The IEEE 802.16 standard also known as WiMAX (Worldwide Interoperability for Microwave Access) is a promising technology responsible for providing wireless broadband access to end users, fixed, mobile and with high-rate data transmission. The main feature provided by this standard to end users is the provision of quality of service (QoS - Quality of Service) through scheduling mechanisms, connection admission control (CAC - Connection Admission Control) and policing in both the base station (BS - Base station) and the subscriber station (SS - Subscriber Station). As these mechanisms are not defined by IEEE 802.16 and directly affect the performance of WiMAX networks, a considerable number of studies focusing on these topics has been proposed in the areas of scheduling and CAC. In this context it is proposed and evaluated in this work a mechanism for traffic policing based on the token bucket technique for controlling data flow generated by the stations in the network. The traffic policing mechanism is applied to all classes of IEEE 802.16d standard. A temporary storage queue was added to the proposed mechanism in order to offer to the packages of nrtPS and BE classes, which were not admitted to the network transmission at the first opportunity, a new chance of being admitted. Results based on modeling and simulation showed that the proposed policing mechanism has satisfactory performance. / O padrão IEEE 802.16, também conhecido como WiMAX (Worldwide Interoperability for Microwave Access), é uma tecnologia promissora responsável por oferecer acesso banda larga sem fio para usuários finais, fixos, móveis e com alta taxa de transmissão de dados. A principal característica fornecida por este padrão aos usuários finais é o provimento de qualidade de serviço (QoS - Quality of Service) através de mecanismos de escalonamento, controle de admissão de conexões (CAC - Control Admission Connection) e policiamento tanto na estação base (BS - Base Station) quanto na estação do assinante (SS - Subscriber Station). Como esses mecanismos não são definidos pelo padrão IEEE 802.16 e afetam diretamente o desempenho das redes WiMAX, um número considerável de pesquisas focalizando estes tópicos tem sido propostas. Neste contexto é proposto e avaliado nesta dissertação um mecanismo de policiamento de tráfego para o tráfego uplink baseado na técnica token bucket para controlar o fluxo de dados gerado pelas estações presentes na rede. O mecanismo de policiamento de tráfego é aplicado a todas as classes do padrão IEEE 802.16d. Uma fila de espera foi adicionada ao mecanismo proposto com o objetivo de oferecer aos pacotes das classes nrtPS e BE, que não foram admitidos na rede na primeira oportunidade de transmissão, uma nova possibilidade de serem admitidos. Os resultados obtidos, baseados em modelagem e simulação, permitiram concluir que o mecanismo de policiamento proposto apresenta desempenho satisfatório. / Mestre em Ciências

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-10-25T12:55:35Z No. of bitstreams: 2 Dissertação - Henrique Valle de Lima - 2018.pdf: 6140413 bytes, checksum: 4bb41779722574af9e9b07103ad3ba20 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-10-25T13:11:28Z (GMT) No. of bitstreams: 2 Dissertação - Henrique Valle de Lima - 2018.pdf: 6140413 bytes, checksum: 4bb41779722574af9e9b07103ad3ba20 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-10-25T13:11:28Z (GMT). No. of bitstreams: 2 Dissertação - Henrique Valle de Lima - 2018.pdf: 6140413 bytes, checksum: 4bb41779722574af9e9b07103ad3ba20 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-09-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / LTE (Long Term Evolution) in unlicensed band (LTE-U) has emerged as a promising solution to the problem of the huge growth in mobile data traffic. It expands the benefits of LTE with bands of the unlicensed 5 GHz spectrum, mainly used in IEEE 802.11. But uncertainties as to the availability of these bands make the adoption of LTE-U a great challenge. In this dissertation, we propose a mixed linear programming approach for allocating resources in order to expand service by LTE-U. Subsequently, we propose a stochastic programming approach, taking into account the randomness of the unlicensed band, allocating resources under a certain control in the risk of conflict with IEEE-802.11. We used three models of the literature for the demand for IEEE 802.11 in our tests. The results highlight the importance of prior knowledge about the distribution of this demand. / A LTE (Long Term Evolution) em banda não-licenciada (LTE-U) surgiu como uma solução promissora para o problema do enorme crescimento no tráfego de dados móveis. Ela amplia os benefícios da LTE com bandas do espectro não-licenciado de 5 GHz, usado principalmente em IEEE 802.11. Mas incertezas quanto à disponibilidade dessas bandas tornam a adoção da LTE-U um grande desafio. Nesta dissertação, propomos uma abordagem de programação linear mista, para alocação de recursos a fim de expandir o atendimento por LTE-U. Posteriormente, propomos uma abordagem de programação estocástica, levando em consideração a aleatoriedade da banda não-licenciada, alocando recursos sob um certo controle no risco de conflito com o IEEE 802.11. Usamos três modelos da literatura para a demanda por IEEE 802.11 em nossos testes. Os resultados destacam a importância do conhecimento prévio sobre a distribuição dessa demanda.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-10-25T14:26:59Z No. of bitstreams: 2 Dissertação - Walisson Gobbo de Aguas - 2018.pdf: 21788863 bytes, checksum: f0bc1f69408a7740ea628458461baf2d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-10-25T14:28:33Z (GMT) No. of bitstreams: 2 Dissertação - Walisson Gobbo de Aguas - 2018.pdf: 21788863 bytes, checksum: f0bc1f69408a7740ea628458461baf2d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-10-25T14:28:33Z (GMT). No. of bitstreams: 2 Dissertação - Walisson Gobbo de Aguas - 2018.pdf: 21788863 bytes, checksum: f0bc1f69408a7740ea628458461baf2d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-09-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The development of new technologies is mainly related to the construction of devices that aim in some way to assist the human being in his tasks, making them faster, easier and more precise. Since the discovery of the transistor, more than 70 years ago by John Bardeen and Walter Brattain, there has been a huge revolution, and new research areas have been created, especially in cooperative robotics and multi-agent. With the steady increase in the number of robots in an industrial environment, scientists and technologists have often faced problems of cooperation and coordination between different robots and their self-control in a workspace. This led to the evolution of autonomous multirobotic cooperative systems. Developers of multi-robotic autonomous systems needed a model to test the proposed theories in terms of effectiveness and efficiency. Not surprisingly, they began to focus on robot soccer. Robots soccer players have great demands in all areas of robot technology, mechanics, sensors and artificial intelligence. Thus, the objective of this work is to develop a small multi-agent system (7.5x7.5x7.5cm) intended to play soccer in a predetermined dynamic environment. A prototype will be developed for comparison purposes with a previously developed robot focusing on improvements to the multiagent controller system and the physical structure of the hardware. / O desenvolvimento de novas tecnologias está ligado principalmente à construção de dispositivos que visam de alguma forma auxiliar o ser humano em suas tarefas, tornando-as mais rápidas, fáceis e precisas. Desde a descoberta do transistor, a mais de 70 anos por John Bardeen e Walter Brattain, ocorreu uma revolução enorme, fazendo com que novas áreas de pesquisas fossem criadas, principalmente em robótica cooperativa e multiagentes. Com o aumento constante do número de robôs em um ambiente industrial, cientistas e tecnólogos frequentemente enfrentaram problemas de cooperação e coordenação entre diferentes robôs e seu autocontrole em um espaço de trabalho. Isso levou à evolução dos sistemas autônomos cooperativos multi-robóticos. Os desenvolvedores de sistemas autônomos multi-robóticos precisavam de um modelo para testar as teorias propostas em termos de eficácia e eficiência. Não é uma surpresa que eles começaram a se concentrar no futebol de robôs. Os robôs jogadores de futebol possuem grandes demandas em todas as áreas da tecnologia de robôs, mecânica, sensores e de inteligência artificial. Dessa forma o objetivo desse trabalho é desenvolver um sistema multiagente de dimensões reduzidas (7,5x7,5x7,5cm) destinado a jogar futebol em um ambiente dinâmico pré determinado. Um protótipo será desenvolvido para fins de comparação com um robô já desenvolvido anteriormente tendo como foco melhorias no sistema controlador do multiagente e na estrutura física do hardware.

Este trabalho apresenta um modelo analítico para a análise de vazão (throughput) da camada MAC do IEEE 802.11. A proposta se diferencia da maioria dos desenvolvimentos realizados na área por apresentar uma modelagem de ambientes com estações não-saturadas, levando em consideração o perfil do tráfego gerado pelas camadas superiores ao nível de enlace. Dessa maneira, o modelo permite uma análise do desempenho de aplicações reais sobre redes sem fio, a partir de resultados provenientes de um modelo matemático, enquanto diversos outros trabalhos avaliam somente situações de saturação das estações. Simulações utilizando Network Simulator 2 e comparações com resultados obtidos em trabalhos análogos desenvolvidos por outros pesquisadores validam o modelo proposto. Cenários com variações na quantidade de estações e carga oferecida à rede são avaliados utilizando o modelo teórico e comparados aos resultados simulados, provendo uma análise do comportamento dos limites de vazão do sistema. As estruturas do IEEE 802.11 MAC foram estudadas a fim de embasar o desenvolvimento do modelo proposto. Também foi realizada uma pesquisa a respeito de Cadeias de Markov, que serve como estrutura básica para a descrição do IEEE 802.11 DCF. / This work provides an analytical model to compute the IEEE 802.11 DCF throughput. The proposed analysis differs from most of the related work by presenting scenario modeling with unsaturated stations, accounting for the traffic characteristics generated by the upper layers to the data link layer. As a consequence, the proposed model allows for an accurate analysis of real applications over wireless networks, based on mathematical model results, while several other researches evaluate only saturate stations situations. Simulations ran using Network Simulator 2 and comparisons with results obtained on similar works developed by other researchers are used to validate the proposed model. Scenarios with different number of stations and offered loads are evaluated using the theoretical model and compared to the simulated results, providing an analysis on the behavior of the maximum throughput provided by the network. A study was made on the structures and mechanisms of IEEE 802.11 MAC in order to support the development of the proposed model. A research on Markov Chains was also done, since it is the basic structure used to describe the IEEE 802.11 DCF.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / As redes locais sem fio (Wireless Local Area Networks - WLANs) IEEE 802.11 atingem taxas de transmissÃo de dados relativamente altas quando comparadas `a outras redes sem fio, por exemplo, Bluetooth. Essas altas taxas de transmissÃao tÃm interessado as operadoras de redes celulares, as quais comeÃam a ver as redes IEEE 802.11 como um complemento as suas redes de acesso. Esta interoperabilidade entre sistemas celulares e WLANs tem sido um tema bastante discutido na literatura. Por exemplo, o 3GPP (Third Generation Partnership Project) define seis nÂıveis para a total integraÃÃo das redes celulares de terceira geraÃÃo com as redes locais sem fio. No entanto, a integraÃÃo com suporte a mobilidade ainda nÃo foi especificada, o que à necessÃrio para viabilizar a transparÃncia de transmissÃo de voz e dados para os usuÃrios finais. Esta dissertaÃÃo apresenta entÃo duas abordagens para o gerenciamento de mobilidade na integraÃÃo do sistema 3G UMTS com as redes IEEE 802.11: uma baseada no SIP (Session Initiation Protocol ) e a outra no MIP versÃo 6 (Mobile IP version 6 - MIPv6). A proposta estende a arquitetura Loose Interworking e utiliza os requisitos do nÃvel 4 do 3GPP. Para especificar a proposta, as abordagens de integraÃÃo das redes UMTS e IEEE 802.11 foram modeladas em diagramas de seqÃÃncia e, em seguida, mapeadas para a tÃcnica de descriÃÃo formal SDL (Specification and Description Language). SDL, que à bastante utilizada para especificar formalmente sistemas de telecomunicaÃÃes, apresenta procedimentos de simulaÃÃo e validaÃÃo que sÃo aplicados para avaliar a especificaÃÃo e, em conseqÃÃncia, as abordagens propostas. / Wireless Local Area Networks (WLANs) IEEE 802.11 reach relatively high data transmission rates when compared to other wireless networks, such as Bluetooth. These high data transmission rates have gained attention from the cellular networks operators, which have been considering IEEE 802.11 networks as a complement to their access networks. This interoperability between cellular systems and WLANs has been frequently discussed in the literature. For example, 3GPP (Third Generation Partnership Project) has defined six levels for the complete integration of the third generation cellular networks and WLANs. However, the mobility support has not been specified yet, which is necessary to make feasible voice and data transmission transparence for the final users. Thus, this work presents two approaches for the mobility management of the integration between UMTS and IEEE 802.11 networks: the first one is based on SIP (Session Initiation Protocol), and the other one is based on MIPv6 (Mobile IP version 6). This proposal extends the Loose Interworking architecture and uses the fourth level of the 3GPP specification. First, these approaches are modeled using sequence diagrams and, then, they are mapped to the SDL (Specification and Description Language) formal description technique. SDL, which is largely used to formally specify telecommunications systems, presents simulation and validation procedures that are applied to evaluate the specification and, consequently, the proposed approaches.

O objetivo deste trabalho foi o desenvolvimento de um sistema de aquisição, processamento e armazenamento de sinais adquiridos de um arranjo de sensores embasado na norma IEE 1451.4 , resultando num sistema de sensores plug&play. O sistema de aquisição de sinais proposto permitirá monitorar diversos tipos de sensores para as mais variadas aplicações nos campos da área biomédica, automação industrial, monitoramento ambiental dentre outras. O sistema de aquisição proposto é constituído por um módulo chamado de STIM (\"Smart Transducer Interface Module\") cujo elemento principal é um microcontrolador com arquitetura RISC de propósito geral, [Johnson 2001]. O módulo STIM é conectado a um computador via interface serial (RS232) para transmitir dados dos sensores e receber comandos de controle. Os sensores analógicos aqui utilizados foram adequados ao sistema utilizando-se da técnica chamada MMI (Mixed Mode Interface) em conformidade com a norma IEEE 1451.4, transformando os sensores em um sistema plug&play. O módulo STIM é monitorado por um software residente no computador PC permitindo que os dados adquiridos dos sensores sejam visualizados e gravados em arquivo para posterior estudo. A obtenção de um sistema de sensores plug&play foi desenvolvida utilizando a estrutura TEDS (Transducer Electronic Data Sheet) gravada em uma memória serial não volátil. O TEDS possui informações e especificações técnicas do transdutor de acordo com um modelo (template) conforme a norma IEEE 1451.4, tal que, quando um sensor é conectado, o sistema exibe na tela do computador informações tais como, o canal conectado, o tipo de sensor, o modelo, número de série, nome do fabricante e a data de fabricação. Neste trabalho foram implementados três módulos MMI utilizando três sensores analógicos, temperatura, pressão e pH. Estes três módulos MMI possibilitaram realizar medidas comparativas que fundamentam o funcionamento do sistema. / The purpose of this work was the development of an acquisition, processing and storage system of a signal from an arrangement of sensors based on IEEE 1451.4 standard, resulting in a plug&play sensors system. The acquisition signal system proposed will permit to monitoring several kinds of sensors for a variety application in the fields of biomedical, industrial automation and environment and many others. The system proposed is formed by a module, called STIM (Smart Transducer Interface Module) that the main element is a general purpose microcontroller with RISC architecture, [Johnson 2001]. The STIM module is connected with a PC computer by serial interface (RS232) to transmit the data from sensors and to receive the control commands. The analog sensors here utilized was adapted to the system utilizing a technique called MMI (Mixed Mode Interface) attending the IEEE 1451.4 standard, transforming the sensors in a plug&play system. The STIM module is assisted by a PC via resident software that will permit the acquired data viewing and recording in file for further study. The plug&play sensors system was developed utilize the TEDS structure (Transducer Electronic Data Sheet) recorded in a non volatile serial memory. The TEDS has specifications and technical information from the transducer according a model (template) in conformity of IEEE 1451.4 standard , as well, when a sensor is connected , the system shows information on the PC screen, as the connected channel , the kind of the sensor , the model , serial number, producer name and produced date. In this work three MMI modules were implemented utilizing three analog sensors; temperature, pressure and pH. These three MMI modules let\'s realize comparative measurements that grounds the system operation.

This thesis describes the design and implementation of the generator frames used for information transfer in wireless networks. At the beginning of the thesis there is described the introduction to the issue of data transmission in wireless networks 802.11 and the analysis of existing tools. Then it is designed language for describing the structure of their own frames and designed their own tools. The work also deals with the subsequent implementation of the resulting tool. Finally the results of the test are mentioned.

Véhicule-à-tous (V2X) se réfère à un Système de Transport Intelligent (ITS) où les véhicules et l'infrastructure sont interconnectés. Cette connectivité permet une connaissance précise des conditions de circulation sur l'ensemble du réseau routier, ce qui contribue à améliorer la sécurité routière, réduire les temps d'encombrement et éviter les pertes économiques. Cette communication permet aussi une variété de nouvelles applications pour la sécurité routière et l'infodivertissement. Bien que la communauté de scientifique ait réalisé de grands progrès dans l'étude sur le V2X, il reste encore des défis à surmonter et des problèmes clés qui doivent être étudiés plus en profondeur. Cette thèse considère deux des questions les plus importantes; fiabilité et sécurité des communications V2X. Du point de vue de la fiabilité, nous proposons d'abord une méthode basée sur la modélisation de l'utilisateur pour évaluer la capacité de la norme DSRC IEEE 802.11p à répondre aux exigences de Qualité De Service (QoS) de la diffusion des messages de sécurité. La nouveauté de la méthode réside dans son application qui élimine le problème de la définition d'un modèle Markovien par la détermination des moments d'équilibre du processus de retard. Cette méthode fournit des informations importantes sur les paramètres de conception IEEE 802.11p et sur ses fonctionnalités, ce qui permet d'améliorer la configuration proposée. De plus, nous proposons un modèle Régénératif pour résoudre le problème de la caractérisation des processus de trafic interconnecté dans les réseaux V2X hybrides à grande échelle. Ce dernier est une préoccupation majeure pour parvenir à une opérabilité efficace et adéquate pour les réseaux de véhicules à grande échelle. Du point de vue de la sécurité, nous introduisons une nouvelle méthodologie d'optimisation. Notre méthodologie lie les exigences de QoS des différentes classes d'application avec le paramètre de conception de base du mécanisme de résolution de contention dans le protocole MAC IEEE 802.11p. En outre, un nouvel algorithme de détection d'attaque de brouillage dans l'environnement véhiculaire est proposé. L'algorithme utilise la méthodologie d'optimisation développée pour définir un seuil de détection et intègre la méthode séquentielle de détection pour détecter les attaques de brouillage à chaque fois que la valeur seuil est franchie. Des expérimentations analytiques et de simulation approfondies ont été effectuées pour chaque contribution afin de montrer la validité des méthodes/modèles proposés et de prouver leur efficacité. / Vehicle-to-anything (V2X) refers to an Intelligent Transportation System (ITS) where the vehicles and infrastructure systems are all interconnected with each other. This connectivity provides precise knowledge of the traffic situations across the entire road network which in turn helps to enhance traffic safety, reduce congestion time, avoid economic losses, in addition to enable a variety of novel ITS applications for road safety and passenger infotainment. V2X communications is based on two technologies; Dedicated Short-Range Communications (DSRC) which is an essential technology for realizing V2X and cellular networks which provide an o_-the-shelf potential solution for V2X communications. Although the research community has achieved much great progress on V2X study, there are still some challenges that need to be overcome and some key issues that need to be further investigated. This thesis considers two of the most prominent issues; reliability and security of V2X communications. From the reliability perspective, we first propose User Model-based Method to evaluate the capacity of IEEE 802.11p-based DSRC standard to meet the Quality-of-Service (QoS) requirements of safety messages dissemination. The novelty of the method lies in its application which avoids the problem of defining a Markovian model by determining the steady state moments of the induced delay process. This applicability feature provides important insights about IEEE 802.11p design parameters and its functionality leading to proposed reconfigurations for enhanced performance. Moreover, we propose Regenerative model, that we believe to be the first to address the problem of interconnected-traffic process characterization in large-scale hybrid V2X networks. The latter is a primary concern in achieving efficient and adequate operability for large-scale vehicular networks. From the security perspective, we introduce a new optimization methodology which ties the QoS requirements of different application classes with the basic design parameters of the contention resolution mechanism in IEEE 802.11p MAC protocol. In addition, a novel detection algorithm for jamming attacks in the vehicular environment is proposed. The algorithm utilizes the developed optimization methodology to de_ne a detection threshold. By integrating the sequential detection of change method it traces and detects jamming attacks whenever the threshold value is crossed. Analytical and simulation experimentations have been performed for each contribution to show the validity of the proposed methods/models and to prove their efficiency.

The necessity of interconnecting objects more and more, possibly with high mobility, has pushed the telecommunications industry to recently develop new wireless standards in order to guarantee tracking of devices and to provide integration with well-known worldwide networks such as the Internet. Within these standards the role played by power consumption is implicit, hence power consumption needs to be as low as possible in order to fulfill long-life requirements and to offer the opportunity of locating and moving smart objects in the coverage area while relying only on batteries as the device's power source.  Considering the importance of identifying and tracking these smart objects with high accuracy and high precision, this document propose an implementation of an IEEE 802.15.4a MAC layer, exploiting ultra-wideband wireless technology, with a time synchronization algorithm included for precise Time Difference of Arrival indoor positioning. Nevertheless, this thesis demonstrates the advantages of using UWB for indoor wireless communication, due to its accuracy in localization and its robustness against interference. A demonstration network has been analyzed consisting of four main base stations optimistically displaced at the corners of a room gathering timestamps from a central tag moving within the space where the UWB signal is within range. These timestamps are collected in one of the base station which plays the role of the coordinator and sends this information to a server which computes the position of the tag using TDOA formulation. The main focus of this work is the synchronization algorithms used to synchronize the four base stations and secondly to synchronize the coordinator with the tag. Particular interest is placed on the protocol, the kind of messages exchanged, and the procedure used to maintain a good level of synchronization and to avoid unwanted clock drifts. Moreover the thesis gives some hints of potential future improvements and proposes a possible solution for large-scale scenarios involving the installation of additional base stations for higher coverage and integration of a larger number of tags, with a focus on synchronization, collision avoidance, and routing procedures to better Fit the situation of a larger network and more tags.  As a result, all the assumptions and the methodologies applied give evidence of how difficult it is to meet contemporary requirements for position accuracy, low power consumption, limited memory, and small message exchange when utilizing low-power and lossy networks and to address problems which need to be further studied in the future. The results of this thesis project offer a good proof of the possibility to reach high accuracy in terms of localization when exploiting UWB radio technology and redundant time synchronization algorithms with the help of TDOA measurements. / Nödvändigheten av sammankopplade objekt mer och mer, eventuellt med hög rörlighet, har drivit telekombranschen till nyligen utveckla nya tråadlösa standarder för att garantera spåarning av enheter och att ge integration med välkända världsomspännande nätverk som Internet. Inom dessa standarder roll strömförbrukningen är implicit, måaste därför strömförbrukningen ska vara såa låag som möjligt för att uppfylla låang livslängd krav och erbjuda möjligheten att lokalisera och flytta smarta objekt i täckningsområadet medan enbart med hjälp av batterier som enhetens strömkälla. Med tanke påa vikten av att identiera och spåara dessa smarta objekt med hög noggrannhet och hög precision, detta dokument föreslåa ett genomförande av en IEEE 802.15.4a MAC-lager, utnyttja ultrabredbandsteknik tråadlös teknik, med en tidssynkronisering algoritm ingåar för exakt tidsskillnaden för ankomst inomhus positionering. Ändåa visar denna avhandling fördelarna med att använda UWB för inomhus tråadlös kommunikation, påa grund av dess noggrannhet i lokalisering och robusthet mot störningar. En demonstration nätverk har analyserats beståar av fyra huvudsakliga basstationer optimistiskt förskjutna i hörnen av ett rum samla tidsstämplar fråan en central tagg flyttar inom utrymme där UWB signalen är inom räckhåall.  Dessa tidsangivelser samlas i en av basstationen som spelar rollen av samordnare och skickar denna information till en server som beräknar position taggen med TDOA formulering. Tyngdpunkten i detta arbete är att synkronisering algoritmer som används för att synkronisera de fyra basstationer dels att synkronisera samordnaren med taggen. Särskilt intresse läggs vid protokollet, den typ av utbytta meddelanden och det förfarande som används för att upprätthåalla en god nivåa av synkronisering och för att undvika oönskade klocka drivor. Dessutom avhandlingen ger nåagra tips om potentiella framtida förbättringar och föreslåar en möjlig lösning för storskaliga scenarier som innebär installation av ytterligare basstationer för högre täckning och integration av ett större antal taggar, med fokus påa synkronisering, att undvika kollision och routing förfaranden för att bättre passa situationen i ett större nätverk och fler taggar.  Som ett resultat, som tillämpas alla antaganden och metoder vittnar om hur svåart det är att uppfylla dagens krav påa positionsnoggrannhet, låag strömförbrukning, begränsat minne, och småa utbyte av meddelanden vid användning med låag effekt och förstörande nätverk och att ta itu med problem som måaste studeras vidare i framtiden. Resultaten fråan denna avhandling projekt erbjuder en bra bevis påa möjligheten att nåa hög noggrannhet vad gäller lokalisering vid utnyttjande UWB radioteknik och redundanta tid algoritmer synkronisering med hjälp av TDOA mätningar.

Les systèmes de transport intelligents coopératifs permettent la communication des véhicules entre eux ainsi qu'avec l'infrastructure, afin d'assurer la disponibilité des informations d'une manière plus fiable sur les véhicules, leurs positions et les conditions de la route. Cet échange d'informations pertinentes permet d'améliorer la sécurité routière, réduire les incidents du trafic et d'assurer l'efficacité de la mobilité des véhicules. IEEE 802.11p est standardisé comme la technologie par défaut pour les communications des véhicules. Dans ce contexte, le standard européen ETSI s'attaque en particulier aux applications de la sécurité routière. Pour ce faire, il standardise plusieurs types de messages comme CAM (Cooperative Awareness Message) et DENM (Decentralised Event Notification Message). Les CAMs sont des messages de diffusion à un seul-saut, envoyés par chaque véhicule contenant des informations sur sa position, sa vitesse, sa direction, etc., afin d'assurer une coopération lucide entre les autres usagers de la route (y compris les véhicules). Les DENMs sont envoyés à la détection d'un événement sur la route, comme le cas d'un accident, embouteillages, etc. Si nécessaire, une communication multi-saut, exploitant des algorithmes de routage standardisés, est mise en {oe}uvre pour disséminer ces messages au-delà de la portée du transmetteur. La faiblesse de 802.11p réside dans la congestion du canal radio due à la bande passante limitée (5.9 GHz). Afin de pallier à cela, ETSI a proposé un cadre pour le contrôle de la congestion appelé DCC (Distributed Congestion Control). Celui-ci permet l'échange d'informations, en particulier l'état du canal radio, entre les couches de la pile protocolaire. Ainsi, chaque protocole de communication contrôle ses propres paramètres pour éviter la congestion du canal. Par ailleurs beaucoup d'approches de contrôle de la congestion DCC existent pour les messages CAM tel que le contrôle de la période de génération des CAMs sur la couche Facilities. La puissance de transmission ou le débit sur la couche Accès, etc. En revanche, peu de travaux ont été faits sur DENMs. A cet égard, nous avons proposé une approche DCC sur la couche GeoNetworking qui contrôle les paramètres de routage en se basant sur l'état du canal radio. Une évaluation du dual-DCC, à savoir CAM sur Facilities et DENM sur GeoNet, a démontré l'efficacité de l'approche proposée. En outre, certaines applications tel que la gestion d'une flotte de véhicules, ont besoin d'un centre de contrôle localisé sur Internet qui communique avec la flotte. Pour ce type d'échange, une communication hybride (IP et Géo) est nécessaire. De plus pour assurer la fluidité de la communication, la gestion de la mobilité est primordiale. Tout en restant dans le cadre de l'architecture Mobile IP, nous proposons notre approche d'adressage qui constitue une adresse IP routable avec une adresse GeoNetworking, ce qui permet de traiter le problème d'accessibilité des véhicules en mouvement sur la route à partir d'une entité située sur Internet. Contrairement à Mobile IP, notre approche permet de réduire la surcharge de la signalisation. Et cela grâce au partitionnement de la route en zones de routage (RA) de telle sorte que l'accès à Internet se fait via une passerelle RSU-FA qui contrôle la RA. Chaque RA regroupe un certain nombre de RSUs. / Cooperative intelligent transport systems allow vehicles to communicate with each other as well as with the infrastructure in order to ensure the availability of information more reliably on vehicles, their positions and road conditions. This exchange of relevant information improves road safety, reduces traffic incidents and ensures efficient mobility of vehicles. IEEE 802.11p is standardized as the default technology for vehicle communications. In this context, the European ETSI standard addresses in particular road safety applications. To do this, it standardizes several types of messages such as CAM (Cooperative Awareness Message) and DENM (Decentralized Event Notification Message). CAMs are single-hop broadcast messages, sent by each vehicle containing information on its position, speed, direction, etc., in order to ensure lucid cooperation between other road users (including vehicles). The DENMs are sent when there is a detection of an event on the road, as in the case of an accident, traffic jams, etc. If necessary, multi-hop communication, using standardized routing algorithms, is implemented to disseminate these messages beyond the scope of the transmitter. The weakness of 802.11p lies in congestion of the radio channel due to the limited bandwidth (5.9 GHz). In order to compensate for this, ETSI proposed a framework for congestion control called DCC (Distributed Congestion Control). This allows the exchange of information, in particular the state of the radio channel, between the layers of the protocol stack. Thus, each communication protocol controls its own parameters to avoid congestion of the channel. In addition, many DCC congestion control approaches exist for CAM messages such as the control of the CAM generation period on the Facilities layer. Transmission power or data rate on the Access layer, etc. On the other hand, little works have been done on DENMs. In this regard, we proposed a DCC approach on the GeoNetworking layer which controls the routing parameters based on the state of the radio channel. An evaluation of the dual-DCC, namely CAM on Facilities and DENM on GeoNet, demonstrated the effectiveness of the proposed approach. In addition, some applications such as managing a fleet of vehicles require a localized control center that communicates with the fleet. For this type of exchange, a hybrid communication (IP and Geo) is necessary. Moreover, to ensure the fluidity of communication, the management of mobility is paramount. While remaining within the framework of the Mobile IP architecture, we propose our approach of addressing which constitutes a routable IP address with a geonetworking address, which makes it possible to deal with the problem of accessibility of vehicles moving on the road from of an entity on the Internet. Unlike Mobile IP, our approach reduces the overhead of signaling. This is done by partitioning the road into routing area (RA) in such a way that the access to the Internet is via a RSU-FA gateway that controls the RA. Each RA regroups a number of RSUs.