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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Analyzing YouTube Content Demand Patternsand Cacheabilityin a Swedish Municipal Network

Wang, Hantao January 2013 (has links)
User Generated Content (UGC) has boosted a high popularity since the birth of a wide range of web services allowing the distribution of such user-produced media content, whose patterns vary from textual information, photo galleries to videos on site. The boom of Internet of Things and the newly released HTML5 accelerate the development of multimedia patterns as well as the technology of distributing it. YouTube, as one of the most popular video sharing site, enjoys the top most numbers of video views and video uploads per day in the world. With the rapid growing of multimedia patterns as well as huge bandwidth demand from subscribers, the sheer volume of the traffic is going to severely strain the network resources.</p><p>Therefore, analyzing media streaming traffic patterns and cacheability in live IP-access networks today leads a hot issue among network operators and content providers. One possible solution could be caching popular contents with a high replay rate in a proxy server on LAN border or in users' terminals.</p><p>Based on the solution, this thesis project focuses on developing a measurement framework to associate network cacheability with video category and video duration under a typical Swedish municipal network. Experiments of focused parameters are performed to investigate potential user behavior rules. From the analysis of the results, Music traffic gets a rather ideal network gain as well as a remarkable terminal gain, indicating that it is more efficient to be stored close to end user. Film&Animation traffic, however, is preferable to be cached in the network due to its high net gain. Besides, it is optimal to cache the video clips with a length between 3 and 5 minutes, especially the Music and Film&Animation traffic. In addition, more than half of the replays occur during 16.00-24.00 and peak hours appear on average from 18.00 to 22.00. Lastly, only around 16% of the videos are global popular and very few heavy users tend to be local popular video viewers, depicting local limits and independent user interests
112

Developing an emulator for 360° video : intended for algorithm development

Lindskog, Eric January 2020 (has links)
Streaming 360° video has become more commonplace with content delivery services such as YouTube having support for it. By its nature, 360° video requires more bandwidth as only a fraction of the image is actually in view, while the user is expecting the same "in view" quality as with a regular video. Several studies and lots of work have been done to mitigate this higher demand for bandwidth. One solution is advanced algorithms that take in to account the direction that the user is looking when fetching the video from the server; e.g., by fetching content that is not in the user’s view at a lower quality or by not fetching this data at all. Developing these algorithms is a timely process, especially in the later stages where tweaking one parameter might require the video to be re-encoded, and therefore taking up time that could otherwise be spent on getting results and continued iteration on the algorithm. The viewer should also be considered as the best experience might not correlate with the mathematically best solution calculated by the algorithm. This thesis presents a modular emulator that allows for easy implementation of fetching algorithms that make use of state-of-the-art techniques. It intends to reduce the time it takes to iterate over an algorithm through removing the need to set up a server and encode the video in all of the wanted quality levels when a parameter change would require it. It also makes it easy to include the viewer in the process so that the subjective performance is taken into consideration. The emulator is evaluated through the implementation and evaluation of two algorithms, one serving as a baseline to the second one, which is based on an algorithm developed by another group of researchers. These algorithms are tested on two different types of 360° videos, under four different network conditions and with two values for the maximum buffer size. The results from the evaluation of the two algorithms suggest that the emulator functions as intended from a technical point of view, and as such fulfills its purpose. There is, however, future work that would further prove the emulators performance in regards to replicating real scenarios and a few examples are suggested.
113

Vidéoconférence basée sur les ressources internes de l'entreprise / Video conference based on enterprise desktop grid

Sorokin, Roman 24 February 2017 (has links)
Il existe deux approches classiques et bien comprises des tâches de traitement vidéo pour la vidéoconférence. Le premier utilise une unité centralisée de contrôle multipoint. Dans la deuxième approche, les tâches de traitement vidéo sont directement traitées dans les clients. La performance est ensuite limitée par les caractéristiques du périphérique. Dans cette thèse, nous proposons une troisième approche alternative. Nous proposons un système qui distribue des tâches de traitement vidéo en temps réel sur les ressources internes de l'entreprise. Une méthode dédiée de prise de décision basée sur les multi-attributs est conçue pour tenir compte de la variété des attributs qui influent sur la qualité de l'expérience. Des algorithmes de distribution et de redistribution de tâches sont élaborés. Nous testons ensuite l'approche proposée au moyen de la simulation afin d'étudier l'impact des principaux paramètres critiques. L'approche proposée pose une question sur laquelle un PC peut être utilisé comme plate-forme pour le serveur multimédia. Nous estimons une qualité perçue des flux vidéo afin d'étudier l'influence de la charge CPU. Nous avons également élaboré des algorithmes, combinant l'approche Cloud / Fog avec différents types de serveurs multimédia. Le résultat fournit une solution de conférence optimisée en termes de coût tant pour le fournisseur que pour le consommateur, ainsi que pour l'expérience de l'utilisateur final. En combinant les algorithmes élaborés et l'architecture avec les résultats de l'expérimentation, nous concluons que la solution proposée peut être utilisée comme une nouvelle approche de la problématique de la vidéoconférence. / There exist two classical and well-understood approaches to video processing tasks for videoconferencing. The first one is using a centralized Multipoint Control Unit (MCU). In the second approach, the video processing tasks are directly handled in endpoints. Performance is then restricted by device characteristics, especially in the case of mobile devices. In this thesis, we propose a third alternative approach. We propose a system, which distributes real-time video processing tasks on enterprise desktop grid. A dedicated Multi Attribute Decision Making method is designed in order to take into account the variety of attributes impacting Quality of Experience. A number of task distribution and redistribution algorithms are elaborated. We then test the proposed approach by means of simulation in order to study the impact of the main critical parameters. The proposed approach arises a question to which extent a PC can be used as a platform for media server and how CPU load affects the quality of provided video conference. We estimate a perceived quality of video streams in order to investigate CPU load influence. Also we elaborated algorithms, combining Cloud/Fog approach with different types of media servers, the result provides an optimized conferencing solution in the terms of cost for both provider and consumer as well as in terms of end user experience. Combining elaborated algorithms and architecture with experimentation results we conclude that proposed solution can be used as a novel approach to video conferencing problematic.
114

The Contribution of Eye Tracking to Quality of Experience Assessment of 360-degree video

van Kasteren, Anouk January 2019 (has links)
The research domain on the Quality of Experience (QoE) of 2D video streaming has been well established. However, a new video format is emerging and gaining popularity and availability: VR 360-degree video. The processing and transmission of 360-degree videos brings along new challenges such as large bandwidth requirements and the occurrence of different distortions. The viewing experience is also substantially different from 2D video, it offers more interactive freedom on the viewing angle but can also be more demanding and cause cybersickness. Further research on the QoE of 360-videos specifically is thus required.The first goal of this thesis is to complement earlier research by (Tran, Ngoc, Pham, Jung, and Thank, 2017) testing the effects of quality degradation, freezing, and content on the QoE of 360-videos. The second goal is to test the contribution of visual attention as influence factor in the QoE assessment. Data will be gathered through subjective tests where participants watch degraded versions of 360-videos through an HMD with integrated eye-tracking sensors. After each video they will answer questions regarding their quality perception, experience, perceptual load, and cybersickness.Results of the first part show overall rather low QoE ratings and it decreases even more as quality is degraded and freezing events are added. Cyber sickness was found not to be an issue. The effects of the manipulation on visual attention were minimal. Attention was mainly directed by content, but also by surprising elements. The addition of eye-tracking metrics did not further explain individual differences in subjective ratings. Nevertheless it was found that looking at moving objects increased the negative effect of freezing events and made participants less sensitive for quality distortions. The results of this thesis alone are not enough to successfully regard visual attention as an influence factor in 360-video.
115

Impact of fixed-rate fingerprinting defense on cloud gaming experience / Påverkan av fixed-rate fingerprinting försvar på cloud gamingupplevelsen

Thang, Kent, Nyberg, Adam January 2023 (has links)
Cloud gaming has emerged as a popular solution to meet the increasing hardware de-mands of modern video games, allowing players with dated or non-sufficient hardwareto access high-quality gaming experiences. However, the growing reliance on cloud ser-vices has led to heightened concerns regarding user privacy and the risk of fingerprintingattacks. In this paper, we investigate the effects of varying send rates on cloud gamingQoS and QoE metrics when applying a fixed-rate fingerprinting defense, BuFLO. Findingsshow that lower send rates impact both client-side and host-side applied defense differ-ently. Based on the results, specific send rates are suggested for maintaining a stable cloudgaming experience. The research offers insights into the trade-offs between security andperformance in cloud gaming and provides recommendations for mitigating fingerprintingattacks. Future work may investigate alternative defenses, device types, and connectionmethods.
116

Evaluación de la QoE en un sistema de streaming adaptativo de vídeo 3D basado en DASH

Guzmán Castillo, Paola Fernanda 06 September 2022 (has links)
[ES] La distribución de contenidos multimedia, y en particular el streaming de vídeo, domina actualmente el tráfico global de Internet y su importancia será incluso mayor en el futuro. Miles de títulos se agregan mensualmente a los principales proveedores de servicios, como Netflix, YouTube y Amazon. Y de la mano del consumo de contenidos de alta definición que se convierte en la principal tendencia, se puede observar nuevamente un incremento en el consumo de contenidos 3D. Esto ha hecho que las temáticas relacionadas con la producción de contenidos, codificación, transmisión, Calidad de Servicio (QoS) y Calidad de Experiencia (QoE) percibidas por los usuarios de los sistemas de distribución de vídeo 3D sean un tema de investigación con numerosas contribuciones en los últimos años. Esta tesis aborda el problema de la prestación de servicios de transmisión de vídeo 3D bajo condiciones de red de ancho de banda variable. En este sentido, presenta los resultados de la evaluación de la QoE percibida por los usuarios de los sistemas de vídeo 3D, analizando principalmente el impacto de los efectos introducidos en dos de los elementos de la cadena de procesamiento de vídeo 3D: la etapa de codificación y el proceso de transmisión. Para analizar los efectos de la codificación en la calidad del vídeo 3D, en la primera etapa se aborda la evaluación objetiva y subjetiva de la calidad del vídeo, comparando el rendimiento de diferentes estándares y métodos de codificación, con el fin de identificar aquellos que logran la mejor relación entre calidad, tasa de bits y tiempo de codificación. Así mismo, en el contexto de la transmisión en un entorno simulcast, se evalúa la eficacia de la utilización de las codificaciones asimétricas para la transmisión de vídeo 3D, como una alternativa para la reducción del ancho de banda manteniendo la calidad global. En segundo lugar, para el estudio del impacto y el rendimiento del proceso de transmisión, se ha trabajado sobre la base de un sistema de transmisión dinámica adaptativa sobre HTTP (DASH) en el contexto de la transmisión de vídeo tanto 2D como 3D, utilizando diferentes escenarios de variación de ancho de banda. El objetivo ha sido el desarrollo de un marco de referencia para la evaluación de la QoE en escenarios de transmisión adaptativa de vídeo 3D, que permite analizar el impacto en la QoE del usuario frente a diferentes patrones de variación del ancho de banda, así como el rendimiento del algoritmo de adaptación frente a estos escenarios. El trabajo se enfoca en identificar el impacto en la Calidad de Experiencia del usuario que tienen aspectos como: la frecuencia, el tipo, el alcance y la ubicación temporal de los eventos de variación del ancho de banda. El sistema propuesto permite realizar mediciones de rendimiento de forma automatizada y sistemática para la evaluación de los sistemas DASH en el servicio de distribución de vídeo 2D y 3D. Se ha utilizado Puppeteer, la librería Node.js desarrollada por Google, que proporciona una API de alto nivel, para automatizar acciones en el protocolo Chrome Devtools, como iniciar la reproducción, provocar cambios de ancho de banda y guardar los resultados de los procesos de cambio de calidad, marcas de tiempo, paradas, etc. A partir de estos datos, se realiza un procesamiento que permite la reconstrucción del vídeo visualizado, así como la extracción de métricas de calidad y la evaluación de la QoE de los usuarios utilizando la recomendación ITU-T P.1203. / [CA] La distribució de continguts multimèdia, i en particular el streaming de vídeo, domina actualment el trànsit global d'Internet i la seua importància serà fins i tot mes gran en el futur. Milers de títols s'afegeixen mensualment als principals proveïdors de serveis, com ara Netflix, YouTube i Amazon. I de la mà del consum de continguts d'alta definició que es converteix en la tendència principal, es pot observar novament un increment en el consum de continguts 3D. Això ha fet que les temàtiques relacionades amb la producció de continguts, codificació, transmissió, Qualitat de Servei (QoS) i Qualitat d'Experiència (QoE) percebudes pels usuaris dels sistemes de distribució de vídeo 3D siguen un tema de recerca amb nombroses contribucions en els últims anys. Aquesta tesi aborda el problema de la prestació de serveis de transmissió de vídeo 3D sota condicions de xarxa d'ample de banda variable. En aquest sentit, presenta els resultats de l'avaluació de la QoE percebuda pels usuaris dels sistemes de vídeo 3D, analitzant principalment l'impacte dels efectes introduïts en dos dels elements de la cadena de processament de vídeo 3D: l'etapa de codificació i el procés de transmissió. Per analitzar els efectes de la codificació en la qualitat del vídeo 3D, a la primera etapa s'aborda l'avaluació objectiva i subjectiva de la qualitat del vídeo, comparant el rendiment de diferents estàndards i mètodes de codificació, per tal d'identificar aquells que aconsegueixen la millor relació entre qualitat, taxa de bits i temps de codificació. Així mateix, en el context de la transmissió en un entorn simulcast, s'avalua l'eficàcia de la utilització de les codificacions asimètriques per la transmissió de vídeo 3D, com una alternativa per la reducció de l'ampleada de banda mantenint la qualitat global. En segon lloc, per a l'estudi de l'impacte i el rendiment del procés de transmissió, s'ha treballat sobre la base d'un sistema de transmissió dinàmica adaptativa sobre HTTP (DASH) en el context de la transmissió de vídeo tant 2D com 3D, utilitzant diferents escenaris de variació d'ample de banda. L'objectiu ha estat el desenvolupament d'un marc de referència per a l'avaluació de la QoE en escenaris de transmissió adaptativa de vídeo 3D, que permet analitzar l'impacte en la QoE de l'usuari davant de diferents patrons de variació de l'ample de banda; així com el rendiment de l'algorisme d'adaptació davant d'aquests escenaris. El treball s'enfoca a identificar l'impacte a la Qualitat d'Experiència de l'usuari que tenen aspectes com ara: la freqüència, el tipus, l'abast i la ubicació temporal dels esdeveniments de variació de l'ample de banda. El sistema proposat permet realitzar mesuraments de rendiment de manera automatitzada i sistemàtica per a l'avaluació dels sistemes DASH en el servei de distribució de vídeo 2D i 3D. S'ha utilitzat Puppeteer, la llibreria Node.js desenvolupada per Google, que proporciona una API d'alt nivell, per automatitzar accions al protocol Chrome Devtools, com iniciar la reproducció, provocar canvis d'ample de banda i desar els resultats dels processos de canvi de qualitat, marques de temps, parades, etc. A partir d'aquestes dades, es fa un processament que permet la reconstrucció del vídeo visualitzat, així com l'extracció de mètriques de qualitat i l'avaluació de la QoE dels usuaris fent servir la recomanació ITU-T P.1203. / [EN] The distribution of multimedia content, and in particular video streaming, currently dominates global Internet traffic and will become even more important in the future. Thousands of titles are added monthly to major service providers such as Netflix, YouTube and Amazon. In addition to the consumption of high-definition content becoming the main trend, an increase in the consumption of 3D content can be observed again. This fact has caused that issues related to content production, encoding, transmission, Quality of Service (QoS) and Quality of Experience (QoE) perceived by users of 3D video distribution systems became a research topic with numerous contributions in recent years. This thesis addresses the problem of providing 3D video streaming services under variable bandwidth network conditions. In this sense, it presents the results of the evaluation of the QoE perceived by the users of 3D video systems, analyzing mainly the impact of the effects introduced in two of the elements of the 3D video processing chain: the encoding stage and the transmission process. To analyze the effects of the encoding process on the quality of 3D video, the first stage deals with the objective and subjective evaluation of video quality, comparing the performance of different encoding standards and methods, in order to identify those that achieve the best ratio between quality, bit rate and encoding time. Also, in the context of transmission in a simulcast environment, the advantages of using asymmetric coding for 3D video transmission is evaluated as an alternative for bandwidth reduction while maintaining overall quality. Secondly, for the study of the impact and performance of the transmission process, the work has been carried out on the basis of an adaptive dynamic over HTTP (DASH) transmission system in the context of both 2D and 3D video transmission, using different bandwidth variation scenarios. The aim has been to develop a framework for the evaluation of QoE in 3D adaptive video streaming scenarios, which allows analyzing the impact on the user's QoE against different bandwidth variation patterns, as well as the performance of the adaptation algorithm under these scenarios. The work focuses on identifying the impact on the user's Quality of Experience in aspects such as: frequency, type, range and temporal location of bandwidth variation events. The proposed system allows to perform performance measurements in an automated and systematic way for the evaluation of DASH systems in the 2D and 3D video distribution service. The tool Puppeteer, the Node.js library developed by Google, has been used, which provides a high-level API to automate actions in the Chrome Devtools protocol, such as starting playback, causing bandwidth changes and saving the results of the quality change processes, timestamps, stops, etc. From this data, a further processing is performed that allows the reconstruction of the displayed video, as well as the extraction of quality metrics and the evaluation of the QoE of the users using the ITU-T P.1203 recommendation. / Guzmán Castillo, PF. (2022). Evaluación de la QoE en un sistema de streaming adaptativo de vídeo 3D basado en DASH [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/186354 / TESIS
117

A IPTV como modalidade de educação: um estudo de caso no ensino de engenharia. / IPTV how modality education: a case study in engineering education.

Marcos Jolbert Cáceres Azambuja 17 December 2013 (has links)
A modalidade de Educação a Distância (EAD) ocupa atualmente um lugar importante no desenvolvimento e expansão da Educação no Brasil. A EAD a partir de novas tecnologias, teve um grande impulso, principalmente aquela que envolve a rede Internet. O uso das tecnologias digitais em espaços educativos permitiu que a comunicação, interação, armazenamento e distribuição de conteúdos para o processo educativo, fossem realizados de maneira mais eficiente. Em meio à diversidade de mídias e tecnologias na atualidade, a IPTV surge como uma nova proposta, um veículo de comunicação interativo que possibilita novas perspectivas para a modalidade de EAD. Neste contexto, a IPTV torna-se fundamental, pois possibilita através de seu alto índice de interatividade e qualidade na entrega de conteúdos síncronos e assíncronos oferecer uma gama cada vez maior de opções para seus usuários. O presente trabalho tem como objetivo apresentar elementos visando o uso da IPTV como modalidade de Educação no sistema a distância, para a entrega de conteúdos no Ensino de Engenharia, buscando reduzir as distâncias no processo de ensino-aprendizagem. Dessa forma, são apresentados os benefícios da integração da IPTV e a Educação em Engenharia, dentro de uma estratégia de Educação a Distância na IPTV. / Distance Education (DE) plays an important role nowadays on the development and expansion of education in Brazil. Due to new technologies, DE had a great propulsion, mainly on those which involve the Internet. The use of digital technologies in educational spaces allowed that communication, interaction, storage and distribution of content became more efficient. In between the diversity of medias and technologies, IPTV arises as a new proposal; an interactive communication tool which enables new perspectives for DE. In this context, IPTV is paramount, since its high rates of interaction and synchronous and asynchronous content delivery quality enables a great range of options for its users. This work aims at presenting elements of IPTV use as a modality of DE in the content delivering for Engineering Teaching and Learning, focusing the reduction of distances in the teaching and learning process. Thus, it is presented benefits of the integration between IPTV and Engineering Education through a strategy of DE in IPTV.
118

Impactos da varia??o de aplica??es e de hardware local na vaz?o de redes de computadores com virtualiza??o de desktops

Oliveira, Vitor Chaves de 10 December 2012 (has links)
Made available in DSpace on 2016-04-04T18:31:36Z (GMT). No. of bitstreams: 1 Vitor Chaves de Oliveira.pdf: 1928054 bytes, checksum: 49bf6198a68438069d6ef8b9a2ec77e9 (MD5) Previous issue date: 2012-12-10 / In recent years, virtualization computing has become a worldwide reality present in datacenters servers of most organizations. The motivations for the use of this solution are focused primarily on cost reduction and increases in availability, integrity and security of data. Based on these benefits, recently it was started the use of this technology for personal computers as well. That is, for desktops, giving birth to the so-called desktop virtualization. Given the technical advantages of the approach, its growth has been so significant that, before 2014, it is expected to be present in over 90% of organizations. However, this new method is completely based on a physical client-server architecture, which increases the importance of the communication network that makes this technique possible. Therefore, analyzing the network in order to investigate the effects according to the environment implemented, becomes crucial. In this work it s varied the local s client hardware and the application, i.e. the service used. The purpose was to detail their effects on computer networks in a Quality of Service (QoS) parameter, throughput. Secondarily are outlined perceptions regarding the Quality of Experience (QoE). / Nos ?ltimos anos, a virtualiza??o computacional se tornou uma realidade nos servidores presentes nos data-centers da maioria das organiza??es no mundo. As motiva??es para o emprego desta solu??o est?o centradas, primordialmente, na redu??o de custos e em aumentos na disponibilidade, na integridade e na seguran?a dos dados. Com base nestes benef?cios, recentemente, se come?ou a aproveitar esta tecnologia tamb?m para os computadores pessoais. Isto ?, para os desktops, dando origem a chamada virtualiza??o de desktop. Dadas as vantagen t?cnicas da abordagem, seu crescimento tem sido t?o expressivo que, antes de 2014, se espera que ela esteja presente em mais de 90% das organiza??es. Todavia, este m?todo ? totalmente baseado em uma arquitetura cliente-servidor f?sica, o que aumenta a import?ncia da rede de comunica??o que torna a t?cnica poss?vel. Logo, analisar a rede, a fim de investigar os impactos de acordo com o ambiente implementado, se torna fundamental. Neste trabalho variamos o hardware local do cliente e a aplica??o, isto ?, o servi?o utilizado. A finalidade foi a de detalhar seus efeitos, em redes de computadores, em um par?metro de Qualidade de Servi?o (QoS), a vaz?o. Secundariamente s?o esbo?adas percep??es de Qualidade da Experi?ncia (QoE).
119

A IPTV como modalidade de educação: um estudo de caso no ensino de engenharia. / IPTV how modality education: a case study in engineering education.

Azambuja, Marcos Jolbert Cáceres 17 December 2013 (has links)
A modalidade de Educação a Distância (EAD) ocupa atualmente um lugar importante no desenvolvimento e expansão da Educação no Brasil. A EAD a partir de novas tecnologias, teve um grande impulso, principalmente aquela que envolve a rede Internet. O uso das tecnologias digitais em espaços educativos permitiu que a comunicação, interação, armazenamento e distribuição de conteúdos para o processo educativo, fossem realizados de maneira mais eficiente. Em meio à diversidade de mídias e tecnologias na atualidade, a IPTV surge como uma nova proposta, um veículo de comunicação interativo que possibilita novas perspectivas para a modalidade de EAD. Neste contexto, a IPTV torna-se fundamental, pois possibilita através de seu alto índice de interatividade e qualidade na entrega de conteúdos síncronos e assíncronos oferecer uma gama cada vez maior de opções para seus usuários. O presente trabalho tem como objetivo apresentar elementos visando o uso da IPTV como modalidade de Educação no sistema a distância, para a entrega de conteúdos no Ensino de Engenharia, buscando reduzir as distâncias no processo de ensino-aprendizagem. Dessa forma, são apresentados os benefícios da integração da IPTV e a Educação em Engenharia, dentro de uma estratégia de Educação a Distância na IPTV. / Distance Education (DE) plays an important role nowadays on the development and expansion of education in Brazil. Due to new technologies, DE had a great propulsion, mainly on those which involve the Internet. The use of digital technologies in educational spaces allowed that communication, interaction, storage and distribution of content became more efficient. In between the diversity of medias and technologies, IPTV arises as a new proposal; an interactive communication tool which enables new perspectives for DE. In this context, IPTV is paramount, since its high rates of interaction and synchronous and asynchronous content delivery quality enables a great range of options for its users. This work aims at presenting elements of IPTV use as a modality of DE in the content delivering for Engineering Teaching and Learning, focusing the reduction of distances in the teaching and learning process. Thus, it is presented benefits of the integration between IPTV and Engineering Education through a strategy of DE in IPTV.
120

Gerenciamento de mobilidade transparente com suporte integrado a QoS/QoE em redes heterogêneas

SILVA JUNIOR, Reinaldo Boulhosa Ramos da 29 February 2012 (has links)
Submitted by Samira Prince (prince@ufpa.br) on 2012-09-25T13:49:05Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_GerenciamentoMobilidadeTransparente.pdf: 1960227 bytes, checksum: cdee7a38877b77966f5d08c6b0818cbb (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2012-09-28T13:58:08Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_GerenciamentoMobilidadeTransparente.pdf: 1960227 bytes, checksum: cdee7a38877b77966f5d08c6b0818cbb (MD5) / Made available in DSpace on 2012-09-28T13:58:08Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_GerenciamentoMobilidadeTransparente.pdf: 1960227 bytes, checksum: cdee7a38877b77966f5d08c6b0818cbb (MD5) Previous issue date: 2012-03 / Os avanços nas tecnologias de comunicação sem fio, a demanda por novas aplicações multimídia em tempo real, com requisitos de Qualidade de Serviço (QoS) e Qualidade de Experiência (QoE), e a proliferação de equipamentos móveis, originam o surgimento de soluções que permitem mobilidades horizontais e verticais em redes heterogêneas, de modo transparente. Esses dispositivos móveis apresentam múltiplas interfaces sem fio, onde os usuários se conectam para realizar tarefas e serviços variados no seu dia a dia, mediante a tecnologia de redes diferentes, proporcionando um cenário heterogêneo com diversas oportunidades de conectividade para os usuários móveis. Visando solucionar o problema de várias conexões, feitas por usuários móveis, em uma mesma rede Wi-Fi (Wireless Fidelity) e/ou WiMAX (Worldwide Interoperability for Microwave Access) com diferentes serviços executados, porém, utilizando incorretamente a rede, esta dissertação propõe uma técnica hierárquica de decisão de mobilidade transparente, baseada em uma função de custo, no padrão IEEE 802.21 e no mapeamento de classes de serviço para garantir QoS/QoE para usuários em períodos de mobilidade chamada de MIH2Q, onde essa política informa a melhor rede para ser utilizada, de acordo com o serviço utilizado pelo usuário móvel. A avaliação do impacto e os benefícios da proposta são feitas através de simulação no NS-2 (Network Simulator - version 2) e no evalvid, utilizando métricas de QoS e QoE para verificação dos resultados. / Advances in wireless communications technology, and the demands for new real-time multimedia applications that meet the Quality of Service (QoS) and Quality of Experience (QoE) requirements, together with the proliferation of mobile equipment, have given rise to new solutions that allow horizontal and vertical mobility in transparent heterogeneous networks. These mobile devices have multiple wireless interfaces where the users are connected so that they can carry out several tasks and services on a daily basis through the technology of different networks that allow a heterogeneous scenario with a wide range of connectivity opportunities for the mobile users. This dissertation sets out a fast decision hierarchical technique for transparent mobility based on cost function in the IEEE 802.21 Standard and class-of-service mapping, to ensure QoS/QoE for the users in periods of mobility called M1H2Q, during which this policy gives information about the best network that can be used for the service employed by the mobile user. It seeks to overcome the problem of having several connections being made by mobile users on the same Wireless Fidelity (wi-fi) network and/or WiMAX (Worldwide Interoperability for Microwave Access) with different services being executed, even though the network is not used correctly. The effects and benefits of the scheme were assessed through NS-2 simulation (Network Simulator- Version 2) and Evalvid, and the QoS and QoE metrics were used to check the results.

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