In order to realize effective infotainment systems for vehicles, we need to have context-aware applications that use the latest (live) information for an enhanced user experience. Such up-to-date information is now abundantly available on the Internet, due to the explosive growth of the Web 2.0. In earlier times, it was difficult and expensive for vehicles to connect to the Internet. Recent advances in vehicular ad-hoc networks (VANETs) have enabled vehicles to connect to the Internet through road side infrastructures, with little to no additional cost. However, there are several problems with directly using Internet data in a vehicle, such as (1) Internet data sources have their own interfaces, which keep changing over time, needing frequent application updates, (2) information provided by multiple data sources needs to be preprocessed and fused before use, and (3) vehicles employ propriety platforms for infotainment systems, which makes an application update even more cumbersome. Furthermore, accessing multiple Internet sources may cause unnecessary overhead over the VANET bandwidth. In this thesis, we propose a cloud-based middleware framework for vehicular infotainment application development. The proposed framework follows service oriented architecture in which data filtering and fusion functionalities are delegated to the cloud. Data filtering and fusion reduce the data flow over VANET. Furthermore, because most the the processing is done on the cloud, the client becomes lightweight and loosely coupled with Internet resources and underlying platforms. We also propose a class based fusion method to combine information from multiple sources. The efficacy of the proposed framework is validated by developing an enhanced navigation (eDirection) application for the vehicle, as well as three infotainment applications: context-aware music, news, and weather.

Because Vehicular Ad Hoc Networks (VANETs) often have a high packet loss rate, the formerly used protocol for video streaming, Real-time Transport Protocol (RTP), is no longer suitable for this specific environment. Previous conducted research has offered many new protocols to solve this problem; however, most of them cannot make full use of the existing Internet video streaming resources like RTP servers. Our work proposes two models to solve this compatibility issue. The first model is called the converter model. Based on this model, we first modify RTP using Erasure Coding (EC) technique in order to adapt it to the high packet loss rate of VANETs. This newly developed protocol is called EC-RTP. And, we then developed two converters. The first converter stands on the boundary between the Internet and VANETs. It receives the RTP packets which sent from Internet. And then it translates them to the EC-RTP packets. These packets are transported over the VANETs. The second converter receives these EC-RTP packets, translates them back to the RTP packets. It then sends them to the RTP player, so that the RTP player can play these packets. To make EC-RTP can carry more kinds of video streams other than RTP, we proposed a second model. The second model is called the redundancy tunnel. Based on this model, we let the protocol between the two converters carry RTP protocol as its payload. We use the same technique as we have used to modify RTP. At last, we did some experiments with Android tablets. The experiment results show our solution can use the same player to play the same video resources as RTP does. However, unlike RTP, it can reduce packet loss rate.

Accompanying the increasing interest on Vehicle Ad-hoc Network (VANET), there is a request for high quality and real-time video streaming on VANET, for safety and infotainment applications. Video Streaming on VANET faces extra issues, comparing to the Mobile Ad-hoc Network (MANET), like the high dynamic topology. However, there are also benefits in VANET, like large buffer and battery capacity, predictable motion of vehicles and powerful CPU and GPU. Video streaming on VANET can be highly improved by these features. However the poor performance of wireless networks is an critical issue for video streaming in VANET. The high packet loss probability of wireless networks significantly reduces the quality of the transmitted video. An error recovery process is proposed in our research for high quality and real-time video streaming in VANET, which is call Multi-path Error Recovery Video Streaming (MERVS). The performance improvement of wireless networks is also considered in our research. The cross layer technique is adopted in our research, in order to increase the accuracy on the network condition monitoring and to guarantee the fairness on network resource distribution. Cross layer protocols on both the Media Access Control (MAC) layer and the Network layer are proposed to improve the performance collaboratively. The contribution of my researches are: 1) I proposed a MERVS, which provides high quality and real-time video streaming; 2) several improvement techniques are also designed to improve the performance of MERVS; 3) simulation results verifies that MERVS can have a higher quality on transmitted video comparing to the existing protocols in an acceptable delay.

Vehicular Ad Hoc Networks (VANETs) are no longer a futuristic promise but rather an attainable technology. Vehicles are already equipped with a variety of computational devices that control or assist drivers in many tasks such as localization, safely breaking, parking and passengers entertainment. The majority of services envisioned for VANETs either require the provision of multimedia support or have it as an extremely beneficial additional feature. In particular, video streaming capabilities over VANETs are crucial to the development of interesting and valuable services. However,VANETs’ highly dynamic topology poses as a demanding challenge to the fulfillment of video streaming’s stringent requirements. The main goal on this thesis is the development of feasible solutions that support the streaming of video content over VANETs. Initially, the main issues of VANETs are explained through both a discussion of its characteristics and the results of some preliminary conclusions. Based on this understanding of VANETs’ peculiarities, three distinguishing solutions are designed REACT-DIS, REDEC and VIRTUS; the two first for video dissemination and the later for video unicast. These solutions offer a great advancement towards the provision of video streaming capabilities but packet loss is still an issue at high data rates. In order to improve the delivery ratios reached by the previous solutions, redundancy is used as an error correction mechanism. The use of redundancy is ideal for VANETs in handling packet loss as they do not require any interaction between source and receivers nodes. Sophisticated coding techniques were used for an efficient use of the increase on entropy of the information sent by the source node. It was also evaluated the selective use of redundancy solely on packets carrying the crucial information of I-frames. Although this selective approach obtained lower overall delivery ratios than when redundancy is used for all packets, the video quality obtained similar improvements under a much lower cost. The evaluation on the use of redundancy has considered the impact on the rate by which unique video content is received at end-users which is fundamental to understand the resolution of videos that can be displayed. This thesis provides several contributions as it advances the knowledge in the peculiarities of VANETs, solutions for video streaming over VANETs and the use of redundancy as an error correction mechanism for video streaming over VANETs.

Vehicular ad hoc networks (VANETs) facilitate vehicles to broadcast beacon messages to ensure road safety. The rogue nodes in VANETs broadcast malicious information leading to potential hazards, including the collision of vehicles. Previous researchers used either cryptography, trust values, or past vehicle data to detect rogue nodes, but they suffer from high processing delay, overhead, and false-positive rate (FPR). We propose fog-based rogue nodes detection (F-RouND), a fog computing scheme, which dynamically creates a fog utilizing the on-board units (OBUs) of all vehicles in the region for rogue nodes detection. The novelty of F-RouND lies in providing low processing delays and FPR at high vehicle densities. The performance of our F-RouND framework was carried out with simulations using OMNET ++ and SUMO simulators. Results show that F-RouND ensures 45% lower processing delays, 12% lower overhead, and 36% lower FPR at high vehicle densities compared to existing rogue nodes detection schemes.

No description available.

Vehicular Ad hoc NETworks (VANETs), an emerging technology, would allow vehicles to form a self-organized network without the aid of a permanent infrastructure. As a prerequisite to communication in VANETs, an efficient route between communicating nodes in the network must be established, and the routing protocol must adapt to the rapidly changing topology of vehicles in motion. This is one of the goals of VANET routing protocols. In this thesis, we present an efficient routing protocol for VANETs, called the Reliable Inter-VEhicular Routing (RIVER) protocol. RIVER utilizes an undirected graph that represents the surrounding street layout where the vertices of the graph are points at which streets curve or intersect, and the graph edges represent the street segments between those vertices. Unlike existing protocols, RIVER performs real-time, active traffic monitoring and uses this data and other data gathered through passive mechanisms to assign a reliability rating to each street edge. The protocol then uses these reliability ratings to select the most reliable route. Control messages are used to identify a node’s neighbors, determine the reliability of street edges, and to share street edge reliability information with other nodes.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-07-01T11:50:27Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação-Thiago Montenegro Uchôa.pdf: 2911250 bytes, checksum: 312f4263ccccb634993c9a52552ee408 (MD5) / Made available in DSpace on 2016-07-01T11:50:27Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação-Thiago Montenegro Uchôa.pdf: 2911250 bytes, checksum: 312f4263ccccb634993c9a52552ee408 (MD5) Previous issue date: 2015-08-28 / As VANETs (Vehicular Ad hoc Networks) têm atraído bastante atenção por sua gama de aplicações e flexibilidade. Alguns exemplos são streaming de áudio e vídeo, tráfego de mensagens de emergência, alertas de colisão, dentre outras aplicações. Com as VANETs, os veículos e infraestruturas ao redor trocam informações de uma forma coordenada, orquestrando as rotas veiculares. Nas VANETs há uma troca de informações que vão além da interveicular, V2V (Vehicle to Vehicle). Estas formas de comunicação se dão entre veículo e infraestrutura e são denominadas V2I (Vehicle to Infraestructure). Com a concentração de veículos aumentando, há uma tendência de incremento na interferência interveicular, reduzindo assim os níveis de SINR e, consequentemente, diminuindo as taxas de transmissão entre os dispositivos. Algoritmos de controle de potência de transmissão foram propostos em diversas áreas. Um exemplo é a aplicação em cenários de comunicação celular, porém poucos trabalhos abordam o controle de potência de transmissão em uma aplicação de VANETs. Poucos trabalhos foram simulados em cenários de alta concentração. Este trabalho mostra resultados de simulações que analisam o efeito do controle de potência de transmissão em um cenário envolvendo de 250 a 2000 veículos. Com o objetivo de reduzir o impacto das altas potências de transmissão nas VANETs, é proposto um algoritmo, GRaPhiC, utilizando teoria dos jogos, visando reduzir a potência de transmissão dos dispositivos conectados à VANET. É então modelado um cenário utilizando teoria dos jogos não cooperativos. Este algoritmo fornece incentivo suficiente para que os nós desta rede não aumentem deliberadamente sua potência de transmissão. Para isto, é proposta uma função utilidade capaz de reduzir a potência de transmissão dos veículos, caso um conjunto de condições seja obedecida. Para validar os resultados deste trabalho, foram conduzidas simulações em diversos cenários. Para isto, foi utilizado o arcabouço do Veins. Os resultados demonstram que apesar de uma redução da potência de transmissão, que pode chegar a 24% da potência de transmissão inicial, a taxa de transmissão média não é afetada. Em um cenário de veículos elétricos, esta redução da potência de transmissão média se torna imprescindível. / VANETs (Vehicular Ad hoc Networks) have attracted much attention for its range of applications and flexibility. Some real examples are streaming video and audio, emergency messaging, traffic collision alerts, among other applications. With VANETs,vehicles and infrastructure around exchange information in a coordinated way, orchestrating vehicular routes. In the field of VANETs, there is an exchange of information that goes beyond intervehicular, V2V (Vehicle to Vehicle). These forms of communication are between vehicle and infrastructure and are called V2I (Vehicle to Infrastructure). With the increasing concentration of vehicles, there is an increasing trend in intervehicular interference, thereby reducing the SINR levels, and consequently decreasing the transmission rate between the devices. Transmit power control algorithms have been proposed in several areas. An example is the application in cellular communication scenarios, but few studies address the transmission power control in an application of VANETs. Few studies have simulated vehicles in high concentrated scenarios. This work shows results of simulations to analyze the effect of transmission power control in a scenario involving 250 of the 2000 carriers. In order to reduce the impact of high power transmission in VANETs, an algorithm, GRaPhiC, and proposed using game theory in order to reduce the transmission power of the devices connected to the VANET. It is then modeled a scenario using the theory of noncooperative games. This algorithm provides enough incentive for this network not deliberately increase their transmission power. For this, it is proposed a utility function capable of reducing the transmission power of vehicles if a set of conditions is complied with. To validate the results of this study, simulations were conducted in various scenarios. For this, we used the framework Veins. The results demonstrate that although a reduction of the transmission power, that can reach 24% of the initial transmission power, the average transmission rate is not affected. In a scenario of electric vehicles, this reduction in the average transmit power is indispensable.

Cette thèse traite de l'optimisation des communications dans les réseaux véhiculaires à l'aided'une plate-forme de simulation réaliste. Un environnement réaliste implique des modèles demobilité adaptés aux véhicules ainsi que des modèles de couche physique détaillés (modèles decanaux et chaîne de transmission numérique).Notre travail a d'abord consisté à concevoir une plate-forme de simulation réaliste dédiée auxVANETs (Vehicular Ad hoc NETworks). Cette plate-forme a été complétée par un modèle depropagation semi-déterministe que nous avons conçu. L'avantage de ce modèle, appelé UMCRT,est d'avoir un réalisme équivalent à un modèle déterministe tout en réduisantsignificativement le temps de calcul. Ce modèle a été validé par comparaison avec unsimulateur déterministe à tracé de rayons.Nous avons ensuite utilisé cette plate-forme pour évaluer des protocoles de routage.L'efficacité de ces différents protocoles ad hoc testés en conditions réalistes nous a permis defocaliser notre étude sur les protocoles réactifs. De cette évaluation, nous avons retenu AODV(Ad hoc On demand Distance Vector) auquel nous avons notamment appliqué une métriquecross layer pour pallier la baisse de performance induite par le réalisme. Nous avons ensuiteutilisé une technique de tuning appliquée à des protocoles réactifs. Finalement, nous avonsévalué différentes couches physiques, SISO (Simple Input Simple Output) et MIMO (MultipleImput Multiple Output).Ces travaux montrent que seules des améliorations combinées à différents niveaux (physique etréseau) permettraient d'apporter une amélioration significative des performances. / This thesis deals with the optimization of communications in vehicular networks by using arealistic simulation platform. A realistic environment implies the usage of mobility modelsadapted to vehicles and also highly detailed physical models (channel models and digitaltransmission chain).The first part of our work has consisted in the design of a realistic simulation platformdedicated to VANETs (Vehicular Ad hoc NETworks). This platform has been completed by asemi-deterministic propagation model which we have designed. This model called UM-CRThas the advantage to have the same level of realism than a deterministic model while requiringmuch less computation time. This model has been validated by comparison with a deterministicray tracing simulator.We then have used this platform to evaluate routing protocols. The efficiency of different adhoc routing protocols in realistic conditions has led us to focus our study on the family ofreactive protocols. From this evaluation we have selected AODV (Ad hoc On demandDistance Vector) to which we have applied a cross-layer metric in order to reduce theperformance degradation caused by the realistic environment. We then have used a tuningtechnique with reactive protocols. Finally, we have evaluated several SISO and MIMOphysical layers. This work shows that only improvements combined at different levels (physicaland network) can yield a significant increase in performance.

The transmitting of video content over Vehicular Ad Hoc Networks (VANETs) faces a great number of challenges caused by strict QoS (Quality of Service) requirements and highly dynamic network topology. In order to tackle these challenges, multipath forwarding schemes can be regarded as potential solutions. However, route coupling effect and the path length growth severely impair the performance of multipath schemes. In this thesis, the current research status about video streaming over VANETs as well as multipath transmissions are reviewed. With the demand to discover a more suitable solution, we propose the Location-Aware Multipath Video Streaming (LIAITHON+) protocol to address video streaming over urban VANETs. LIAITHON+ uses location information to discover relatively short paths with minimal route coupling effect. The performance results have shown it outperforms the underlying single path solution as well as the node-disjoint multipath solution. In addition, the impact of added redundancy on the multipath solution is investigated through LIAITHON+. According to the results, added redundancy has a different impact depending on the data rate.