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To prevent unauthorized access of multimedia content, effective access control and efficient key management schemes are of crucial importance for multimedia live streaming applications. To address the network heterogeneity, this thesis investigates scalable and multilevel access control, where a single bit stream can offer access to different levels of service. It uses the POSET hash-based structure to explore the data dependency between different layers in scalable coding, and proposes a secure and efficient key management scheme that uses public information and hash functions to reduce the rekey overhead. For those applications that require strict forward/backward security, sequential rekey is used to update keys. This thesis also addresses frequent membership update in live streaming, and considers applications that can tolerate a small amount of content leak. Through exploring their unique characteristics in membership dynamics, the proposed schemes reduce the rekey cost significantly. / Digital Signals and Image Processing

<p>Packet transmission scheduling plays a key role in Quality of Service (QoS) support for real-time traffic and efficient radio resource utilization in a wireless mesh network (WMN). It is a highly complicated problem due to the fact that any scheduling decision at one mesh access point (AP) may affect the scheduling decisions in the entire network. The strict delay requirement of real-time applications makes the scheduling problem even more challenging.</p> <p> In this thesis, the packet transmission scheduling problem for real-time constant-bit-rate (CBR) traffic in a WMN is first formulated as a standard integer linear programming problem, which takes into consideration both the multihop packet transmission delay and timeline coordinations of the mesh APs. The objective is to efficiently utilize the radio resources, subject to available bandwidth of the mesh APs, co-channel interference, and packet transmission latency requirement.</p> <p>Two heuristic schemes, namely AP-based scheduling (ABS) and connection-based scheduling (CBS) schemes, are then proposed to support real-time CBR traffic. ABS makes scheduling decisions on a per-AP basis. Scheduling decisions at APs with a higher traffic load are determined before those at APs with a lower traffic load. ABS achieves close-to-optimum capacity but may go through multiple iterations before reaching a feasible solution. CBS makes scheduling decisions on a connection-by-connection basis. It gives a higher priority to connections with more hops. In CBS, connections with a lower priority can only use resources remaining from serving all higher priority connections. CBS requires much lower complexity than ABS while achieving capacity performance slightly lower than ABS.</p> <p>We extend the proposed ABS and CBS scheduling schemes for supporting real-time variable bit rate (VBR) traffic in a WMN. By combining the concept of effective bandwidth and the proposed scheduling schemes, both delay and packet loss performance of the VBR traffic can be effectively satisfied. The scheduling schemes are further extended for supporting real-time traffic in a WMN with multi-radio APs.</p> <p>All the scheduling decisions are done at the time when new connection requests arrive and the results are used to make admission control decisions. In this sense, the work in this thesis is for both packet transmission scheduling and admission control for real-time traffic in WMNs.</p> / Thesis / Doctor of Philosophy (PhD)

The master thesis is focused on the Universal Mobile Telecommunications System (UMTS) - the third-generation cell phone technology. The first part describes the development of mobile networks and the structure of the UMTS. The second part, the main part of the thesis, is focused on the planning procedure of the UMTS access network. It consists of an explanation of the general planning procedure and a specific project designing the coverage of Pelhřimov surroundings. The final part of the thesis contains a laboratory problem including instructions.

The diploma thesis is concerned with solving security problems in local computer networks. The main part deals with the solution of authorization of wireless clients against the RADIUS server and with the proposal of domain controller using open-source products and the tools of operating system GNU/Linux.

Cette thèse démontre l'importance des informations réseau inter-couche pour les applications réseaux. Cette dissertation présente une nouvelle architecture de contrôle d'accès dans laquelle le contrôleur est mutualisé dans le Cloud. Cette architecture permet d'adresser un marché clé pour des clients ne pouvant acheter du matériel spécialisé. Plusieurs verrous techniques ont du être résolus pour pouvoir implémenter cette architecture, en effet les informations du réseau privé ne sont plus disponible au niveau du contrôleur ce qui l'empêche de correctement contrôler l'activité des utilisateurs. Une première implémentation est présentée dans le chapitre 2, elle utilise des équipements spécialisés capable d'interagir avec le contrôleur centralisé. Cette implémentation comportant des faiblesses, nous nous sommes intéressés à une approche par réseaux logiciels. Une solution innovante pour partager des informations inter-couche à l'extérieur d'un réseau SDN est présentée dans le chapitre 3. Elle permet d'intercepter et de modifier des flux de données utilisateurs à la volée afin de transmettre des informations à l'intérieur de la couche applicative. Cette solution a été implémentée dans le contrôleur OpenDaylight et montre des résultats très encourageants. Couplée au contrôleur centralisé, cette solution permet de fournir une solution complète de contrôle d'accès réseau qui est simple à déployer et configurer et extensible aisément. / This thesis presents the importance of cross-layer network information for network applications in the context of network access control. The dissertation exposes a novel architecture in which a network access controller is mutualized in the Cloud. This architecture allows to address a key market segment for clients unwilling to buy expensive hardware to control their network. Multiple challenges come into play when hosting the controller remotely. Indeed cross-layer information are no longer available which prevents the controller from correctly controlling users activity. A first implementation to share cross-layer information is presented in chapter 2. It leverages specialized session border controllers to send these data in the application protocol, here HTTP. Then chapter 3 presents an innovative solution for the cross-layering problem which allows to intrumentalize network flows with SDN protocols. The solution focuses on a web portal redirection but is extendable to any kind of protocols. The implementation permits to intercept and modify flows in order to input cross-layer data within another network protocol. This solution was implemented in the OpenDaylight OpenFlow controller and shows great results. The mutualized approach coupled with the SDN cross-layer framework allow to build flexible networks with almost no configuration of on-site equipments. The central network controller reduces the overal cost of the solution by being mutualized among multiple clients. Moreover, having the ability to intrumentalize network traffic in software allows to implement any kind of custom behavior on the runtime.

O objeto do estudo diz respeito a como demandas individuais podem resultar em demandas coletivas. Interesses são relações entre necessidades e os bens capazes de satisfazê-las. Nesse sentido, interesses podem ser entendidos como uma demanda por um bem. Interesses coletivos se relacionam a bens capazes de satisfazer necessidades de uma coletividade. O conflito de interesses ocorre nos casos em que o atendimento a um interesse importa a denegação de outro. O Direito pode ser visto como um instrumento ético de resolução de conflito de interesses. O processo civil tradicionalmente foi concebido para a resolução de conflitos individuais. Com o reconhecimento dos interesses coletivos pelo Direito, novas técnicas processuais foram desenvolvidas para permitir a resolução de conflitos coletivos. Apesar disso, o número de demandas individuais relacionadas com questões coletivas cresce exponencialmente, causando o congestionamento de processos nos tribunais e a denegação de justiça. Questões estruturais, culturais e legais são fatores que levam a esse problema. Novas técnicas deveriam ser implementadas para a conversão de demandas individuais em demandas coletivas nos casos em que o seu objeto seja incindível e pertinente a uma coletividade. / The scope of the study pertains to how individual claims may result in collective (aggregated) claims. Interests are relationships between needs and the goods that can fulfill them. In this sense, interests can be conceived as a claim for a good. Collective interests relate to goods that are able to satisfy needs of a group of people. A conflict of interests takes place when the accomplishment of one precludes the other. The Law may be conceived as an ethical tool to the resolution of conflict of interests. Traditional litigation schemes were designed for the resolution of individual conflicts. With the recognition of collective rights by the Law, new civil procedure techniques were developed to allow resolution of collective conflicts. Despite that, the number of individual claims related to collective issues grows exponentially, causing a backlog of cases and the denial of justice. Structural, cultural and legal issues are factors leading to this problem. New techniques should be designed to convert individual claims into collective claims in cases where their object is indivisible and pertains to a group.

O objeto do estudo diz respeito a como demandas individuais podem resultar em demandas coletivas. Interesses são relações entre necessidades e os bens capazes de satisfazê-las. Nesse sentido, interesses podem ser entendidos como uma demanda por um bem. Interesses coletivos se relacionam a bens capazes de satisfazer necessidades de uma coletividade. O conflito de interesses ocorre nos casos em que o atendimento a um interesse importa a denegação de outro. O Direito pode ser visto como um instrumento ético de resolução de conflito de interesses. O processo civil tradicionalmente foi concebido para a resolução de conflitos individuais. Com o reconhecimento dos interesses coletivos pelo Direito, novas técnicas processuais foram desenvolvidas para permitir a resolução de conflitos coletivos. Apesar disso, o número de demandas individuais relacionadas com questões coletivas cresce exponencialmente, causando o congestionamento de processos nos tribunais e a denegação de justiça. Questões estruturais, culturais e legais são fatores que levam a esse problema. Novas técnicas deveriam ser implementadas para a conversão de demandas individuais em demandas coletivas nos casos em que o seu objeto seja incindível e pertinente a uma coletividade. / The scope of the study pertains to how individual claims may result in collective (aggregated) claims. Interests are relationships between needs and the goods that can fulfill them. In this sense, interests can be conceived as a claim for a good. Collective interests relate to goods that are able to satisfy needs of a group of people. A conflict of interests takes place when the accomplishment of one precludes the other. The Law may be conceived as an ethical tool to the resolution of conflict of interests. Traditional litigation schemes were designed for the resolution of individual conflicts. With the recognition of collective rights by the Law, new civil procedure techniques were developed to allow resolution of collective conflicts. Despite that, the number of individual claims related to collective issues grows exponentially, causing a backlog of cases and the denial of justice. Structural, cultural and legal issues are factors leading to this problem. New techniques should be designed to convert individual claims into collective claims in cases where their object is indivisible and pertains to a group.

Neste trabalho foi investigado o problema de autoria automatizada de informação multimídia sob a perspectiva da computação ubíqua de modo geral, e da interação do usuário com aplicações de captura e accesso (C&A) de modo particular. O objetivo do projeto foi a definição de operadores sobre interação do usuário em ambientes e em aplicações para permitir a geração automática de documentos multimídia interativos, um dos temas de pesquisa da área de engenharia de documentos. A abordagem da proposta foi a generalização dos operadores Inkteractors, definidos sobre a interação do usuário com aplicações baseadas em tinta eletrônica, considerando a interação do usuário na voz, mensagens de texto, vídeo e lousa. Como resultado foram definido os novos Interactors: operadores de interação sobre informação capturada em aplicações que envolvem interação do usuário com as mídias. Os Interactors foram validados no contexto de engenharia de documentos ao serem utilizados para a geração automática de documentos multimídia interativos, associados a aplicações de C&A para oferecer novas possibilidades de indexar, visualizar e acessar os documentos multimídia / This study investigated the problem of automated authoring of multimedia information from the perspective of ubiquitous computing in general, and the user interaction with applications of capture and acess (C&A) in particular. The project goal was to formalize operators on user interaction environments and applications to enable automatic generation of interactive multimedia documents, one of the themes of the research area of document engineering. The proposed approach is a generalization of the Inkteractors operators, defined on the user interaction with electronic ink-based applications on the users interaction with digital voice, text messaging, video and whiteboard. As a result we defined the new Interactors: interaction operators of captured information in applications that involve user interaction with the media. TheInteractors were validated in the context of document engineering to be used for the automatic generation of interactive multimedia documents, and in C&A aplications to offer new possibilities for indexing, viewing and accessing multimedia documents

Abstract This thesis set out to achieve the following objectives: (1) To identify the priorities and expectations that the Geelong community has of its public health care system. (2) To determine if there is a common view on the attributes of a just health system. (3) To consider a method of utilising the data in the determination of health care priority setting in Barwon Health. (4) To determine a model of community participation which enables ongoing input into the decision making processes of Barwon Health. The methodology involved a combination of qualitative and quantitative research. The qualitative work involved the use of focus groups that were conducted with 64 members of the Geelong community. The issues raised informed the development of the interview schedule that was the basis of the quantitative study, which surveyed a representative sample of 400 members of the Geelong community. Prior to reporting on this work, the areas of distributive justice, scarcity and community participation in health care were considered. The research found that timely access to public hospitals, emergency care and aged care services were the major priorities; for many people, the cost was less relevant than a quality service. Shorter waiting times and increased staffing levels were strongly supported. Increased taxes were nominated as the best means of financing the health system they sought. Community based services were less relevant than hospital services but health education was supported. An egalitarian approach to resource distribution was favoured although the community was prepared to discriminate in favour of younger people and against older people. There was strong support for the community to be involved in decision making in the public health care system through surveys or focus groups but very little support was given to priorities being determined by politicians, administrators and to a lesser extent, medical professionals.