New advances in mobile-computer technology, together with the advent of wireless networking, introduce new requirements, capabilities and concerns to the computer science and industry. In this paper, we discuss the sp...
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The Quality of Service (QoS) within the dynamically changing nature of wireless networks, experiences many issues, specifically in providing high and maintainable levels of QoS for high demand multimedia applications....
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ISBN:
(纸本)1841021571
The Quality of Service (QoS) within the dynamically changing nature of wireless networks, experiences many issues, specifically in providing high and maintainable levels of QoS for high demand multimedia applications. This paper explores the current technologies and solutions developed to overcome these issues and looks particularly at Mobiware - A middleware solution currently being researched at the Centre of Telecommunications Research, Columbia University, New York. This paper presents a proposed extension to Mobiware that could provide a solution to enhance QoS in dynamic wireless networks, such as wireless ATM, for high demand multimedia content.
Peer-to-Peer (P2P) computing is becoming increasingly popular as the Web continues to grow in both content and the number of connected devices. P2P provides a network that relies on the computing power and bandwidth o...
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This paper presents a framework for preventing both selfishness and denial-of-service attacks in peer-to-peer media streaming systems. Our framework, called Oversight, achieves prevention of these undesirable activiti...
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ISBN:
(纸本)0819461113
This paper presents a framework for preventing both selfishness and denial-of-service attacks in peer-to-peer media streaming systems. Our framework, called Oversight, achieves prevention of these undesirable activities by running a separate peer-to-peer download rate enforcement protocol along with the underlying peer-to-peer media streaming protocol. This separate Oversight protocol enforces download rate limitations on each participating peer. These limitations prevent selfish or malicious nodes from downloading an overwhelming amount of media stream data that could potentially exhaust the entire system. Since Oversight is based on a peer-to-peer architecture, it can accomplish this enforcement functionality in a scalable, efficient, and decentralized way that fits better with peer-to-peer media streaming systems compared to other solutions based on central server architectures. As peer-to-peer media streaming systems continue to grow in popularity, the threat of selfish and malicious peers participating in such large peer-to-peer networks will continue to grow as well. For example, since peer-to-peer media streaming systems allow users to send small request messages that result in the streaming of large media objects, these systems provide an opportunity for malicious users to exhaust resources in the system with little effort expended on their part. However, Oversight addresses these threats associated with selfish or malicious peers who cause such disruptions with excessive download requests. We evaluated our Oversight solution through simulations and our results show that applying Oversight to peer-to-peer media streaming systems can prevent both selfishness and denial-of-service attacks by effectively limiting the download rates of all nodes in the system.
The part III of Audio Video Standard of China (AVS) is the first Hi-Fi audio coding standard in China public domain. Through nonlinear quantization and Context-dependent Bitplane entropy Coding (CBC), It offers distin...
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ISBN:
(纸本)9781424405169
The part III of Audio Video Standard of China (AVS) is the first Hi-Fi audio coding standard in China public domain. Through nonlinear quantization and Context-dependent Bitplane entropy Coding (CBC), It offers distinct features of nonlinear quantization noise adaptation and high efficiency Fine Grain Scalability (FGS), but also imposes great challenges on fixed-point implementation with high precision requirement and stringent computational resource restriction. This paper presents tuned optimization strategies for fixed-point arithmetic, buffer manipulation, entropy decoding, and CBC decoding loop reduction to address the challenges. The demonstration real-time implementation on fixed-point DSP TMS320C5509A shows that our design optimization cuts down computational, complexity from over 200 MIPs to 60 MIPs while preserving over 15 effective bits precision for 16-bit PCM output.
Error concealment using information hiding has been an efficient tool to combat channel impairments that degrade the transmitted data quality by introducing channel errors/packet losses. The proposed model takes a str...
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ISBN:
(纸本)9781424409969
Error concealment using information hiding has been an efficient tool to combat channel impairments that degrade the transmitted data quality by introducing channel errors/packet losses. The proposed model takes a stream of multimedia content and the binarised stream is subjected to bit level enhanced mapping procedure (PRASAN - Enhanced NFD approach) accompanied with a set of convergence models that ensure a high degree of convergence for a given error norm. The mapping is performed between the current frames with respect to the previous frame in case of video data. This approach often referred to as the correlation generation is followed by convergence mathematical function generation. This function is derived based on trying out the various convergence methodologies in a weighted round robin environment and choosing the best matching function by computing the mean square error. This error is termed map-fault and is kept a minimum. The test data taken are subjected to noisy channel environments and the Power Signal to Noise Ratios obtained experimentally support firmly the advantage of the proposed methodology in comparison to existing approaches.
This paper proposes a cross-layer optimization framework that provides efficient allocation of wireless network resources across multiple types of applications to maximize network capacity and user satisfaction. We de...
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ISBN:
(纸本)1595933069
This paper proposes a cross-layer optimization framework that provides efficient allocation of wireless network resources across multiple types of applications to maximize network capacity and user satisfaction. We define a novel optimization scheme based on the Mean Opinion Score (MOS) as the unifying metric. Our experiments, applied to scenarios where users simultaneously run three types of applications, such as realtime voice, video conferencing and file download, confirm that MOS-based optimization leads to significant improvement in terms of user perceived quality when compared to throughput-based optimization. Copyright 2006 ACM.
The evolution of high-performance networks has resulted in the development of new applications with Quality of Service (QoS) requirements. In this paper we review and evaluate the Simple Host (SH) traffic management m...
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ISBN:
(纸本)3540393684
The evolution of high-performance networks has resulted in the development of new applications with Quality of Service (QoS) requirements. In this paper we review and evaluate the Simple Host (SH) traffic management mechanism that enables QoS provisioning within source-routed loss-less interconnect networks. SH provides statistical QoS guarantees for brokered multimedia traffic while supporting limited amounts of unbrokered background traffic. The results obtained from simulation show how to configure SH to provide statistical QoS based on jitter and latency requirements in an efficient manner.
Flash memory is widely adopted in various consumer products, especially for embedded systems. With strong demands on product designs for overhead control and performance requirements, vendors must have an effective de...
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ISBN:
(纸本)0769525539
Flash memory is widely adopted in various consumer products, especially for embedded systems. With strong demands on product designs for overhead control and performance requirements, vendors must have an effective design for the mapping of logical block addresses (LBA's) and physical addresses of data over flash memory. This paper targets such an essential issue by proposing a configurable mapping method that could trade the main-memory overhead with the system performance under the best needs of vendors. A series of experiments is conducted to provide insights on different configurations of the proposed method.
The spread of Massively Multiplayer Online Game (MMOG) which is the multiplayer playing game in virtual space via the Internet is the one of major topic in today's Internet. A typical architecture of MMOG is based...
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