Os dispositivos móveis passaram por grandes transformações na última década e tornaram-se complexos computadores dotados de grande poder de processamento e memória, além de prover aos usuários diversos recursos como sensores e câmeras de alta resolução. O uso de dispositivos móveis para diversas tarefas aumentou consideravelmente, o que levantou uma grande preocupação com o o alto consumo de energia desses dispositivos. Portanto, estudos tem sido realizados no sentido de encontrar soluções para diminuir o custo de energia das aplicações que executam em dispositivos móveis. Uma das alternativas mais utilizadas é o \\textit{computation offloading}, cujo objetivo é transferir a execução de uma tarefa para uma plataforma externa com o intuito de aumentar desempenho e reduzir consumo de recursos, como a bateria, por exemplo. Decidir sobre usar ou não esta técnica implica entender a influência de fatores como a quantidade de dados processados, a quantidade de computação envolvida, e o perfil da rede. Muitos estudos tem sido realizados para estudar a influência de diversas opções de rede wireless, como 3G, 4G e Wifi, mas nenhum estudo investigou a influência das escolhas de comunicação no custo de energia. Portanto, o objetivo deste trabalho é apresentar uma investigação sobre a influência da quantidade de dados, da quantidade de computação e dos protocolos de comunicação ou estilo arquitetural no consumo de energia quando a técnica de \\textit{computation offloading} é utilizada. Neste estudo, foram comparados REST, SOAP, Socket e RPC na execução de algoritmos de ordenação de diferentes complexidades aplicados sobre vetores de diversos tamanhos e tipos de dados. Os resultados mostram que a execução local é mais econômica com algoritmos menos complexos, pequeno tamanho de entrada e tipo de dados menos complexos. Quando se trata de execução remota, o REST é a escolha mais econômica seguida por Socket. Em geral, REST é mais econômico com vetores do tipo Object, independentemente da complexidade do algoritmo e tamanho do vetor, enquanto Socket é mais econômico com entradas maiores e com vetores de tipos primitivos, como Int e Float / Mobile devices have significantly changed in the last decade and they become complex computer machines equipped with large processing power and memory. Moreover, they provide users with several resources such as sensors and high resolution cameras. The usage of mobile devices has significantly increased in the past years, which raised an important concern regarding the high energy consumption. Therefore, several investigations have been conducted aiming at finding solutions to reduce the energy cost of mobile applications. One of the most used strategy is called computation offloading, whose main goal is to transfer the execution of a task to an external platform aiming at increasing performance and reducing resource consumption, including the battery. Deciding towards offloading certain tasks requires to understand the influence of the amount of data, amount of computation, and the network profile. Several studies have investigated the influence of different wireless flavours, such as 3G, 4G and wifi, but no study has investigated the influence of the communication choices on the energy cost. Therefore, the purpose of this research project is to present an investigation on the influence of the amount of data, amount of computation and the communication protocols and architectural style on the energy consumption in the context of the computation offloading technique. In this study, we compare REST, SOAP, Socket and RPC when executing algorithms of different complexities and different input sizes and types. Results show that local execution is more economic with less complex algorithms and small input data. When it comes to remote execution, REST is the most economic choice followed by Socket. In general, REST is the most economic choice when applied on Object type arrays, regardless the complexity and size, while Socket is the most economic choice with large arrays and primitive types such as integers and floats

Asset management is a time consuming and error prone process. Information Technology (IT) personnel typically perform this task manually by visually inspecting assets to identify misplaced assets. If this process is automated and provided to IT personnel it would prove very useful in keeping track of assets in a server rack. A mobile based solution is proposed to automate this process. The asset management application on the tablet captures images of assets and searches an annotated database to identify the asset. We evaluate the matching performance and speed of asset matching using three different image feature descriptors. Methods to reduce feature extraction and matching complexity were developed. Performance and accuracy tradeoffs were studied, domain specific problems were identified, and optimizations for mobile platforms were made. The results show that the proposed methods reduce complexity of asset matching by 67% when compared to the matching process using unmodified image feature descriptors. / by Reena Ursula Friedel. / Thesis (M.S.C.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.

"Advances in ubiquitous displays and wireless communications have fueled the emergence of exciting mobile graphics applications including 3D virtual product catalogs, 3D maps, security monitoring systems and mobile games. Current trends that use cameras to capture geometry, material reflectance and other graphics elements means that very high resolution inputs is accessible to render extremely photorealistic scenes. However, captured graphics content can be many gigabytes in size, and must be simplified before they can be used on small mobile devices, which have limited resources, such as memory, screen size and battery energy. Scaling and converting graphics content to a suitable rendering format involves running several software tools, and selecting the best resolution for target mobile device is often done by trial and error, which all takes time. Wireless errors can also affect transmitted content and aggressive compression is needed for low-bandwidth wireless networks. Most rendering algorithms are currently optimized for visual realism and speed, but are not resource or energy efficient on mobile device. This dissertation focuses on the improvement of rendering performance by reducing the impacts of these problems with UbiWave, an end-to-end Framework to enable real time mobile access to high resolution graphics using wavelets. The framework tackles the issues including simplification, transmission, and resource efficient rendering of graphics content on mobile device based on wavelets by utilizing 1) a Perceptual Error Metric (PoI) for automatically computing the best resolution of graphics content for a given mobile display to eliminate guesswork and save resources, 2) Unequal Error Protection (UEP) to improve the resilience to wireless errors, 3) an Energy-efficient Adaptive Real-time Rendering (EARR) heuristic to balance energy consumption, rendering speed and image quality and 4) an Energy-efficient Streaming Technique. The results facilitate a new class of mobile graphics application which can gracefully adapt the lowest acceptable rendering resolution to the wireless network conditions and the availability of resources and battery energy on mobile device adaptively."

Made available in DSpace on 2015-03-05T13:56:59Z (GMT). No. of bitstreams: 0 Previous issue date: 13 / Hewlett-Packard Brasil Ltda / O avanço do poder computacional de dispositivos móveis e a popularização destes equipamentos, tem avançado a demanda por uma nova classe de aplicações: aplicações móveis. Com isso, surgem novos modelos de programação que buscam explorar um novo cenário computacional. Com o objetivo de explorar ao máximo a característicade mobilidades dos dispositivos recém mencionados, temos como resultado, a materialização de modelos de programação em estruturas computacionais, implementadas por ferramentas de desenvolvimento e suporte à execução de software. Esta dissertação apresenta um estudo sobre estas ferramentas de suporte a execução de aplicação móveis, tendo como foco a exploração do ambiente de computação móvel MHolo. Para isso, foi construída uma aplicação móvel real, denominada "Acompanhamento de um Evento Científico", que abrange mobilidade, distribuição e consciência ao contexto. O modelo para esta aplicação foi baseado em um evento científico genérico e, como apectos de trabalho, este modelo foi mapeado e impl / The growth of computational power in mobile devices and the popularization of these devices, has introduced the need of a new class of applications: mobile applications. As a consequence, the number of programming models which try to explore a new computational scenery. Aiming to explore the mobility of such devices at their maximum, we have as result, the materialization of programming models in computational structures, implemented by software development and execution support tools. This work presents a study about those tools that support the execution of mobile applications, focusing the exploration of MHolo mobile computing enviroment.

Made available in DSpace on 2015-03-05T13:58:26Z (GMT). No. of bitstreams: 0 Previous issue date: 15 / Nenhuma / O crescimento do poder computacional dos dispositivos portáteis como PDAs, handhelds e notebooks é uma realidade na última década. Paralelamente, as redes sem fio (por exemplo Wi-Fi e bluetooth), tiveram um crescimento vinculado a estes equipamentos, facilitando a comunicação e troca de informações entre os mesmos. Nesse escopo surgiu a computação ubíqua. No escopo da computação ubíqua, as aplicações devem ser sensíveis à rede, recursos, localização física e contexto, ou seja, podem ter seu comportamento alterado durante sua execução, devido à mobilidade constante dos dispositivos móveis. Neste cenário o Holoparadigma apresenta-se como uma proposta de solução para a manipulação das questões associadas à mobilidade, já que possui um modelo de programação intuitivo, tornando possível a modelagem de ambientes utilizando as suas abstrações. Este trabalho apresenta o HLS, um modelo para desenvolvimento de aplicações sensíveis à localização utilizando o ambiente do Holoparadigma. O HLS é um modelo que inclui um

Os aplicativos móveis, desenvolvidos originalmente para a área do entretenimento, hoje estão presentes nos mais diversos domínios, sendo comuns inclusive em áreas de alto valor agregado, como: varejista, logística, bancária, médica, entre outras. Portanto, a qualidade e correção dos aplicativos móveis tornam-se obrigatórios e as atividades de teste essenciais. Porém a qualidade das aplicações móveis nem sempre é satisfatória. Isso ocorre devido ao fato dessas aplicações sofrerem com a pressão do mercado e passarem por um processo muito rápido de desenvolvimento, onde geralmente a fase de testes é negligenciada ou realizada de forma superficial, pela própria equipe de desenvolvimento, comprometendo assim a qualidade da aplicação. Este trabalho propõe uma abordagem baseada no Behavior Driven Development para ajudar na definição de testes de sistema para aplicativos nativos do Android. A abordagem proposta utiliza os arquivos de leiaute da aplicação para extrair informações sobre os componentes da interface e sobre os eventos esperados pelo sistema. A partir dessas informações, é possível verificar a cobertura dos cenários existentes em relação aos eventos disponíveis na interface com o usuário. Além disso, é possível identificar elementos do leiaute que não são exercitados pelos cenários existentes. A abordagem proposta é implementada por uma ferramenta chamada Android Behavior Testing Tool que, por meio da interpretação dos cenários do Behavior Driven Development, fornece uma visão geral do fluxo comportamental da aplicação ao testador (visão hoje não disponível), proporcionando assim uma noção de fácil compreensão sobre a cobertura dos testes em relação aos elementos da interface do aplicativo. Desta forma, o testador pode julgar a integridade dos casos de teste disponíveis em relação às funcionalidades implementadas e, se necessário, implementar novos testes. A ferramenta também faz uso dos arquivos de leiaute do aplicativo para identificar os componentes da interface que não foram testados e gera, neste caso, modelos de cenários no formato do BDD, automatizando assim a tarefa de escrita dos mesmos. A abordagem proposta foi utilizada em quatro aplicativos Android e se mostrou útil, uma vez que, em três estudos de caso foram detectados bugs oriundos de inconsistências lógicas nos cenários ou elementos não exercitados pelos cenários. / Mobile applications, originally developed for entertainment, nowadays are present in a wide range of domains, being common even in areas of high value such as retailer, logistics, banking, and medical, among others. However, the quality and correctness of mobile applications become mandatory and testing activities are essential. However, the quality of mobile applications is not always good enough. This is because these applications suffer from market pressure and pass through a very rapid development process where the testing phase usually is neglected or superficially performed by the development team itself, thus compromising the quality of the application. This work proposes an approach based on Behavior Driven Development to help to define system tests for native Android applications. The proposed approach uses the application's layout files to extract information about the interface components and the events expected by the system. From this information, it is possible to check out the coverage of existing test scenarios against events available in the user interface. In addition, it is possible to identify unexercised usage scenarios from the existing test scenarios. The proposed approach is implemented by a tool called Android Behavior Testing Tool which, through the interpretation of the BDD usage scenarios, provides to the tester an overview of the behavioral flow of the application (otherwise unavailable), thus providing a notion of easy understanding of test coverage in relation to the application interface elements. In this way, the tester can judge the integrity of the available test cases in relation to the functionalities implemented and, if necessary, implement new tests. The tool also makes use of the application's layout files to identify untested interface components and in this case generates test scenario models in the BDD format, thus automating the writing task of the scenarios. The proposed approach was used in four Android applications and proved to be useful, since in three case studies bugs were detected. Detected bugs originated from logical inconsistencies in the test scenarios or elements that were not exercised by the scenarios.

A Mobile Cloud Computing (MCC) system is a cloud-based system that is accessed by the users through their own mobile devices. MCC systems are emerging as the product of two technology trends: 1) the migration of personal computing from desktop to mobile devices and 2) the growing integration of large-scale computing environments into cloud systems. Designers are developing a variety of new mobile cloud computing systems. Each of these systems is developed with different goals and under the influence of different design constraints, such as high network latency or limited energy supply. The current MCC systems rely heavily on Computation Offloading, which however incurs new problems such as scalability of the cloud, privacy concerns due to storing personal information on the cloud, and high energy consumption on the cloud data centers. In this dissertation, I address these problems by exploring different options in the distribution of computation across different computing nodes in MCC systems. My thesis is that "the use of design and simulation tools optimized for design space exploration of the MCC systems is the key to optimize the distribution of computation in MCC." For a quantitative analysis of mobile cloud computing systems through design space exploration, I have developed netShip, the first generation of an innovative design and simulation tool, that offers large scalability and heterogeneity support. With this tool system designers and software programmers can efficiently develop, optimize, and validate large-scale, heterogeneous MCC systems. I have enhanced netShip to support the development of ever-evolving MCC applications with a variety of emerging needs including the fast simulation of new devices, e.g., Internet-of-Things devices, and accelerators, e.g., mobile GPUs. Leveraging netShip, I developed three new MCC systems where I applied three variations of a new computation distributing technique, called Reverse Offloading. By more actively leveraging the computational power on mobile devices, the MCC systems can reduce the total execution times, the burden of concentrated computations on the cloud, and the privacy concerns about storing personal information available in the cloud. This approach also creates opportunities for new services by utilizing the information available on the mobile device instead of accessing the cloud. Throughout my research I have enabled the design optimization of mobile applications and cloud-computing platforms. In particular, my design tool for MCC systems becomes a vehicle to optimize not only the performance but also the energy dissipation, an aspect of critical importance for any computing system.

Yau Chin Hang Herman. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 90-92). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- To A Localization --- p.10 / Chapter 2.1 --- Linear Estimator --- p.13 / Chapter 2.2 --- The Approximate Maximum Likelihood (AML) estimator --- p.14 / Chapter 2.3 --- Estimator for Linear BS --- p.18 / Chapter 3 --- TDoA Localization --- p.22 / Chapter 3.1 --- AML in TDoA localization --- p.27 / Chapter 4 --- Discussions of Application Considerations --- p.32 / Chapter 4.1 --- The Non-Line-of-Sight Problem --- p.33 / Chapter 4.2 --- Multipath Propagation --- p.34 / Chapter 4.3 --- Optimum placement of 4 sensors --- p.35 / Chapter 5 --- Simulation Studies --- p.44 / Chapter 5.1 --- Measures of Accuracy --- p.45 / Chapter 5.2 --- Simulations for non-linear array BSs --- p.47 / Chapter 5.2.1 --- Simulation 1: MS locating inside the enclosed area formed by 3BSs --- p.48 / Chapter 5.2.2 --- Simulation 2: The MS is outside the enclosed area formed by 3 BSs --- p.52 / Chapter 5.2.3 --- Simulation 3: The MS is inside the enclosed area formed by 6 BSs --- p.55 / Chapter 5.2.4 --- Simulation 4: The MS locates outside the enclosed area formed by 6 BSs --- p.58 / Chapter 5.3 --- ML estimator for linear array --- p.62 / Chapter 5.3.1 --- Simulation 5: Three BSs with equal spacing --- p.62 / Chapter 5.3.2 --- Simulation 6: Three BSs with non-equal spacing --- p.64 / Chapter 5.4 --- TDOA localization simulations --- p.66 / Chapter 5.4.1 --- Simulation 7: TDOA localization with 4 equal spacing microphones and the speaker is inside the enclosed area --- p.66 / Chapter 5.5 --- To see the performance of optimum placement --- p.69 / Chapter 5.5.1 --- Simulation 8: Optimum placement of the 4th microphone if the other three are fixed --- p.70 / Chapter 5.5.2 --- Simulation 9: Fixing 2 microphone and find the optimum placement of the other two microphones --- p.74 / Chapter 5.5.3 --- Simulation 10: The optimum placement of microphones without constraint --- p.78 / Chapter 6 --- Conclusions and Suggestions for future work --- p.81 / Chapter 6.1 --- Conclusions --- p.81 / Chapter 6.2 --- Suggestion for future work --- p.83 / Appendices --- p.85 / Chapter A --- The relationship between range variance and range difference variance --- p.85 / Chapter B --- The Cramer-Rao Lower Bound (CRLB) for TDoA and ToA cases --- p.87

Yu Sheung Fan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 96-99). / Abstracts in English and Chinese. / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Background: Context-Aware Applications --- p.2 / Chapter 1.1.1 --- Definitions of Context --- p.2 / Chapter 1.1.2 --- Existing Applications --- p.3 / Chapter 1.1.3 --- Review --- p.6 / Chapter 1.2 --- Research Motivation --- p.6 / Chapter 1.3 --- Research Contributions --- p.8 / Chapter 1.4 --- Thesis Outline --- p.8 / Chapter 2. --- Location-sensing Technologies --- p.9 / Chapter 2.1 --- Global Positioning System (GPS) --- p.9 / Chapter 2.2 --- Existing indoor Location-sensing Systems --- p.11 / Chapter 2.2.1 --- Active Badge --- p.11 / Chapter 2.2.2 --- The Bat System --- p.12 / Chapter 2.2.3 --- RADAR --- p.13 / Chapter 2.2.4 --- PinPoint 3D-iD --- p.14 / Chapter 2.2.5 --- Easy Living --- p.15 / Chapter 2.3 --- System Properties and Risks --- p.16 / Chapter 2.3.1 --- Accuracy --- p.17 / Chapter 2.3.2 --- Cost --- p.18 / Chapter 2.3.3 --- User Privacy --- p.18 / Chapter 2.3.4 --- Location Representation --- p.19 / Chapter 2.3.5 --- Other Limitations --- p.20 / Chapter 2.4 --- Design Goals --- p.20 / Chapter 2.4.1 --- Operate Inside Buildings --- p.21 / Chapter 2.4.2 --- Preserve User Privacy --- p.21 / Chapter 2.4.3 --- Low Cost --- p.22 / Chapter 2.4.4 --- Fast Response --- p.22 / Chapter 2.4.5 --- Spatial Recognition --- p.23 / Chapter 2.4.6 --- Easy Administration and Deployment --- p.23 / Chapter 2.5 --- Summary --- p.23 / Chapter 3. --- System Design --- p.25 / Chapter 3.1 --- System Architecture --- p.25 / Chapter 3.2 --- Position-sensing Platform --- p.28 / Chapter 3.2.1 --- Platform Architecture --- p.29 / Chapter 3.2.2 --- Transmission Format --- p.30 / Chapter 3.2.3 --- Distance Measurement --- p.31 / Chapter 3.2.4 --- Position Estimation --- p.32 / Chapter 3.2.5 --- Noise Cancellation --- p.35 / Chapter 3.2.6 --- Location Inference --- p.36 / Chapter 3.3 --- Summary --- p.38 / Chapter 4. --- System Implementation --- p.39 / Chapter 4.1 --- Communication Technologies --- p.39 / Chapter 4.1.1 --- Ultrasound --- p.40 / Chapter 4.1.2 --- Radio Frequency Identification (RFID) --- p.40 / Chapter 4.1.3 --- Infrared Data Association (IrDA) --- p.41 / Chapter 4.1.4 --- Bluetooth --- p.42 / Chapter 4.2 --- Technologies Overview --- p.43 / Chapter 4.2.1 --- Positioning --- p.44 / Chapter 4.2.2 --- Networking --- p.44 / Chapter 4.2.3 --- Communication Protocol --- p.45 / Chapter 4.2.4 --- Range --- p.45 / Chapter 4.2.5 --- Angle Dependency --- p.45 / Chapter 4.2.6 --- Hardware supports --- p.46 / Chapter 4.3 --- Hardware --- p.46 / Chapter 4.3.1 --- Mobile Receiver --- p.46 / Chapter 4.3.2 --- Transmitter --- p.47 / Chapter 4.4 --- Software --- p.47 / Chapter 4.4.1 --- Communication Protocol --- p.48 / Chapter 4.4.2 --- Programming Environment --- p.48 / Chapter 4.4.3 --- Signal Generation Routine --- p.48 / Chapter 4.4.4 --- Position Estimation Routine --- p.50 / Chapter 4.5 --- Summary --- p.53 / Chapter 5. --- Evaluation --- p.55 / Chapter 5.1 --- Platform Calibration --- p.55 / Chapter 5.1.1 --- Outliers Elimination --- p.56 / Chapter 5.1.2 --- Delay Determination --- p.58 / Chapter 5.1.3 --- Window Size Determination --- p.61 / Chapter 5.1.4 --- Revised Position Estimation Algorithm --- p.63 / Chapter 5.2 --- Platform Evaluation - IrDA Figure 5.9: Experimental setup for distance performance evaluation --- p.64 / Chapter 5.2.1 --- Distance Measurement Figure 5.10: IrDA horizontal distance measurement experiment results --- p.66 / Chapter 5.2.2 --- Position Estimation - Static --- p.66 / Chapter 5.2.3 --- Position Estimation - Mobile --- p.68 / Chapter 5.3 --- Platform Evaluation - Bluetooth --- p.69 / Chapter 5.3.1 --- Distance Measurement --- p.69 / Chapter 5.3.2 --- Position Estimation - Static --- p.70 / Chapter 5.3.3 --- Position Estimation ´ؤ Mobile --- p.71 / Chapter 5.4 --- Summary --- p.73 / Chapter 6. --- Applications --- p.74 / Chapter 6.1 --- Potential Applications --- p.74 / Chapter 6.1.1 --- Resource Tracking Systems --- p.75 / Chapter 6.1.2 --- Shopping Assistance System --- p.76 / Chapter 6.1.3 --- Doctor Tracking System --- p.77 / Chapter 6.1.4 --- Tourist Guide Application --- p.78 / Chapter 6.1.5 --- Other Applications --- p.79 / Chapter 6.2 --- System Limitations --- p.79 / Chapter 6.3 --- Summary --- p.79 / Chapter 7. --- Conclusion --- p.80 / Chapter 7.1 --- Summary --- p.80 / Chapter 7.2 --- Future Work --- p.81 / Chapter Appendix A: --- IrDA --- p.86 / Chapter A.1 --- IrDA Physical Layer --- p.86 / Chapter A.2 --- Physical Aspects of IrDA Physical Layer --- p.87 / Chapter A.3 --- Discovering Other IrDA Devices --- p.88 / Chapter A.4 --- Connection of IrDA Devices --- p.89 / Chapter Appendix B: --- Bluetooth --- p.91 / Chapter B.1 --- Bluetooth Stack --- p.91 / Chapter B.2 --- Radio --- p.92 / Chapter B.3 --- Frequency Hopping --- p.92 / Chapter B.4 --- Package Structure --- p.92 / Chapter B.5 --- The Link Controller --- p.93 / Chapter B.6 --- The Link Manager --- p.93 / Chapter B.7 --- Logical Link Control and Adaptation Protocol --- p.94 / Chapter B.8 --- The Service Discovery Protocol --- p.94 / Chapter B.9 --- Encryption and Security --- p.95 / Bibliography --- p.96

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O avanÃo tecnolÃgico na Ãrea de arquiteturas computacionais tem proporcionado o uso de sistemas de computaÃÃo em muitas aplicaÃÃes que ainda nÃo se haviam se beneficiado com esta tecnologia. Em particular, as arquiteturas computacionais distribuÃdas, associadas com a computaÃÃo mÃvel e a comunicaÃÃo mÃvel, alargaram o horizonte de aplicabilidade em grande proporÃÃo. Dentre as aplicaÃÃes que se beneficiaram com estes avanÃos, a Telemedicina desponta com diversas Ãreas mÃdicas fazendo uso desta tecnologia. Por Telemedicina, entende-se a distribuiÃÃo de assistÃncia mÃdica e a colaboraÃÃo do conhecimento mÃdico à distÃncia, por intermÃdio do uso dos atuais meios de comunicaÃÃo. Muitas soluÃÃes propostas para suportar Telemedicina se baseiam na arquitetura Cliente-Servidor. Esta arquitetura apresenta uma baixa confiabilidade pelo fato de contar com um elemento central (Servidor) para prover os serviÃos solicitados. à claro que redundÃncia pode ser incorporada em nÃvel de servidor, mas ao alto preÃo de ter-se que garantir a consistÃncia dos servidores replicados. Nesta dissertaÃÃo, à proposta uma arquitetura computacional peer-to-peer (P2P), que elimina o elemento central encontrado na arquitetura Cliente-Servidor. à discutida a importÃncia de se utilizar esta tecnologia na oferta de serviÃos de assistÃncia mÃdica especializada a distÃncia, propondo um estilo de colaboraÃÃo direto entre mÃdicos, a partir da interligaÃÃo entre equipamentos computacionais. Dentro deste contexto, à apresentada uma soluÃÃo, denominada JMED, que à desenvolvida por meio de uma plataforma de programaÃÃo para o ambiente da computaÃÃo de rede distribuÃda Peer-to-Peer, conhecida por JXTA. JMED foi implementada e sua aplicaÃÃo em Telemedicina foi validada a partir de uma aplicaÃÃo voltada para segunda opiniÃo mÃdica, fazendo uso tanto de sistemas de computadores, como de telefones celulares. / In the last years Research and Development (R&D) in the area of computer systems and communication systems have started a technological revolution which has made it possible to conceive a number of new products, particularly embedded systems, from cell phones to medical equipments. The area which makes use of both technologies above is frequently known as Information Technology (IT). IT has boosted a number of research projects and has established as a research area in its own. Among the applications which have benefited from IT, Telemedicine is one that stands out. Telemedicine is the distribution of medical care, as well as medical knowledge cooperation at distance by using IT. Many solutions proposals to support Telemedicina if base on the architecture Client-Server. This architecture presents low Reliability for the fact to count on a central element (Server) to provide the requested services. It is clearly that redundancy can be incorporated in server level, but to the high price to have itself that to guarantee the consistency of the talked back servers. In this dissertation we propose a communication architecture based on peer-to-peer (P2P) computing, that it decides the problem of the architecture Client-Server. The importance is argued of if to use this technology in offers in the distance of services of specialized medical assistance, considering a direct style of contribution between doctors, from the interconnection between computational equipment. The proposed system, named JMED, was developed using programming platform for distributed P2P computing known as JXTA. JMED was implemented and we showed that is can be used in Telemedicine application by designing an application known as âsecond opinionâ, where computers and cell phones were used as communication stations.