Computer Networks

Computer networks represent a main component of the economy of information. Their appliance spans from WiFi tofficellular net¬works, enabling the foundations of the Web. Some fundamental problems of computer networking, from performing distributed applications to multiple-access and bandwidth allocation, are being investigated. For each problem, various design strategies are developed to assess its performance in practical applications. Many interconnections are considered in computer networking, and various aspects of computer system analysis using queueing network models are illustrated by particular case studies. A number of important modelling techniques are summarized in the algorithmic form, for all main widely-used networking technologies. Network Management is the process of controlling a complex data network so as to maximize its efficiency and productivity. An architecture for dynamic network reconfiguration is presented in the first section of the book, giving the auto reconfiguration using the directory server, which is used to store and maintain configuration information. The following seven chapters of the book present various techniques to improve Ad hoc networks and appliance of technolo¬gies such as Low-rate Distributed Denial-of-Service (LDDoS) and multiple-input and multiple-output (MIMO) technology. The remaining content of this book focuses on the advances of specific methods and algorithms in the field of QoS framework and Internet. The specific advances discussed in this book include the use of ordered successive interference cancellation, new QoS frameworks, as well as the advances in Internet of things. The recently proposed TCP-targeted LDDoS attacks send fewer packets to attack legitimate flows by exploiting the vulnerability in TCP’s congestion control mechanism. Congestion Participation Rate (CPR) metric is presented as well as a CPR-based ap¬proach to detect and filter LDDoS attacks by their intention to congest the network. The major innovation of the CPR-base ap¬proach is its ability to identify LDDoS flows. The effectiveness of CPR is analysed theoretically by quantifying the average CPR difference between normal TCP flows and LDDoS flows and showing that CPR can differentiate them. In computer networks systems, multiple-input and multiple-output, (MIMO) technology can be employed because of the enormous benefits it offers. It is the technique of using multiple antennas at the transmitter to propagate signal through multiple propagation paths to multiple antennas at the receiver. This can be used to significantly increase communication performance, measured by data throughput, and link reliability without additional bandwidth or increased transmit power. It achieves this goal by spreading the same total transmit power over the antennas to achieve an array gain that improves the spectral efficiency, chan¬nel capacity and link reliability. These benefits are not without setbacks due to mutual coupling of the antennas, correlation of the signals and the degree of matching between the receiver and the load. Some general expressions are formulated showing the impact, on the capacity of the MIMO channel, by both antenna coupling and spatial correlation due to the propagation environment. Due to heterogeneous channel conditions in MIMO wireless networks, it is challenging for video broadcasting to map scalable video layers to proper MIMO transmit antennas to minimize the average overall video transmission distortion. Channel scheduling problem for broadcasting scalable video content over MIMO wireless networks is investigated. An adaptive channel scheduling based unequal error protection (UEP) video broadcasting scheme is proposed. In the scheme, video layers are protected unequally by being mapped to appropriate antennas, and the average overall distortion of all receivers is minimized. This scheme is formulated into a non-linear combinatorial optimization problem. Ordered successive interference cancellation (OSIC) is adopted with minimum mean square error (MMSE) detection to enhance the multiple-input multiple-output (MIMO) system performance. The optimum detection technique improves the error rate performance but increases system complexity. Therefore, MMSE-OSIC detection is used which reduces error rate compared to traditional MMSE with low complexity. The system performance is analyzed in composite fading environment that includes multipath and shadowing effects known as Weibull-Gamma (WG) fading. Along with the composite fading, a generalized noise that is additive white generalized Gaussian noise (AWGGN) is considered to show the impact of wireless scenario. This noise model includes various forms of noise as special cases such as impulsive, Gamma, Laplacian, Gaussian, and uniform. Consequently, generalized function is used to model noise. The average symbol error probability (ASEP) of MIMO system is computed for 16-quadrature amplitude modulation (16-QAM) using MMSE-