由於VANET上的行動節點移動速度快，加上受到道路及交通號制的限制，導致網路拓樸快速改變，容易造成網路斷訊，影響資料封包在網路上的傳送效能。在傳統的MANET上有許多用來傳送資料封包的路由機制，並不直接適用在VANET上。隨著Global Position System (GPS)的普及，越來越多的車輛都具備GPS，用以輔助行車定位之用。在本研究中我們將透過GPS取得車輛的地理資訊，提出一個適用於VANET中以車行方向為基礎的貪婪路由演算法(MDBG)。 本論文目的在強化VANET網路上資料封包的路由選擇策略。所提出的路由機制將會透過hello message來取得相鄰車輛的位置和車行方向，並利用目標要求(DREQ)、目標回應(DREP)來獲得目標車輛的資訊。進而運用車輛的車行方向，選擇適當的相鄰車輛找出一條穩定的路由路徑。當來源車輛和目標車輛的車行方向相同時，AODV能有不錯的效能表現。而我們的路由演算法(MDBG)將強化當來源車輛和目標車輛的車行方向相反，並且逐漸遠離時的效能表現。實驗模擬的結果顯示MDBG在封包到達率、吞吐量和平均端對端延遲上較之於AODV及DSR演算法有更優異的表現。 / Packets transmission over VANET is intermittent due to rapid change of network topology. This comes from both high mobility of mobile nodes and road limitation. Intermittent transmission causes inefficient packet delivery. Those routing protocols applicable to MANET might not be suitable for VANET. On the other hand, Global Position System (GPS) is becoming prevalent in assisting positioning for vehicles. In this research, we develop a Moving Direction Based Greedy (MDBG) routing algorithm for VANET. MDBG algorithm is based on the geographical information collected by GPS. The objective of the thesis is to enhance routing decision in packet delivery. The "hello message" is used to retrieve the locations and moving directions of neighboring vehicles. Destination REQuest (DREQ) and Destination REPly (DREP) messages are used to retrieve target vehicle information. The source vehicle will thus use these information together with its own moving direction information to establish a stable routing path by selecting appropriate neighboring vehicles. AODV algorithm is proved to have good performance as both the source vehicle and target vehicle have the same moving direction. MDBG algorithm is proposed to leverage the problem as source vehicle and target vehicle move far apart in opposite directions. Simulation results show that MDBG outperforms both AODV and DSR in packet arrival rate, throughput and average end-to-end delay.

Dans cette thèse, nous analysons les réseaux des systèmes temps-réel distribués et plus particulièrement ceux des domaines de l’avionique et de l’automobile. Nous nous sommes focalisés sur deux protocoles : « Avionic Full DupleX Switched Ethernet » (AFDX), « Audio Vidéo Bridging Ethernet » (AVB). Dans ces domaines critiques, le déterminisme du réseau doit être garanti. Il consiste, notamment, en la détermination d’une borne garantie du délai de bout en bout de traversée du réseau pour chaque trame ; et un dimensionnement des files d’attente des trames suffisamment grand pour garantir qu’aucune d’entre elle ne débordera et ainsi, éviter toute perte de trame.Il existe plusieurs méthodes pour l’évaluation des délais et nous avons, principalement, travaillé sur la méthode « Forward end-to-end delay Analysis » (FA). FA avait déjà été définie avec la politique d’ordonnancement « First-In-First-Out » dans le contexte de l’AFDX. Nous sommes repartis de cette approche, nous l’avons reformulé et généralisé à n’importe quel réseau Ethernet commuté. Nous l’avons aussi étendu aux priorités statiques et au protocole AVB et sa politique de service « Credit Based Shaper ». Pour chaque contribution, des démonstrations formelles ont été présentées et une expérimentation incluant une comparaison de FA avec les principales approches d’évaluation sur un exemple industriel. Finalement, nous avons développé et démontré formellement une approche pour le dimensionnement des files d’attente en termes de nombre de trames. Cette approche a été expérimentée également sur une configuration industrielle. / In this thesis, we analyze networks in the context of distributed real-time systems, especially in the fields of avionics, with “Avionics Full DupleX Switched Ethernet” (AFDX), and automobile, with “Audio Video Bridging Ethernet” (AVB). For such applications, network determinism needs to be guaranteed. It involves, in particular, assessing a guaranteed bound on the end-to-end traversal time across the network fr each frame; and dimensioning the buffers in order to avoid any loss of frame because of a buffer overflow.There are several methods for worst-case delay analysis, and we have mainly worked on the “Forward end-to-end Delay Analysis” (FA) method. FA had already been developed for “First-In-First-Out” scheduling policy in the AFDX context, so we generalized it to any Switched Ethernet network. We have also extended it to handle static priorities and the AVB protocol, shaping policy named “Credit Based Shaper” (CBS). Each contribution has been formaly proved and experiments have been led on industrial configurations. For our experimentations, we have compared our results with the results of competing approaches. Finally, we have developed and formally demonstrated an approach for buffer dimensioning in terms of number of frames. This approach has also been tested on an industrial configuration and has produced tight bounds.

Dans cette thèse, nous présentons notre travail sur la gestion des pannes dans les systèmes distribués, avec comme motivation principale le suivi de fautes et de changements brusques dans de grands systèmes informatiques comme la grille et le cloud.Au lieu de construire une connaissance complète a priori du logiciel et des infrastructures matérielles comme dans les méthodes traditionnelles de détection ou de diagnostic, nous proposons d'utiliser des techniques spécifiques pour effectuer une surveillance de bout en bout dans des systèmes de grande envergure, en laissant les détails inaccessibles des composants impliqués dans une boîte noire.Pour la surveillance de pannes d'un système distribué, nous modélisons tout d'abord cette application basée sur des sondes comme une tâche de prédiction statique de collaboration (CP), et démontrons expérimentalement l'efficacité des méthodes de CP en utilisant une méthode de la max margin matrice factorisation. Nous introduisons en outre l’apprentissage actif dans le cadre de CP et exposons son avantage essentiel dans le traitement de données très déséquilibrées, ce qui est particulièrement utile pour identifier la class de classe de défaut de la minorité.Nous étendons ensuite la surveillance statique de défection au cas séquentiel en proposant la méthode de factorisation séquentielle de matrice (SMF). La SMF prend une séquence de matrices partiellement observées en entrée, et produit des prédictions comportant des informations à la fois sur les fenêtres temporelles actuelle et passé. L’apprentissage actif est également utilisé pour la SMF, de sorte que les données très déséquilibrées peuvent être traitées correctement. En plus des méthodes séquentielles, une action de lissage pris sur la séquence d'estimation s'est avérée être une astuce pratique utile pour améliorer la performance de la prédiction séquentielle.Du fait que l'hypothèse de stationnarité utilisée dans le surveillance statique et séquentielle devient irréaliste en présence de changements brusques, nous proposons un framework en ligne semi-Supervisé de détection de changement (SSOCD) qui permette de détecter des changements intentionnels dans les données de séries temporelles. De cette manière, le modèle statique du système peut être recalculé une fois un changement brusque est détecté. Dans SSOCD, un procédé hors ligne non supervisé est proposé pour analyser un échantillon des séries de données. Les points de changement ainsi détectés sont utilisés pour entraîner un modèle en ligne supervisé, qui fournit une décision en ligne concernant la détection de changement à parti de la séquence de données en entrée. Les méthodes de détection de changements de l’état de l’art sont utilisées pour démontrer l'utilité de ce framework.Tous les travaux présentés sont vérifiés sur des ensembles de données du monde réel. Plus précisément, les expériences de surveillance de panne sont effectuées sur un ensemble de données recueillies auprès de l’infrastructure de grille Biomed faisant partie de l’European Grid Initiative et le framework de détection de changement brusque est vérifié sur un ensemble de données concernant le changement de performance d'un site en ligne ayant un fort trafic. / In this dissertation, we present our work on fault management in distributed systems, with motivating application roots in monitoring fault and abrupt change of large computing systems like the grid and the cloud. Instead of building a complete a priori knowledge of the software and hardware infrastructures as in conventional detection or diagnosis methods, we propose to use appropriate techniques to perform end-To-End monitoring for such large scale systems, leaving the inaccessible details of involved components in a black box.For the fault monitoring of a distributed system, we first model this probe-Based application as a static collaborative prediction (CP) task, and experimentally demonstrate the effectiveness of CP methods by using the max margin matrix factorization method. We further introduce active learning to the CP framework and exhibit its critical advantage in dealing with highly imbalanced data, which is specially useful for identifying the minority fault class.Further we extend the static fault monitoring to the sequential case by proposing the sequential matrix factorization (SMF) method. SMF takes a sequence of partially observed matrices as input, and produces predictions with information both from the current and history time windows. Active learning is also employed to SMF, such that the highly imbalanced data can be coped with properly. In addition to the sequential methods, a smoothing action taken on the estimation sequence has shown to be a practically useful trick for enhancing sequential prediction performance.Since the stationary assumption employed in the static and sequential fault monitoring becomes unrealistic in the presence of abrupt changes, we propose a semi-Supervised online change detection (SSOCD) framework to detect intended changes in time series data. In this way, the static model of the system can be recomputed once an abrupt change is detected. In SSOCD, an unsupervised offline method is proposed to analyze a sample data series. The change points thus detected are used to train a supervised online model, which gives online decision about whether there is a change presented in the arriving data sequence. State-Of-The-Art change detection methods are employed to demonstrate the usefulness of the framework.All presented work is verified on real-World datasets. Specifically, the fault monitoring experiments are conducted on a dataset collected from the Biomed grid infrastructure within the European Grid Initiative, and the abrupt change detection framework is verified on a dataset concerning the performance change of an online site with large amount of traffic.

Atualmente, os usuários desejam obter, fornecer, compartilhar e interagir com informações e serviços com conteúdo multimídia em qualquer lugar, a qualquer momento e com qualquer dispositivo. Para que isso seja possível, um dos grandes desafios é assegurar a QoS (Quality of Service) fim a fim (entre o usuário final e a organização provedora de serviço) para a disponibilização de serviços móveis e interativos com conteúdo multimídia para os usuários finais. Em geral esse tipo de serviço têm maior exigência de QoS, pois além dos parâmetros de redes, possuem parâmetros específicos para áudio, imagem e vídeo, além de exigirem sincronização de áudio e vídeo, e a QoS fim a fim deve considerar parâmetros de QoS sob a percepção do usuário final. Com isso, o objetivo deste trabalho é propor um método para o levantamento de parâmetros de QoS para o estabelecimento de USLAs (User Service Level Agreements - Acordo do Nível de Serviço do Usuário) entre a organização provedora de serviço e o usuário final para serviços móveis e interativos com conteúdo multimídia em um ambiente de convergência tecnológica. O método consiste em quatro passos: 1. identificação do serviço a ser oferecido ao usuário final e elaboração de um grafo em árvore, que tem como objetivo identificar outros serviços que podem compor o serviço a ser oferecido ao usuário final; 2. mapeamento dos parâmetros de QoS em um metamodelo; 3. validação do metamodelo, para que se possa extrair do metamodelo os parâmetros de QoS; 4. elaboração do USLA. Este trabalho propõe um primeiro passo para solucionar a falta de métodos padronizados para o estabelecimento de USLA para serviços móveis e interativos com conteúdo multimídia sob a percepção do usuário final. Além de facilitar a identificação e composição de serviços e parâmetros, por meio de um metamodelo que proporciona a integração de classes de serviços que podem ser facilmente reutilizadas e customizadas, de acordo, com o tipo de serviço oferecido pela organização provedora de serviço e pela necessidade do usuário final. / In these days the final users wish to obtain, to furnish and to interact using interactive services with multimedia content anywhere, anytime and with any kind of user device. One of the biggest challenges is to assure the End-to End Quality of Service (E2E QoS) in the delivering of the interactive and multimedia services for moving users. In general, this kind of users have more strict requirements needs, because, besides of the computer network parameters, they need specify specific parameters like sound, image and video and their synchronization, on the users\' point of the view - perceived QoS. The main objective of this thesis is to present the application of a method for eliciting the E2E QoS parameters aiming the establishment of the User Service Level Agreement - USLA between the service provider and the final user applied to interactive and mobile services with multimedia content, inserted on a technological convergence environment. The method is a four steps method that consists of (1) an identification of the service to be offered to the final user and the elaboration of a tree graph aiming the identification of the composition of the service by other services (2) mapping the QoS parameters in a metamodel (3) validation of the metamodel, and extraction of the E2E QoS parameters (4) elaboration the USLA. This thesis proposes a first step to solve the lack of standardized methods for the establishment of the USLA for interactive and mobile services with multimedia content under the users\' perception. Besides of facilitating the identification and the composition of services and parameters, using a metamodel, that provides the integration of classes of services, that can be easily reused and customized, according, with the type of service offered for the service provider to the final user.

A contração muscular gerada por impulsos elétricos provenientes de duas fontes nervosas distintas pode ser alternativa no tratamento de lesões do plexo braquial e na paralisia facial. O objetivo desta tese foi avaliar e comparar diferentes técnicas de reinervação dupla com a técnica de reinervação única do músculo gastrocnêmio em ratos. Cinquenta ratos Wistar adultos, após terem seu nervo fibular direito seccionado, foram divididos em cinco grupos com relação ao procedimento realizado no nervo tibial: controle (C); seccionado (S); neurorrafia término-terminal (TT); neurorrafia primária associada à transferência nervosa fibular para tibial de maneira término-lateral (TL); e neurorrafia término-terminal convergente entre os cotos proximais dos nervos tibial e fibular com o coto distal do nervo tibial (TTC). Os resultados foram avaliados 12 semanas após o experimento por meio do teste da marcha, eletromiografia, índice de massa do músculo gastrocnêmio e contagem axonal no coto distal do nervo tibial. Os grupos de reinervação dupla (TL e TTC) revelaram maiores resultados funcionais (p < 0,05) em relação ao grupo de reinervação única (TT). O grupo TTC apresentou maior amplitude (p=0,006) e maior latência (p=0,041) do que o grupo TT. Em relação ao índice de massa muscular, não houve diferença entre os grupos de reinervação (p > 0,705). A análise histológica revelou maior densidade axonal no grupo TTC em relação ao grupo TT (p=0,001) e ao grupo TL (p=0,002). Ambas técnicas de dupla reinervação revelaram recuperação funcional do músculo gastrocnêmio mais precoce e maior quando comparadas à técnica de reinervação única (TT). Os animais do grupo TTC apresentaram maior número de axônios regenerados no coto distal do nervo tibial do que os do grupo TT e TL / Muscle contraction generated by electrical impulses simultaneously originating from two different neural sources may be an interesting treatment alternative for facial palsy and brachial plexus injury. The purpose of this thesis was to evaluate and compare distinct double reinnervation techniques with single reinnervation technique of gastrocnemius muscle in rats. Fifty adult Wistar rats underwent transection of their right peroneal nerve and were divided into five groups related to tibial nerve procedure: the control group (C), tibial nerve section group (S), tibial nerve end-to-end neurorrhaphy (EE) group, tibial nerve primary repair associated with end-to-side peroneal-to-tibial nerve transfer (ES) group, and tibial nerve repair by convergent end-to-end neurorrhaphy between the proximal stumps of the tibial and peroneal nerves to the distal stump of the tibial nerve (CEE) group. The outcomes were assessed 12 weeks after the experiment by use of a walking track, electromyography, gastrocnemius muscle mass index, and histomorphometric analysis of the distal tibial nerve. The double reinnervation groups (ES and CEE) showed greater functional recovery (p < 0.05) than the single reinnervation group (EE). The CEE group showed greater amplitude (p=0.006) and higher latency (p=0.041) than the EE group. There was no difference in the muscle mass index among the reinnervation groups (p > 0.705). Histologic analysis revealed greater axonal density in the CEE group than EE group (p=0.001) and ES group (p=0.002). The double reinnervation techniques showed earlier and greater functional recovery of the gastrocnemius muscle than did the single reinnervation technique. The CEE group showed a higher number of regenerated axons in the distal tibial nerve stump

Uma das principais características dos sistemas de informação e de comunicação é permitir que os usuários finais utilizem e disponibilizem serviços interativos com conteúdo multimídia a qualquer hora, em qualquer lugar, com qualquer dispositivo e em movimento, independentemente da tecnologia de rede utilizada. Um desafio que surge face a essa nova característica dos serviços é como identificar os requisitos de QoS (Qualidade de Serviço) fim-a-fim sob a ótica do usuário final em um ambiente convergente e heterogêneo com o intuito de evoluir as relações entre o usuário final e o Provedor de Serviços para o estabelecimento de um contrato com níveis de serviço personalizado. Este trabalho apresenta uma pesquisa para a elaboração de uma ferramenta genérica e aberta para mapear a qualidade percebida pelo usuário em requisitos técnicos de QoS através da captura do fluxo de pacotes gerado entre as aplicações que compõem um serviço e simula atrasos, jitter, perdas e banda percebida com o objetivo de permitir ao usuário final identificar e expressar os valores desses parâmetros tornando transparente os aspectos tecnológicos que envolvem esta identificação. A definição de um ambiente de simulação que hospeda o serviço, o desenvolvimento de um simulador de QoS específico e uma nova relação entre o usuário e o Provedor de Serviços também são abordados. / One of the main characteristics of communication and information systems is to allow final users to use and make available multimedia content interactive services at any time, anywhere, in motion and using any device regardless of network technology. Under this perspective a challenge arises on how to identify the QoS (Quality of Service) requirements in a convergent and heterogeneous environment end-to-end user centric way, in order to evolve the relationship between users and service providers aiming the establishment of personalized demands through personalized agreements. This work presents a study for the development of an open and generic tool for mapping the user perceived quality in QoS requirements through the capture of the packet flow generated between the applications of a service and simulates delays, jitter, loss of packets and bandwidth in order to allow the end user to identify and express the values of these parameters making transparent all the technological aspects involved in this identification. The definition of a service simulation environment, the development of a QoS simulator and a new relationship between users and services providers are also addressed.

Tout comportement défectueux d’un système temps-réel critique, comme celui utilisé dans le réseau avionique ou le secteur nucléaire, peut mettre en danger des vies. Par conséquent, la vérification et validation de ces systèmes est indispensable avant leurs déploiements. En fait, les autorités de sécurité demandent d’assurer des garanties déterministes. Dans cette thèse, nous nous intéressons à obtenir des garanties temporelles, en particulier nous avons besoin de prouver que le temps de réponse de bout-en-bout de chaque flux présent dans le réseau est borné. Ce sujet a été abordé durant de nombreuses années et plusieurs approches ont été développées. Après une brève comparaison entre les différentes approches existantes, une semble être un bon candidat. Elle s’appelle l’approche par trajectoire; cette méthode utilise les résultats établis par la théorie de l'ordonnancement afin de calculer une limite supérieure. En réalité, la surestimation de la borne calculée peut entrainer la rejection de certification du réseau. Ainsi une première partie du travail consiste à détecter les sources de pessimisme de l’approche adoptée. Dans le cadre d’un ordonnancement FIFO, les termes ajoutant du pessimisme à la borne calculée ont été identifiés. Cependant, comme les autres méthodes, l’approche par trajectoire souffre du problème de passage à l’échelle. En fait, l’approche doit être appliquée sur un réseau composé d’une centaine de commutateur et d’un nombre de flux qui dépasse les milliers. Ainsi, il est important qu’elle soit en mesure d'offrir des résultats dans un délai acceptable. La première étape consiste à identifier, dans le cas d’un ordonnancement FIFO, les termes conduisant à un temps de calcul important. L'analyse montre que la complexité du calcul est due à un processus récursif et itératif. Ensuite, en se basant toujours sur l’approche par trajectoire, nous proposons de calculer une limite supérieure dans un intervalle de temps réduit et sans perte significative de précision. C'est ce qu'on appelle l'approche par trajectoire scalable. Un outil a été développé permettant de comparer les résultats obtenus par l’approche par trajectoire et notre proposition. Après application sur un réseau de taille réduite (composé de 10 commutateurs), les résultats de simulations montrent que la durée totale nécessaire pour calculer les bornes des milles flux a été réduite de plusieurs jours à une dizaine de secondes. / In critical real-time systems, any faulty behavior may endanger lives. Hence, system verification and validation is essential before their deployment. In fact, safety authorities ask to ensure deterministic guarantees. In this thesis, we are interested in offering temporal guarantees; in particular we need to prove that the end-to-end response time of every flow present in the network is bounded. This subject has been addressed for many years and several approaches have been developed. After a brief comparison between the existing approaches, the Trajectory Approach sounded like a good candidate due to the tightness of its offered bound. This method uses results established by the scheduling theory to derive an upper bound. The reasons leading to a pessimistic upper bound are investigated. Moreover, since the method must be applied on large networks, it is important to be able to give results in an acceptable time frame. Hence, a study of the method’s scalability was carried out. Analysis shows that the complexity of the computation is due to a recursive and iterative processes. As the number of flows and switches increase, the total runtime required to compute the upper bound of every flow present in the network understudy grows rapidly. While based on the concept of the Trajectory Approach, we propose to compute an upper bound in a reduced time frame and without significant loss in its precision. It is called the Scalable Trajectory Approach. After applying it to a network, simulation results show that the total runtime was reduced from several days to a dozen seconds.

Uma das principais características dos sistemas de informação e de comunicação é permitir que os usuários finais utilizem e disponibilizem serviços interativos com conteúdo multimídia a qualquer hora, em qualquer lugar, com qualquer dispositivo e em movimento, independentemente da tecnologia de rede utilizada. Um desafio que surge face a essa nova característica dos serviços é como identificar os requisitos de QoS (Qualidade de Serviço) fim-a-fim sob a ótica do usuário final em um ambiente convergente e heterogêneo com o intuito de evoluir as relações entre o usuário final e o Provedor de Serviços para o estabelecimento de um contrato com níveis de serviço personalizado. Este trabalho apresenta uma pesquisa para a elaboração de uma ferramenta genérica e aberta para mapear a qualidade percebida pelo usuário em requisitos técnicos de QoS através da captura do fluxo de pacotes gerado entre as aplicações que compõem um serviço e simula atrasos, jitter, perdas e banda percebida com o objetivo de permitir ao usuário final identificar e expressar os valores desses parâmetros tornando transparente os aspectos tecnológicos que envolvem esta identificação. A definição de um ambiente de simulação que hospeda o serviço, o desenvolvimento de um simulador de QoS específico e uma nova relação entre o usuário e o Provedor de Serviços também são abordados. / One of the main characteristics of communication and information systems is to allow final users to use and make available multimedia content interactive services at any time, anywhere, in motion and using any device regardless of network technology. Under this perspective a challenge arises on how to identify the QoS (Quality of Service) requirements in a convergent and heterogeneous environment end-to-end user centric way, in order to evolve the relationship between users and service providers aiming the establishment of personalized demands through personalized agreements. This work presents a study for the development of an open and generic tool for mapping the user perceived quality in QoS requirements through the capture of the packet flow generated between the applications of a service and simulates delays, jitter, loss of packets and bandwidth in order to allow the end user to identify and express the values of these parameters making transparent all the technological aspects involved in this identification. The definition of a service simulation environment, the development of a QoS simulator and a new relationship between users and services providers are also addressed.

Atualmente, os usuários desejam obter, fornecer, compartilhar e interagir com informações e serviços com conteúdo multimídia em qualquer lugar, a qualquer momento e com qualquer dispositivo. Para que isso seja possível, um dos grandes desafios é assegurar a QoS (Quality of Service) fim a fim (entre o usuário final e a organização provedora de serviço) para a disponibilização de serviços móveis e interativos com conteúdo multimídia para os usuários finais. Em geral esse tipo de serviço têm maior exigência de QoS, pois além dos parâmetros de redes, possuem parâmetros específicos para áudio, imagem e vídeo, além de exigirem sincronização de áudio e vídeo, e a QoS fim a fim deve considerar parâmetros de QoS sob a percepção do usuário final. Com isso, o objetivo deste trabalho é propor um método para o levantamento de parâmetros de QoS para o estabelecimento de USLAs (User Service Level Agreements - Acordo do Nível de Serviço do Usuário) entre a organização provedora de serviço e o usuário final para serviços móveis e interativos com conteúdo multimídia em um ambiente de convergência tecnológica. O método consiste em quatro passos: 1. identificação do serviço a ser oferecido ao usuário final e elaboração de um grafo em árvore, que tem como objetivo identificar outros serviços que podem compor o serviço a ser oferecido ao usuário final; 2. mapeamento dos parâmetros de QoS em um metamodelo; 3. validação do metamodelo, para que se possa extrair do metamodelo os parâmetros de QoS; 4. elaboração do USLA. Este trabalho propõe um primeiro passo para solucionar a falta de métodos padronizados para o estabelecimento de USLA para serviços móveis e interativos com conteúdo multimídia sob a percepção do usuário final. Além de facilitar a identificação e composição de serviços e parâmetros, por meio de um metamodelo que proporciona a integração de classes de serviços que podem ser facilmente reutilizadas e customizadas, de acordo, com o tipo de serviço oferecido pela organização provedora de serviço e pela necessidade do usuário final. / In these days the final users wish to obtain, to furnish and to interact using interactive services with multimedia content anywhere, anytime and with any kind of user device. One of the biggest challenges is to assure the End-to End Quality of Service (E2E QoS) in the delivering of the interactive and multimedia services for moving users. In general, this kind of users have more strict requirements needs, because, besides of the computer network parameters, they need specify specific parameters like sound, image and video and their synchronization, on the users\' point of the view - perceived QoS. The main objective of this thesis is to present the application of a method for eliciting the E2E QoS parameters aiming the establishment of the User Service Level Agreement - USLA between the service provider and the final user applied to interactive and mobile services with multimedia content, inserted on a technological convergence environment. The method is a four steps method that consists of (1) an identification of the service to be offered to the final user and the elaboration of a tree graph aiming the identification of the composition of the service by other services (2) mapping the QoS parameters in a metamodel (3) validation of the metamodel, and extraction of the E2E QoS parameters (4) elaboration the USLA. This thesis proposes a first step to solve the lack of standardized methods for the establishment of the USLA for interactive and mobile services with multimedia content under the users\' perception. Besides of facilitating the identification and the composition of services and parameters, using a metamodel, that provides the integration of classes of services, that can be easily reused and customized, according, with the type of service offered for the service provider to the final user.

This dissertation introduces, implements, and evaluates the novel concept of "Service Paths", which are system-level abstractions that capture and describe the dynamic dependencies between the different components of a distributed enterprise application. Service paths are dynamic because they capture the natural interactions between application services dynamically composed to offer some desired end user functionality. Service paths are distributed because such sets of services run on networked machines in distributed enterprise data centers. Service paths cross multiple levels of abstraction because they link end user application components like web browsers with system services like http providing communications with embedded services like hardware-supported data encryption. Service paths are system-level abstractions that are created without end user, application, or middleware input, but despite these facts, they are able to capture application-relevant performance metrics, including end-to-end latencies for client requests and the contributions to these latencies from application-level processes and from software/hardware resources like protocol stacks or network devices. Beyond conceiving of service paths and demonstrating their utility, this thesis makes three concrete technical contributions. First, we propose a set of signal analysis techniques called ``E2Eprof' that identify the service paths taken by different request classes across a distributed IT infrastructure and the time spent in each such path. It uses a novel algorithm called ``pathmap' that computes the correlation between the message arrival and departure timestamps at each participating node and detect dependencies among them. A second contribution is a system-level monitoring toolkit called ``SysProf', which captures monitoring information at different levels of granularity, ranging from tracking the system-level activities triggered by a single system call, to capturing the client-server interactions associated with a service paths, to characterizing the server resources consumed by sets of clients or client behaviors. The third contribution of the thesis is a publish-subscribe based monitoring data delivery framework called ``QMON'. QMON offers high levels of predictability for service delivery and supports utility-aware monitoring while also able to differentiate between different levels of service for monitoring, corresponding to the different classes of SLAs maintained for applications.