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An observable trend in recent years is the increasing demand for more complex services designed to be used with portable or automotive embedded devices. The problem is that these devices may lack the computational resources necessary to comply with service requirements. To solve it, cloud and edge computing, and in particular, the recent multi-access edge computing (MEC) paradigm, have been proposed. By offloading the processing of computational tasks from devices or vehicles to an external network, a larger amount of computational resources, placed in different locations, becomes accessible. However, this in turn creates the issue of deciding where each task should be executed. In this paper, we model the problem of computation offloading of vehicular applications to solve it using deep reinforcement learning (DRL) and evaluate the performance of different DRL algorithms and heuristics, showing the advantages of the former methods. Moreover, the impact of two scheduling techniques in computing nodes and two reward strategies in the DRL methods are also analyzed and discussed.

Vehicular networks have attracted a lot of research attention in the last decades. The main goal of vehicular communication is to ensure road safety by enabling the peri- odic communications between vehicles and between vehicles and other participants, such as roadside units.Cellular-Vehicle-to-Everything (C-V2X) is a leading technology for vehicular net- works. LTE-V2X is the first C-V2X technology, followed by 5G-V2X, and in both, resource allocation mechanisms play an important role in their performance. The resource allocation algorithms proposed in C-V2X must meet the requirements of V2X applications.Certainly, the safety-related applications are the most critical and time-constrained V2X applications. For this reason, in the first part of this thesis, we propose a clustering-based resource allocation algorithm for safety V2V communications, the Maximum Inter-Centroids Reuse Distance (MIRD), which aims to improve the reli- ability of safety V2V communications.In the second part of this thesis, we address resource allocation in 5G-V2X technology. Before performing resource allocation in 5G-V2X, we first consider the flexibility of the NR frame structure of 5G by focusing our interest on the 5G numerology concept. Therefore, we first investigate the impact of 5G numerologies on V2X application performance. Through simulations, we showed that choosing the appropriate numerology is a trade-off between V2X applications requirements, Inter-Carrier Interference (ICI) and Inter-Symbol Interference (ISI).Next, we propose a new resource allocation algorithm, namely the Priority and Satisfaction-based Resource Allocation in Mixed Numerology (PSRA-MN). In the PSRA-MN algorithm, we first select the appropriate numerology considering the channel conditions and the vehicle speed. Then, we apply a prioritization policy in favor of the safety-related traffic to ensure the required resources for the safety- related traffic, and the remaining resources after the safety allocation are optimally allocated to the non-safety vehicles so that the average satisfaction rate is maxi- mized. The proposed PSRA-MN algorithm is validated by simulations. The ob- tained results show that PSRA-MN outperforms the traditional resource allocation algorithms in terms of average allocation rate, average satisfaction rate and average delay., Les réseaux véhiculaires ont connu un vrai progrès technologique dans le domaine de la recherche scientifique au cours des dernières décennies. L’intégration des technologies de communications sans fil dans le domaine du transport a abouti à l’émergence d’un nouveau paradigme, à savoir les communications Vehicle-to-Everything (V2X). Ce dernier signifie les communications entre véhicules et tout autre objet. L’objectif primordial des commu- nications véhiculaires, est d’assurer la sécurité routière à travers l’échange des messages périodiques entre les véhicules et entre les véhicules et d’autres participants, tels que les unités de bord de route ou les piétons.La technologie C-V2X (Cellular-Vehicle-to-Everything) est une technologie émergente pour les réseaux véhiculaires standardisée par la 3GPP, dans laquelle les communications véhiculaires se basent sur les réseaux cellulaires. Le LTE-V2X est la première technologie C-V2X, suivie par la 5G-V2X. Les mécanismes d’allocation des ressources jouent un rôle important dans les performances des communications V2X. Pour cette raison, les algo- rithmes d’allocation des ressources proposés pour la technologie C-V2X doivent fortement répondre aux exigences des applications véhiculaires. Cependant, les applications liées à la sécurité routière sont les applications véhiculaires les plus critiques en termes de fiabilité et en termes de temps de latence. Pour cette raison, dans la première partie de cette thèse, nous proposons un algorithme d’allocation des ressources en LTE-V2X qui se base sur la technique du "clustering". Cet algorithme, nommé MIRD (Maximum Inter-Centoid Reuse Distance), vise à améliorer la fiabilité des communications véhiculaires de type sécurité routière.Dans la deuxième partie de cette thèse, nous abordons l’allocation des ressources radio dans la technologie 5G-V2X. Avant d’entamer le processus d’allocation des ressources radio en 5G-V2X, nous nous intéressons d’abord en premier lieu à la flexibilité de la trame radio de la 5G en concentrant notre intérêt sur le concept de numérologie. À cette fin, nous étudions d’abord l’impact du choix de la numérologie sur les performances des applications véhiculaires. Par le biais de simulations, nous avons abouti à prouver que le choix de la numérologie appropriée est un compromis entre les exigences des applications véhiculaires, les interférences inter-porteuses et les interférences inter-symboles. En deuxième lieu, nous proposons un algorithme d’allocation des ressources en considérant à la fois le trafic de sécurité routière et celui non lié à la sécurité routière. Dans cet algorithme, nommé PSRA-MN (Priority and Satisfaction-based Resource Allocation with Mixed Numerology), nous procédons d’abord au choix de la numérologie appropriée en tenant en compte les conditions du canal radio et la vitesse du véhicule. Ensuite, nous appliquons une politique de priorisation en faveur du trafic lié à la sécurité routière afin de garantir les ressources demandées par ce type de trafic. Puis, les ressources restantes sont allouées de manière optimale aux véhicules dont le trafic est non lié à la sécurité routière afin de maximiser le taux de satisfaction moyen de ces véhicules. L’algorithme PSRA-MN est validé par des simulations. Les résultats obtenus montrent que cet algorithme permet d’atteindre de meilleures performances en comparaison avec les algorithmes traditionnels, tel que le MAX-C/I, en termes de taux d’allocation moyen, de taux de satisfaction moyen, et de temps de latence moyen.

With the advances in wireless communications and the Internet of Things (IoT), various vehicular applications such as image-aided navigation and autonomous driving are emerging. These vehicular applications require a significant number of computation resources and a lower processing delay. However, these resource-limited and power-constrained vehicles may not meet the requirements of processing these vehicular applications. By offloading these vehicular applications to the edge cloud, vehicular edge computing (VEC) is deemed a novel paradigm for improving vehicular performance. However, how to optimize the allocation of computation resources of both vehicles and VEC servers to reduce the energy and delay is a challenging issue when deploying the VEC systems. In this article, we try to address this issue and propose a vehicular application offloading and computational resources allocation strategy. We formulate an optimization problem and present an efficient offloading scheme for vehicular applications. Extensive simulation results are offered to analyze the performances of the proposed scheme. In comparison with the benchmark schemes, the proposed scheme can outperform them in terms of computation cost.

Vehicle target tracking is a sub-field of increasing and increasing interest in the vehicular networking research area, in particular for its potential application in dense urban areas with low associated costs, e.g., by exploiting existing monitoring infrastructures and cooperative collaboration of regular vehicles. Inspired by the concept of trap coverage area, we have originally designed and implemented an original protocol for vehicle tracking in wide-scale urban scenarios, called TCAP. TCAP is capable of achieving the needed performance while exploiting a limited number of inexpensive sensors (e.g., public-authority cameras already installed at intersections for traffic monitoring), and opportunistic vehicle collaboration, with high scalability and low overhead if compared with state-of-the-art literature. In particular, the wide set of reported results show i) the suitability of our TCAP tracking in the challenging urban conditions of high density of vehicles, ii) the very weak dependency of TCAP performance from topology changes/constraints (e.g., street lengths and speed limits), iii) the TCAP capability of self-adapting to differentiated runtime conditions.

[EN] A novel compact broadband monopole antenna inspired by a Vivaldi antenna is presented. In order to get a compact solution, the profile of a slot Vivaldi antenna has been modified and a wideband antenna covering LTE700, GSM850, GSM900, DCS1800, PCS1900, WCDMA2100, Bluetooth, WiMAX2350, WLAN2400, and LTE2600 standards has been obtained, with a size reduction length of 30% over conventional monopole antennas. In contrast to traditional designs using Vivaldi antennas, a compact design with omnidirectional radiation pattern is proposed. Simulated and measured results are provided, which verify the broadband behavior of the antenna. In addition, the proposed design is perpendicularly mounted to a ground plane, being then suitable for mobile communications in vehicular applications., This work was supported by project SEESAW (P.O.R. 2007-2013-bando 2009-Azione 1.1.2), by the Spanish Ministry of Education and Science under projects TEC2010-20841-C04-01, CSD2008-00068, and by the Government of Ecuador under the SENESCYT.

[EN] In this letter, a three-dimensional antenna solution for automotive applications is presented. The proposed solution is formed by two independent antennas, perpendicularly placed inside a plastic cover with a shark-fin shape. The antennas, designed with low-cost materials, exhibit omnidirectional radiation patterns in the azimuthal plane. The first antenna is a doubleshorted monopole that provides service from 698 to 960 MHz (in the LTE700, GSM850, and GSM900 bands), whereas the second antenna is a drop-shaped monopole that operates from 1.7 to 2.7 GHz (in the DCS1800, PCS1900, WCDMA2100, WLAN2400, LTE2600, WiMAX2350, and Wi-Fi at 2.4-GHz bands), and from 5.1 to 6 GHz (in theWi-Fi at 5 GHz and C2C bands). Results show a good matching and radiation efficiency at all bands., This work was supported by Project SEESAW P.O.R. 2007-2013-bando 2009-Azione 1.1.2, the Spanish Ministry of Economics and competitiveness under Projects TEC2013-47360-C3-3-P and CSD2008-00068, and the Government of Ecuador under the SENESCYT.

The subject of this paper concerns the development of a vehicular hydrogen tank system, using a commercial interstitial metal hydride as storage material. The design of the tank was intended to feed a fuel cell in a light prototype vehicle, and the chosen hydride material, Hydralloy C5 by GfE, was expected to be able to absorb and desorb hydrogen in a range of pressure suitable for this purpose. A systematic analysis of the material in laboratory scale allows an extrapolation of the thermodynamic and reaction kinetics data. The following development of the modular tank was done according to the requirements of the prototype vehicle propulsion system and led to promising intermediate results. The modular approach granted flexibility in the design, allowing both to reach carefully the design goals and to learn the limiting factors in the sorption process. Proper heat management and suitable equipment remain key factors in order to achieve the best performances.

The demand for safe and secure journeys over roads and highways has been growing at a tremendous pace over recent decades. At the same time, the smart city paradigm has emerged to improve citizens’ quality of life by developing the smart mobility concept. Vehicular Ad hoc NETworks (VANETs) are widely recognized to be instrumental in realizing such concept, by enabling appealing safety and infotainment services. Such networks come with their own set of challenges, which range from managing high node mobility to securing data and user privacy. The Software Defined Networking (SDN) paradigm has been identified as a suitable solution for dealing with the dynamic network environment, the increased number of connected devices, and the heterogeneity of applications. While some preliminary investigations have been already conducted to check the applicability of the SDN paradigm to VANETs, and its presumed benefits for managing resources and mobility, it is still unclear what impact SDN will have on security and privacy. Security is a relevant issue in VANETs, because of the impact that threats can have on drivers’ behavior and quality of life. This paper opens a discussion on the security threats that future SDN-enabled VANETs will have to face, and investigates how SDN could be beneficial in building new countermeasures. The analysis is conducted in real use cases (smart parking, smart grid of electric vehicles, platooning, and emergency services), which are expected to be among the vehicular applications that will most benefit from introducing an SDN architecture. © 2016 by the authors; licensee MDPI, Basel, Switzerland.

In order to perform sensing tasks, most current Intelligent Transportation Systems (ITS) rely on expensive sensors, which offer only limited functionality. A more recent trend consists of using Wireless Sensor Networks (WSN) for such purpose, which reduces the required investment and enables the development of new collaborative and intelligent applications that further contribute to improve both driving safety and traffic efficiency. This paper surveys the application of WSNs to such ITS scenarios, tackling the main issues that may arise when developing these systems. The paper is divided into sections which address different matters including vehicle detection and classification as well as the selection of appropriate communication protocols, network architecture, topology and some important design parameters. In addition, in line with the multiplicity of different technologies that take part in ITS, it does not consider WSNs just as stand-alone systems, but also as key components of heterogeneous systems cooperating along with other technologies employed in vehicular scenarios.

We propose Roadside Unit (RSU) Clouds as a novel way to offer non-safety application with QoS for VANETs. The architecture of RSU Clouds is delineated, and consists of traditional RSUs and specialized micro-datacenters and virtual machines (VMs) using Software Defined Networking (SDN). SDN offers the flexibility to migrate or replicate virtual services and reconfigure the data forwarding rules dynamically. However, frequent changes to service hosts and data flows not only result in degradation of services, but are also costly for service providers. In this paper, we use Mininet to analyze and formally quantify the reconfiguration overhead. Our unique RSU Cloud Resource Management (CRM) model jointly minimizes reconfiguration overhead, cost of service deployment and infrastructure routing delay. To the best of our knowledge, we are the first to utilize this approach. We compare the performance of purist approach to our Integer Linear Programming (ILP) model and our innovative heuristic for the CRM technique and discuss the results. We will show the benefits of a holistic approach in Cloud Resource Management with SDN. Scopus

Los recientes esfuerzos de investigación realizados desde la comunidad académica, la industria automovilística y el sector de transportes, apuntan a los sistemas inteligentes de transporte como una tecnología clave para mejorar la seguridad en las carreteras, la eficiencia en el tráfico y el confort de los conductores. Las redes vehiculares Ad Hoc [VANETs] tienen el potencial de habilitar aplicaciones para seguridad en el tráfico, eficiencia en el transporte y movilidad sostenible. Los métodos de diseminación y los mecanismos de enrutamiento desempeñan un papel esencial en el diseño y la caracterización de las aplicaciones vehiculares. Este artículo provee un marco de referencias de las redes vehiculares ad hoc, describe sus conceptos fundamentales, los estándares de comunicación y las aplicaciones vehiculares. Presenta además los protocolos de enrutamiento para VANETs y los resultados de la simulación para el protocolo Geocast Distributed Robust Geocast. Recent research efforts of academia, automotive industry and transportation sector point to Intelligent Transportation Systems as a key technology for improving road safety, traffic efficiency and comfort driving. Vehicular Ad Hoc Networks (VANETs) have significant potential to enable applications for traffic safety efficiency transportation and sustainable mobility. The dissemination methods and routing mechanisms play an essential role in the design and characterization of vehicular applications. This article provides an overview of vehicular ad hoc networks; we describe the fundamental concepts, communication standards and vehicular applications. This paper also presents a survey on routing protocols for VANETs and simulation results for Distributed Robust Geocast.

Best Paper Award ; http://www.isat.fr/jnct2013/index.html

This thesis focuses on developing methods and models making it possible to evaluate quantitative measures characterizing the dependability of mobile services as perceived by the users. These models and measures are aimed at providing support to the designers during the selection and analysis of candidate architectures that are well suited to fulfill the dependability requirements. We consider the case of vehicular applications using inter-vehicle communications based on ad-hoc networks and may have access to services located on fixed infrastructure. We propose an approach combining: 1) dependability models based on stochastic activity networks, in order to describe the system failure modes and associated recovery mechanisms, and 2) simulation and analytical models allowing the estimation of connectivity characteristics, taking into account different mobility scenarios and environment. This approach is illustrated on three case studies including a virtual black box based on cooperative data replication and backup, and an automated highway system (Platooning application).; Cette thèse porte sur le développement de méthodes et de modèles permettant de quantifier la sûreté de fonctionnement d'applications embarquées sur des systèmes mobiles. L'objectif est de fournir des indicateurs pour l'analyse et la sélection des architectures les plus adaptées pour satisfaire les exigences de sûreté de fonctionnement. Nous considérons le cas des applications véhiculaires utilisant des communications inter-véhicules basées sur des réseaux ad-hoc et pouvant avoir accès à des services situés sur des infrastructures fixes. Nous proposons une approche combinant: 1) des modèles de sûreté de fonctionnement utilisant des réseaux d'activités stochastiques permettant de décrire les modes défaillances et de restauration des systèmes considérés et 2) des simulations et des modèles analytiques de scénarios de mobilité permettant d'estimer des caractéristiques de connectivité de ces systèmes. Cette approche est illustrée sur trois cas d'études dont un système d'autoroute automatisée, et une boîte noire virtuelle basée sur la réplication et la sauvegarde coopérative des données.

International audience; In this paper, an approach for the design of antennas suitable for vehicular applications is presented. The resulting solutions are light, low-profile and they exhibit good impedance match and omnidirectional radiation pattern over the band of interest. Two representative test cases are reported to demonstrate the effectiveness of the proposed approach.