77 research outputs found

    Secure Authentication Mechanism for Cluster based Vehicular Adhoc Network (VANET): A Survey

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    Vehicular Ad Hoc Networks (VANETs) play a crucial role in Intelligent Transportation Systems (ITS) by facilitating communication between vehicles and infrastructure. This communication aims to enhance road safety, improve traffic efficiency, and enhance passenger comfort. The secure and reliable exchange of information is paramount to ensure the integrity and confidentiality of data, while the authentication of vehicles and messages is essential to prevent unauthorized access and malicious activities. This survey paper presents a comprehensive analysis of existing authentication mechanisms proposed for cluster-based VANETs. The strengths, weaknesses, and suitability of these mechanisms for various scenarios are carefully examined. Additionally, the integration of secure key management techniques is discussed to enhance the overall authentication process. Cluster-based VANETs are formed by dividing the network into smaller groups or clusters, with designated cluster heads comprising one or more vehicles. Furthermore, this paper identifies gaps in the existing literature through an exploration of previous surveys. Several schemes based on different methods are critically evaluated, considering factors such as throughput, detection rate, security, packet delivery ratio, and end-to-end delay. To provide optimal solutions for authentication in cluster-based VANETs, this paper highlights AI- and ML-based routing-based schemes. These approaches leverage artificial intelligence and machine learning techniques to enhance authentication within the cluster-based VANET network. Finally, this paper explores the open research challenges that exist in the realm of authentication for cluster-based Vehicular Adhoc Networks, shedding light on areas that require further investigation and development

    Comparative Study of Simulators for Vehicular Networks

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    Vehicular Adhoc networks (VANETs) are composed of vehicles connected with wireless links to exchange data. VANETs have become the backbone of the Intelligent Transportation Systems (ITS) in smart cities and enable many essential services like roadside safety, traffic management, platooning, etc with vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications. In any form of research testing and evaluation plays a crucial role. However, in VANETs, real-world experiments require high investment, and heavy resources and can cause many practical difficulties. Therefore, simulations have become critical and the primary way of evaluating VANETs' applications. Furthermore, the upfront challenge is the realistic capture of the networking mechanism of VANETs, which varies from situation to situation. Several factors may contribute to the successful achievement of a random realistic networking behavior. However, the biggest dependency is a powerful tool for the implementation, which could probably take into account all the configuration parameters, loss factors, mobility schemes, and other key features of a VANET, yet give out practical performance metrics with a good trade-off between investment of resources and the results. Hence, the aim of this research is to evaluate some simulators in the scope of VANETs with respect to resource utilization, packet delivery, and computational time

    Holons:Towards a systematic approach to composing systems of systems

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    The world's computing infrastructure is increasingly differentiating into self-contained distributed systems with various purposes and capabilities (e.g. IoT installations, clouds, VANETs, WSNs, CDNs, ...). Furthermore, such systems are increasingly being composed to generate systems of systems that offer value-added functionality. Today, however, system of systems composition is typically ad-hoc and fragile. It requires developers to possess an intimate knowledge of system internals and low-level interactions between their components. In this paper, we outline a vision and set up a research agenda towards the generalised programmatic construction of distributed systems as compositions of other distributed systems. Our vision, in which we refer uniformly to systems and to compositions of systems as holons, employs code generation techniques and uses common abstractions, operations and mechanisms at all system levels to support uniform system of systems composition. We believe our holon approach could facilitate a step change in the convenience and correctness with which systems of systems can be built, and open unprecedented opportunities for the emergence of new and previously-unenvisaged distributed system deployments, analogous perhaps to the impact the mashup culture has had on the way we now build web applications

    TDMP-Reliable Target Driven and Mobility Prediction based Routing Protocol in Complex VANET

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    Vehicle-to-everything (V2X) communication in the vehicular ad hoc network (VANET), an infrastructure-free mechanism, has emerged as a crucial component in the advanced Intelligent Transport System (ITS) for special information transmission and inter-vehicular communications. One of the main research challenges in VANET is the design and implementation of network routing protocols which manage to trigger V2X communication with the reliable end-to-end connectivity and efficient packet transmission. The organically changing nature of road transport vehicles poses a significant threat to VANET with respect to the accuracy and reliability of packet delivery. Therefore, a position-based routing protocol tends to be the predominant method in VANET as they overcome rapid changes in vehicle movements effectively. However, existing routing protocols have some limitations such as (i) inaccurate in high dynamic network topology, (ii) defective link-state estimation (iii) poor movement prediction in heterogeneous road layouts. In this paper, a target-driven and mobility prediction (TDMP) based routing protocol is therefore developed for high-speed mobility and dynamic topology of vehicles, fluctuant traffic flow and diverse road layouts in VANET. The primary idea in TDMP is that the destination target of a driver is included in the mobility prediction to assist the implementation of the routing protocol. Compared to existing geographic routing protocols which mainly greedily forward the packet to the next-hop based on its current position and partial road layout, TDMP is developed to enhance the packet transmission with the consideration of the estimation of inter-vehicles link status, and the prediction of vehicle positions dynamically in fluctuant mobility and global road layout.Comment: 35 pages,16 Figure

    Investigating seamless handover in VANET systems

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    Wireless communications have been extensively studied for several decades, which has led to various new advancements, including new technologies in the field of Intelligent Transport Systems. Vehicular Ad hoc Networks or VANETs are considered to be a long-term solution, contributing significantly towards Intelligent Transport Systems in providing access to critical life-safety applications and infotainment services. These services will require ubiquitous connectivity and hence there is a need to explore seamless handover mechanisms. Although VANETs are attracting greater commercial interest, current research has not adequately captured the realworld constraints in Vehicular Ad hoc Network handover techniques. Due to the high velocity of the vehicles and smaller coverage distances, there are serious challenges in providing seamless handover from one Road Side Unit (RSU) to another and this comes at the cost of overlapping signals of adjacent RSUs. Therefore, a framework is needed to be able to calculate the regions of overlap in adjacent RSU coverage ranges to guarantee ubiquitous connectivity. This thesis is about providing such a framework by analysing in detail the communication mechanisms in a VANET network, firstly by means of simulations using the VEINs framework via OMNeT++ and then using analytical analysis of the probability of successful packet reception. Some of the concepts of the Y-Comm architecture such as Network Dwell Time, Time Before Handover and Exit Times have been used to provide a framework to investigate handover issues and these parameters are also used in this thesis to explore handover in highly mobile environments such as VANETs. Initial investigation showed that seamless communication was dependant on the beacon frequency, length of the beacon and the velocity of the vehicle. The effects of each of these parameters are explored in detail and results are presented which show the need for a more probabilistic approach to handover based on cumulative probability of successful packet reception. In addition, this work shows how the length of the beacon affects the rate of change of the Signal-to-Noise ratio or SNR as the vehicle approaches the Road-Side Unit. However, the velocity of the vehicle affects both the cumulative probability as well as the Signal-to-Noise ratio as the vehicle approaches the Road-Side Unit. The results of this work will enable systems that can provide ubiquitous connectivity via seamless handover using proactive techniques because traditional models of handover are unable to cope with the high velocity of the vehicles and relatively small area of coverage in these environments. Finally, a testbed has been set-up at the Middlesex University, Hendon campus for the purpose of achieving a better understanding of VANET systems operating in an urban environment. Using the testbed, it was observed that environmental effects have to be taken into considerations in real-time deployment studies to see how these parameters can affect the performance of VANET systems under different scenarios. This work also highlights the fact that in order to build a practical system better propagation models are required in the urban context for highly mobile environments such as VANETs

    SCALABLE MULTI-HOP DATA DISSEMINATION IN VEHICULAR AD HOC NETWORKS

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    Vehicular Ad hoc Networks (VANETs) aim at improving road safety and travel comfort, by providing self-organizing environments to disseminate traffic data, without requiring fixed infrastructure or centralized administration. Since traffic data is of public interest and usually benefit a group of users rather than a specific individual, it is more appropriate to rely on broadcasting for data dissemination in VANETs. However, broadcasting under dense networks suffers from high percentage of data redundancy that wastes the limited radio channel bandwidth. Moreover, packet collisions may lead to the broadcast storm problem when large number of vehicles in the same vicinity rebroadcast nearly simultaneously. The broadcast storm problem is still challenging in the context of VANET, due to the rapid changes in the network topology, which are difficult to predict and manage. Existing solutions either do not scale well under high density scenarios, or require extra communication overhead to estimate traffic density, so as to manage data dissemination accordingly. In this dissertation, we specifically aim at providing an efficient solution for the broadcast storm problem in VANETs, in order to support different types of applications. A novel approach is developed to provide scalable broadcast without extra communication overhead, by relying on traffic regime estimation using speed data. We theoretically validate the utilization of speed instead of the density to estimate traffic flow. The results of simulating our approach under different density scenarios show its efficiency in providing scalable multi-hop data dissemination for VANETs

    Quality of service aware data dissemination in vehicular Ad Hoc networks

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    Des systĂšmes de transport intelligents (STI) seront Ă©ventuellement fournis dans un proche avenir pour la sĂ©curitĂ© et le confort des personnes lors de leurs dĂ©placements sur les routes. Les rĂ©seaux ad-hoc vĂ©hiculaires (VANETs) reprĂ©sentent l'Ă©lĂ©ment clĂ© des STI. Les VANETs sont formĂ©s par des vĂ©hicules qui communiquent entre eux et avec l'infrastructure. En effet, les vĂ©hicules pourront Ă©changer des messages qui comprennent, par exemple, des informations sur la circulation routiĂšre, les situations d'urgence et les divertissements. En particulier, les messages d'urgence sont diffusĂ©s par des vĂ©hicules en cas d'urgence (p.ex. un accident de voiture); afin de permettre aux conducteurs de rĂ©agir Ă  temps (p.ex., ralentir), les messages d'urgence doivent ĂȘtre diffusĂ©s de maniĂšre fiable dans un dĂ©lai trĂšs court. Dans les VANETs, il existe plusieurs facteurs, tels que le canal Ă  pertes, les terminaux cachĂ©s, les interfĂ©rences et la bande passante limitĂ©e, qui compliquent Ă©normĂ©ment la satisfaction des exigences de fiabilitĂ© et de dĂ©lai des messages d'urgence. Dans cette thĂšse, en guise de premiĂšre contribution, nous proposons un schĂ©ma de diffusion efficace Ă  plusieurs sauts, appelĂ© Dynamic Partitioning Scheme (DPS), pour diffuser les messages d'urgence. DPS calcule les tailles de partitions dynamiques et le calendrier de transmission pour chaque partition; Ă  l'intĂ©rieur de la zone arriĂšre de l'expĂ©diteur, les partitions sont calculĂ©es de sorte qu'en moyenne chaque partition contient au moins un seul vĂ©hicule; l'objectif est de s'assurer que seul un vĂ©hicule dans la partition la plus Ă©loignĂ©e (de l'expĂ©diteur) est utilisĂ© pour diffuser le message, jusqu'au saut suivant; ceci donne lieu Ă  un dĂ©lai d'un saut plus court. DPS assure une diffusion rapide des messages d'urgence. En outre, un nouveau mĂ©canisme d'Ă©tablissement de liaison, qui utilise des tonalitĂ©s occupĂ©es, est proposĂ© pour rĂ©soudre le problĂšme du problĂšme de terminal cachĂ©. Dans les VANETs, la Multidiffusion, c'est-Ă -dire la transmission d'un message d'une source Ă  un nombre limitĂ© de vĂ©hicules connus en tant que destinations, est trĂšs importante. Par rapport Ă  la diffusion unique, avec Multidiffusion, la source peut simultanĂ©ment prendre en charge plusieurs destinations, via une arborescence de multidiffusion, ce qui permet d'Ă©conomiser de la bande passante et de rĂ©duire la congestion du rĂ©seau. Cependant, puisque les VANETs ont une topologie dynamique, le maintien de la connectivitĂ© de l'arbre de multidiffusion est un problĂšme majeur. Comme deuxiĂšme contribution, nous proposons deux approches pour modĂ©liser l'utilisation totale de bande passante d'une arborescence de multidiffusion: (i) la premiĂšre approche considĂšre le nombre de segments de route impliquĂ©s dans l'arbre de multidiffusion et (ii) la seconde approche considĂšre le nombre d'intersections relais dans l'arbre de multidiffusion. Une heuristique est proposĂ©e pour chaque approche. Pour assurer la qualitĂ© de service de l'arbre de multidiffusion, des procĂ©dures efficaces sont proposĂ©es pour le suivi des destinations et la surveillance de la qualitĂ© de service des segments de route. Comme troisiĂšme contribution, nous Ă©tudions le problĂšme de la congestion causĂ©e par le routage du trafic de donnĂ©es dans les VANETs. Nous proposons (1) une approche de routage basĂ©e sur l’infonuagique qui, contrairement aux approches existantes, prend en compte les chemins de routage existants qui relaient dĂ©jĂ  les donnĂ©es dans les VANETs. Les nouvelles demandes de routage sont traitĂ©es de sorte qu'aucun segment de route ne soit surchargĂ© par plusieurs chemins de routage croisĂ©s. Au lieu d'acheminer les donnĂ©es en utilisant des chemins de routage sur un nombre limitĂ© de segments de route, notre approche Ă©quilibre la charge des donnĂ©es en utilisant des chemins de routage sur l'ensemble des tronçons routiers urbains, dans le but d'empĂȘcher, dans la mesure du possible, les congestions locales dans les VANETs; et (2) une approche basĂ©e sur le rĂ©seau dĂ©fini par logiciel (SDN) pour surveiller la connectivitĂ© VANET en temps rĂ©el et les dĂ©lais de transmission sur chaque segment de route. Les donnĂ©es de surveillance sont utilisĂ©es en entrĂ©e de l'approche de routage.Intelligent Transportation Systems (ITS) will be eventually provided in the near future for both safety and comfort of people during their travel on the roads. Vehicular ad-hoc Networks (VANETs), represent the key component of ITS. VANETs consist of vehicles that communicate with each other and with the infrastructure. Indeed, vehicles will be able to exchange messages that include, for example, information about road traffic, emergency situations, and entertainment. Particularly, emergency messages are broadcasted by vehicles in case of an emergency (e.g., car accident); in order to allow drivers to react in time (e.g., slow down), emergency messages must be reliably disseminated with very short delay. In VANETs, there are several factors, such as lossy channel, hidden terminals, interferences and scarce bandwidth, which make satisfying reliability and delay requirements of emergency messages very challenging. In this thesis, as the first contribution, we propose a reliable time-efficient and multi-hop broadcasting scheme, called Dynamic Partitioning Scheme (DPS), to disseminate emergency messages. DPS computes dynamic partition sizes and the transmission schedule for each partition; inside the back area of the sender, the partitions are computed such that in average each partition contains at least a single vehicle; the objective is to ensure that only a vehicle in the farthest partition (from the sender) is used to disseminate the message, to next hop, resulting in shorter one hop delay. DPS ensures fast dissemination of emergency messages. Moreover, a new handshaking mechanism, that uses busy tones, is proposed to solve the problem of hidden terminal problem. In VANETs, Multicasting, i.e. delivering a message from a source to a limited known number of vehicles as destinations, is very important. Compared to Unicasting, with Multicasting, the source can simultaneously support multiple destinations, via a multicast tree, saving bandwidth and reducing overall communication congestion. However, since VANETs have a dynamic topology, maintaining the connectivity of the multicast tree is a major issue. As the second contribution, we propose two approaches to model total bandwidth usage of a multicast tree: (i) the first approach considers the number of road segments involved in the multicast tree and (ii) the second approach considers the number of relaying intersections involved in the multicast tree. A heuristic is proposed for each approach. To ensure QoS of the multicasting tree, efficient procedures are proposed for tracking destinations and monitoring QoS of road segments. As the third contribution, we study the problem of network congestion in routing data traffic in VANETs. We propose (1) a Cloud-based routing approach that, in opposition to existing approaches, takes into account existing routing paths which are already relaying data in VANETs. New routing requests are processed such that no road segment gets overloaded by multiple crossing routing paths. Instead of routing over a limited set of road segments, our approach balances the load of communication paths over the whole urban road segments, with the objective to prevent, whenever possible, local congestions in VANETs; and (2) a Software Defined Networking (SDN) based approach to monitor real-time VANETs connectivity and transmission delays on each road segment. The monitoring data is used as input to the routing approach
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