12,056 research outputs found
Exploiting Traffic Balancing and Multicast Efficiency in Distributed Video-on-Demand Architectures
Distributed Video-on-Demand (DVoD) systems are proposed as a
solution to the limited streaming capacity and null scalability of centralized
systems. In a previous work, we proposed a fully distributed large-scale VoD
architecture, called Double P-Tree, which has shown itself to be a good approach
to the design of flexible and scalable DVoD systems. In this paper, we
present relevant design aspects related to video mapping and traffic balancing in
order to improve Double P-Tree architecture performance. Our simulation results
demonstrate that these techniques yield a more efficient system and considerably
increase its streaming capacity. The results also show the crucial importance
of topology connectivity in improving multicasting performance in
DVoD systems. Finally, a comparison among several DVoD architectures was
performed using simulation, and the results show that the Double P-Tree architecture
incorporating mapping and load balancing policies outperforms similar
DVoD architectures.This work was supported by the MCyT-Spain under contract TIC 2001-2592 and partially supported by the Generalitat de Catalunya- Grup de Recerca Consolidat 2001SGR-00218
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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
The effectiveness of the creativity trigger module in achieving higher levels of creative thinking among prospective teachers
The unoptimised level of creative thinking is seen as an issue among Semester 8 prospective teachers in Malaysian Teacher-Education Institutes (IPG). This could impede their teaching of creative thinking as one of the four components of 21st century skills in schools. In relation to this, this study sets out to investigate prior creativity levels of IPG prospective teachers and develop the Creativity Trigger Module (CTM) as a training module for enhancing their creativity. The Torrance Tests of Creative Thinking (TTCT) was used to compare the prior creativity levels of four respondent groups and test the effectiveness of the CTM on five dimensions of figural creativity, namely fluency, originality, elaboration, resistance to premature closure, abstractness of titles, and their overall creativity. A two-stage cluster sampling technique identified two IPGs with 68 respondents in the state of Johor namely, IPG-Kampus Tun Hussein Onn, Batu Pahat (IPGKTHO) as the control group site (34 respondents), and IPG- Kampus Temenggong Ibrahim, Johor Bahru (IPGKTI) as the treatment group site (34 respondents). Mathematics (MT) and Design and Technology (RBT) are the only two specialist subject combinations that provided enough sample size at both test sites. A quasi-experimental research design was used and this involved intact classes. Data analysis was carried out as follows: ANOVA, ANCOVA, and Wilcoxon Signed Rank Test analysis for TTCT scores while data analysis based on the NVivo software was used for the focus group interviews. Findings on prior creativity levels showed average or low creativity levels among all 4 test groups with IPGKTHO and RBT options having significantly higher posttest marks as compared to IPGKTI and MT option respectively. The CTM was found to improve significantly respondents’ posttest marks for the treatment group in all the five dimensions of figural creativity and, their overall creativity. Feedback from respondents revealed positive support for the CTM. In conclusion, the prior creativity of IPG prospective teachers was at an unoptimised level before treatment but the CTM has been successfully developed as an effective resource for enhancing the creative thinking levels among IPG prospective teachers
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 clients’ upstream capacity. A major limitation of P2P live streaming is that playout rates are constrained by clients’ upstream capac- ities – typically much lower than downstream capacities – which limit the quality of the delivered stream. To leverage P2P architectures without sacri- ficing quality, CPs must commit additional resources to complement clients’ 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
Architecture for Cooperative Prefetching in P2P Video-on- Demand System
Most P2P VoD schemes focused on service architectures and overlays
optimization without considering segments rarity and the performance of
prefetching strategies. As a result, they cannot better support VCRoriented
service in heterogeneous environment having clients using free VCR controls.
Despite the remarkable popularity in VoD systems, there exist no prior work
that studies the performance gap between different prefetching strategies. In
this paper, we analyze and understand the performance of different prefetching
strategies. Our analytical characterization brings us not only a better
understanding of several fundamental tradeoffs in prefetching strategies, but
also important insights on the design of P2P VoD system. On the basis of this
analysis, we finally proposed a cooperative prefetching strategy called
"cooching". In this strategy, the requested segments in VCR interactivities are
prefetched into session beforehand using the information collected through
gossips. We evaluate our strategy through extensive simulations. The results
indicate that the proposed strategy outperforms the existing prefetching
mechanisms.Comment: 13 Pages, IJCN
Optical network technologies for future digital cinema
Digital technology has transformed the information flow and support infrastructure for numerous application domains, such as cellular communications. Cinematography, traditionally, a film based medium, has embraced digital technology leading to innovative transformations in its work flow. Digital cinema supports transmission of high resolution content enabled by the latest advancements in optical communications and video compression. In this paper we provide a survey of the optical network technologies for supporting this bandwidth intensive traffic class. We also highlight the significance and benefits of the state of the art in optical technologies that support the digital cinema work flow
An Efficient Transport Protocol for delivery of Multimedia An Efficient Transport Protocol for delivery of Multimedia Content in Wireless Grids
A grid computing system is designed for solving complicated scientific and
commercial problems effectively,whereas mobile computing is a traditional
distributed system having computing capability with mobility and adopting
wireless communications. Media and Entertainment fields can take advantage from
both paradigms by applying its usage in gaming applications and multimedia data
management. Multimedia data has to be stored and retrieved in an efficient and
effective manner to put it in use. In this paper, we proposed an application
layer protocol for delivery of multimedia data in wireless girds i.e.
multimedia grid protocol (MMGP). To make streaming efficient a new video
compression algorithm called dWave is designed and embedded in the proposed
protocol. This protocol will provide faster, reliable access and render an
imperceptible QoS in delivering multimedia in wireless grid environment and
tackles the challenging issues such as i) intermittent connectivity, ii) device
heterogeneity, iii) weak security and iv) device mobility.Comment: 20 pages, 15 figures, Peer Reviewed Journa
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