Context. In the present network inventive world, there is a quick expansion of switches and protocols, which are used to cope up with the increase in customer requirement in the networking. With increasing demand for higher bandwidths and lower latency and to meet these requirements new network paths are introduced. To reduce network load in present switching network, development of new innovative switching is required. These required results can be achieved by Software Define Network or Traditional layer-3 technologies.Objectives. In this thesis, the end to end (e2e) transmission performance of OpenFlow and Layer-3 switches and their dynamic characteristics are investigated using network simulation.Methods. To replicate real life network topology and evaluate e2e transmission performance, a simulation based test-bed is implemented for both OpenFlow switch and layer-3 switch. The test beds are implemented using Network Simulator-3 (NS3). A two-tire network topology is designed with specified components for performance evaluation.Results. The performance metrics like throughput, average delay, simulation time and Packet Delivery Ratio (PDR) are measured, results are analyzed statistically and are compared. The behavior of network traffic in both the topologies are understood using NS-3 and explained further in the thesis.Conclusions. The analytical and statistical results from simulation show that OpenFlow switching performs relatively better than layer-3 switching.

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Made available in DSpace on 2014-12-17T14:55:51Z (GMT). No. of bitstreams: 1 MarceloHRN_DISSERT.pdf: 1910960 bytes, checksum: 696b69a0c65216fcf9b33e58073b32ab (MD5) Previous issue date: 2012-08-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This dissertation describes the implementation of a WirelessHART networks simulation module for the Network Simulator 3, aiming for the acceptance of both on the present context of networks research and industry. For validating the module were imeplemented tests for attenuation, packet error rate, information transfer success rate and battery duration per station / Esta disserta??o descreve a implementa??o de um m?dulo de simula??o para redes WirelessHART, utilizando o simulador de redes Network Simulator 3, tendo em vista a aceita??o que ambos possuem no atual contexto de pesquisa e na ind?stria. Para valida??o do m?dulo foram implementados testes quanto a atenua??o dos sinais transmitidos, probabilidade de perda pacotes (Packet Error Rate PER), probabilidade de que uma informa??o produzida seja recebida no destino e dura??o da bateria nas esta??es

Made available in DSpace on 2014-12-17T14:55:18Z (GMT). No. of bitstreams: 1 ViniciusSVS_TESE.pdf: 2375594 bytes, checksum: e3d85d405a408eb605711ffd55dbe760 (MD5) Previous issue date: 2014-03-17 / The monitoring of patients performed in hospitals is usually done either in a manual or semiautomated way, where the members of the healthcare team must constantly visit the patients to ascertain the health condition in which they are. The adoption of this procedure, however, compromises the quality of the monitoring conducted since the shortage of physical and human resources in hospitals tends to overwhelm members of the healthcare team, preventing them from moving to patients with adequate frequency. Given this, many existing works in the literature specify alternatives aimed at improving this monitoring through the use of wireless networks. In these works, the network is only intended for data traffic generated by medical sensors and there is no possibility of it being allocated for the transmission of data from applications present in existing user stations in the hospital. However, in the case of hospital automation environments, this aspect is a negative point, considering that the data generated in such applications can be directly related to the patient monitoring conducted. Thus, this thesis defines Wi-Bio as a communication protocol aimed at the establishment of IEEE 802.11 networks for patient monitoring, capable of enabling the harmonious coexistence among the traffic generated by medical sensors and user stations. The formal specification and verification of Wi-Bio were made through the design and analysis of Petri net models. Its validation was performed through simulations with the Network Simulator 2 (NS2) tool. The simulations of NS2 were designed to portray a real patient monitoring environment corresponding to a floor of the nursing wards sector of the University Hospital Onofre Lopes (HUOL), located at Natal, Rio Grande do Norte. Moreover, in order to verify the feasibility of Wi-Bio in terms of wireless networks standards prevailing in the market, the testing scenario was also simulated under a perspective in which the network elements used the HCCA access mechanism described in the IEEE 802.11e amendment. The results confirmed the validity of the designed Petri nets and showed that Wi-Bio, in addition to presenting a superior performance compared to HCCA on most items analyzed, was also able to promote efficient integration between the data generated by medical sensors and user applications on the same wireless network / O monitoramento de pacientes realizado nos hospitais normalmente ? feito de forma manual ou semi-automatizada, em que os membros da equipe de sa?de precisam constantemente se deslocar at? os pacientes para verificarem o estado de sa?de em que eles se encontram. A ado??o desse procedimento, todavia, compromete a qualidade do monitoramento realizado, uma vez que a escassez de recursos f?sicos e humanos nos hospitais tende a sobrecarregar os membros da equipe de sa?de e assim impedir que os mesmos se desloquem aos pacientes com a freq??ncia adequada. Diante disso, diversos trabalhos existentes na literatura especificam alternativas voltadas ? melhoria desse monitoramento mediante o uso de redes sem fio. Nesses trabalhos, a rede ? destinada apenas ao tr?fego de dados gerados por sensores m?dicos e n?o existe a possibilidade da mesma ser alocada para o envio de informa??es oriundas de aplica??es presentes nas esta??es de usu?rio existentes no hospital. Todavia, em se tratando de ambientes de automa??o hospitalar, esse aspecto constitui-se em um ponto negativo, haja vista que os dados gerados nessas aplica??es podem estar diretamente relacionados ao monitoramento de pacientes realizado. Desse modo, esta tese define o Wi-Bio como sendo um protocolo de comunica??o voltado ao estabelecimento de redes de monitoramento de pacientes IEEE 802.11 capazes de permitir a conviv?ncia harmoniosa entre os tr?fegos gerados por sensores m?dicos e esta??es de usu?rio. A especifica??o e verifica??o formal do Wi-Bio foram feitas mediante o projeto e an?lise de modelos em redes de Petri e sua valida??o foi realizada atrav?s simula??es efetuadas na ferramenta Network Simulator 2 (NS2). As simula??es realizadas no NS2 foram projetadas para retratarem um ambiente real de monitoramento de pacientes correspondente a um andar do setor de enfermarias do Hospital Universit?rio Onofre Lopes (HUOL), localizado na cidade de Natal/RN. Al?m disso, no intuito de verificar a viabilidade do Wi-Bio quanto aos padr?es de redes sem fio vigentes no mercado, o cen?rio de testes tamb?m foi simulado sob uma perspectiva em que os elementos da rede utilizavam o mecanismo de acesso HCCA descrito na emenda IEEE 802.11e. Os resultados obtidos atestaram a validade das redes de Petri projetadas e mostraram que o Wi-Bio, al?m de apresentar um desempenho superior ao do HCCA na maioria dos quesitos analisados, tamb?m se mostrou capaz de promover uma integra??o eficiente entre os dados gerados por sensores m?dicos e aplica??es de usu?rio sob a mesma rede sem fio

Context: Wireless Mesh Network (WMN) is a form of ad-hoc network with flexible backhaul infrastructure and configuration, provides adaptive wireless internet connectivity to end users with high reliability. WMN is a wireless network consisting of mesh clients, mesh routers and gateways which are organized in a mesh topology with decentralized nature can consume more energy for data transmission. The networking performance of WMNs can be degraded due to the fact of high energy consumption for data transmission. Therefore, energy efficiency is the primary factor for attaining eminent performance. Organizing efficient routing and proper resource allocation can save huge amount of energy. Objectives: The main goal of this thesis is to reduce the energy consumption in WMNs. To do this, a new energy efficient routing algorithm is suggested. Adaptive rates based on rate allocation strategy and end to end delay metric are used mainly for optimal path selection in routing, which may in turn reduces the resource utilization and energy consumption. Method: An energy efficient routing algorithm is implemented by using the Ad hoc OnDemand Distance Vector (AODV) routing protocol. The RREQ packet in AODV is modified by adding a new field known as delay parameter which measures end to end delay between nodes. Adaptive rates obtained from Rate allocation policy are considered in the routing process to reduce energy consumption in the network. Energy measurement of the WMN and its performance is evaluated by measuring the metrics such as Throughput, End-to-End delay, Packet Delivery Ratio (PDR). For performing the simulation process, in this thesis, Network Simulator - 3 (NS-3) which is an open source discrete-event network simulator in which simulation models can be executed in C++ and Python is used. Using NetAnim-3.107 animator in NS-3-25.1, traffic flows between all the nodes are displayed. Results: The results are taken for existing algorithm and proposed algorithm for 25,50,75 and 100 nodes. Comparison of results shows that the total energy consumption is reduced for proposed algorithm for in all four scenarios. Conclusion: Energy efficient routing algorithm is implemented in different scenarios of radio access networks and energy is saved. Due to this algorithm even the performance metrics, Throughput, End-to-End delay, Packet Delivery Ratio (PDR) have shown eminent performance.

Este trabalho propõe o desenvolvimento de um simulador de redes Profibus DP que reproduz o comportamento de uma rede real. A simulação de redes em condições de falha permite aos usuários experimental situações que podem ocorrer em instalações reais, facilitando o treinamento de manutenção e antecipando ações corretivas. O simulador permite o treinamento de usuários que utilizam ferramentas de diagnóstico. Auxilia no estudo do protocolo Profibus DP e também contribui com o desenvolvimento da ferramenta Profidoctor que é um sistema especialista com o objetivo de fazer a análise de problemas de rede. / This work aims development of Profibus DP network simulator that reproduces real network behavior. The network simulation under fault conditions allows experiment situations that may occur in real network installations, helping in maintenance training and corrective actions. This simulator tool helps in diagnostic tool users training, Profibus DP protocol learning and also assists development of new tool Profidoctor: an expert system that will report complete analysis of network problems.

Networks of small, often mobile, polarimetric radars are gaining popularity in the hydrometeorology community due to their rainfall observing capabilities and relative low purchase cost. In recent years, a number of installations have become operational around the globe. The problem of signal attenuation by intervening rainfall has been recognized as the major source of error in rainfall estimation by short-wavelength (C-, X, K-band) radars. The simultaneous observation of precipitation by multiple radars creates new prospects for better and more robust attenuation correction algorithms and, consequently, yields more accurate rainfall estimation. The University of Iowa hydrometeorology group's acquisition of a network of four mobile, polarimetric, X-band radars has resulted in the need for a thoughtful evaluation of the instrument. In this work, we use computer simulations and the data collected by The University of Iowa Polarimetric Radar Network to study the performance of attenuation correction methods in single-radar and network-based arrangements. To support the computer simulations, we developed a comprehensive polarimetric radar network simulator, which replicates the essential aspects of the radar network rainfall observing process. The simulations are based on a series of physics- and stochastic-based simulated rainfall events occurring over the area of interest. The characteristics of the simulated radars are those of The University of Iowa Polarimetric Radar Network. We assess the correction methods by analyzing the errors in reflectivity and rainfall rate over the area of interest covered by the network's radars. To enable the implementation of the attenuation correction methods to the data collected by The University of Iowa Polarimetric Radar Network, we first developed a set of utilities to assist with efficient data collection and analysis. Next, we conducted a series of calibration tests to evaluate the relative calibration and channel balance of the 2 network's radars. Finally, in an attempt to verify the results obtained via computer simulations, we applied the set of attenuation correction algorithms to the data collected by The University of Iowa Polarimetric Radar Network.

BSD Socket API for Simulator is a project to run untouched Real World Application (RWA) binaries on the powerful modern general-purpose network simulators. BSD Socket API for Simulator is designed to eliminate most of the drawbacks of previous works. It is simulator independence, so it can make use of the powerful functionality and versatile tools provided by modern general-purpose simulators such as NS-2. It is fully compatible with BSD Socket API, so RWA can be run on it without re-linking and re-compiling. It is transparent to the RWA, so RWAs are run on BSD Socket API for Simulator as they are on normal operating systems. BSD Socket API for Simulator is built on the concept of message redirecting. It has two critical parts: shared library and customized simulator application. The shared library is loaded into the address space of RWA. On one hand, messages sent by RWA are captured by the shared library and redirected to the customized simulator application. On the other hand, messages from simulator are redirected by the customized simulator application to the shared library. BSD Socket API for Simulator has been intensively tested. The test results show that it functions as expected and it has an acceptable performance.

Este trabalho propõe o desenvolvimento de um simulador de redes Profibus DP que reproduz o comportamento de uma rede real. A simulação de redes em condições de falha permite aos usuários experimental situações que podem ocorrer em instalações reais, facilitando o treinamento de manutenção e antecipando ações corretivas. O simulador permite o treinamento de usuários que utilizam ferramentas de diagnóstico. Auxilia no estudo do protocolo Profibus DP e também contribui com o desenvolvimento da ferramenta Profidoctor que é um sistema especialista com o objetivo de fazer a análise de problemas de rede. / This work aims development of Profibus DP network simulator that reproduces real network behavior. The network simulation under fault conditions allows experiment situations that may occur in real network installations, helping in maintenance training and corrective actions. This simulator tool helps in diagnostic tool users training, Profibus DP protocol learning and also assists development of new tool Profidoctor: an expert system that will report complete analysis of network problems.

Orientador: Prof. Raphael Yokoingawa de Camargo / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Neurociência e Cognição, 2014. / Nowadays, utilizing co-processors, accelerators and specially GPGPU computation are widely accepted as a new paradigm of High Performance Computing (HPC). However, developing softwares that can utilize available resources still remains a challenging task. In other side, scientist have used legacy CPU-based simulators for decades and many of them are still the main tools in different fields of science. In fact, any activity that can combine the legacy simulators with powerful co-processors devices is in the main interest. In this project, we design and develop a simulation engine, Parallel Neural Network Simulator (PN2S), to communicate with MOOSE simulator (A well-known tools by Neuroscientists) and provide CUDA based execution for simulating realistic neural network models. The simulation engine maps the voltage distribution in neuron¿s body to sets of linear systems and solve them on GPU. To provide usable functionality, we also developed solver for active channels which support Hodgkin-Huxley model of ionic channels. We compared the engine with CPU version for both homogeneous simple models and randomly generated heterogeneous network. The evaluation focused on performance and also covered the accuracy of the simulation. The experimental results, showed that by facilitating PN2S engine, we can significantly increase the performance of a simulation engine, since its execution is quite transparent to the users and major parts of the host simulator.