On dynamic server provisioning in multichannel P2P live streaming

To guarantee the streaming quality in live peer-to-peer (P2P) streaming channels, it is preferable to provision adequate levels of upload capacities at dedicated streaming servers, compensating for peer instability and time-varying peer upload bandwidth availability. Most commercial P2P streaming systems have resorted to the practice of overprovisioning a fixed amount of upload capacity on streaming servers. In this paper, we have performed a detailed analysis on 10 months of run-time traces from UUSee, a commercial P2P streaming system, and observed that available server capacities are not able to keep up with the increasing demand by hundreds of channels. We propose a novel online server capacity provisioning algorithm that proactively adjusts server capacities available to each of the concurrent channels, such that the supply of server bandwidth in each channel dynamically adapts to the forecasted demand, taking into account the number of peers, the streaming quality, and the channel priority. The algorithm is able to learn over time, has full Internet service provider (ISP) awareness to maximally constrain P2P traffic within ISP boundaries, and can provide differentiated streaming qualities to different channels by manipulating their priorities. To evaluate its effectiveness, our experiments are based on an implementation of the algorithm, which replays real-world traces. © 2011 IEEE.published_or_final_versio

Minimum node degree of k-connected vehicular ad hoc networks in highway scenarios

A vehicular ad hoc network (VANET) is a specific type of mobile ad hoc networks (MANETs); it can provide direct or multi-hop vehicle-to-vehicle (V2V), vehicle-to-roadside (V2R), vehicle-to-pedestrian (V2P), and vehicle-to-internet (V2I)communications based on the pre-existing road layouts. The emerging and promising VANET technologies have drawn tremendous attention from the government, academics, and industry over the past few years and have been increasingly available for a large number of cutting edge applications that can be classified into road safety, traffic efficiency, and infotainment categories. Due to the unique characteristics of VANETs, such as high mobility with an organized but constrained pattern, and diverse radio propagation conditions, the conventional researches dedicated for general MANETs cannot be directly applied to VANETs. This paper presents an analytical framework to investigate the minimum node degree of k-connected VANETs, with a homogeneous range assignment in highway scenarios. We simulate the mobility patterns with realistic vehicular traces, model the network topology as a two-path fading geometric random graph, and conduct extensive experiments on the derived analytical results. Through a combination of mathematical modeling and simulations, we derive a probabilistic bound for the minimum node degree of a homogeneous vehicular ad hoc network in highway scenarios. The analytical framework is useful in the study of connectivity and estimation of performance in one-dimensional vehicular ad hoc networks

Framing the Internet in China: Cross-Cultural Comparisons of Newspapers’ Coverage in China, Hong Kong, Singapore, the United States, and the United Kingdom

This study introduced the framing theory, Shoemaker and Reese’s hierarchical model, and Hofstede’s cultural dimensions into a cross-cultural comparative analysis of news coverage of the Internet in China from 2000 to 2004 in selected newspapers in China, Hong Kong, Singapore, the United States and the United Kingdom. Significant differences were found to exist across the societies in both the salience of Internet-related issues and the usage of generic news frames. The issue of Internet diffusion and use was most frequently mentioned in the newspapers from China, Singapore, and the United Kingdom. The U.S. newspapers paid most attention to the issue of Internet censorship and regulations; whereas the issue of e-commerce and Internet business most frequently appeared in the newspapers from Hong Kong. In terms of generic news frames, the newspapers from China were significantly more likely to use the human interest, morality and leadership frames. The newspapers from Hong Kong mainly relied on the factual and economic consequences frames to report the Internet in mainland China. The U.S. and U.K. newspapers were distinct for their highly frequent usage of the conflict frame. This study also investigated how much variations in media framing could be explained by such national-level factors as freedom status and cultural dimensions across societies. Logistic regression models indicated that the patterns of influence varied across the societies with different types of news frames and their associations with different types of Internet-related issues. The cultural dimension of long-/short-term orientation was found to be a general factor influencing the presence of different types of news frames. In addition, a literature review of the changing Chinese media suggests that the Chinese press has become increasingly diversified in both structure and function. Therefore, another goal of the study was to test the influence of extramedia-level factors within a society by examining whether the framing of the Internet in the leading Party organ newspaper, the People’s Daily, would differ from the Beijing Youth Daily, a local newspaper with national influence and more financial and operational autonomy. They differed from each other in presenting the politically sensitive issue, Internet censorship and regulations

Speech quality prediction for voice over Internet protocol networks

Merged with duplicate record 10026.1/878 on 03.01.2017 by CS (TIS). Merged with duplicate record 10026.1/1657 on 15.03.2017 by CS (TIS)This is a digitised version of a thesis that was deposited in the University Library. If you are the author please contact PEARL Admin ([email protected]) to discuss options.IP networks are on a steep slope of innovation that will make them the long-term carrier of all types of traffic, including voice. However, such networks are not designed to support real-time voice communication because their variable characteristics (e.g. due to delay, delay variation and packet loss) lead to a deterioration in voice quality. A major challenge in such networks is how to measure or predict voice quality accurately and efficiently for QoS monitoring and/or control purposes to ensure that technical and commercial requirements are met. Voice quality can be measured using either subjective or objective methods. Subjective measurement (e.g. MOS) is the benchmark for objective methods, but it is slow, time consuming and expensive. Objective measurement can be intrusive or non-intrusive. Intrusive methods (e.g. ITU PESQ) are more accurate, but normally are unsuitable for monitoring live traffic because of the need for a reference data and to utilise the network. This makes non-intrusive methods(e.g. ITU E-model) more attractive for monitoring voice quality from IP network impairments. However, current non-intrusive methods rely on subjective tests to derive model parameters and as a result are limited and do not meet new and emerging applications. The main goal of the project is to develop novel and efficient models for non-intrusive speech quality prediction to overcome the disadvantages of current subjective-based methods and to demonstrate their usefulness in new and emerging VoIP applications. The main contributions of the thesis are fourfold: (1) a detailed understanding of the relationships between voice quality, IP network impairments (e.g. packet loss, jitter and delay) and relevant parameters associated with speech (e.g. codec type, gender and language) is provided. An understanding of the perceptual effects of these key parameters on voice quality is important as it provides a basis for the development of non-intrusive voice quality prediction models. A fundamental investigation of the impact of the parameters on perceived voice quality was carried out using the latest ITU algorithm for perceptual evaluation of speech quality, PESQ, and by exploiting the ITU E-model to obtain an objective measure of voice quality. (2) a new methodology to predict voice quality non-intrusively was developed. The method exploits the intrusive algorithm, PESQ, and a combined PESQ/E-model structure to provide a perceptually accurate prediction of both listening and conversational voice quality non-intrusively. This avoids time-consuming subjective tests and so removes one of the major obstacles in the development of models for voice quality prediction. The method is generic and as such has wide applicability in multimedia applications. Efficient regression-based models and robust artificial neural network-based learning models were developed for predicting voice quality non-intrusively for VoIP applications. (3) three applications of the new models were investigated: voice quality monitoring/prediction for real Internet VoIP traces, perceived quality driven playout buffer optimization and perceived quality driven QoS control. The neural network and regression models were both used to predict voice quality for real Internet VoIP traces based on international links. A new adaptive playout buffer and a perceptual optimization playout buffer algorithms are presented. A QoS control scheme that combines the strengths of rate-adaptive and priority marking control schemes to provide a superior QoS control in terms of measured perceived voice quality is also provided. (4) a new methodology for Internet-based subjective speech quality measurement which allows rapid assessment of voice quality for VoIP applications is proposed and assessed using both objective and traditional MOS test methods

Mediating the political impacts of the Internet: the case of China.

Qiu Linchuan (Jack).Thesis (M.Phil.)--Chinese University of Hong Kong, 1999.Includes bibliographical references (leaves 169-173).Abstracts in English and Chinese.Chapter Chapter 1 --- Introduction --- p.1The Objectives --- p.1The Assumptions --- p.2The Case --- p.4Methods --- p.9The Conceptual Framework --- p.11Chapter Chapter 2 --- Theoretical Background --- p.18Communication Technology as A Democratizer --- p.18Democratizer or Something Else? --- p.23The Concept of Mediation --- p.27The Mediationist Perspective --- p.33Chapter Chapter 3 --- China's Cyberspace --- p.37China 's Nets and Netizens --- p.40Bamboo Curtains Unfurled --- p.53Virtual Censorship vs. Mass Media Regulation: a Comparison --- p.67Concluding Remarks --- p.75Chapter Chapter 4 --- The Processes of Mediation --- p.79Internet Audience and Their Exposure --- p.80The Rugged Route from Exposure to Expression --- p.88The Gap between Virtuality and Reality --- p.98Concluding Remarks --- p.108Chapter Chapter 5 --- The Consequences of Mediation --- p.110Evaluating the Consequences --- p.110Selecting Online Arenas --- p.113Data Gathering and Coding --- p.119Findings --- p.130Concluding remarks --- p.147Chapter Chapter 6 --- Discussions --- p.151Summary --- p.151Methodological Issues --- p.154Broader Implications --- p.164Bibliography --- p.16

Smart Monitoring and Control in the Future Internet of Things

The Internet of Things (IoT) and related technologies have the promise of realizing pervasive and smart applications which, in turn, have the potential of improving the quality of life of people living in a connected world. According to the IoT vision, all things can cooperate amongst themselves and be managed from anywhere via the Internet, allowing tight integration between the physical and cyber worlds and thus improving efficiency, promoting usability, and opening up new application opportunities. Nowadays, IoT technologies have successfully been exploited in several domains, providing both social and economic benefits. The realization of the full potential of the next generation of the Internet of Things still needs further research efforts concerning, for instance, the identification of new architectures, methodologies, and infrastructures dealing with distributed and decentralized IoT systems; the integration of IoT with cognitive and social capabilities; the enhancement of the sensing–analysis–control cycle; the integration of consciousness and awareness in IoT environments; and the design of new algorithms and techniques for managing IoT big data. This Special Issue is devoted to advancements in technologies, methodologies, and applications for IoT, together with emerging standards and research topics which would lead to realization of the future Internet of Things