Design of an adaptive-rate video-streaming service with different classes of users

The provision of end-to-end Quality of Service (QoS) for multimedia services over IP-based networks is already an open issue. To achieve this goal, service providers need to manage Service Level Agreements (SLAs), which specify parameters of the services operation such as availability and performance. Additional mechanisms are needed to quantitatively evaluate the user-level SLA parameters. This work is focused on the evaluation and assessment of different design options of an adaptive VoD service providing several classes of users and fulfilling the SLA commitments. Based on a straightforward Markov Chain, Markov-Reward Chain (MRC) models are developed in order to obtain various QoS measures of the adaptive VoD service. The MRC model has a clear understanding with the design and operation of the VoD system.5th IFIP International Conference on Network Control & Engineering for QoS, Security and MobilityRed de Universidades con Carreras en Informática (RedUNCI

Design of an adaptive-rate video-streaming service with different classes of users

The provision of end-to-end Quality of Service (QoS) for multimedia services over IP-based networks is already an open issue. To achieve this goal, service providers need to manage Service Level Agreements (SLAs), which specify parameters of the services operation such as availability and performance. Additional mechanisms are needed to quantitatively evaluate the user-level SLA parameters. This work is focused on the evaluation and assessment of different design options of an adaptive VoD service providing several classes of users and fulfilling the SLA commitments. Based on a straightforward Markov Chain, Markov-Reward Chain (MRC) models are developed in order to obtain various QoS measures of the adaptive VoD service. The MRC model has a clear understanding with the design and operation of the VoD system.5th IFIP International Conference on Network Control & Engineering for QoS, Security and MobilityRed de Universidades con Carreras en Informática (RedUNCI

Design of an adaptive-rate video-streaming service with different classes of users

The provision of end-to-end Quality of Service (QoS) for multimedia services over IP-based networks is already an open issue. To achieve this goal, service providers need to manage Service Level Agreements (SLAs), which specify parameters of the services operation such as availability and performance. Additional mechanisms are needed to quantitatively evaluate the user-level SLA parameters. This work is focused on the evaluation and assessment of different design options of an adaptive VoD service providing several classes of users and fulfilling the SLA commitments. Based on a straightforward Markov Chain, Markov-Reward Chain (MRC) models are developed in order to obtain various QoS measures of the adaptive VoD service. The MRC model has a clear understanding with the design and operation of the VoD system.5th IFIP International Conference on Network Control & Engineering for QoS, Security and MobilityRed de Universidades con Carreras en Informática (RedUNCI

An adaptive algorithm for Internet multimedia delivery in a DiffServ environment.

To meet the Quality of Service (QoS) requirements of multimedia applications and to reduce the network congestion, several service models and mechanisms have been proposed. Among these, Differentiated Service (DiffServ) architecture has been considered as a scalable and flexible QoS architecture for the Internet. DiffServ provides class-based QoS guarantees. Applications in different classes receive different QoS and are priced differently. If network congestion occurs, DiffServ may not be able to guarantee the QoS for the application. Thus, the QoS may not reflect the price paid for the service. A problem of considerable economic and research importance is how to achieve a good price and quality tradeoff even at times of congestion. This thesis presents an Adaptive Class Switching Algorithm (ACSA) which intends to provide good quality with good price for real-time multimedia applications in a DiffServ environment. The ACSA algorithm combines the techniques of Real-time Transport Protocol (RTP), DiffServ, and Adaptation together. It also takes both QoS and price into account to provide users a good QoS with a good price. The algorithm dynamically selects the most suitable class based on both the QoS feedback received and the highest user utility. The user utility is a function of quality, price, and the weight which reflects the relative sensitivity to quality and price. The class with the highest user utility is the class that provides the best quality and price tradeoff. The QoS feedback is conveyed by RTP\u27s Control Protocol (RTCP) Receiver Reports. The results of simulation demonstrate that ACSA can react fast to the current class state in the network and reflects the best QoS and price tradeoff. It always seeks to find a class which provides the highest user utility except when the Internet is congested and the required QoS in all classes can not be satisfied. If this happens, the real-time multimedia flow chooses Best-Effort class with no payment. (Abstract shortened by UMI.) Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .F46. Source: Masters Abstracts International, Volume: 44-01, page: 0389. Thesis (M.Sc.)--University of Windsor (Canada), 2005

Modelo para previsão da qualidade de experiência na transmissão de vídeo sobre IP

Resumo: A demanda por conteúdo de vídeo tem apresentado um crescimento significativo nesta década. Paralelamente a este aumento de demanda há o desafio em se atender à qualidade de experiência (QoE) esperada pelo usuário e ao mesmo tempo realizar o provisionamento otimizado de recursos da rede. Nesta dissertação propõe-se um modelo para previsão da QoE em função do nível de utilização do canal e do número de fluxos agregados de vídeos. O estudo mostra como a latência, o tamanho do GoP (Group of Pictures), a compactação espacial e o padrão de movimento do vídeo afetam a QoE e como estes fatores são representados pelo modelo proposto. Uma das principais aplicações previstas para o modelo é no controle de admissão de novos fluxos na rede. Os modelos de previsões que geram uma boa estimativa de QoE baseado em parâmetros de rede são essenciais para que os administradores de rede possam realizar o dimensionamento de recursos sobre os efeitos da variação dos vários fatores na QoE. O método utilizado para obter o modelo foi através de simulações de transmissão de vídeos em uma topologia dumbbell, com níveis de agregação variáveis, configuração de um modelo de perda de Gilbert-Elliott e latência reproduzindo as condições de perda de uma rede de acesso do tipo ADSL (Asymmetric Digital Subscriber Line) típica. O modelo foi parametrizado a partir da transmissão simulada de vídeos disponíveis publicamente e codificados no padrão MPEG-4 (Moving Pictures Experts Group). Para realizar a avaliação da qualidade utilizou-se o PSNR (Peak signal-to-noise ratio) com o objetivo de avaliar os efeitos a degradação relativa da QoE em diversas situações. A análise da degradação observada da qualidade nas várias situações simuladas permitiu realizar a modelagem desta variável em função do nível de utilização e do número de fluxos agregados para diversos cenários. O modelo utiliza dois parâmetros, nomeados como parâmetro de localização e de forma. É também apresentado um estudo sobre os efeitos da variação do grau de compactação espacial, do tamanho do GoP, do padrão de movimento do vídeo de referência e da latência no gargalo da rede. Os resultados indicam que o modelo proposto pode prever adequadamente os efeitos da variação de diversos parâmetros na qualidade de experiência e pode ser aplicado para soluções em controle de admissão, na análise de desempenho de sistemas de transmissão e simulações de sistemas multimídia