Tesis sobre el tema "Vehicular Application"
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Kaveh, Shafiee. "Application-based packet routing in vehicular networks". Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42787.
Texto completoOliveira, Filipe Ferreira de. "REINVENT : accessing vehicular networks in mobile application". Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/11564.
Texto completoAs redes veiculares têm sido alvo de grandes avanços tecnológicos, e a comunicação entre veículos é hoje uma realidade que tem despertado o interesse tanto ao nível da investigação como de alguns dos principais fabricantes de automóveis com o intuito de criar um conjunto de serviços para melhorar a experiência dos utilizadores deste tipo de redes. Por outro lado, os dispositivos móveirs como smartphones, tablets ou PDA’s também são uma área emergente no mundo das tecnologias devido ao enorme aumento de capacidade computacional que sofreram nos últimos anos. Embora as redes veiculares tenham sido alvo de grandes avanços tecnológicos continuam a encontrar obstáculos para a sua afirmação devido à indisponibilidade de dispositivos nos veículos que permitam usufruir das suas potencialidades. Esta falta de dispositivos pode ser ultrapassada aliando o mundo dos dispositivos móveis com as redes veiculares. Utilizando o potencial das redes veiculares e a capacidade computacional dos novos dispositivos móveis pode-se explorar um cenário de criação de serviços e aplicações de segurança, controlo e eficiência de tráfego e entretenimento. O presente trabalho propõe-se a estudar, criar e testar uma solução para a integração das duas áreas tecnológicas referidas anteriormente. Neste documento é descrita uma arquitectura de alto nível que permite a integração de aplicações móveis com as redes veiculares, abstraindo as camadas de transporte e de rede com um módulo de software que fornece os métodos necessários para as aplicações usufruírem dos serviços das redes veiculares. O resultado final deste trabalho é uma arquitectura de software para integração em aplicações Android que permite utilizar a rede veicular para comunicação entre as aplicações. Ao longo deste documento é descrito todo o processo de implementação desta arquitectura, e posteriormente é apresentada a implementação de aplicações exemplo para experimentação da arquitectura e avaliação do seu desempenho. No âmbito da Dissertação foram criados cenários para realização de testes de desempenho das aplicações em ambientes reais e simulados. Estes testes serviram para identificar a viabilidade da utilização do REINVENT em dispositivos com diferentes características de hardware, e também para identificar potenciais pontos de atraso na estrutura da arquitectura criada. Os resultados obtidos permitiram constatar que a utilização desta arquitectura não induz qualquer tipo de interferência nem atraso no normal funcionamento das aplicações, e que o REINVENT pode ser utilizado na criação de novas aplicações móveis no âmbito das redes veiculares.
Vehicular networks have been the subject of major technological progress, and the communication between vehicles is a reality that has been the subject of interest both in terms of research and of some of the major car manufacturers in order to create a set of services to enhance the user experience of such networks. On the other hand, mobile devices such as smartphones, tablets and PDA's are also an emerging technology in the world due to the enormous increase of computing power they got in recent years. Although vehicular networks have been the subject of great technological advances, they continue to encounter obstacles to their raising due to unavailability of devices in vehicles that allow the use of its potential. This lack of devices can be overcome by combining the world of mobile devices with vehicular networks. Using the potential of vehicular networks and computational capabilities of new mobile devices, a set of scenarios can be explored in order to create services and applications for security, control and efficiency of traffic and entertainment. This work proposes to study, create and test a solution for the integration of the two technology areas mentioned above, applications and vehicular networks. In this Dissertation we describe a high-level architecture that allows the integration of mobile applications with vehicular networks by abstracting transport and network layers with a software architecture that provides the methods needed for the applications to take advantage of vehicular networks services. The end result of this work is a software architecture for integration into Android applications that allows the use of vehicular network for relaying communication between applications. Throughout this document, the whole process of the architecture implementation is described as well as two example applications for proof of concept, testing purpose and performance evaluation. In order to test the performance of the REINVENT module in the applications, two test scenario environments were created, a simulated environment, integrating a VANET simulation framework with mobile devices, and a real environment using an on board unit for vehicle communication purposes. These tests served to identify the feasibility of using REINVENT in devices with different hardware characteristics, and also to identify potential sources of delay in the structure of the architecture created. The results revealed that the use of this module does not induce any interference or delay on the normal operation of applications, and REINVENT can be used in creating new mobile applications in the context of vehicular networks.
Vieira, Leandro Kravczuk. "Performance Analysis of a VoIP application in vehicular networks". Universidade Federal do CearÃ, 2011. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=7291.
Texto completoAs redes veiculares surgiram como um caso particular de redes mÃveis e passaram a formar um campo especÃfico de pesquisa na Ãrea de redes de computadores. Elas tÃm sido alvo de inÃmeras pesquisas cientÃficas nos Ãltimos anos, cujo principal foco à o desenvolvimento do Sistema Inteligente de Transporte. AlÃm disso, dado que os automÃveis sÃo cada vez mais importantes na vida das pessoas, embarcar softwares inteligentes em seus carros pode melhorar substancialmente a qualidade de vida dos usuÃrios. Esse fato, somado à significante demanda do mercado por mais confiabilidade, seguranÃa e entretenimento nos veÃculos, levou ao desenvolvimento e suporte significantes para as redes veiculares e suas aplicaÃÃes. Dentre estas aplicaÃÃes pode-se citar a utilizaÃÃo do VoIP. Entretanto, os aplicativos VoIP sofrem com problemas de atraso, perda de pacotes e jitter. Estes desafios tÃcnicos se agravam ainda mais quando utilizado em redes sem fio. Um fator que influencia diretamente a utilizaÃÃo de uma aplicaÃÃo em redes em fio à o protocolo de roteamento. O roteamento à uma tarefa desafiadora devido à alta mobilidade dos nÃs, à instabilidade dos enlaces sem-fio e a diversidade de cenÃrios. Por essa razÃo, diversos protocolos de roteamento foram projetados com o objetivo de solucionar um ou mais problemas especÃficos de cada cenÃrio. Entretanto, apesar de existirem vÃrias soluÃÃes propostas para o problema do roteamento em redes veiculares, nenhuma soluÃÃo geral foi encontrada, ou seja, nenhum protocolo proposto obteve desempenho considerÃvel nos diversos cenÃrios existentes nas redes veiculares. Sendo assim, nesta dissertaÃÃo, analisamos atravÃs de simulaÃÃes o impacto da densidade, do alcance de transmissÃo, da mobilidade e do tipo de protocolo de roteamento no desempenho de uma aplicaÃÃo VoIP nos cenÃrios urbano e de rodovia em redes veiculares.
Vehicular networks have emerged as a particular case of mobile networks and then became a specific field of research in computer networks. They have been the subject of numerous scientific research in recent years, whose main focus is the development of Intelligent Transport System. Furthermore, given that cars are increasingly important in people's lives, smart board software in their cars can substantially improve the quality of life of users. This fact and the significant market demand for more reliability, security and entertainment in vehicles, has led to significant development and support for vehicular networks and their applications. Among these applications we can mention the use of VoIP, however, VoIP applications suffer from problems of delay, packet loss and jitter. These technical challenges are further aggravated when used in wireless networks. One factor that directly influences the use of an application in wireless networks is the routing protocol. Routing is a challenging task due to the high node mobility, the instability of wireless links and the diversity of scenarios. For this reason, several routing protocols have been designed with the goal of solving one or more specific problems of each scenario. However, although there are several proposed solutions to the problem routing in vehicular networks, no general solution was found, in other words, any proposed protocol obtained considerable performance in the various scenarios that exist in vehicular networks. Thus, in this paper, we analyze through simulations the impact of density, of the reach of transmission, the mobility and the type of routing protocol on the performance of a VoIP application in urban and highway scenarios of vehicular networks.
Shameerpet, Tanuja. "APPLICATION OF PEER TO PEER TECHNOLOGY IN VEHICULAR COMMUNICATION". OpenSIUC, 2021. https://opensiuc.lib.siu.edu/theses/2827.
Texto completoGamati, E. "Information collection algorithm for vehicular ad-hoc networks (application domain: Urban Traffic Wireless Vehicular Ad-Hoc Networks (VANETs))". Thesis, Nottingham Trent University, 2013. http://irep.ntu.ac.uk/id/eprint/4/.
Texto completoGoudarzi, Forough. "Non-cooperative beaconing control in vehicular ad hoc networks". Thesis, Brunel University, 2017. http://bura.brunel.ac.uk/handle/2438/15608.
Texto completogona, rishitha. "Application of Micro Cloud for Cooperative Vehicles". OpenSIUC, 2020. https://opensiuc.lib.siu.edu/theses/2730.
Texto completoLu, Guangqian. "A Lane Detection, Tracking and Recognition System for Smart Vehicles". Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32077.
Texto completoAlodadi, Khaled. "Detecting non-line of sight to prevent accidents in Vehicular Ad hoc Networks". Thesis, De Montfort University, 2015. http://hdl.handle.net/2086/12268.
Texto completoAndrade, Ccalluche Mayra Alexsandra, Dominguez Lusian Maximiliano, Santa Cruz Katherine Dora Reyes y Acosta Ruty Ines Yrrazabal. "Service Car Express". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2018. http://hdl.handle.net/10757/652185.
Texto completoThe present work corresponds to the course of Business Development 2, throughout the development we will apply concepts and tools learned throughout the career of the UPC University. Currently, Peru presents a gradual growth in the automotive fleet, with a greater concentration in Lima Metropolitana and Callao. Sample of this can be seen in everyday life, when see traffic everywhere. Service Car Xpress, raises the business idea that points to the automotive sector, car care and vehicle advice. Our idea is directed to B and C socioeconomic status and to people or companies that have vehicles considered second-hand or to those who are planning to acquire a vehicle within districts such as Miraflores, Surco, Chorrillos, Barranco, San Miguel, Surquillo and Jesús María. Service Car Xpress, arrives with a different value proposition, services purely at home trying to reduce the lost time of our customers while they are in workshops, we are going to make it be something simply practical and innovative, available at the time. In order to fulfill this value proposition, ScarX has created a business model that, through technology is going to optimize the time a car service can take. We offer our clients the highest quality in all processes taking advantage of all available resources.
Trabajo de investigación
Matus, Icaza Vicente. "Development of a visible light communications versatile research platform with potential application on vehicular networks". Tesis, Universidad de Chile, 2018. http://repositorio.uchile.cl/handle/2250/152113.
Texto completoLas redes vehiculares ad-hoc (VANets) son un nuevo paradigma en comunicación móvil que se plantea que podría permitir el despliegue de sistemas de transporte inteligente (ITS), más seguros, eficientes y amigables con el medioambiente. Se cuenta con el estándar DSRC de comunicaciones vehiculares pero no está comprobado que sea capaz de ofrecer la robustez y seguridad que necesitan los ITS. Las comunicaciones por luz visible (VLCs), son tecnologías de comunicación inalámbricas basadas en la modulación de intensidad de luz. Se realizan con dispositivos opto-electrónicos como diodos LED y foto-diodos. Se plantea que éstas podrían complementar a las radio-frecuencias (RF), como las del protocolo DSRC, por ejemplo, y permitir a las VANets entregar un mejor servicio, sobre todo en ambientes congestionados. En el presente trabajo, se realizó el desarrollo de una plataforma con herramientas para prototipado de enlaces VLC con aplicación en VANets bajo la hipótesis que las tecnologías existentes de illuminación en automóviles y señales de tránsito son una infraestructura que permite implementar VLCs en ambientes vehiculares. Primero se consultó el estado del arte de VANets y de VLCs, enfocado en entender el origen del interés por la implementación de redes vehiculares, así como sus desafíos y cómo las VLCs pueden mejorar el desempeño de dichos sistemas. Se estudiaron tecnologías aplicables a los sistemas de información y comunicaciones de las redes vehiculares con enfoque en las VLC. Un grupo fueron las plataformas de hardware programable como radios definidas por software (SDRs) y las placas Arduino. Otro tema fue la red de control interna de los vehículos y cómo existen interfaces para acceder a ella y obtener mediciones de los sensores e incluso dar instrucciones a los actuadores del auto. También, se revisaron los transductores de una red VLC: los diodos LED y fotodiodos, incluyendo la electrónica necesaria para su funcionamiento. Finalmente, se implementó un sistema de comunicaciones por VLC, basado en SDRs y optoelectrónica, y también un sistema adquisición de datos para la red de control del vehículo, basado en Arduino y un circuito integrado ELM327. Ambos sistemas se diseñaron modulares y se construyeron robustos. Se logró con ellos la transmisión de datos por luz y la lectura de datos del area de control del vehículo. Actualmente, el sistema desarrollado está en manos de un grupo de investigación que se dedica a estudiar las tecnologías de comunicación vehicular. También se está trabajando en una publicación con la evaluación de los sistemas implementados.
Este trabajo ha sido parcialmente financiado por ERANet-LAC Proyecto "RETRACT" Código ELAC2015/T10-0761, FONDECYT iniciación N° 11160517, FONDECYT Posdoctorado N° 3170021
Retief, Herman Lafras. "A review of hydrogen storage for vehicular application and the determination of the effect of extraction boil–off / Retief H.L". Thesis, North-West University, 2012. http://hdl.handle.net/10394/8222.
Texto completoThesis (MIng (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2012.
Bai, Chumeng. "Evaluation and Improvement of Decentralized Congestion Control for Multiplatooning Application". Thesis, KTH, Radio Systems Laboratory (RS Lab), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-232849.
Texto completoPlatooning (fordonskonvojer) har potential att bli ett genombrott i öka vägkapaciteten och minska bränsleförbrukning, eftersom det tillåter en kedja av fordon att noga följa varandra på vägen. När antalet fordon ökar, kommer att plutoner följa varandra i vad som benämns multiplatooning (konvoj av fordonskonvojer). Många kooperativ intelligenta transportsystem (C-ITS) tillämpningar förlitar sig på regelbundet utbytte beacons bland fordon att förbättra traffiksäkerheten. Dock som antalet uppkopplade fordon ökar, kan nätverket bli överbelastat på grund av regelbundet utbytte beacons. Utan någon trängsel kontrollmetod, får därför säkerhet kritiska meddelanden såsom kooperativ medvetenhet meddelanden (CAMs) inte levereras i tid i höga fordon densitet scenarier. Både Europeiska institutet för telekommunikationsstandarder (ETSI) och Institute el och elektroniska tekniker (IEEE) har arbetat på olika standarder för att stödja vehicular kommunikation. ETSI definieras den decentraliserade överbelastning kontroll (DCC) mekanism som anpassar överföring parametrar (meddelande hastighet, överföra datahastighet och sändningseffekt, etc.) för att hålla kanalen belastningen under kontroll. ETSI DCC använder en tre-state maskin med RELAXED, ACTIVE och RESTRICTIVE stater. I denna avhandling har genomfört vi denna tre-state maskin genom att anpassa meddelande hastighet baserat på kanal upptagen förhållandet (CBR). Vi nämna detta meddelande-hastighet baserat tre-state machine DCC-3. DCC-3 har förmågan att kontrollera kanal belastning; Det har dock otillbörlighet och instabilitet problem på grund av de dramatiska parameterändringar mellan stater. Därför vi indelat det ACTIVE tillståndet för DCC-3 i fem undertillstånd och hänvisar till detta som DCC-7. Vi benchmarkade DCC-3 mot statiska leda (STB), dynamisk leda (DynB), linjära MEssage Rate integrerad kontroll (LIMERIC) och DCC-7 med olika utvärdering statistik med olika antal plutoner. Våra resultat från Plexe simulator visar att DCC-7 har bästa prestanda när man överväger alla utvärdering statistik, inklusive CBR, mellan receptionen tid (IRT), kollisioner, säker tid baserat och rättvisa. Vi fann dessutom använda Sändareffektstyrning kan avsevärt förbättra prestanda för CBR och kollision priser.
Hadiwardoyo, Seilendria Ardityarama. "Modelling and Real Deployment of C-ITS by Integrating Ground Vehicles and Unmanned Aerial Vehicles". Doctoral thesis, Universitat Politècnica de València, 2019. http://hdl.handle.net/10251/118796.
Texto completo[CAT] Per a proporcionar un entorn de trànsit viari més segur i eficient, els sistemes ITS o Sistemes Intel·ligents de Transport representen una solució dotada d'avanços tecnològics d'avantguarda. La integració d'elements de transport com auto móvils juntament amb elements d'infraestructura com Road Side Units (RSUs) situats al llarg de lav via de comunicació permeten oferir un entorn de xarxa connectat amb multiples serveis, inclusa connectivitat a Internet. Aquesta integració es connex amb el terme C-ITS o Sistemes Intel·ligents de Transport Cooperatius , com ara els automòbils, amb elements d'infraestructura, com ara les road side units (RSU) o pals situats al llarg de la carretera, per a aconseguir un entorn de xarxa que oferisca nous serveis a més de connectivitat a Internet. Aquesta integració s'expressa amb el terme C-ITS, o sistemes intel·ligents de transport cooperatius. La connexió d'automòbils amb dispositius d'infraestructura permet crear xarxes vehiculars connectades (V2X) vehicle a dispositiu, que ofreixen la possibilitat de nous desplegaments en aplicacions C-ITS, com ara les relacionades amb la seguretat. Avui dia, amb l'ús massiu dels telèfons intel·ligents, i a causa de la flexibilitat i mobilitat que presenten, es fan esforços per integrar-los amb els automòbils. De fet, amb el suport adequat d'unitat a bord (OBU), els telèfons intel·ligents es poden integrar perfectament amb les xarxes vehiculars, permetent als conductors usar els seus telèfons intel·ligents com a dispositius per a participar en els serveis de C-ITS, a fi de millorar la seguretat al volant entre altres. Tòpic est, que hui dia representa un tema rellevant d'investigació. Un problema a solucionar sorgeix quan les comunicacions vehiculars ateixen inferències i bloquejos del senyal deguts a l'escenari. De fet, l'impacte de la vegetació i els edificis, tant en àrees urbanes com rurals, pot afectar la qualitat del senyal. Algunes estratègies de millorar la comunicació vehicular en aquest tipus d'entorn consisteix a desplegar UAVs o vehicles aeris no tripulats (drones), els quals actuen com a enllaços de comunicació entre vehicles. De fet, l'ús d'UAVs ofereix importants avantatges d'implementació, ja que tenen una gran flexibilitat en termes de mobilitat, a més d'un rang de comunicacions millorat. Per a avaluar la qualitat de les comunicacions, s'han de realitzar mesures en escenaris reals. No obstant això, a causa del cost de les implementacions i desplegaments reals d'UAV i el seu ús combinat amb vehicles, aquests experiments reals podrien no ser factibles per a activitats d'investigació amb recursos limitats. Per tant, la metodologia basada en simulació es converteixen en l'opció preferida entre els investigadors per a avaluar les comunicacions entre UAV i vehicles terrestres. Aconseguir models de propagació de senyal correctes i representatius que puguen importar-se als entorns de simulació resulta crucial per a obtenir un major grau de realisme, especialment per a simulacions que involucren el moviment d'UAV en qualsevol lloc de l'espai 3D. En particular, cal tenir en compte la informació d'elevació del terreny per a intentar caracteritzar els efectes de propagació del senyal. En aquesta tesi doctoral proposem enfocaments tant teòrics com empírics per a estudiar la integració de xarxes vehiculars que combinen automòbils i UAV, així com l'impacte de l'entorn en la qualitat de les comunicacions. Aquesta tesi presenta una aplicació, una metodología de mesurament en escenaris reals i un nou model de simulació, els quals contribueixen a modelar, desenvolupar i implementar serveis C-ITS. Més específicament, proposem un model de simulació que té en compte les característiques del terreny en 3D, per a aconseguir resultats fiables de comunicació entre UAV i vehicles terrestres.
[EN] To provide a safer road traffic environment and make it more convenient, Intelligent Transport Systems (ITSs) are proposed as a solution endowed with cutting-edge technological advances. The integration of transportation elements like cars together with infrastructure elements like Road Side Units to achieve a networking environment offers new services in addition to Internet connectivity. This integration comes under the term Cooperative Intelligent Transport System (C-ITS). Connecting cars with surrounding devices forming vehicular networks in Vehicle-to-Everything (V2X) open new deployments in C-ITS applications like safety-related ones. With the massive use of smartphones nowadays, and due to their flexibility and mobility, several efforts exist to integrate them with cars. In fact, with the right support from the vehicle's On-Board Unit (OBU), smartphones can be seamlessly integrated with vehicular networks. Hence, drivers can use their smartphones as a device to participate in C-ITS services for safety purposes, among others, which is a quite interesting research topic. A significant problem arises when vehicular communications face signal obstructions caused by the environment. In fact, the impact of vegetation and buildings, whether in urban and rural areas, can result in a lower signal quality. One way to enhance vehicular communication networks is to deploy Unmanned Aerial Vehicles (UAVs) to act as relays for communication between cars, or ground vehicles. In fact, UAVs offer important deployment advantages, as they offer great flexibility in terms of mobility, in addition to an enhanced communications range. To assess the quality of the communications, a set of measurements must take place. However, due to the cost of real deployments of UAVs and cars, real experiments might not be feasible for research activities with limited resources. Hence, simulation experiments become the preferred option to assess UAV-to- car communications. Achieving correct and representative signal propagation models that can be imported to the simulation environments becomes crucial to obtain a higher degree of realism, especially for simulations involving UAVs moving anywhere throughout the 3D space. In particular, terrain elevation information must be taken into account when attempting to characterize signal propagation effects. In this research work, we propose both theoretical and empirical approaches to study the integration of vehicular networks combining cars and UAVs, and we study the impact of the surrounding environment on the communications quality. An application, a measurement framework, and a simulation model are presented in this thesis in an effort to model, develop, and deploy C-ITS services. More specifically, we propose a simulation model that takes into account 3D terrain features to achieve reliable UAV-to-car communication results.
I want to thank the Spanish government through the Ministry of Economy and Competitiveness (MINECO) and the European Union Commission through the European Social Fund (ESF) for co-financing and granting me the fellowship to fund my studies in Spain and my research stay in Russia. In addition, I would to thank the National Institute of Informatics for granting me the internship fund and the Japanese government through the Japan Society for the Promotion of Science (JSPS) for supporting my research work in Japan.
Hadiwardoyo, SA. (2019). Modelling and Real Deployment of C-ITS by Integrating Ground Vehicles and Unmanned Aerial Vehicles [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/118796
TESIS
Costa, André Amaral. "Assessing WiMAX for vehicular communications applications". Master's thesis, Universidade de Aveiro, 2008. http://hdl.handle.net/10773/1952.
Texto completoOs acidentes rodoviários têm um enorme impacto na sociedade, quer devido às perdas humanas daí resultantes quer devido aos custos económicos a si associados. Por todo o mundo, esta situação levou ao estudo de mecanismos que permitem aumentar a segurança nas estradas. Por exemplo, na Europa estão a ser financiados vários projectos para desenvolver estes mecanismos e a maior parte das iniciativas em curso requerem a possibilidade dos veículos comunicarem entre si e/ou com estações que se encontram fixas junto à estrada. Devido aos requisitos de mobilidade dos veículos, as tecnologias de comunicação sem fios têm um papel crucial neste tipo de aplicações. Neste sentido, esta dissertação avalia a adequação da tecnologia de comunicação sem fios WiMAX para a transmissão de serviços de segurança rodoviária e/ou outros, entre os veículos e a infraestrutura, usando para isso os mecanismos integrados de diferenciação de tráfego desta mesma tecnologia de comunicação. Especificamente, o objectivo é avaliar se estes mecanismos são apropriados para fornecer os serviços atrás mencionados tendo em conta os seus requisitos tempo-real (largura de banda, latência, variação da latência, etc.).
Road accidents have a huge impact on the society, both because of the resulting human life losses and injuries as well as because of the associated economic costs. This situation fostered the study of mechanisms for increasing road safety all over the world. In Europe, several projects are being funded to develop such mechanisms. Many of the approaches that are being pursued require the ability of the vehicles to communicate with each other and/or with fixed roadside equipments. Due to the mobility constraints, wireless technologies have a crucial role in this kind of applications. This dissertation assesses the suitability of the WiMAX wireless technology for supplying vehicle to infrastructure road safety services and others, using this communication technology integrated quality of service mechanisms that provides traffic differentiation. Specifically, the purpose is to evaluate if these mechanisms are appropriate to provide the referred services taking in account their real-time requirements (bandwidth, latency, jitter, etc.).
Wöhrle, Wolfgang Richard [Verfasser], Klaus Peter [Akademischer Betreuer] Sedlbauer, Klaus Peter [Gutachter] Sedlbauer, Gunnar [Gutachter] Grün y Anton [Gutachter] Maas. "Vehicular Climatization Effectiveness : Application of Thermal Perception Models for the Assessment of Direct Passenger Conditioning Concepts in Vehicles / Wolfgang Richard Wöhrle ; Gutachter: Klaus Peter Sedlbauer, Gunnar Grün, Anton Maas ; Betreuer: Klaus Peter Sedlbauer". München : Universitätsbibliothek der TU München, 2020. http://d-nb.info/1225479991/34.
Texto completoMarfia, Gustavo. "P2P vehicular applications mobility, fairness and scalability /". Diss., Restricted to subscribing institutions, 2009. http://proquest.umi.com/pqdweb?did=1998391911&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Texto completoWang, Yuan-Fang. "Computer Vision Analysis for Vehicular Safety Applications". International Foundation for Telemetering, 2015. http://hdl.handle.net/10150/596451.
Texto completoIn this paper, we present our research on using computer-vision analysis for vehicular safety applications. Our research has potential applications for both autonomous vehicles and connected vehicles. In particular, for connected vehicles, we propose three image analysis algorithms that enhance the quality of a vehicle's on-board video before inter-vehicular information exchange takes place. For autonomous vehicles, we are investigating a visual analysis scheme for collision avoidance during back up and an algorithm for automated 3D map building. These algorithms are relevant to the telemetering domain as they involve determining the relative pose between a vehicle and other vehicles on the road, or between a vehicle and its 3D driving environment, or between a vehicle and obstacles surrounding the vehicle.
Soleimani, Hossein. "LTE/LTE-Advanced for Vehicular Safety Applications". Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/37840.
Texto completoMeireles, Tiago Hipkin. "Wireless protocols to support vehicular safety applications". Doctoral thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/16287.
Texto completoIn the last decades the number of vehicles travelling in European road has raised significantly. Unfortunately, this brought a very high number of road accidents and consequently various injuries and fatalities. Even after the introduction of passive safety systems, such as seat belts, airbags, and some active safety systems, such as electronic brake system (ABS) and electronic stabilization (ESP), the number of accidents is still too high. Approximately eight per cent of the fatal accidents occur in motorways, in the Portuguese case, the number of fatalities has remained constant in the first decade of the 21st century. The evolution of wireless communications, along with the north-American and European policies that reserve spectrum near the 5,9GHz band for safety applications in the vehicular environment, has lead to the development of several standards. Many of these applications are based on the possibility of using a wireless communication system to warn drivers and passengers of events occurring on the road that can put at risk their own safety. Some examples of safety applications are the hard-brake warning, the wrong-way warning and the accident warning. This work aims to contribute in defining a communication protocol that guarantees the timely dissemination of safety critical events, occurring in scenarios with a high number of vehicles or in the neighbourhood of so called motorway “blackspots”, to all vehicles in the zone of interest. To ensure information integrity and user trust, the proposed system is based on the motorway infrastructure, which will validate all events reported by the vehicles with the usage of several means, such as video surveillance or other sensors. The usage of motorway infrastructure that has full motorway coverage using fixed stations also known as road side units, allows to have a global vision of the interest zone, avoiding the problems associated to networks that depend solely on vehicle to vehicle communication, generally total ad-hoc networks. By using the infrastructure, it is possible to control medium access, avoiding possible badly intended intrusions and also avoiding the phenomenon known as alarm showers or broadcast storm that occur when all vehicles want to simultaneously access the medium to warn others of a safety event. The thesis presented in this document is that it is possible to guarantee in time information about safety events, using an architecture where the road side units are coordinated among themselves, and communicate with on board units (in vehicles) that dynamically register and deregister from the system. An exhaustive and systematic state of the art of safety applications and related research projects is done, followed by a study on the available wireless communications standards that are able to support them. The set of standards IEEE802.11p and ETSI-G5 was created for this purpose and is found to be the more adequate, but care is taken to define a scenario where WAVE enabled and non-enabled vehicles can coexist. The WAVE medium access control protocol suffers from collision problems that do not guarantee a bounded delay, therefore a new protocol (V-FTT) is proposed, based on the adaptation of the Flexible Time Triggered protocol to the vehicular field. A theoretical analysis of the V-FTT applied to WAVE and ETSI-G5 is done, including quantifying a real scenario based on the A5 motorway from Lisbon to Cascais, one of the busiest Portuguese motorways. We conclude the V-FTT protocol is feasible and guarantees a bounded delay.
Nas últimas décadas tem-se assistido a um aumento do número de veículos a circular nas vias rodoviárias europeias, trazendo consigo um elevado número de acidentes e como consequência muitos feridos e vítimas mortais. Apesar da introdução de sistemas de segurança passivos, tais como cintos de segurança, airbags e de alguns sistemas de segurança activos, tais como o sistema electrónico de travagem (ABS) e o sistema electrónico de estabilidade (ESP), o número de acidentes continua a ser demasiado elevado. Aproximadamente oito por cento dos acidentes fatais na Europa ocorrem em auto-estradas, no caso Português, o número de vítimas mortais tem-se mantido constante ao longo da primeira década do século XXI. A evolução das comunicações sem fios, acompanhada de políticas europeias e norte-americanas no sentido de reservar frequências próximas dos 5,9GHz para aplicações de segurança no ambiente veicular, levou à especificação de várias normas. A maior parte destas aplicações baseiam-se na possibilidade de usar um sistema confiável de comunicação sem fios para alertar os condutores e passageiros de veículos para eventos ocorridos nas estradas que possam colocar em risco a sua segurança. Exemplos de aplicações de segurança crítica são o aviso de travagem brusca, o aviso de veículo em contra mão e o aviso de acidente na estrada. Este trabalho contribui para a definição de protocolos de comunicação capazes de garantir que a informação sobre eventos relacionados com situações de segurança crítica, que ocorram em cenários com um elevado número de veículos em zonas urbanas ou na vizinhança dos chamados “pontos negros” das auto-estradas, é disseminada com pontualidade por todos os veículos localizados na zona de interesse Por uma questão da integridade das comunicações e confiança dos condutores, o sistema proposto baseia-se na infra-estrutura do concessionário da auto-estrada, que validará os eventos reportados pelos veículos usando vários meios à sua disposição, como por exemplo sistemas de videovigilância e outros sensores. O uso de uma infra-estrutura de comunicações, que dispõe de cobertura integral a partir de estações fixas, permite uma visão global da zona coberta, evitando os problemas associados a redes baseadas apenas na comunicação entre veículos, que são em geral totalmente ad-hoc. O uso da infra-estrutura permite, entre outras vantagens, controlar o acesso ao meio, evitando simultaneamente intrusões de estranhos ao sistema e o fenómeno conhecido como “chuva de alarmes” desencadeado quando todos os veículos querem aceder simultaneamente ao meio para avisar os restantes da existência dum evento de segurança crítica. A tese apresentada neste documento defende que é possível garantir informação atempada sobre eventos que põem em risco a segurança dos veículos a partir de uma arquitectura de interligação entre as estações de comunicações fixas, coordenadas entre si, e unidades móveis (veículos) que se registam e se desligam dinamicamente do sistema. Nesta tese faz-se um levantamento exaustivo e sistemático das aplicações de segurança abordando projectos de investigação relacionados, estudam-se as tecnologias de comunicação sem fios disponíveis e a sua possibilidade de suportar aplicações de segurança rodoviária. Desta análise, conclui-se que a norma norte americana WAVE/IEEE802.11p e a europeia ETSI-G5, criadas especificamente para o efeito são as que mais se adequam à finalidade desejada. Considera-se que o cenário de utilização é evolutivo, podendo coexistirem veículos que não dispõem de sistemas de comunicação com outros que suportam a norma WAVE. Dado que o protocolo de acesso ao meio proposto pela norma WAVE não garante um acesso determinístico ao meio partilhado, propõe-se um novo protocolo, o Vehicular Flexible Time-Triggered protocol (VFTT). Faz-se a análise teórica da viabilidade do protocolo proposto para a norma WAVE e respectiva norma europeia (ETSI-G5). Quantifica-se o protocolo VFTT para um cenário real: a auto-estrada A5 Lisboa-Cascais, uma das autoestradas portuguesas mais movimentadas. Conclui-se que o protocolo é viável e garante um atraso restringido temporalmente.
Bastani, Saeed. "Reliability and Efficiency of Vehicular Network Applications". Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/10078.
Texto completoTaya, Akihiro. "Cooperative Vehicular Communications for High Throughput Applications". Kyoto University, 2019. http://hdl.handle.net/2433/244580.
Texto completoKumar, Kundan. "High Efficiency Power Converters for Vehicular Applications". Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3424474.
Texto completoL’utilizzo dell’elettronica di potenza nei sistemi di propulsione elettrica porta all'utilizzo ottimale ed efficiente dei motori di trazione e delle sorgenti di energia (batterie e/o celle a combustibile) attraverso il ricorso a convertitori statici e al loro controllo. L’elettronica di potenza è utilizzata anche per implementare più conversioni dell’energia fornita dalle sorgenti per alimentare i vari carichi, la maggior parte delle quali richiede forme d'onda di tensione diverse (AC o DC) e/o diversi livelli di tensione. Questo elaborato si concentra sulle soluzioni volte a migliorare l'efficienza dei convertitori di potenza per applicazioni veicolari, tema che è di grande interesse per la limitata quantità di energia accumulabile a bordo. Sono prese in considerazione sia le applicazioni di trazione che le applicazioni di ricarica degli accumulatori realizzate con mezzi conduttivi o con i sistemi di trasferimento di potenza senza fili (WPT). Il miglioramento dell’efficienza degli azionamenti di trazione produce un incremento dell'efficienza dell’intero powertrain del veicolo, che si traduce in un incremento dell’autonomia del veicolo, mentre l’impiego di convertitori di potenza efficienti si rende necessario per la ricarica di batterie con capacità sempre maggiori. Le perdite dei dispositivi di potenza sono ancora più significative quando operano ad alte frequenze di lavoro per compattare le dimensioni degli elementi filtranti e/o dei trasformatori. Le perdite nei dispositivi di potenza possono essere minimizzate rendendo la commutazione soft o sostituendo i dispositivi convenzionali con i dispositivi di nuova generazione basati su materiali semiconduttori con ampia banda proibita (WBG). Nell’elaborato, sono illustrate le proprietà dei materiali semiconduttori WBG e si analizza il funzionamento dei dispositivi basati su questi materiali per comprendere le loro caratteristiche e prestazioni. Le perdite di singoli dispositivi (come diodi, IGBT, MOSFET) nonché il funzionamento di convertitori di potenza per varie applicazioni sono esaminati in dettaglio. Per valutare le prestazioni dei dispositivi SiC quando vengano impiegati nei veicoli elettrici, è preso in esame un azionamento di trazione in AC impiegato per la propulsione di una tipica automobile elettrica di classe C. Due versioni di invertitore sono esaminate, una costruita con convenzionali Si IGBT e l'altra con MOSFET SiC, ed è calcolata la potenza persa nei dispositivi a semiconduttore delle due versioni di invertitore mentre l’automobile percorre il ciclo normalizzato di guida europeo (NEDC). Dal confronto dei risultati è emerso che l'utilizzo dei MOSFET SiC riduce le perdite nel convertitore di trazione di circa 5%, ottenendo un uguale incremento dell’autonomia dell’automobile. Per completare lo studio, si è successivamente esteso il calcolo dell’efficienza all’intero azionamento di trazione, comprendente il motore e il riduttore. Si è quindi studiato un raddrizzatore con circuito di correzione del fattore di potenza (PFC), utilizzato per ridurre la distorsione di corrente in linea. Lo studio è iniziato considerando sia la configurazione di base che quella interleaved e individuando i parametri circuitali. Dopo aver scelto la configurazione interleaved, sono determinate le ampiezze delle tensioni e delle correnti presenti nel raddrizzatore PFC e i valori ottenuti sono verificati mediante un software di simulazione di circuiti di potenza. E’ anche studiato un dispositivo per l'elaborazione digitale dei segnali (DSP) nel quale implementare il controllo del raddrizzatore PFC. Infine è progettato un prototipo di raddrizzatore PFC con configurazione interleaved. Il processo di progettazione e le specifiche dei componenti sono brevemente descritti. Un prototipo di rettificatore sincrono (SR) è stato sviluppato per lo stadio di uscita di un sistema WPT. In confronto con i raddrizzatori convenzionali, in un SR i diodi sono sostituiti da MOSFET con diodi in antiparallelo. I MOSFET sono dispositivi bidirezionali caratterizzati da una bassa caduta di tensione e dalla direzionalità nel condurre la corrente. Durante il tempo morto, entrano in conduzione i diodi in antiparallelo ai MOSFET. Al termine del tempo morto, ai MOSFET sono applicati segnali di comando che li portano in conduzione per tutta la restante parte del semiperiodo, riducendo così le perdite di conduzione. La durata del tempo morto è ottimizzata utilizzando dispositivi di commutazione veloci basati su materiali semiconduttori SiC. Il prototipo è stato progettato e sperimentato alla frequenza di rete. I risultati sperimentali ottenuti hanno confermato sia i risultati analitici che le simulazioni. L’elevato valore di efficienza ottenuto sul prototipo operante alla frequenza di rete fanno prevedere che il suo impiego alle alte frequenze operative dei sistemi WPT possa dare risultati ancora migliori. Si sono studiati i convertitori isolati di potenza DC-DC impiegati nei caricabatteria di tipo conduttivo per veicoli elettrici. Si sono prese in considerazione due topologie di convertitori DC-DC, il convertitore con doppio ponte attivo (DAB) e quello con un unico ponte attivo (SAB). Per entrambe le topologie è analizzato il funzionamento in condizioni di regime. Per il convertitore SAB sono esaminate due possibili modalità di funzionamento: conduzione discontinua di corrente (DCM) e conduzione di corrente continua (CCM). Si è analizzato il funzionamento in soft-switching, ottenuto con l’inserzione di condensatori ausiliari, sia del convertitore SAB che di quello DAB. E’ individuata la zona di funzionamento in soft-switching per i due convertitori in funzione delle tensioni e delle correnti di uscita. Infine, è stata eseguita un’analisi comparativa del funzionamento in soft-switching dei due convertitori. Il lavoro di tesi è stato realizzato presso il Laboratorio di "Sistemi Elettrici per l'Automazione e Automotive" diretto dal Prof. Giuseppe Buja. Il laboratorio fa parte del Dipartimento di Ingegneria Industriale dell'Università degli Studi di Padova, Italia.
Santucci, Alberto. "Supercapacitors and energy management strategies for vehicular applications". Thesis, University of Surrey, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.616312.
Texto completoCorser, George P. "Securing location privacy in vehicular applications and communications". Thesis, Oakland University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10169186.
Texto completoVehicular communications systems may one day save lives, reduce fuel consumption, and advance connectivity, but they may also transmit information which could be deanonymized to obtain personal information. Vehicle location data are of special concern because they could be used maliciously. This dissertation presents a systematic study resulting in novel definitions, metrics and methods for evaluating and applying location privacy preserving protocols specifically in vehicular settings.
Previous work in vehicular network privacy has not thoroughly considered vehicular mobility patterns. Previous work in vehicular network privacy has not solved the problem of collusion between MAC layer and application layer attackers. As defenses against location privacy attacks, previous work has favored the privacy methods of anonymization and obfuscation, but these methods have weaknesses. Spatial-temporal cloaking, for example, requires overhead of trusted third parties, and provides little protection in low vehicle densities especially when applications require frequent precise location data. Little published work has addressed the "location" part of location privacy, the geographical distance of location privacy, focusing instead on the size of the anonymity set. The need for new metrics is indicated.
The present research addresses these issues. In addition to new definitions and metrics, this study develops privacy methods which would (1) accommodate vehicular mobility patterns, (2) defend against collusion by MAC and application layer attackers, (3) produce privacy solutions which depend on cooperation neither by large numbers of other motorists nor by trusted third parties, and (4) function in low vehicle densities, notably during the transition period between system initialization and full saturation, (5) provide protection even when applications require frequent and precise location queries, and (6) provide protection over a geographical range beyond a vehicle's wireless communications range and provide protection over measurable and lengthy spans of time. Finally, it presents a new metric for measuring privacy (KDT), an equation to estimate the safety impact of privacy protocols (SSTE), and three new privacy models, Endpoint Protection Zones (EPZ), Privacy by Decoy (PBD) and Random Rotation of Vehicular Trajectory (RRVT).
Tummala, Gopi Krishna. "Automatic Camera Calibration Techniques for Collaborative Vehicular Applications". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1545874031461163.
Texto completoGustafsson, Thomas. "Maintaining data consistency in embedded databases for vehicular systems". Licentiate thesis, Linköping : Univ, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-5681.
Texto completoAbrahamsson, Johan. "Kinetic Energy Storage and Magnetic Bearings : for Vehicular Applications". Doctoral thesis, Uppsala universitet, Elektricitetslära, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-212106.
Texto completoCarter, Noah. "Building Data Visualization Applications to Facilitate Vehicular Networking Research". Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/honors/459.
Texto completoSchack, Moritz [Verfasser]. "Integrated Simulation of Communication Applications in Vehicular Environments / Moritz Schack". Aachen : Shaker, 2013. http://d-nb.info/1051575648/34.
Texto completoJarupan, Boangoat. "CROSS-LAYER DESIGN FOR LOCATION- AND DELAY-AWARE COMMUNICATION IN VEHICULAR NETWORKS". The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306504587.
Texto completoTogou, Mohammed Amine. "Enhancing infotainment applications quality of service in vehicular ad hoc networks". Thèse, Troyes, 2017. http://hdl.handle.net/1866/19537.
Texto completoThe fact that vehicular ad hoc network accommodates two types of communications, Vehicle-to-Vehicle and Vehicle-to-Infrastructure, has opened the door for a plethora of interesting applications to thrive. Some of these applications, known as infotainment applications, focus on enhancing the passengers' experience. They have rigid requirements in terms of delivery delay and throughput. Numerous approaches have been proposed, at medium access control and routing layers, to enhance the quality of service of such applications. However, existing schemes have several shortcomings. Subsequently, the design of new and efficient approaches is vital for the proper functioning of infotainment applications. This work proposes three schemes. The first is a novel routing protocol, labeled SCRP. It leverages real-time vehicular traffic information to create backbones over road segments and connect them at intersections using bridge nodes. These nodes are responsible for collecting connectivity and delay information, which are used to select routing paths with low end-to-end delay. The second is an altruistic service channel selection scheme, labeled ASSCH. It first collects real-time service channels information and feeds it to a stochastic model that predicts the state of these channels in the near future. The least congested channels are then selected to be used. The third is an analytical model for the performance of the IEEE 802.11p Enhanced Distributed Channel Access mechanism that considers various factors, including the transmission opportunity (TXOP), unexploited by IEEE 802.11p.
Sharkey, Patrick S. "Optimisation of charge-air coolers for vehicular applications using numerical techniques". Thesis, University of Brighton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309180.
Texto completoChristou, George Alexander. "Fluid mechanics of ported shroud centrifugal compressor for vehicular turbocharger applications". Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/101492.
Texto completoCataloged from PDF version of thesis.
Includes bibliographical references (pages 183-187).
This thesis presents an investigation of the effects of Ported Shroud (PS) self-recirculating casing treatment used in turbocharger centrifugal compressors for increasing the operable range. Computed results, assessed with experimental measurements on ported and non-ported variants of a representative turbocharger compressor, are used to determine the impact of the PS on the flow field and hence performance. It is shown that the main flow path perceives the PS flow as a combination of flow actuations that include injection and removal of mass flow, and injection of axial momentum and tangential momentum. A computational model in which the presence of the PS is replaced by imposed boundary conditions that reflect the individual flow actuations has thus been formulated and implemented. The removal of a fraction of the inducer mass flow was determined to be the dominant flow actuation in setting the performance of PS compressors. Mass flow removal reduces the flow blockage associated with the impeller tip leakage flow and increases the diffusion in the main flow path. Adding swirl to the injected flow in the direction opposite of the wheel rotation results in an increase of the stagnation pressure ratio and a decrease of the efficiency. The loss generation in the flow path has been defined to rationalize efficiency changes associated with PS operation.
by George Alexander Christou.
Ph. D.
Patra, Subhadeep. "Development and evaluation of smartphone-based ITS applications for vehicular networks". Doctoral thesis, Universitat Politècnica de València, 2019. http://hdl.handle.net/10251/124058.
Texto completo[CAT] Una de les àrees d'investigació que està rebent més atenció recentment és la de vehicles autònoms. Els investigadores estan en este moment centrats en el tercer dels cinc nivells d'autonomia, els quals són: assistència en la conducció, automatització parcial, automatització condicional, alta automatització i automatització completa. Malgrat els ràpids progressos que s'estan donant en este camp, l'adopció d'estes solucions portarà temps no sols degut a qüestions legals, sinó també pel fet que els avanços tecnològics s'enfronten a un lent recolzament per part dels fabricants. A més a més, la baixa taxa de renovació de vehicles de carretera, dificulta el desplegament de tecnologies innovadores com és el cas de la xarxa vehicular. Huit anys després de la introducció de la norma 802.11p per a la comunicació vehicular de l'Institut d'Enginyers Elèctrics i Electrònics (IEEE), els vehicles que s'utilitzen a diari encara manquen de la capacitat de comunicar-se entre sí. Este fet impedeix l'ús de les moltes aplicacions de seguretat del Sistema d'Intel·ligència de Transport (SIT) que aprofita la xarxa vehicular per a l'intercanvi de dades. La forma òbvia de tractar aquest problema és posar les tecnologies disponibles a la disposició dels usuaris comuns per a desenvolupar solucions que es puguen implementar fàcilment, còmodes d'adoptar i, a més a més, econòmiques. Per aquesta raó, traslladem la nostra atenció als dispositius intel·ligents, especialment als telèfons intel·ligents, els quals han recorregut un llarg camí des de la primera introducció de telèfons mòbils a finals del segle XX. Hui en dia quasi tots porten un en la butxaca on siga que vagen, permetent-los no sols fer cridades, sinó també mesurar i controlar diferents paràmetres amb l'ajuda dels molts sensors integrats que estan disponibles per a estos dispositius compactes però potents. El nostre objectiu és estudiar els efectes de la integració dels telèfons intel·ligents a la xarxa vehicular per a desenvolupar aplicacions de seguretat del SIT. L'elecció dels telèfons intel·ligents ací no està sols justificada per la seua àmplia disponibilitat i ús, sinó també perquè estan evolucionant cap a terminals d'alt rendiment amb microprocessadors de múltiples nuclis dotats amb un grup suficientment divers de sensors. En esta tesi proposem tres diferents aplicacions de seguretat SIT per a telèfons intel·ligents, dissenyats per a aprofitar l'entorn de xarxa vehicular: una aplicació de generació d'advertència anomenada Messiah que alerta els conductors de la presència de vehicles d'emergència en les proximitats; una aplicació Advertència de Col·lisió Frontal (ACF) que adverteix els conductors si no mantenen la distància de seguretat mínima entre el vehicle que va davant i el que el segueix; i, per últim, una aplicació que té com objectiu ajudar els conductors amb assistència visual durant l'avançament, anomenat EYES. Totes aquestes aplicacions han sigut desenvolupades per a la plataforma Android, i depenen de la transmissió de dades entre vehicles. Donat que els vehicles que utilitzem a diari no admeten la possibilitat de comunicar-se entre sí, també dissenyem GRCBox, que és una unitat integrada de baix cost que permet la comunicació de Vechicle a Tot (V2X). A partir del nostre estudi d'aplicacions per a dispositius mòbils dissenyats per a xarxes vehiculars, descobrim que l'ús de telèfons intel·ligents proporciona una nova direcció per a la investigació relacionada amb SIT i xarxes vehiculars al permetre l'adopció ràpida de les solucions existents, on els usuaris poden descarregar i utilitzar les aplicacions amb un sol clic a un botó. Però al mateix temps, la portabilitat i la compacitat dels dispositius els fa limitats en termes de velocitat, potència de processament i precisió del sensor integrat, cosa que afecta al rendiment de les aplicacions.
[EN] One of the research areas that is receiving a lot of attention recently is autonomous vehicles. Researchers are currently focused on the third level of autonomy out of the five levels, which are: drive assistance, partial automation, conditional automation, high automation, and full automation. Even though rapid progress is being made in this field, the adoption of these solutions will take time not only due to legal issues, but also due to the fact that technological improvements face slow endorsement by manufacturers. Also, the slow renewal rate of vehicles on road hinders the deployment of novel technologies, as is the case of Vehicular Networks (VNs). Eight years after the introduction of the IEEE 802.11p standard for vehicular communication, vehicles used on a daily basis still lack the capability of communicating with one other. This fact impedes the use of the many ITS safety applications that take advantage of VNs for data exchange. The obvious way to handle this problem is to use the available technologies at the disposal of common users to develop solutions that are easily deployable, effortless to adopt, and moreover, cost effective. For this reason we shift our attention to smart devices, specially smartphones, which have come a long way since the first introduction of mobile phones in the late 20th century. Nowadays, nearly everyone carries one in their pocket anywhere they go, allowing them to not only make calls, but also to measure and monitor different parameters with the help of the many on-board sensors that are available to these compact yet powerful devices. Our objective is to study the effects of integrating smartphones to vehicular networks, to develop ITS safety applications. The choice of smartphones here is not only justified by their wide availability and use, but also because they are evolving towards high performance terminals with multi-core microprocessors packed with a sufficiently diverse group of sensors. In this thesis we propose three different ITS safety applications for smartphones, designed to take advantage of the vehicular network environment: a warning generation application called Messiah that alerts drivers of the presence of emergency vehicles in close proximity; a FCW application which warns drivers if a minimum safe distance is not maintained between the vehicle ahead and the one following it; and lastly an application that aims to aid drivers with visual assistance while overtaking, named EYES. All these applications have been developed for the Android platform, and are dependent on the data transmission among vehicles. Since vehicles we use on a day to day basis still do not accommodate the possibility to communicate with one another, we also designed the GRCBox, which is a low cost on-board unit that supports V2X communication. From our study of applications for mobile devices designed for VNs, we found that the use of smartphones provides a new direction to research related to ITS and VNs by allowing a quick adoption of the existing solutions, where users are able to download and use applications just by one click of a button. But at the same time, the portability and compactness of the devices makes them limited in terms of speed, processing power, and accuracy of the on-board sensor, thus affecting the performance of the applications. In our case, the simpler Messiah application performed very well, while the EYES application that is dependent on GPS data, and the FCW application which required heavy processing and use of the camera due to its dependence on plate recognition, were affected by the hardware limitations of the smartphones.
Patra, S. (2019). Development and evaluation of smartphone-based ITS applications for vehicular networks [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/124058
TESIS
mezzarobba, mario. "Study of innovative electric machines for high efficiency vehicular traction applications". Doctoral thesis, Università degli studi di Padova, 2013. http://hdl.handle.net/11577/3422648.
Texto completoQuesta tesi contiene alcuni dei temi riguardanti le macchine elettriche per trazione veicolare che si sono arontati durante i tre anni di dottorato di ricerca. Il lavoro è suddiviso in due parti. La prima parte si concentra su aspetti tecnologici e riguarda alcuni studi ed attività sperimentali che vanno a risolvere alcune problematiche comuni delle macchine elettriche per trazione, in particolare il deflussaggio e le pulsazioni di coppia. La seconda parte, invece risulta essere più teorica e si concentra su alcuni metodi matematici di modellizzazione ed analisi sviluppati per facilitare la progettazione e lo studio delle macchine elettriche che si è portato avanti durante il periodo di dottorato. I capitoli della prima parte sono così suddivisi: 1. Sviluppo e sperimentazione di un motore a magneti permanenti prototipale; interamente concepito, progettato e realizzato presso l'Università degli Studi di Trieste; in cui un nuovo metodo di deflussagio per alte velocità è stato implementato. Inoltre tale tecnologia è stata assoggettata a brevetto. 2. Ottimizzazione multi obiettivo di un motore sincrono a magneti permanenti a riluttanza assistita per applicazioni nell'industria automobilistica. L'ottimizzazione aveva lo scopo di supportare un progetto industrale portato avanti da un nostro partner ed ancora in atto, di conseguenza nessun prototipo è ancora stato realizzato. 3. Studio e ottimizzazione di una bietta magnetica per motori con statore a cave aperte, in grado di ridurre la pulsazione di coppia. La seconda parte propone dei metodi di analisi numerica delle macchine elettriche sviluppati per modellizzare ed analizzare diversi tipi di macchine a magneti permanenti. La principale criticità alla quale questi capitoli tentano di dare soluzione è quello di trovare dei metodi di analisi delle macchine a magneti permanenti accurati, senza dover ricorrere a simulazioni transitorie agli elementi niti, che come è noto sono molto dispendiose in termini di tempo.
Lin, Trista Shuenying. "Smart parking : Network, infrastructure and urban service". Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0138/document.
Texto completoSmart parking, allowing drivers to access parking information through their smart-phone, is proposed to ease drivers' pain. We first spotlight the manner to collect parking information by introducing the multi-hop sensor network architecture, and how the network is formed. We then introduce the traffic intensity models by looking at the vehicle's arrival and departure probabilities, following the heavy-tailed distribution. We study the deployment strategy of wireless on-street parking sensor layouts. We define a multiple-objective problem and solve it with two real street parking maps. In turn, we present a Publish-Subscribe service system to provide good parking information to drivers. We illustrate the system with a vehicular network and point out the importance of content and context of a driver’s message. To evaluate the resilience, we propose an extended Publish-Subscribe model, and evaluate it under different unforeseen circumstances. Our work is based on the premise that large-scale parking sensors are deployed in the city. We look at the whole picture of urban service from viewpoint of the municipality. As such, we shed light on two main topics: the information collection on sensor deployment and an extended version of Publish-Subscribe messaging paradigm. Our work gives a guideline from network-related perspectives for city before launching a smart parking or any similar real-time urban service. It also provides a meaningful evaluation platform for testing more realistic datasets, such as real vehicle traces or network traffic
Lyamin, Nikita. "Performance evaluation of safety critical ITS-G5 V2V communications for cooperative driving Applications". Doctoral thesis, Universitat Pompeu Fabra, 2019. http://hdl.handle.net/10803/665484.
Texto completoEls Sistemes de Transport Intel·ligents (ITS) tenen com a objectiu proporcionar serveis innovadors relacionats amb diferents modes de transport i gestió del trànsit, i permetre que els usuaris en facin un ús més segur, més coordinat i més intel·ligent. Cooperative-ITS (C-ITS) fa possible la connectivitat entre vehicles, entre vehicles i la infraestructura de la carretera, entre senyals de trànsit, i amb altres usuaris de la carretera. Per tal de permetre la comunicació entre vehicles, l'Institut Europeu de les Telecomunicacions (ETSI) va crear el ITS-G5 - un conjunt de normes C-ITS. Tenint en compte els objectius de C-ITS, les comunicacions entre vehicles han de ser fiables i eficients.Lobjectiu d'aquesta tesi és l'avaluació del rendiment i l'eficiència de les comunicacions ITS-G5 per donar suport a les aplicacions de conducció cooperativa. La tesi inclou vuit articles científics al voltant de tres àrees de recerca: avaluació del rendiment dels protocols de baliseig ITS-G5; estudi del rendiment dels mecanismes de control de la congestió ITS-G5; i estudi de d’atacs de tipus Denial-of-Service (DoS) i els seus mètodes de detecció. En primer lloc, s’inclou una descripció general dels objectius d'estandardització actuals i futurs respecte a la conducció cooperativa C-ACC / platooning. Després, com a part de la primera àrea de recerca, es demostra a través de diversos estudis, que l'enfocament de balisa adaptativa on la generació de missatges està acoblada a la variació de velocitat dels ITS-s originadors, pot portar a un efecte de sincronització de missatges similar en el domini del temps quan els vehicles adapten de manera cooperativa la seva velocitat. Així, s’explica detalladament la causa d'aquest fenomen i s’estudia per a una àmplia gamma de paràmetres. En relació amb el segon problema, primer s’estudia la influència de diferents configuracions base del ITS-G5 en el consum de combustible, demostrant que amb una configuració adequada es pot millorar l'estalvi de combustible. Després, s’estudia el mecanisme de control de congestió definit per ITS-G5, que afectarà el funcionament de totes les aplicacions de C-ITS de conducció cooperativa ja que es un component obligatori, avaluant la seva influència en el rendiment de les aplicacions, i donant recomanacions de millora. Finalment, en l’àrea de l'última direcció d'investigació, es proposen dos mètodes de detecció de DoS en temps real. El principal avantatge de les tècniques de detecció presentades és la seva curta fase d'aprenentatge, que no excedeix d’uns pocs segons, i el seu baix retard de detecció d'uns pocs centenars de milisegons. Sota alguns supòsits, els algoritmes proposats demostren la capacitat de detectar certs tipus d'atacs amb alta probabilitat de detecció.
Los Sistemas de Transporte Inteligentes (ITS) tienen como objetivo proporcionar servicios innovadores relacionados con diferentes modos de transporte y gestión del tráfico, y permitir que los usuarios hagan un uso más seguro, más coordinado y más inteligente. Cooperative-ITS (C-ITS) hace posible la conectividad entre vehículos, entre vehículos y la infraestructura de la carretera, entre señales de tráfico, y con otros usuarios de la carretera. Para permitir la comunicación entre vehículos, el Instituto Europeo de las Telecomunicaciones (ETSI) creó el ITS-G5 - un conjunto de normas C-ITS. Teniendo en cuenta los objetivos de C-ITS, las comunicaciones entre vehículos deben ser fiables y eficientes. El objetivo de esta tesis es la evaluación del rendimiento y la eficiencia de las comunicaciones ITS-G5 para dar soporte a las aplicaciones de conducción cooperativa. La tesis incluye ocho artículos científicos en torno a tres áreas de investigación: evaluación del rendimiento de los protocolos de baliza ITS-G5; estudio del rendimiento de los mecanismos de control de la congestión ITS-G5; y estudio de de ataques de tipo Denial-of-Service (DoS) y sus métodos de detección. En primer lugar, se incluye una descripción general de los objetivos de estandarización actuales y futuros respecto a la conducción cooperativa C-ACC / platooning. Luego, como parte de la primera área de investigación, se demuestra a través de varios estudios, que el enfoque de baliza adaptativa donde la generación de mensajes está acoplada a la variación de velocidad de los ITS-s originadores, puede llevar a un efecto de sincronización de mensajes similar en el dominio del tiempo cuando los vehículos adaptan de manera cooperativa su velocidad. Así, se explica detalladamente la causa de este fenómeno y se estudia para una amplia gama de parámetros. En relación con el segundo problema, primero se estudia la influencia de diferentes configuraciones base del ITS-G5 en el consumo de combustible, demostrando que con una configuración adecuada se puede mejorar el ahorro de combustible. Después, se estudia el mecanismo de control de congestión definido por ITS-G5, que afectará el funcionamiento de todas las aplicaciones de C-ITS de conducción cooperativa ya que es un componente obligatorio, evaluando su influencia en el rendimiento de las aplicaciones, y dando recomendaciones de mejora. Finalmente, en el área de la última dirección de investigación, se proponen dos métodos de detección de DoS en tiempo real. La principal ventaja de las técnicas de detección presentadas es su corta fase de aprendizaje, que no excede de unos pocos segundos, y su bajo retraso de detección de unos pocos cientos de milisegundos. Bajo algunos supuestos, los algoritmos propuestos demuestran la capacidad de detectar ciertos tipos de ataques con alta probabilidad de detección.
Schmidt, David. "Knot Flow Classification and its Applications in Vehicular Ad-Hoc Networks (VANET)". Digital Commons @ East Tennessee State University, 2020. https://dc.etsu.edu/etd/3723.
Texto completoJafarian, Javad. "Modelling and analysis of wireless MAC protocols with applications to vehicular networks". Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/modelling-and-analysis-of-wireless-mac-protocols-with-applications-to-vehicular-networks(3695e637-12eb-4fde-9c31-08b3b46e8f55).html.
Texto completoAhmadvand, Samaneh. "Efficient Visibility Restoration Method Using a Single Foggy Image in Vehicular Applications". Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/38486.
Texto completoHadded, Mohamed. "Design and optimization of access control protocols in Vehicular Ad Hoc Networks (VANETs)". Thesis, Evry, Institut national des télécommunications, 2016. http://www.theses.fr/2016TELE0023/document.
Texto completoRoad crashes and their damages represent a serious issue and are one of the main causes of people death. In this context, Vehicular Ad hoc NETworks (VANETs) are deployed to reduce the risk of road accident as well as to improve passengers’ comfort by allowing vehicles to exchange different kinds of data which ranges widely from road safety and traffic management to infotainment. Nowadays, safety applications are receiving a great deal of attention from researchers as well as from automobile manufacturers. In this thesis, we particularly focus on safety-critical applications, designed to provide drivers assistance in dangerous situations and to avoid accidents in highway environments. Such applications must guarantee to the vehicles access to the medium and have strict requirements regarding end-to-end delay and packet loss ratio. Therefore, our main goal is to propose new medium access control and routing protocols, which can efficiently adapt to frequent changing VANET network topologies. After a comprehensive overview of free-contention MAC protocols, we propose several solutions, based on Time Division Multiple Access Technique (TDMA). We have designed DTMAC, a fully distributed TDMA-based MAC protocol, which does not rely on an expensive infrastructure. DTMAC uses vehicles’ locations and a slot reuse concept to ensure that vehicles in adjacent areas have collision-free schedule. Using simulations, we prove that DTMAC provides a lower rate of access and merging collisions than VeMAC, a well-known TDMA based MAC protocol in VANET. Then, in order to ensure that event-driven safety messages can be sent over a long distance, we propose TRPM, a TDMA aware Routing Protocol for Multi-hop communication. Our routing scheme is based on a cross layer approach between the MAC and the routing layers, in which the intermediate vehicles are selected using TDMA scheduling information. Simulation results show that TRPM provides better performances in terms of average end-to-end delay, average number of hops and average delivery ratio. In the second part, we focus on coordinator-based TDMA scheduling mechanisms. First, we propose the Centralized TDMA based MAC protocol (CTMAC) which uses Road Side Units (RSUs) as a central coordinator to create and maintain the TDMA schedules. CTMAC implements an Access Collision Avoidance mechanism that can prevent the access collision problem occurring more than twice between the same vehicles that are trying to access the channel at the same time. Using simulation we show an improvement in terms of access and merging collisions as well as the overhead required to create and maintain the TDMA schedules compared to distributed scheduling mechanisms. However, in the CTMAC protocol, fast moving vehicles will need to compete for new slots after a short period of time when they leave their current RSU area, which makes a centralized scheduling approach very expensive. In order to further improve the performance of coordinator-based TDMA scheduling mechanisms, we focus on cluster-based TDMA MAC protocols in which some vehicles in the network are elected to coordinate the channel access, allowing the vehicles to remain connected with their channel coordinator for a longer period of time. To this end, first we propose an adaptive weighted clustering protocol, named AWCP, which is road map dependent and uses road IDs and vehicle directions to make the clusters’ structure as stable as possible. Then, we formulate the AWCP parameter tuning as a multi-objective problem and we propose an optimization tool to find the optimal parameters of AWCP to ensure its QoS. Next, we propose ASAS, an adaptive slot assignment strategy for a cluster-based TDMA MAC protocol. This strategy is based on a cross layer approach involving TDMA and AWCP. The objective is to overcome the inter-cluster interference issue in overlapping areas by taking into account vehicles’ locations and directions when the cluster head assign slots
Barrachina, Villalba Javier. "Using Ontologies and Intelligent Systems for Traffic Accident Assistance in Vehicular Environments". Doctoral thesis, Universitat Politècnica de València, 2014. http://hdl.handle.net/10251/39004.
Texto completoBarrachina Villalba, J. (2014). Using Ontologies and Intelligent Systems for Traffic Accident Assistance in Vehicular Environments [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/39004
TESIS
Soua, Ahmed. "Vehicular ad hoc networks : dissemination, data collection and routing : models and algorithms". Phd thesis, Institut National des Télécommunications, 2013. http://tel.archives-ouvertes.fr/tel-00919774.
Texto completoHu, Xiping. "A platform for building context-aware mobile crowdsensing applications in vehicular social networks". Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/55236.
Texto completoApplied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
Rossi, Giorgia. "Optimised protocols for time-critical applications and internetworking in vehicular ad-hoc networks". Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/56212.
Texto completoMartínez, Domínguez Francisco José. "Improving Vehicular ad hoc Network Protocols to Support Safety Applications in Realistic Scenarios". Doctoral thesis, Universitat Politècnica de València, 2011. http://hdl.handle.net/10251/9195.
Texto completoMartínez Domínguez, FJ. (2010). Improving Vehicular ad hoc Network Protocols to Support Safety Applications in Realistic Scenarios [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/9195
Palancia
Andrenacci, Stefano. "De Bruijn sequences in spread spectrum systems: problems and performance in vehicular applications". Doctoral thesis, Università Politecnica delle Marche, 2012. http://hdl.handle.net/11566/242316.
Texto completoThis thesis deals with the analysis about a possible utilization of a particular set of sequences, the so-called de Bruijn sequences, in a Direct Sequence Spread Spectrum (DSSS) vehicular radar system. Compared with other spreading codes adopted in DSSS systems, the greater the span of the set is, the more the number of de Bruijn sequences exponentially increases and theoretically permits to assign each radar a different generated sequence, as a specific key. By this way it is possible to develop a self-consistent radar system, which is able to work without any infrastructure required to assign sequences, as it happens in the case conventional spreading codes, like Gold codes or Kasami codes, are adopted. Due to their both favourable auto- and cross-correlation properties they are particularly indicated for automotive systems in which there are the needs of detecting accurately a target and performing in a multi-user radar environment. Considering their good correlation properties and their huge number, de Bruijn sequences could be used not only in vehicular radar systems but also in other Spread Spectrum and so, they are evaluated in various scenarios like downlink and uplink channel of DS-CDMA systems. In fact, in standard version de Bruijn sequences, if accurately selected, have the property of orthogonality and so they are tested in a downlink channel of a DS-CDMA system. In addition, from de Bruijn sequences another particular set of sequences, the so-called modified de Bruijn sequences, can be derived. These sequences show better performance in terms of cross-correlation properties and could be used in uplink channel of DS-CDMA system. In order to verify the performance in a real test-bed, a preliminary implementation on Software Defined Radios is also developed. Finally they are adopted and compared in simulated multiuser DSSS radar scenarios. The analysis done and the performance results obtained suggest to evolve this radar solution to a cognitive radar approach using computer vision systems as external aid sensor which can outperform actual solutions.
Balador, Ali. "Design and Evaluation of Efficient Medium Access Control Solutions for Vehicular Environments". Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/64073.
Texto completo[ES] Recientemente, los avances en las tecnologías inalámbricas y las mejoras en términos de capacidades de sensorización y computación de los dispositivos electrónicos, han dado lugar a una transición gradual hacia servicios y aplicaciones de los Sistemas Inteligentes de Transporte (ITS). Estas aplicaciones tienen como objetivo mejorar la seguridad vial, proporcionar una navegación inteligente, y promover la conducción eco-eficiente. Las redes vehiculares ad hoc (VANETs) proporcionan una infraestructura de comunicaciones para ITS al equipar los coches con sensores avanzados y dispositivos de comunicación que permiten el intercambio directo de información entre vehículos. Los diferentes tipos de aplicaciones ITS se basan en dos tipos de mensajes: mensajes periódicos conocidos como beacons y mensajes asociados a eventos. Los mensajes periódicos incluyen información relativa a la ubicación geográfica, la velocidad y la aceleración, entre otros, y sólo son distribuidos entre los vehículos vecinos. A diferencia de estos beacons, los mensajes asociados a eventos sólo se generan cuando se produce un evento crítico de interés general, el cual se propaga dentro del área de interés de dicho evento y mientras éste siga activo. La fiabilidad del intercambio de información es uno de los principales problemas para las comunicaciones vehiculares, debido principalmente a que las aplicaciones de seguridad dependen directamente de la eficacia de estas transmisiones. Un protocolo de Control de Acceso al Medio (MAC) debe garantizar la difusión fiable de información a todos los vehículos vecinos dentro de unos límites máximos de retardo, proporcionándoles las notificaciones oportunas respecto a condiciones de conducción inseguras y otros eventos peligrosos. Por otra parte, las aplicaciones de información y entretenimiento, así como las aplicaciones orientadas al confort, también requieren transmisiones fiables extremoa-extremo. Sin embargo, la alta movilidad de los vehículos, la variabilidad de la topología, así como la falta de una unidad central de control, son factores que hacen que el diseño de un protocolo MAC fiable para entornos vehiculares sea una tarea especialmente compleja, especialmente cuando son necesarias estrategias de difusión eficientes. El protocolo MAC IEEE 802.11p, una modificación ya aprobada al estándar IEEE 802.11 original para entornos de comunicación vehiculares, es un protocolo de acceso que no es capaz de garantizar unos límites de retardo con la fiabilidad necesaria para estos entornos, especialmente en escenarios de alta utilización del canal inalámbrico. Este problema es particularmente importante a la hora de implementar aplicaciones de conducción (semi-)automática, como el caso de grupos de vehículos donde la separación entre vehículos se reduce drásticamente, y el sistema de control que gestiona y mantiene el grupo requiere de un intercambio frecuente de información fiable y acotado en retardo. En esta tesis se proponen nuevos protocolos MAC compatibles con los estándares IEEE 802.11 y 802.11p basados en el ajuste del tamaño de la ventana de contención para aplicaciones unicast en rede MANETs y VANETs. Los resultados experimentales obtenidos comparando nuestras propuestas con las soluciones existentes muestran que los protocolos propuestos son capaces de mejorar la tasa de entrega de paquetes y el retardo medio extremo-a-extremo para aplicaciones unicast. En lo que respecta a la difusión eficiente de mensajes broadcast en entornos VANET, se han propuesto soluciones MAC basadas en el uso de tokens que mejoran las prestaciones de aplicaciones de conducción segura basadas en el estándar 802.11p, tanto en autopistas, zonas urbanas, y escenarios con grupos de vehículos. Los resultados experimentales muestran que las soluciones propuestas superan claramente al protocolo 802.11p cuando es necesario entregar mensajes y notificaciones de eventos con restricc
[CAT] Recentment, els avan en les tecnologies sense fils i les millores en termes de capacitats de sensorització i computació dels dispositius electrònics, han donat lloc a una transició gradual cap a serveis i aplicacions dels sistemes intelligents de transport (ITS). Aquestes aplicacions tenen com a objectiu millorar la seguretat vial, proporcionar una navegació intelligent, i promoure la conducció ecoeficient. Les xarxes vehiculars ad hoc (VANET) proporcionen una infraestructura de comunicacions per a ITS, ja que equipen els cotxes amb sensors avançats i dispositius de comunicació que permeten l'intercanvi directe d'informació entre vehicles. Els diversos tipus d'aplicacions ITS es basen en dos classes de missatges: missatges periòdics coneguts com a beacons i missatges associats a esdeveniments. Els missatges periòdics inclouen informació relativa a la ubicació geogràfica, la velocitat i l'acceleració, entre uns altres, i només són distribuïts entre els vehicles veïns. A diferència d'aquests beacons, els missatges associats a esdeveniments només es generen quan es produeix un esdeveniment crític d'interès general, el qual es propaga dins de l àrea d'interès d'aquest esdeveniment i mentre aquest seguisca actiu. La fiabilitat de l'intercanvi d'informació és un dels principals problemes per a les comunicacions vehicular, principalment perquè les aplicacions de seguretat depenen directament de l'eficàcia d'aquestes transmissions. Un protocol de control d'accés al medi (MAC) ha de garantir la difusió fiable d'informació a tots els vehicles veïns dins d'uns límits màxims de retard, i proporcionar-los les notificacions oportunes respecte a condicions de conducció insegures i altres esdeveniments perillosos. D'altra banda, les aplicacions d'informació i entreteniment, com també les aplicacions orientades al confort, també requereixen transmissions fiables extrema-extrem. No obstant això, l'alta mobilitat dels vehicles, la variabilitat de la topologia, i la falta d'una unitat central de control, són factors que fan que el disseny d'un protocol MAC fiable per a entorns vehiculars siga una tasca especialment complexa, especialment quan són necessàries estratègies de difusió eficients. El protocol MAC IEEE 802.11p, una modificació ja aprovada a l'estàndard IEEE 802.11 original per a entorns de comunicació vehiculars, és un protocol d'accés que no és capa garantir uns límits de retard amb la fiabilitat necessària per a aquests entorns, especialment en escenaris d'alta utilització del canal sense fil. Aquest problema és particularment important a l'hora d'implementar aplicacions de conducció (semi)automàtica, com el cas de grups de vehicles en què la separació entre vehicles es redueix dràsticament, i el sistema de control que gestiona i manté el grup requereix un intercanvi freqüent d'informació fiable i delimitat en retard. En aquesta tesi es proposen nous protocols MAC compatibles amb els estàndards IEEE 802.11 i 802.11p basats en l'ajust de les dimensions de la finestra de contenció per a aplicacions unicast en xarxes MANET i VANET. Els resultats experimentals obtinguts comparant les nostres propostes amb les solucions existents mostren que els protocols proposats són capa de millorar la taxa de lliurament de paquets i el retard mitjà extrem-a-extrem per a aplicacions unicast. Pel que fa a la difusió eficient de missatges broadcast en entorns VANET, s'han proposat solucions MAC basades en l'ús de tokens que milloren les prestacions d'aplicacions de conducció segura basades en l'estàndard 802.11p, tant en autopistes, zones urbanes, i escenaris amb grups de vehicles. Els resultats experimentals mostren que les solucions proposades superen clarament el protocol 802.11p quan cal lliurar missatges i notificacions d'esdeveniments amb restriccions de latència.
Balador, A. (2016). Design and Evaluation of Efficient Medium Access Control Solutions for Vehicular Environments [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/64073
TESIS
Khan, Mohammad Irfan. "Multi-Service Resource Orchestration for Vehicular Safety Communications". Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS639.
Texto completoWireless channel congestion control and decentralized resource allocation for 802.11p based V2X communication have been widely investigated for a single Cooperative Awareness service, considering mostly homogenous communication requirement per vehicle. Future connected vehicles will be based on multiple V2X services, with heterogenous number of services and communication needs, which existing resource allocation mechanisms does not address. In this thesis, we analyze several decentralized congestion control and channel resource allocation protocols standardized in Europe for initial V2X deployment. We present issues with the existing approach, in particular the inefficient channel capacity utilization, problematic cross layer coordination, inability to balance resources among multiple V2X safety services and distributed resource allocation for asymmetric number of services per vehicle. We propose improvements to the shortcomings, considering the requirements of future V2X scenarios. We demonstrate the limitations of classifying V2X services using static priority for Quality of Service and propose dynamic prioritization. We design a resource orchestrator at the Service Layer to improve cross layer coordination and dynamically distribute the limited channel resource among multiple services of a vehicle. Furthermore, we present a mechanism to decentrally orchestrate channel resource among a mixed distribution of vehicles with diverse channel usage requirements under channel congestion. Analytical and simulation-based results show the validity of our proposed approach, and the V2X application performance improvement it renders, compared to existing standardized protocols