Performance model of interactive video-on-demand systems

An interactive video-on-demand (VoD) system allows users to access video services, such as movies, electronic encyclopedia, interactive games, and educational videos from video servers on a broadband network. This paper develops a performance evaluation tool for the system design. In particular, a user activity model is developed to describe the usage of system resources, i.e., network bandwidth and video server usage, by a user as it interacts with the service. In addition, we allow batching of user requests, and the effect of such batching is captured in a batching model. Our proposed queueing model integrates both the user activity and the batching model. This model can be used to determine the requirements of network bandwidth and video server and, hence, the trade-off in communication and storage costs for different system resource configurations.published_or_final_versio

Projetos de redes para suporte de aplicações de video distribuido

Orientador: Nelson Luis Saldanha da FonsecaDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: As aplicações de vídeo apresentam grande potencial de sucesso comercial na futura Rede Digital de Serviços Integrados de Faixa Larga (RDSI-FL). Estas aplicações serão também as maiores consumidoras de banda passante neste novo ambiente. Sendo assim, a compreensão dos requisitos para se prover serviços de vídeo é de suma importância para o projeto eficiente da rede. Esta dissertação estuda Distributed Home Theatre (DHT), um serviço de vídeo que permite que usuários geograficamente dispersos discutam um filme. Investiga-se aqui o compromisso existente entre a redução da banda passante e a replicação de repositórios de vídeo no projeto de redes para o fornecimento de serviços de DHT. São propostas funções de custo que permitem a avaliação deste compromisso utilizando-se de valores reais. Vários cenários são analisados: Redes sem compartilhamento de fluxo, Redes com compartilhamento de fluxo, Redes com servidores distribuídos e Redes com servidores distribuídos e compartilhamento de fluxo. Técnicas de replicação de cache/ servidor são investigadas e avaliadas frente a parâmetros tais como a distribuição dos usuários e o número de usuários por sessão DHT. A análise é estendida para incluir redes com serviços de Vídeo sob Demanda e Distributed Home Theatre.Abstract: Video services are both a major business driver and a bandwidth consumer for the future broadband integrated network (B-ISDN). Understanding different video services requirements is of paramount importance for network design. In this dissertation we study Distributed Home Theatre (DHT), a video service which allows distributed users to debate a film. We investigate the tradeoff between bandwidth reduction and program replication in the network design for the provision of the DHT services. We propose a framework to analize this tradeoff for real costs. We analize different network scenarios: networks without stream sharing, networks with stream sharing, networks with distributed servers and networks with distributed servers and stream sharing. Serverlcache replication techniques are investigated and evaluated under different user distribution and different number of users per DHT session. Moreover, we analyze networks with both DHT and video on demand services.MestradoMestre em Ciência da Computaçã

Efficient Techniques for Management and Delivery of Video Data

The rapid advances in electronic imaging, storage, data compression telecommunications, and networking technology have resulted in a vast creation and use of digital videos in many important applications such as digital libraries, distance learning, public information systems, electronic commerce, movie on demand, etc. This brings about the need for management as well as delivery of video data. Organizing and managing video data, however, is much more complex than managing conventional text data due to their semantically rich and unstructured contents. Also, the enormous size of video files requires high communication bandwidth for data delivery. In this dissertation, I present the following techniques for video data management and delivery. Decomposing video into meaningful pieces (i.e., shots) is a very fundamental step to handling the complicated contents of video data. Content-based video parsing techniques are presented and analyzed. In order to reduce the computation cost substantially, a non-sequential approach to shot boundary detection is investigated. Efficient browsing and indexing of video data are essential for video data management. Non-linear browsing and cost-effective indexing schemes for video data based on their contents are described and evaluated. In order to satisfy various user requests, delivering long videos through the limited capacity of bandwidth is challenging work. To reduce the demand on this bandwidth, a hybrid of two effective approaches, periodic broadcast and scheduled multicast, is discussed and simulated. The current techniques related to the above works are discussed thoroughly to explain their advantages and disadvantages, and to make the new improved schemes. The substantial amount of experiments and simulations as well as the concepts are provided to compare the introduced techniques with the other existing ones. The results indicate that they outperform recent techniques by a significant margin. I conclude the dissertation with a discussing of future research directions