11,331 research outputs found
A credit-based approach to scalable video transmission over a peer-to-peer social network
PhDThe objective of the research work presented in this thesis is to study
scalable video transmission over peer-to-peer networks. In particular,
we analyse how a credit-based approach and exploitation of social networking
features can play a significant role in the design of such systems.
Peer-to-peer systems are nowadays a valid alternative to the traditional
client-server architecture for the distribution of multimedia content, as
they transfer the workload from the service provider to the final user,
with a subsequent reduction of management costs for the former. On
the other hand, scalable video coding helps in dealing with network
heterogeneity, since the content can be tailored to the characteristics
or resources of the peers. First of all, we present a study that evaluates
subjective video quality perceived by the final user under different
transmission scenarios. We also propose a video chunk selection algorithm
that maximises received video quality under different network
conditions. Furthermore, challenges in building reliable peer-to-peer
systems for multimedia streaming include optimisation of resource allocation
and design mechanisms based on rewards and punishments that
provide incentives for users to share their own resources. Our solution
relies on a credit-based architecture, where peers do not interact with
users that have proven to be malicious in the past. Finally, if peers
are allowed to build a social network of trusted users, they can share
the local information they have about the network and have a more
complete understanding of the type of users they are interacting with.
Therefore, in addition to a local credit, a social credit or social reputation
is introduced. This thesis concludes with an overview of future
developments of this research work
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
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
Recommended from our members
Multimedia delivery in the future internet
The term “Networked Media” implies that all kinds of media including text, image, 3D graphics, audio
and video are produced, distributed, shared, managed and consumed on-line through various networks,
like the Internet, Fiber, WiFi, WiMAX, GPRS, 3G and so on, in a convergent manner [1]. This white
paper is the contribution of the Media Delivery Platform (MDP) cluster and aims to cover the Networked
challenges of the Networked Media in the transition to the Future of the Internet.
Internet has evolved and changed the way we work and live. End users of the Internet have been confronted
with a bewildering range of media, services and applications and of technological innovations concerning
media formats, wireless networks, terminal types and capabilities. And there is little evidence that the pace
of this innovation is slowing. Today, over one billion of users access the Internet on regular basis, more
than 100 million users have downloaded at least one (multi)media file and over 47 millions of them do so
regularly, searching in more than 160 Exabytes1 of content. In the near future these numbers are expected
to exponentially rise. It is expected that the Internet content will be increased by at least a factor of 6, rising
to more than 990 Exabytes before 2012, fuelled mainly by the users themselves. Moreover, it is envisaged
that in a near- to mid-term future, the Internet will provide the means to share and distribute (new)
multimedia content and services with superior quality and striking flexibility, in a trusted and personalized
way, improving citizens’ quality of life, working conditions, edutainment and safety.
In this evolving environment, new transport protocols, new multimedia encoding schemes, cross-layer inthe
network adaptation, machine-to-machine communication (including RFIDs), rich 3D content as well as
community networks and the use of peer-to-peer (P2P) overlays are expected to generate new models of
interaction and cooperation, and be able to support enhanced perceived quality-of-experience (PQoE) and
innovative applications “on the move”, like virtual collaboration environments, personalised services/
media, virtual sport groups, on-line gaming, edutainment. In this context, the interaction with content
combined with interactive/multimedia search capabilities across distributed repositories, opportunistic P2P
networks and the dynamic adaptation to the characteristics of diverse mobile terminals are expected to
contribute towards such a vision.
Based on work that has taken place in a number of EC co-funded projects, in Framework Program 6 (FP6)
and Framework Program 7 (FP7), a group of experts and technology visionaries have voluntarily
contributed in this white paper aiming to describe the status, the state-of-the art, the challenges and the way
ahead in the area of Content Aware media delivery platforms
Modeling and Evaluation of Multisource Streaming Strategies in P2P VoD Systems
In recent years, multimedia content distribution has largely been moved to the Internet, inducing broadcasters, operators and service providers to upgrade with large expenses their infrastructures. In this context, streaming solutions that rely on user devices such as set-top boxes (STBs) to offload dedicated streaming servers are particularly appropriate. In these systems, contents are usually replicated and scattered over the network established by STBs placed at users' home, and the video-on-demand (VoD) service is provisioned through streaming sessions established among neighboring STBs following a Peer-to-Peer fashion. Up to now the majority of research works have focused on the design and optimization of content replicas mechanisms to minimize server costs. The optimization of replicas mechanisms has been typically performed either considering very crude system performance indicators or analyzing asymptotic behavior. In this work, instead, we propose an analytical model that complements previous works providing fairly accurate predictions of system performance (i.e., blocking probability). Our model turns out to be a highly scalable, flexible, and extensible tool that may be helpful both for designers and developers to efficiently predict the effect of system design choices in large scale STB-VoD system
Advanced solutions for quality-oriented multimedia broadcasting
Multimedia content is increasingly being delivered via different types of networks to viewers in a variety of locations and contexts using a variety of devices. The ubiquitous nature of multimedia services comes at a cost, however. The successful delivery of multimedia services will require overcoming numerous technological challenges many of which have a direct effect on the quality of the multimedia experience. For example, due to dynamically changing requirements and networking conditions, the delivery of multimedia content has traditionally adopted a best effort approach. However, this approach has often led to the end-user perceived quality of multimedia-based services being negatively affected. Yet the quality of multimedia content is a vital issue for the continued acceptance and proliferation of these services. Indeed, end-users are becoming increasingly quality-aware in their expectations of multimedia experience and demand an ever-widening spectrum of rich multimedia-based services. As a consequence, there is a continuous and extensive research effort, by both industry and academia, to find solutions for improving the quality of multimedia content delivered to the users; as well, international standards bodies, such as the International Telecommunication Union (ITU), are renewing their effort on the standardization of multimedia technologies. There are very different directions in which research has attempted to find solutions in order to improve the quality of the rich media content delivered over various network types. It is in this context that this special issue on broadcast multimedia quality of the IEEE Transactions on Broadcasting illustrates some of these avenues and presents some of the most significant research results obtained by various teams of researchers from many countries. This special issue provides an example, albeit inevitably limited, of the richness and breath of the current research on multimedia broadcasting services. The research i- - ssues addressed in this special issue include, among others, factors that influence user perceived quality, encoding-related quality assessment and control, transmission and coverage-based solutions and objective quality measurements
VECTORS: Video communication through opportunistic relays and scalable video coding
Crowd-sourced video distribution is frequently of interest in the local
vicinity. In this paper, we propose a novel design to transfer such content
over opportunistic networks with adaptive quality encoding to achieve
reasonable delay bounds. The video segments are transmitted between source and
destination in a delay tolerant manner using the Nearby Connections Android
library. This implementation can be applied to multiple domains, including farm
monitoring, wildlife, and environmental tracking, disaster response scenarios,
etc. In this work, we present the design of an opportunistic contact based
system, and we discuss basic results for the trial runs within our institute.Comment: 13 pages, 6 figures, and under 3000 words for submission to the
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