187 research outputs found
Smart PIN: utility-based replication and delivery of multimedia content to mobile users in wireless networks
Next generation wireless networks rely on heterogeneous connectivity technologies to support various rich media services such as personal information storage, file sharing and multimedia streaming. Due to users’ mobility and dynamic characteristics of wireless networks, data availability in collaborating devices is a critical issue. In this context Smart PIN was proposed as a personal information network which focuses on performance of delivery and cost efficiency. Smart PIN uses a novel data replication scheme based on individual and overall system utility to best balance the requirements for static data and multimedia content delivery with variable device availability due to user mobility. Simulations show improved results in comparison with other general purpose data replication schemes in terms of data availability
Cooperative announcement-based caching for video-on-demand streaming
Recently, video-on-demand (VoD) streaming services like Netflix and Hulu have gained a lot of popularity. This has led to a strong increase in bandwidth capacity requirements in the network. To reduce this network load, the design of appropriate caching strategies is of utmost importance. Based on the fact that, typically, a video stream is temporally segmented into smaller chunks that can be accessed and decoded independently, cache replacement strategies have been developed that take advantage of this temporal structure in the video. In this paper, two caching strategies are proposed that additionally take advantage of the phenomenon of binge watching, where users stream multiple consecutive episodes of the same series, reported by recent user behavior studies to become the everyday behavior. Taking into account this information allows us to predict future segment requests, even before the video playout has started. Two strategies are proposed, both with a different level of coordination between the caches in the network. Using a VoD request trace based on binge watching user characteristics, the presented algorithms have been thoroughly evaluated in multiple network topologies with different characteristics, showing their general applicability. It was shown that in a realistic scenario, the proposed election-based caching strategy can outperform the state-of-the-art by 20% in terms of cache hit ratio while using 4% less network bandwidth
Mathematical analysis of scheduling policies in peer-to-peer video streaming networks
Las redes de pares son comunidades virtuales autogestionadas, desarrolladas en la capa de aplicación sobre la infraestructura de Internet, donde los usuarios (denominados pares) comparten recursos (ancho de banda, memoria, procesamiento) para alcanzar un fin común. La distribución de video representa la aplicación más desafiante, dadas las limitaciones de ancho de banda. Existen básicamente tres servicios de video. El más simple es la descarga, donde un conjunto de servidores posee el contenido original, y los usuarios deben descargar completamente este contenido previo a su reproducción. Un segundo servicio se denomina video bajo demanda, donde los pares se unen a una red virtual siempre que inicien una solicitud de un contenido de video, e inician una descarga progresiva en línea. El último servicio es video en vivo, donde el contenido de video es generado, distribuido y visualizado simultáneamente. En esta tesis se estudian aspectos de diseño para la distribución de video en vivo y bajo demanda. Se presenta un análisis matemático de estabilidad y capacidad de arquitecturas de distribución bajo demanda híbridas, asistidas por pares. Los pares inician descargas concurrentes de múltiples contenidos, y se desconectan cuando lo desean. Se predice la evolución esperada del sistema asumiendo proceso Poisson de arribos y egresos exponenciales, mediante un modelo determinístico de fluidos. Un sub-modelo de descargas secuenciales (no simultáneas) es globalmente y estructuralmente estable, independientemente de los parámetros de la red. Mediante la Ley de Little se determina el tiempo medio de residencia de usuarios en un sistema bajo demanda secuencial estacionario. Se demuestra teóricamente que la filosofía híbrida de cooperación entre pares siempre desempeña mejor que la tecnología pura basada en cliente-servidor
Decentralized Adaptive Helper Selection in Multi-channel P2P Streaming Systems
In Peer-to-Peer (P2P) multichannel live streaming, helper peers with surplus
bandwidth resources act as micro-servers to compensate the server deficiencies
in balancing the resources between different channel overlays. With deployment
of helper level between server and peers, optimizing the user/helper topology
becomes a challenging task since applying well-known reciprocity-based choking
algorithms is impossible due to the one-directional nature of video streaming
from helpers to users. Because of selfish behavior of peers and lack of central
authority among them, selection of helpers requires coordination. In this
paper, we design a distributed online helper selection mechanism which is
adaptable to supply and demand pattern of various video channels. Our solution
for strategic peers' exploitation from the shared resources of helpers is to
guarantee the convergence to correlated equilibria (CE) among the helper
selection strategies. Online convergence to the set of CE is achieved through
the regret-tracking algorithm which tracks the equilibrium in the presence of
stochastic dynamics of helpers' bandwidth. The resulting CE can help us select
proper cooperation policies. Simulation results demonstrate that our algorithm
achieves good convergence, load distribution on helpers and sustainable
streaming rates for peers
A Video On Demand System Architecture For Heterogeneous Mobile Ad Hoc Networks For Different Devices.
this paper proposed new system architecture for Mobile
Ad Hoc Networks (MANETs) on heterogeneous network to provide
optimal Video on Demand (VoD) services to difference types of
devices with optimal bandwidth utilization
Video streaming with quality adaption using collaborative active grid networks
Due to the services and demands of the end
users, Distributed Computing (Grid Technology,
Web Services, and Peer-to-Peer) has been
developedrapidJy in thelastyears. Theconvergence
of these architectures has been possible using
mechanisms such as Collaborative work and
Resources Sharing. Grid computing is a platform to
enable flexible, secure, controlled, scalable,
ubiquitous and heterogeneous services. On the
other hand, Video Streaming applications demand
a greater deployment over connected Internet users.
The present work uses the Acti ve Grid technology
as a fundamental platform to give a solution of
multimediacontentrecovery. This solution takes
into account the following key concepts:
collaborative work, multi-source recovery and
adapti ve quality. A new archi tecture is designed to
deliver video content over a Grid Network. The
acti ve and passi ve roles of the nodes are important
to guarantee a high quality and efficiency for the
video streaming system. The acti ve sender nodes
are the content suppliers, while the passive sender
nodes wiU perform the backup functions, based on
global resource control policies. The aim of the
backup node is minirnize the time to restore the
systemin caseoffailures. In this way, all participant
peers work in a collaborati ve manner following a
mul ti -source recovery scheme.
Furthermore, Video La yered Encoding is used
to manage the video data in a high scalable way,
di viding the video in multiple layers. This video
codification scheme enables thequality adaptation
according to the availability of system resources. In
addition, a buffer by sender peer and by layer is
needed for an effecti ve control ofthe video retrieve.
The QoS will fit considering the state of each buffer
and the measurement tools provide by the Acti ve
Grid on the network nodes. Ke ywords: Peer -to-Peer Grid Architecture,
Services for Active Grids, Streaming Media,
Layered Coding, Quality Adaptation, CoUaborative
Work.Peer Reviewe
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