The development of 3G (the 3rd generation telecommunication) value-added services brings higher requirements of Quality of Service (QoS). Wideband Code Division Multiple Access (WCDMA) is one of three 3G standards, and enhancement of QoS for WCDMA Core Network (CN) becomes more and more important for users and carriers. The dissertation focuses on enhancement of QoS for WCDMA CN. The purpose is to realize the DiffServ (Differentiated Services) model of QoS for WCDMA CN. Based on the parallelism characteristic of Network Processors (NPs), the NP programming model is classified as Pool of Threads (POTs) and Hyper Task Chaining (HTC). In this study, an integrated programming model that combines both of the two models was designed. This model has highly efficient and flexible features, and also solves the problems of sharing conflicts and packet ordering. We used this model as the programming model to realize DiffServ QoS for WCDMA CN. The realization mechanism of the DiffServ model mainly consists of buffer management, packet scheduling and packet classification algorithms based on NPs. First, we proposed an adaptive buffer management algorithm called Packet Adaptive Fair Dropping (PAFD), which takes into consideration of both fairness and throughput, and has smooth service curves. Then, an improved packet scheduling algorithm called Priority-based Weighted Fair Queuing (PWFQ) was introduced to ensure the fairness of packet scheduling and reduce queue time of data packets. At the same time, the delay and jitter are also maintained in a small range. Thirdly, a multi-dimensional packet classification algorithm called Classification Based on Network Processors (CBNPs) was designed. It effectively reduces the memory access and storage space, and provides less time and space complexity. Lastly, an integrated hardware and software system of the DiffServ model of QoS for WCDMA CN was proposed. It was implemented on the NP IXP2400. According to the corresponding experiment results, the proposed system significantly enhanced QoS for WCDMA CN. It extensively improves consistent response time, display distortion and sound image synchronization, and thus increases network efficiency and saves network resource.

Localization and coverage are two important and closely related problems in wireless ad hoc networks. Localization aims to determine the physical locations of devices in a network, while coverage determines if a region of interest is sufficiently monitored by devices. Localization systems require a high degree of coverage for correct functioning, while coverage schemes typically require accurate location information. This thesis investigates the relationship between localization and coverage such that new schemes can be devised which integrate approaches found in each of these well studied problems. This work begins with a thorough review of the current literature on the subjects of localization and coverage. The localization scheduling problem is then introduced with the goal to allow as many devices as possible to enter deep sleep states to conserve energy and reduce message overhead, while maintaining sufficient network coverage for high localization accuracy. Initially this sufficient coverage level for localization is simply a minimum connectivity condition. An analytical method is then proposed to estimate the amount of localization error within a certain probability based on the theoretical lower bounds of location estimation. Error estimates can then be integrated into location dependent schemes to improve on their robustness to localization error. Location error estimation is then used by an improved scheduling scheme to determine the minimum number of reference devices required for accurate localization. Finally, an optimal coverage preserving sleep scheduling scheme is proposed which is robust to localization error, a condition which is ignored by most existing solutions. Simulation results show that with localization scheduling network lifetimes can be increased by several times and message overhead is reduced while maintaining negligible differences in localization error. Furthermore, results show that the proposed coverage preserving sleep scheduling scheme results in fewer active devices and coverage holes under the presence of localization error.

This thesis presents two modern control methods to address the Internet traffic congestion control issues. They are based on a distributed traffic management framework for the fast-growing Internet traffic in which routers are deployed with intelligent or optimal data rate controllers to tackle the traffic mass. The first one is called the IntelRate (Intelligent Rate) controller using the fuzzy logic theory. Unlike other explicit traffic control protocols that have to estimate network parameters (e.g., link latency, bottleneck bandwidth, packet loss rate, or the number of flows), our fuzzy-logic-based explicit controller can measure the router queue size directly. Hence it avoids various potential performance problems arising from parameter estimations while reducing much computation and memory consumption in the routers. The communication QoS (Quality of Service) is assured by the good performances of our scheme such as max-min fairness, low queueing delay and good robustness to network dynamics. Using the Lyapunov’s Direct Method, this controller is proved to be globally asymptotically stable. The other one is called the OFEX (Optimal and Fully EXplicit) controller using convex optimization. This new scheme is able to provide not only optimal bandwidth allocation but also fully explicit congestion signal to sources. It uses the congestion signal from the most congested link, instead of the cumulative signal from a flow path. In this way, it overcomes the drawback of the relatively explicit controllers that bias the multi-bottlenecked users, and significantly improves their convergence speed and throughput performance. Furthermore, the OFEX controller design considers a dynamic model by proposing a remedial measure against the unpredictable bandwidth changes in contention-based multi-access networks (such as shared Ethernet or IEEE 802.11). When compared with the former works/controllers, such a remedy also effectively reduces the instantaneous queue size in a router, and thus significantly improving the queueing delay and packet loss performance. Finally, the applications of these two controllers on wireless local area networks have been investigated. Their design guidelines/limits are also provided based on our experiences.

This diploma thesis deals with various types of relations observable in social networks. First part contains survey of existing papers focused on social media data analysis and visualisations. This survey is followed by research of existing visualisation applications. The contribution of this thesis is a new look at relations on social networks, from the side of relationship between users who write posts on any given topic. To visualize these relations was chosen network graph. On the basis of established criteria existing instruments were evaluated and since any of them did not meet all requirements, I created new application for visualising relations. Thesis also includes a description of selection the appropriate libraries for its implementation, explanation of user interface and a summary of configuration options and customization. The end of the work contains analysis and visualisations made with newly-created tool.

In the past thirty years, the IMP Group's Interaction and Network Approach has gained its increasing popularity in researching economic behaviours among resource-dependent business actors through relational linkages (Håkansson et al., 2004; Turnbull et al., 1996). Within network research, understanding the dynamics in business networks, in which interfirm relationships are regarded as crucial constituents, has been of particular interest (Johnston et al., 2006; Möller and Halinen, 1999). Moreover, technology has been identified as an important component driving the evolution of a business network, where technological change may bring about positive and negative effects on the relationships embedded in this network, and consequently, results in network dynamics (Afuah, 2000; Christensen, 1997; Håkansson and Waluszewski, 2002b; Lundgren, 1995). A perspective of resource interaction (e.g. Håkansson et al., 2009) suggests that technological change needs to be treated as a process rather than a critical event. However the nature of this process as well as how it impacts on the configuration of a technology-based business net and on dynamics of relationships constituting this net remains under-examined.Based on qualitative research methods, a longitudinal single-case study is chosen to conduct an empirical investigation in the optical recording media industry, in order to address the above research problems. To facilitate the data collection, a focal net perspective and an input-process-output model are employed. The focal net under study is characterised as a value-creating and technology-bundled business net. A total of 72 interviews were carried out in three stages and with the focal actor, its customers, suppliers and a complementor. The empirical data allows the research to reconstruct the evolution of the focal business net, which covers a time-span of more than 10 years from 1998 to 2008, and in which major technological change has taken place three times, from CD-R to DVD-/+R, DVD Double Layer and HD/Blu-ray technologies. In the development of the optical recording technology, the focal net has experienced four net reconfigurations in which radical changes of relationships as well as disturbance in resource interaction are observed. Based on the case study result, empirical observations are offered and new insights into the process of the arrival of technological change and net reconfiguration and relationship dynamics affected by this technological arrival are developed. Moreover, theoretical contribution, managerial implications, limitations and future research directions are provided.

Main thesis objective is in social network analysis. Theoretic will describe their origin, development and circumstances under which certain social networks were built. Part with analysis will concern in how to compete with business rivals using CI and will search techniques for proper facebook usage as a company's CI tool by rating of chosen fan facebook pages.

Classification and scheduling are key functionalities of a network processor. Network processors are equipped with application specific integrated circuits (ASIC), so that as IP (Internet Protocol) packets arrive, they can be processed directly without using the central processing unit. A new network processor is proposed called the video network processor (VNP) for real time broadcasting of video streams for IP television (IPTV). This thesis explores the challenge in designing a combined classification and scheduling module for a VNP. I propose and design the classifier-scheduler module which will classify and schedule data for VNP. The proposed module discriminates between IP packets and video packets. The video packets are further processed for digital rights management (DRM). IP packets which carry regular traffic will traverse without any modification. Basic architecture of VNP and architecture of classifier-scheduler module based on content addressable memory (CAM) and random access memory (RAM) has been proposed. The module has been designed and simulated in Xilinx 9.1i; is built in ISE simulator with a throughput of 1.79 Mbps and a maximum working frequency of 111.89 MHz at a power dissipation of 33.6mW. The code has been translated and mapped for Spartan and Virtex family of devices.

Com o crescimento acelerado da complexidade das aplicações e softwares que exigem alto desempenho, o hardware e sua arquitetura passou por algumas mudanças para que pudesse atender essa necessidade. Uma das abordagens propostas e desenvolvidas para suportar essas aplicações, foi a integração de mais de um core de processamento em um único circuito integrado. Inicialmente, a comunicação utilizando barramento foi escolhida, pela sua vantagem de reuso comparado a ponto a ponto. No entanto, com o aumento acelerado da quantidade de cores nos Systems-on-Chip (SoC), essa abordagem passou a apresentar problemas para suportar a comunicação interna. Uma alternativa que vem sendo explorada é a Network-on-Chip (NoC), uma abordagem que propõe utilizar o conhecimento de redes comuns em projetos de comunicação interna de SoC. Esse trabalho fornece uma arquitetura de NoC completa, configurável, parametrizável e no padrão Ethernet. Os três módulos básicos da NoC, Network Adapter (NA), Link e Switch, são implementados e disponibilizados. Os resultados foram obtidos utilizando o FPGA Stratix IV da Altera. As métricas de desempenho utilizadas para validação da NoC são a área no FPGA e o atraso na comunicação. Os parâmetros disponibilizados são referentes as configurações dos módulos desenvolvidos, considerando características apresentadas de aplicações DSP (Digital Signal Processing). O experimento utilizando dois NAs, dois cores e um Switch precisou de 7310 ALUTs do FPGA EP4SGX230KF40C2ES o que corresponde a 4% dos seus recursos lógicos. O tempo gasto para a transmissão de um quadro ethernet de 64 Bytes foi de 422 ciclos de clock a uma frequência de 50MHz. / With the accelerated growth of the complexity of the software and applications that require high performance, hardware and its architecture has undergone a few changes so it could meet that need. One of the proposals and approaches developed to support these applications, was the integration of more than one core processing in a single integrated circuit. Initially, the bus communication architecture was chosen, using for its reuse benefit compared to point-to-point. However, with the cores number increase in Systems-on-Chip (SoC), this approach began to present problems to support internal communication. An alternative that has been explored is the Network-on-Chip (NoC), an approach that proposes to use knowledge of common networks on internal communication projects of SOC. This dissertation focuses is to provide a complete NoC architecture, configurable, customizable and on standard Ethernet. The three NoC basic modules, Network Adapter (NA), Link and Switch, are implemented. The results were obtained using the Stratix IV FPGA. The performance metrics used for NoC validation are silicon area and latency. The available parameters are related to developed modules settings, considering features presented of DSP applications. The experiment using two NA, two cores and one Switch needed 7310 FPGA ALUTs which corresponds to 4% of their logical resources. The time for the transmission of an ethernet frame of 64 Bytes was 422 clock cycles at 50 MHz.

abstract: This dissertation studies the scheduling in two stochastic networks, a co-located wireless network and an outpatient healthcare network, both of which have a cyclic planning horizon and a deadline-related performance metric. For the co-located wireless network, a time-slotted system is considered. A cycle of planning horizon is called a frame, which consists of a fixed number of time slots. The size of the frame is determined by the upper-layer applications. Packets with deadlines arrive at the beginning of each frame and will be discarded if missing their deadlines, which are in the same frame. Each link of the network is associated with a quality of service constraint and an average transmit power constraint. For this system, a MaxWeight-type problem for which the solutions achieve the throughput optimality is formulated. Since the computational complexity of solving the MaxWeight-type problem with exhaustive search is exponential even for a single-link system, a greedy algorithm with complexity O(nlog(n)) is proposed, which is also throughput optimal. The outpatient healthcare network is modeled as a discrete-time queueing network, in which patients receive diagnosis and treatment planning that involves collaboration between multiple service stations. For each patient, only the root (first) appointment can be scheduled as the following appointments evolve stochastically. The cyclic planing horizon is a week. The root appointment is optimized to maximize the proportion of patients that can complete their care by a class-dependent deadline. In the optimization algorithm, the sojourn time of patients in the healthcare network is approximated with a doubly-stochastic phase-type distribution. To address the computational intractability, a mean-field model with convergence guarantees is proposed. A linear programming-based policy improvement framework is developed, which can approximately solve the original large-scale stochastic optimization in queueing networks of realistic sizes. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2020

The foreseen massive deployment of the internet of things (IoT) is expected to suffer from high security risks. This mainly results from the difficulty to monitor and cure the IoT devices in such large-scale deployment. In this thesis, we propose a spatial random deployment of special nodes (firewalls) which can detect and cure infected nodes within certain radius. An important concern is to add sufficient number of firewalls to make an epidemics finite and, hence, prevent malware outbreak over the whole network. The problem will be analyzed using percolation theory. Namely, we derive an upperbound for the critical intensity of spatial firewalls which guarantees prevention of large-scale network epidemics, regardless of the intensity of regular nodes. Using tools from percolation theory, we analyze the proposed solution and show the conditions required to ensure its efficiency.