deployed in smart grid, home networking, health care, and vehicular networking environments. This paper focuses on M2M communications in the vehicular networking context and investigates areas where M2M principles can improve vehicular networking. Since connected vehicles are essentially a network of machines that are communicating, preferably autonomously, vehicular networks can benefit a lot from M2M communications support. The M2M paradigm enhances vehicular networking by supporting large-scale deployment of devices, cross-platform networking, autonomous monitoring and control, visualization of the system and measurements, and security. We also present some of the challenges that still need to be addressed to fully enable M2M support in the vehicular networking environment. Of these, component standardization and data security management are considered to be the most significant challenges.

Optimization method in a vehicle-to-vehicle communication system

Abstract: A method of optimizing a vehicle-to-vehicle communication system is described. One embodiment uses a set of desired and defined metrics of success, combined with pre-recorded operating histories, combined with a series of simulations to optimize certain specific parameters in the vehicle-to-vehicle communication protocol.

Intersection Management using Vehicular Networks

Abstract: Driving through intersections can be potentially dangerous because nearly 23 percent of the total automotive related fatalities and almost 1 million injury-causing crashes occur at or within intersections every year [1]. The impact of traffic intersections on trip delays also leads to waste of human and natural resources. Our goal is to increase the safety and throughput of traffic intersections using co-operative driving. In earlier work [2], we have proposed a family of vehicular network protocols, which use Dedicated Short Range Communications (DSRC) and Wireless Access in Vehicular Environment (WAVE) technologies to manage a vehicle’s movement at intersections Specifically, we have provided a collision detection algorithm at intersections (CDAI) to avoid potential crashes at or near intersections and improve safety. We have shown that vehicle-to-vehicle (V2V) communications can be used to significantly decrease the trip delays introduced by traffic lights and stop signs. In this paper, we investigate the use of more realistic controller models and higher concurrency to improve V2V intersection protocols for autonomous driving at intersections. We quantify the throughput enhancements due to the use of V2V under various driving conditions, while maintaining safe passage through intersections.

Dice the TX power — Improving Awareness Quality in VANETs by random transmit power selection

Abstract: Future safety-related vehicular applications require reliable information exchange provided by cooperative Vehicular Ad-hoc NETworks (VANETs). Although the vehicular WLAN standard IEEE 802.11p has been adapted to the challenging vehicular environment, it has not been adapted to the stringent communication requirements imposed by vehicular applications. In particular, broadcast transmissions are mostly periodic and initiated at common TX powers. This makes potential interferences recurring instead of spurious and lowers the performance of medium access for vehicular applications. In this paper, we propose to leverage recurring interferences by randomly selecting each TX power following a given probability distribution. Such randomization reduces the chances of recurring interferences, and the probability distribution provides control to the applications regarding the required Awareness Quality, in particular by providing a higher Awareness Quality at close range. This concept also reduces congestions by transmitting less at high distances. It is transparent to the applications, and manages to improve the Awareness Quality in a dense highway by a factor 2 to 20, yet at a factor 2 to 3 lower channel load.

Research and Development of Intelligent Transportation Systems

Abstract: Intelligent Transportation Systems (ITS) have been developed for more than ten years in China. Furthermore, a new generation Intelligent Transportation Systems should be launched to meet the requirement of rapid development of transportation in China. Firstly, the development history of Intelligent Transport Systems is summarized in this paper. Secondly, as one of the earliest ITS research center in China, the Intelligent Transportation Systems Center, Wuhan University of Technology is also introduced. It was established in September, 2000, and aims to improve traffic safety, reduce vehicle emission, and save transportation energy in roadway and waterway transportation fields. Its research fields include: driving behavior a safety, traffic safety management and control, assistant driving and intelligent vehicles in roadway, information collection technologies, accident simulation systems, safety warning and emergency systems in water transportation. Several major research projects or fields mentioned above will be introduced in details. Finally, the key areas of ITS during next five years are described, and the development and cooperation in the future are also discussed.

A realistic simulation framework for vehicular networks

Abstract: Research in Vehicular Networks (VNs) has found in simulation the most useful method to test new algorithms and techniques. This is mainly due to the high cost of deploying such systems in real scenarios. When simulating vehicular environments, two different issues must be addressed: mobility and wireless communications. Regarding mobility, several mobility pattern generators have been proposed so far. However, all of them present important drawbacks from the point of view of reproducing realistic mobility over real roadmaps. As for the wireless communications, ns-2 has become one of the most widely used network simulators for wireless communications researchers. However, simulating VNs requires using environments behaving as realistically as possible, and ns-2 presents some deficiencies that make it difficult to obtain accurate vehicular simulations. In this work, we present a realistic simulation framework which combines vehicular mobility over real roadmaps and ns-2 optimizations to obtain more accurate and meaningful results when simulating vehicular environments.

Performance evaluation of IEEE 802.11p for vehicular communication networks

Abstract: IEEE 802.11p is an emerging standard which provides vehicular safety communication through wireless networks. In this paper, the architecture of Wireless Access for Vehicular Environment (WAVE) and IEEE 802.11p standard were analysed. The key parameters of this standard are implemented in ns-2 network simulator to accurately simulate vehicular ad hoc networks (VANETs). The performance of this standard was measured in ns-2 network simulation environment using realistic vehicular mobility models. The main performance metrics for vehicular safety communication; Throughput, End-to-End delay, and Packet loss ratio are analysed in the scenario. In addition, the effect of varying vehicle speed and different message sizes on the performance metrics were measured.

A Stochastic Model for Chain Collisions of Vehicles Equipped With Vehicular Communications

Abstract: Improvement of traffic safety by cooperative vehicular applications is one of the most promising benefits of vehicular ad hoc networks (VANETs) However, to properly develop such applications, the influence of different driving parameters on the event of vehicle collision must be assessed at an early design stage In this paper, we derive a stochastic model for the number of accidents in a platoon of vehicles equipped with a warning collision notification system, which is able to inform all the vehicles about an emergency event In fact, the assumption of communications being used is key to simplify the derivation of a stochastic model The model enables the computation of the average number of collisions that occur in the platoon, the probabilities of the different ways in which the collisions may take place, as well as other statistics of interest Although an exponential distribution has been used for the traffic density, it is also valid for different probability distributions for traffic densities, as well as for other significant parameters of the model Moreover, the actual communication system employed is independent of the model since it is abstracted by a message delay variable, which allows it to be used to evaluate different communication technologies We validate the proposed model with Monte Carlo simulations With this model, one can quickly evaluate numerically the influence of different model parameters (vehicle density, velocities, decelerations, and delays) on the collision process and draw conclusions that shed relevant guidelines for the design of vehicular communication systems, as well as chain collision avoidance applications Illustrative examples of application are provided, although a systematic characterization and evaluation of different scenarios is left as future work

Realistic urban traffic simulation as vehicular Ad-hoc network (VANET) via Veins framework

Abstract: These days wireless communication has impacted our daily lives. The developments achieved in this field have made our lives amazingly simpler, easier, convenient and comfortable. One of these developments has occurred in Car to Car Communication (C2CC). Communication between cars often referred to vehicular ad hoc networks (VANET) has many advantages such as: reducing cars accidents, minimizing the traffic jam, reducing fuel consumption and emissions and etc. For a closer look on C2CC studies the necessity of simulation is obvious. Network simulators can simulate the Ad-hoc network but they cannot simulate the huge traffic of cities. In order to solve this problem, in this paper we study the Veins framework which is used to run a Traffic (SUMO) and a Network (OMNET++) simulator in parallel and we simulate the realistic traffics of the city of Cologne, Germany, as an ad-hoc network.

A content centric approach to dissemination of information in vehicular networks

Abstract: Data dissemination in dynamic environments such as vehicular networks has been a critical challenge. One of the key characteristics of vehicular networks is the high intermittent connectivity. Recent studies have investigated and proven the feasibility of a content-centric networking paradigm for vehicular networks. Content-centric information dissemination has a potential number of applications in vehicular networking, including advertising, traffic and parking notifications and emergency announcements. It is clear and evident that knowledge about the type of content and its relevance can enhance the performance of data dissemination in VANETs. In this paper we address the problem of information dissemination in vehicular network environments and propose a model and solution based on a content-centric approach of networking. We leverage the expansion properties of interacting nodes in a cluster to be interpreted in terms of social connections among nodes and perform a selective random network coding approach. We compare the reliability performance of our method with a conventional random network coding approach and comment on the complexity of the proposed solution.

ICDMS: an intelligent cloud based disaster management system for vehicular networks

Abstract: The importance of emergency response systems cannot be overemphasized today due to the many manmade and natural disasters in the recent years such as September 2001 and the recent Japan earthquake and tsunami disaster. The overall cost of the Japan disaster alone is estimated to have exceeded 300 billion USD. Transportation and telecommunications play a critical role in disaster response and management in order to minimize loss of human life, economic cost and disruptions. Our research is concerned with developing emergency response systems for disasters of various scales with a focus on transportation systems, which exploit ICT developments. In this paper, we leverage Intelligent Transportation Systems including Vehicular Ad hoc Networks, mobile and Cloud Computing technologies to propose an intelligent disaster management system. The system is intelligent because it is able to gather information from multiple sources and locations, including from the point of incident, and is able to let vehicles make effective strategies and decisions of communication protocols usage. Hybrid vehicular communications based on vehicle-to-vehicle and vehicle-to-infrastructure protocols are opportunistically exploited. The effectiveness of our system is demonstrated through modelling the impact of a disaster on a real city transport environment and comparing it with the case where our disaster management system was in place. We report great benefits derived from the adoption of our proposed system in terms of improved and balanced traffic flow and smooth evacuation.

VANET Routing Protocols: Pros and Cons

Abstract: VANET (Vehicular Ad-hoc Network) is a new technology which has taken enormous attention in the recent years. Due to rapid topology changing and frequent disconnection makes it difficult to design an efficient routing protocol for routing data among vehicles, called V2V or vehicle to vehicle communication and vehicle to road side infrastructure, called V2I. The existing routing protocols for VANET are not efficient to meet every traffic scenarios. Thus design of an efficient routing protocol has taken significant attention. So, it is very necessary to identify the pros and cons of routing protocols which can be used for further improvement or development of any new routing protocol. This paper presents the pros and cons of VANET routing protocols for inter vehicle communication.

Probabilistic key distribution in vehicular networks with infrastructure support

Abstract: We propose a probabilistic key distribution protocol for vehicular network that alleviates the burden of traditional public-key infrastructures. Roadside units act as trusted nodes and are used for secret-sharing among vehicles in their vicinity. Secure communication is immediately possible between these vehicles with high probability. Our performance evaluation, which uses both analysis and simulation, shows that high reliability and short dissemination time can be achieved with low complexity.

Vehicle-to-Vehicle Communication System through Wi-Fi Network Using Android Smartphone

Abstract: Although IEEE has already announced 802.11p standard for wireless access in vehicular environment (WAVE) to support Intelligent Transportation System (ITS) communication, it requires additional 802.11p hardware equipment to allow vehicles communicating with others using 802.11p. Therefore, in this paper, we propose an inter-vehicle communication system, operating on android smart phone by using Wi-Fi. To substitute 802.11p onboard unit (OBU) before its widespread use on modern vehicles. Experiment results shows that our system can not only be easily installed in any android devices (android 2.3 and above) but is also more suitable for vehicular ad-hoc network (VANET) scenario than other systems.