265 research outputs found
AngelCast: cloud-based peer-assisted live streaming using optimized multi-tree construction
Increasingly, commercial content providers (CPs) offer streaming solutions using peer-to-peer (P2P) architectures, which promises significant scalabil- ity by leveraging clientsâ upstream capacity. A major limitation of P2P live streaming is that playout rates are constrained by clientsâ upstream capac- ities â typically much lower than downstream capacities â which limit the quality of the delivered stream. To leverage P2P architectures without sacri- ficing quality, CPs must commit additional resources to complement clientsâ resources. In this work, we propose a cloud-based service AngelCast that enables CPs to complement P2P streaming. By subscribing to AngelCast, a CP is able to deploy extra resources (angel), on-demand from the cloud, to maintain a desirable stream quality. Angels do not download the whole stream, nor are they in possession of it. Rather, angels only relay the minimal fraction of the stream necessary to achieve the desired quality. We provide a lower bound on the minimum angel capacity needed to maintain a desired client bit-rate, and develop a fluid model construction to achieve it. Realizing the limitations of the fluid model construction, we design a practical multi- tree construction that captures the spirit of the optimal construction, and avoids its limitations. We present a prototype implementation of AngelCast, along with experimental results confirming the feasibility of our service.Supported in part by NSF awards #0720604, #0735974, #0820138, #0952145, #1012798 #1012798 #1430145 #1414119. (0720604 - NSF; 0735974 - NSF; 0820138 - NSF; 0952145 - NSF; 1012798 - NSF; 1430145 - NSF; 1414119 - NSF
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Multimedia delivery in the future internet
The term âNetworked Mediaâ 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 citizensâ 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 âon the moveâ, 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
An autonomic delivery framework for HTTP adaptive streaming in multicast-enabled multimedia access networks
The consumption of multimedia services over HTTP-based delivery mechanisms has recently gained popularity due to their increased flexibility and reliability. Traditional broadcast TV channels are now offered over the Internet, in order to support Live TV for a broad range of consumer devices. Moreover, service providers can greatly benefit from offering external live content (e. g., YouTube, Hulu) in a managed way. Recently, HTTP Adaptive Streaming (HAS) techniques have been proposed in which video clients dynamically adapt their requested video quality level based on the current network and device state. Unlike linear TV, traditional HTTP- and HAS-based video streaming services depend on unicast sessions, leading to a network traffic load proportional to the number of multimedia consumers. In this paper we propose a novel HAS-based video delivery architecture, which features intelligent multicasting and caching in order to decrease the required bandwidth considerably in a Live TV scenario. Furthermore we discuss the autonomic selection of multicasted content to support Video on Demand (VoD) sessions. Experiments were conducted on a large scale and realistic emulation environment and compared with a traditional HAS-based media delivery setup using only unicast connections
On the Limit of Fountain MDC Codes for Video Peer-To-Peer Networks
Video streaming for heterogeneous types of devices, where nodes have different devices characteristics in terms of computational capacity and display, is usually handled by encoding the video with different qualities. This is not well suited for Peer-To-Peer (P2P) systems, as a single peer group can only share content of the same quality, thus limiting the peer group size and efficiency. To address this problem, several existing works propose the use of Multiple Descriptions Coding (MDC). The concept of this type of video codec is to split a video in a number of descriptions which can be used on their own, or aggregated to improve the global quality of the video. Unfortunately existing MDC codes are not flexible, as the video is split in a defined number of descriptions. In this paper, we focus on the practical feasibility of using a Fountain MDC code with properties similar to existing Fountain erasure codes, including the ability to create any number of descriptions when needed (on the fly). We perform simulations using selected pictures to assess the feasibility of using these codes, knowing that they should improve the availability of the video pieces in a P2P system and hence the video streaming quality. We observe that, although this idea seems promising, the evaluated benefits, demonstrated by the PSNR values, are limited when used in a real P2P video streaming system
Robust P2P Live Streaming
Projecte fet en col.laboraciĂł amb la FundaciĂł i2CATThe provisioning of robust real-time communication services (voice, video, etc.) or media contents through the Internet in a distributed manner is an important challenge,
which will strongly influence in current and future Internet evolution. Aware of this, we
are developing a project named Trilogy leaded by the i2CAT Foundation, which has as
main pillar the study, development and evaluation of Peer-to-Peer (P2P) Live
streaming architectures for the distribution of high-quality media contents. In this
context, this work concretely covers media coding aspects and proposes the use of
Multiple Description Coding (MDC) as a flexible solution for providing robust and
scalable live streaming over P2P networks. This work describes current state of the art
in media coding techniques and P2P streaming architectures, presents the
implemented prototype as well as its simulation and validation results
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
Network coding meets multimedia: a review
While every network node only relays messages in a traditional communication system, the recent network coding (NC) paradigm proposes to implement simple in-network processing with packet combinations in the nodes. NC extends the concept of "encoding" a message beyond source coding (for compression) and channel coding (for protection against errors and losses). It has been shown to increase network throughput compared to traditional networks implementation, to reduce delay and to provide robustness to transmission errors and network dynamics. These features are so appealing for multimedia applications that they have spurred a large research effort towards the development of multimedia-specific NC techniques. This paper reviews the recent work in NC for multimedia applications and focuses on the techniques that fill the gap between NC theory and practical applications. It outlines the benefits of NC and presents the open challenges in this area. The paper initially focuses on multimedia-specific aspects of network coding, in particular delay, in-network error control, and mediaspecific error control. These aspects permit to handle varying network conditions as well as client heterogeneity, which are critical to the design and deployment of multimedia systems. After introducing these general concepts, the paper reviews in detail two applications that lend themselves naturally to NC via the cooperation and broadcast models, namely peer-to-peer multimedia streaming and wireless networkin
QoE assessment for SVC streaming in ENVISION
Scalable video coding has drawn great interest in content delivery in many
multimedia services thanks to its capability to handle terminal heterogeneity
and network conditions variation. In our previous work, and under the umbrella
of ENVISION, we have proposed a playout smoothing mechanism to ensure the
uniform delivery of the layered stream, by reducing the quality changes that
the stream undergoes when adapting to changing network conditions. In this
paper we study the resulting video quality, from the final user perception
under different network conditions of loss and delays. For that we have adopted
the Double Stimulus Impairment Scale (DSIS) method. The results show that the
Mean Opinion Score for the smoothed video clips was higher under different
network configuration. This confirms the effectiveness of the proposed
smoothing mechanism.Comment: IEEE 20th International Conference on Electronics, Circuits, and
Systems (IEEE ICECS 2013), Abu Dhabi : United Arab Emirates (2013
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