78 research outputs found

    DSRC Versus LTE-V2X: Empirical Performance Analysis of Direct Vehicular Communication Technologies

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    Vehicle-to-Vehicle (V2V) communication systems have an eminence potential to improve road safety and optimize traffic flow by broadcasting Basic Safety Messages (BSMs). Dedicated Short-Range Communication (DSRC) and LTE Vehicle-to-Everything (V2X) are two candidate technologies to enable V2V communication. DSRC relies on the IEEE 802.11p standard for its PHY and MAC layer while LTE-V2X is based on 3GPP’s Release 14 and operates in a distributed manner in the absence of cellular infrastructure. There has been considerable debate over the relative advantages and disadvantages of DSRC and LTE-V2X, aiming to answer the fundamental question of which technology is most effective in real-world scenarios for various road safety and traffic efficiency applications. In this paper, we present a comprehensive survey of these two technologies (i.e., DSRC and LTE-V2X) and related works. More specifically, we study the PHY and MAC layer of both technologies in the survey study and compare the PHY layer performance using a variety of field tests. First, we provide a summary of each technology and highlight the limitations of each in supporting V2X applications. Then, we examine their performance based on different metrics

    Cross-Layer Treatment of Mobility for Mobile Ad Hoc Networks

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    The current era of mobile communication is passing through the days of rapidly changing technologies. Such an evolving promising technology is mobile ad hoc networks (MANETs). The communications in ad hoc networks are adversely affected by the link failures in the network layer, and by the hidden station, mobile hidden station, neighborhood capture and asymmetric radio link problems in the MAC layer. All the problems are highly affected by mobility of the stations. If the degree of mobility of any station in a route increases, the route life time decreases. That causes frequent link failures, and results packet retransmissions, additional latency and packet loss. An algorithm to include mobility in a routing protocol to reduce packet losses in a MANET is proposed in this thesis. The proposed algorithm estimates the number of packets that can traverse through the route before it breaks because of mobility. The algorithm is implemented in dynamic source routing protocol, and simulated in Network Simulator-2. The MHS problem arises if a station is hidden due to mobility. Asymmetric/unequal radio links in can occur in MANETs/VANETs for many reasons such as hardware limitations, power saving protocols, shadowing effects, dynamic spectrum managements. A MAC protocol named extended reservation Aloha (ERA) is proposed which partially solves these problems. Then, using the concept of ERA, another MAC protocol named extended sliding frame reservation Aloha (ESFRA), which addresses all the above mentioned MAC problems, is proposed in this thesis. As safety critical information dissemination in DSRC/WAVE systems requires reliability and robustness, a network-MAC cross-layer information dissemination protocol is proposed in this thesis to address those issues. Although the layered architecture is still a good candidate for any design of wireless networks, the researchers are looking for some optimizations by interaction between neighbor layers which is called cross-layer design. So I proposed a network-MAC cross-layer algorithm, cross-layer extended sliding frame reservation Aloha (CESFRA), which solves mobility related problems, confirms low and deterministic end-to-end delay, and is robust and reliable in safety critical information dissemination up to 3rd hop. Discrete time Markov chain (DTMC) and OMNeT++ are used for all the MAC layer analyses

    TDMA-based MAC Protocols for Vehicular Ad Hoc Networks: A Survey, Qualitative Analysis and Open Research Issues

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    International audience—Vehicular Ad-hoc NETworks (VANETs) have attracted a lot of attention in the research community in recent years due to their promising applications. VANETs help improve traffic safety and efficiency. Each vehicle can exchange information to inform other vehicles about the current status of the traffic flow or a dangerous situation such as an accident. Road safety and traffic management applications require a reliable communication scheme with minimal transmission collisions, which thus increase the need for an efficient Medium Access Control (MAC) protocol. However, the design of the MAC in a vehicular network is a challenging task due to the high speed of the nodes, the frequent changes in topology, the lack of an infrastructure, and various QoS requirements. Recently several Time Division Multiple Access (TDMA)-based medium access control protocols have been proposed for VANETs in an attempt to ensure that all the vehicles have enough time to send safety messages without collisions and to reduce the end-to-end delay and the packet loss ratio. In this paper, we identify the reasons for using the collision-free medium access control paradigm in VANETs. We then present a novel topology-based classification and we provide an overview of TDMA-based MAC protocols that have been proposed for VANETs. We focus on the characteristics of these protocols, as well as on their benefits and limitations. Finally, we give a qualitative comparison, and we discuss some open issues that need to be tackled in future studies in order to improve the performance of TDMA-based MAC protocols for vehicle to vehicle (V2V) communications

    Safety Applications and Measurement Tools for Connected Vehicles

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    L'abstract è presente nell'allegato / the abstract is in the attachmen

    Cognitive radio network in vehicular ad hoc network (VANET): a survey

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    Cognitive radio network and vehicular ad hoc network (VANET) are recent emerging concepts in wireless networking. Cognitive radio network obtains knowledge of its operational geographical environment to manage sharing of spectrum between primary and secondary users, while VANET shares emergency safety messages among vehicles to ensure safety of users on the road. Cognitive radio network is employed in VANET to ensure the efficient use of spectrum, as well as to support VANET’s deployment. Random increase and decrease of spectrum users, unpredictable nature of VANET, high mobility, varying interference, security, packet scheduling, and priority assignment are the challenges encountered in a typical cognitive VANET environment. This paper provides survey and critical analysis on different challenges of cognitive radio VANET, with discussion on the open issues, challenges, and performance metrics for different cognitive radio VANET applications

    Cognitive radio network in vehicular ad hoc network (VANET): a survey

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    Cognitive radio network and vehicular ad hoc network (VANET) are recent emerging concepts in wireless networking. Cognitive radio network obtains knowledge of its operational geographical environment to manage sharing of spectrum between primary and secondary users, while VANET shares emergency safety messages among vehicles to ensure safety of users on the road. Cognitive radio network is employed in VANET to ensure the efficient use of spectrum, as well as to support VANET’s deployment. Random increase and decrease of spectrum users, unpredictable nature of VANET, high mobility, varying interference, security, packet scheduling, and priority assignment are the challenges encountered in a typical cognitive VANET environment. This paper provides survey and critical analysis on different challenges of cognitive radio VANET, with discussion on the open issues, challenges, and performance metrics for different cognitive radio VANET applications

    Cognitive radio network in vehicular ad hoc network (VANET): a survey

    Get PDF
    Cognitive radio network and vehicular ad hoc network (VANET) are recent emerging concepts in wireless networking. Cognitive radio network obtains knowledge of its operational geographical environment to manage sharing of spectrum between primary and secondary users, while VANET shares emergency safety messages among vehicles to ensure safety of users on the road. Cognitive radio network is employed in VANET to ensure the efficient use of spectrum, as well as to support VANET’s deployment. Random increase and decrease of spectrum users, unpredictable nature of VANET, high mobility, varying interference, security, packet scheduling, and priority assignment are the challenges encountered in a typical cognitive VANET environment. This paper provides survey and critical analysis on different challenges of cognitive radio VANET, with discussion on the open issues, challenges, and performance metrics for different cognitive radio VANET applications

    ContrĂ´le de Congestion dans les RĂ©seaux VĂ©hiculaires

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    Cette thèse analyse la possibilité d'utiliser des communications sans fil inter-véhiculaires pour améliorer la sécurité routière. Les performances du nouveau réseau ainsi créé (réseau ad-hoc véhiculaire) sont étudiées analytiquement et par des simulations dans un environnement réaliste. La thèse se concentre surtout sur des scénarios avec une forte densité de véhicules. Dans ce cas, l'accès au support devient un problème essentiel, en principal pour les applications de sécurité routière qui nécessitent une qualité de service élevée pour fonctionner dans un tel contexte. Ce travail montre que la version actuelle du standard IEEE 802.11, proposé comme méthode d'accès dans les réseaux véhiculaires, ne peut pas résoudre ce problème de passage à l'échelle pour supporter correctement les applications de sécurité routière. Plusieurs améliorations possibles sont analysées, liées à l'utilisation optimale de certains paramètres du protocole comme la taille de la fenêtre de contention ou bien le seuil de détection de la porteuse. Des nouveaux mécanismes adaptatifs visant ces paramètres sont proposés et les améliorations ainsi obtenues sont non-négligeables. Finalement, une nouvelle méthode d'accès est définie, en tenant compte des caractéristiques des applications de sécurité routière. Toujours basée sur des techniques CSMA, cette technique donne des résultats largement supérieurs à la version standard actuelle. ABSTRACT : The equipment of vehicles with wireless communication devices in order to improve road safety is a major component of a future intelligent transportation system. The success and availability of IEEE 802.11-based products make this technology the main competitor for the Medium Access Control (MAC) layer used in vehicle-to-vehicle communication. The IEEE 802.11p amendment has been specially designed in this special context of wireless access in vehicular environments. However, as all the other approaches based on Carrier Sense Multiple Access (CSMA), this protocol presents scalability problems, which leads to poor performance in high density scenarios, quite frequent in the case of a vehicular ad hoc network (VANET). This thesis studies the congestion control problem in the context of safety vehicular communications, with a special focus on the back-off mechanism and the carrier sense function. First of all, a number of important characteristics presented by the safety messages are discovered and understood by the means of an analytical framework. Second, the lessons learned from the analytical study are put into practice with the design of two adaptive mechanisms (one for the contention window and the other one for the carrier sense threshold) that take into account the local vehicular density. These mechanisms remain simple, but highly efficient, while also being straightforward to integrate in IEEE 802.11 devices. Finally, by taking into account the most important properties of a safety VANET, a new CSMA-based MAC protocol is proposed. This new access method, named Safety Range CSMA (SR-CSMA), relies on the idea that collisions can not be avoided in a high density network. However, by increasing the number of simultaneous transmissions between geographically distant nodes, SR-CSMA manages to better protect the immediate neighborhood, the most important area for safety applications

    A survey on vehicular communication for cooperative truck platooning application

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    Platooning is an application where a group of vehicles move one after each other in close proximity, acting jointly as a single physical system. The scope of platooning is to improve safety, reduce fuel consumption, and increase road use efficiency. Even if conceived several decades ago as a concept, based on the new progress in automation and vehicular networking platooning has attracted particular attention in the latest years and is expected to become of common implementation in the next future, at least for trucks.The platoon system is the result of a combination of multiple disciplines, from transportation, to automation, to electronics, to telecommunications. In this survey, we consider the platooning, and more specifically the platooning of trucks, from the point of view of wireless communications. Wireless communications are indeed a key element, since they allow the information to propagate within the convoy with an almost negligible delay and really making all vehicles acting as one. Scope of this paper is to present a comprehensive survey on connected vehicles for the platooning application, starting with an overview of the projects that are driving the development of this technology, followed by a brief overview of the current and upcoming vehicular networking architecture and standards, by a review of the main open issues related to wireless communications applied to platooning, and a discussion of security threats and privacy concerns. The survey will conclude with a discussion of the main areas that we consider still open and that can drive future research directions.(c) 2022 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
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