4,885 research outputs found
Estimating commitment in a digital market place environment
The future generation of mobile communication shall be a convergence of mobile telephony and information systems which promises to change people's lives by enabling them to access information when, where and how they want. It presents opportunities to offer multimedia applications and services that meet end-toend service requirements. The Digital Marketplace framework will enable users to have separate contracts for different services on a per call basis. In order for such a framework to function appropriately, there has to be some means for the network operator to know in advance if its network will be able to support the user requirements. This paper discusses the methods by which the network operator will be able to determine if the system will be able to support another user of a certain service class and therefore negotiate parameters like commitment, QoS and the associated cost for providing the service, thus making the Digital Marketplace wor
Robust and scalable matching pursuits video transmission using the Bluetooth air interface standard
This paper introduces an error resilient implementation of the matching pursuits algorithm for video coding. The video bitstream is transmitted using a simulation of the Bluetooth air interface standard, which recommends ARQ as a means of overcoming channel errors in the data packets. This approach may be unsuitable for real time and broadcast applications. Therefore, a modified receiver is proposed in this paper, which does not request the retransmission of erroneous packets, but instead passes them to the video decoder to exploit error resilience. This strategy is shown to be superior to a standard compliant system if ARQ cannot be applied. The work confirms that wireless communication standards should support a transparent mode for video applications
Link adaptation algorithms for improved delivery of delay- and error-sensitive packet-data services over wireless networks
Link Adaptation is a radio resource management
technique that assesses the channel conditions and
selects a transport mode, from a set of possible options,
which is optimised for these conditions according to a
predefined criterion. The optimum transport mode is
commonly determined so as to maximise the throughput.
Although this approach may be appropriate for best-effort
services, its suitability for multimedia services, usually
characterised by tight delay and error performance constraints,
has been questioned. As a result, a number of
alternative algorithms have been proposed in the literature.
In this context, this paper presents and evaluates in a
dynamic radio environment several Link Adaptation algorithms
designed to enhance the provision of delay- and
error-sensitive multimedia packet-data services over wireless
systems. The obtained results demonstrate that
significant improvements in terms of throughput, transmission
delay, error performance and operation of Link
Adaptation itself can be obtained with the proposed
schemes.Postprint (published version
Distributed video coding for wireless video sensor networks: a review of the state-of-the-art architectures
Distributed video coding (DVC) is a relatively new video coding architecture originated from two fundamental theorems namely, Slepian–Wolf and Wyner–Ziv. Recent research developments have made DVC attractive for applications in the emerging domain of wireless video sensor networks (WVSNs). This paper reviews the state-of-the-art DVC architectures with a focus on understanding their opportunities and gaps in addressing the operational requirements and application needs of WVSNs
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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
Integer Linear Programming Optimization of Joint RRM Policies for Heterogeneous Wireless Systems
Wireless systems will be characterized by the coexistence of heterogeneous Radio
Access Technologies (RATs) with different, but also complementary, performance and technical
characteristics. These heterogeneous wireless networks will provide network operators the
possibility to efficiently and coordinately use the heterogeneous radio resources, for which novel
Joint Radio Resource Management (JRRM) policies need to be designed. In this context, this work
proposes and evaluates a JRRM policy that simultaneously determines for each user an adequate
combination of RAT and number of radio resources within such RAT to guarantee the user/service
QoS requirements, and efficiently distribute the radio resources considering a user fairness
approach aimed at maximizing the system capacity. To this aim, the JRRM algorithm, which takes
into account the discrete nature of radio resources, is based on integer linear programming
optimization mechanisms
Slight-Delay Shaped Variable Bit Rate (SD-SVBR) Technique for Video Transmission
The aim of this thesis is to present a new shaped Variable Bit Rate (VBR) for video transmission, which plays a crucial role in delivering video traffic over the Internet. This is due to the surge of video media applications over the Internet and the video typically has the characteristic of a highly bursty traffic, which leads to the Internet bandwidth fluctuation. This new shaped algorithm, referred to as Slight Delay - Shaped Variable Bit Rate (SD-SVBR), is aimed at controlling the video rate for video application transmission. It is designed based on the Shaped VBR (SVBR) algorithm and was implemented in the Network Simulator 2 (ns-2). SVBR algorithm is devised for real-time video applications and it has several limitations and weaknesses due to its embedded estimation or prediction processes. SVBR faces several problems, such as the occurrence of unwanted sharp decrease in data rate, buffer overflow, the existence of a low data rate, and the generation of a cyclical negative fluctuation. The new algorithm is capable of producing a high data rate and at the same time a better quantization parameter (QP) stability video sequence. In
addition, the data rate is shaped efficiently to prevent unwanted sharp increment or decrement, and to avoid buffer overflow. To achieve the aim, SD-SVBR has three strategies, which are processing the next Group of Picture (GoP) video sequence and obtaining the QP-to-data rate list, dimensioning the data rate to a higher utilization of the leaky-bucket, and implementing a QP smoothing method by carefully measuring the effects of following the previous QP value. However, this algorithm has to be combined with a network feedback algorithm to produce a better overall video rate control. A combination of several video clips, which consisted of a varied video rate, has been used for the purpose of evaluating SD-SVBR performance. The results showed that SD-SVBR gains an impressive overall Peak Signal-to-Noise Ratio (PSNR) value. In addition, in almost all cases, it gains a high video rate but without buffer overflow, utilizes the buffer well, and interestingly, it is still able to obtain smoother QP fluctuation
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