872 resultados para Padrão IEEE 802.16
Resumo:
VALENTIM, R. A. M. ; MORAIS, A. H. F. ; SOUZA, V. S. V ; ARAUJO JUNIOR, H. B. ; BRANDAO, G. B. ; GUERREIRO, A. M. G. . Rede de Controle em Ambiente Hospitalar: um protocolo multiciclos para automação hospitalar sobre IEEE 802.3 com IGMP Snooping. Revista Ciência e Tecnologia, v. 11, p. 19, 2009
Resumo:
The concepts of the industrial automation are being incorporated in the medical area, in other words, they also pass to be applied in the hospital automation. In this sense, researches have been developed and have usually been approached several of the problems that are pertinent to the processes that can be automated in the hospital environment. Considering that in the automation processes, an imperative factor is the communication, because the systems are usually distributed, the network for data transference becomes itself an important point in these processes. Because this network should be capable to provide the exchange of data and to guarantee the demands that are imposed by the automation process. In this context, this doctorate thesis proposed, specified, analyzed and validated the Multicycles Protocol for Hospital Automation (MP-HA), which is customized to assist the demands in these automation processes, seeking to guarantee the determinism in the communications and to optimize the factor of use of the mean of transmission
Resumo:
The incorporate of industrial automation in the medical are requires mechanisms to safety and efficient establishment of communication between biomedical devices. One solution to this problem is the MP-HA (Multicycles Protocol to Hospital Automation) that down a segmented network by beds coordinated by an element called Service Provider. The goal of this work is to model this Service Provider and to do performance analysis of the activities executed by in establishment and maintenance of hospital networks
Resumo:
The occurrence of transients in electrocardiogram (ECG) signals indicates an electrical phenomenon outside the heart. Thus, the identification of transients has been the most-used methodology in medical analysis since the invention of the electrocardiograph (device responsible for benchmarking of electrocardiogram signals). There are few papers related to this subject, which compels the creation of an architecture to do the pre-processing of this signal in order to identify transients. This paper proposes a method based on the signal energy of the Hilbert transform of electrocardiogram, being an alternative to methods based on morphology of the signal. This information will determine the creation of frames of the MP-HA protocol responsible for transmitting the ECG signals through an IEEE 802.3 network to a computing device. That, in turn, may perform a process to automatically sort the signal, or to present it to a doctor so that he can do the sorting manually
Resumo:
The Ethernet technology dominates the market of computer local networks. However, it was not been established as technology for industrial automation set, where the requirements demand determinism and real-time performance. Many solutions have been proposed to solve the problem of non-determinism, which are based mainly on TDMA (Time Division Multiple Access), Token Passing and Master-Slave. This work of research carries through measured of performance that allows to compare the behavior of the Ethernet nets when submitted with the transmissions of data on protocols UDP and RAW Ethernet, as well as, on three different types of Ethernet technologies. The objective is to identify to the alternative amongst the protocols and analyzed Ethernet technologies that offer to a more satisfactory support the nets of the industrial automation and distributed real-time application
Resumo:
A Wireless Mesh Network (WMN - Wireless Mesh Network) IEEE 802.11s standard to become operational it is necessary to configure the parameters that meet the demands of its users, as regards, for example, the frequency channels, the power antennas, IPs addresses, meshID, topology, among others. This configuration can be done via a CLI (Command - Line Interface) or a remote interface provided by the equipment manufacturer, both are not standardized and homogeneous, like black boxes for the developers, a factor that hinders its operation and standardization. The WMN, as a new standard, is still in the testing phase, and tests are necessary to evaluate the performance of Path Discovery Protocol, as in this case of HWMP (Hybrid Wireless Mesh Protocol), which still has many shortcomings. The configuration and test creation in a WMN are not trivial and require a large workload. For these reasons this work presents the AIGA, a Management Integrated Environment for WMN IEEE 802.11s, which aims to manage and perform testbeds for analyzes of new Path Discovery Protocols in a WMN
Resumo:
Os sensores inteligentes são dispositivos que se diferenciam dos sensores comuns por apresentar capacidade de processamento sobre os dados monitorados. Eles tipicamente são compostos por uma fonte de alimentação, transdutores (sensores e atuadores), memória, processador e transceptor. De acordo com o padrão IEEE 1451 um sensor inteligente pode ser dividido em módulos TIM e NCAP que devem se comunicar através de uma interface padronizada chamada TII. O módulo NCAP é a parte do sensor inteligente que comporta o processador. Portanto, ele é o responsável por atribuir a característica de inteligência ao sensor. Existem várias abordagens que podem ser utilizadas para o desenvolvimento desse módulo, dentre elas se destacam aquelas que utilizam microcontroladores de baixo custo e/ou FPGA. Este trabalho aborda o desenvolvimento de uma arquitetura hardware/software para um módulo NCAP segundo o padrão IEEE 1451.1. A infra-estrutura de hardware é composta por um driver de interface RS-232, uma memória RAM de 512kB, uma interface TII, o processador embarcado NIOS II e um simulador do módulo TIM. Para integração dos componentes de hardware é utilizada ferramenta de integração automática SOPC Builder. A infra-estrutura de software é composta pelo padrão IEEE 1451.1 e pela aplicação especí ca do NCAP que simula o monitoramento de pressão e temperatura em poços de petróleo com o objetivo de detectar vazamento. O módulo proposto é embarcado em uma FPGA e para a sua prototipação é usada a placa DE2 da Altera que contém a FPGA Cyclone II EP2C35F672C6. O processador embarcado NIOS II é utilizado para dar suporte à infra-estrutura de software do NCAP que é desenvolvido na linguagem C e se baseia no padrão IEEE 1451.1. A descrição do comportamento da infra-estrutura de hardware é feita utilizando a linguagem VHDL
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
As Redes da Próxima Geração consistem no desenvolvimento de arquiteturas que viabilizem a continuidade de serviços que proporcionem sempre a melhor conectividade (Always Best Connectivity - ABC) aos usuários móveis com suporte adequado à Qualidade de Experiência (QoE) para aplicações multimídia de alta definição, nesse novo contexto as arquiteturas têm perspectiva orientada a serviços e não a protocolos. Esta tese apresenta uma arquitetura para redes da próxima geração capaz de fornecer acesso heterogêneo sem fio e handover vertical transparente para as aplicações multimídia. A tese considera diferentes tecnologias sem fio e também adota o padrão IEEE 802.21 (Media Independent Handover – MIH) para auxiliar na integração e gerenciamento das redes heterogêneas sem fio. As tecnologias que a arquitetura possui são: IEEE 802.11 (popularmente denominada de WiFi), IEEE 802.16 (popularmente denominada de WiMAX) e LTE (popularmente denominada de redes 4G). O objetivo é que arquitetura tenha a capacidade de escolher entre as alternativas disponíveis a melhor conexão para o momento. A arquitetura proposta apresenta mecanismos de predição de Qualidade de Experiência (Quality of Experience - QoE) que será o parâmetro decisivo para a realização ou não do handover para uma nova rede. A predição para determinar se haverá ou não mudança de conectividade será feita com o uso da inteligência computacional de Redes Neurais Artificiais. Além disso a arquitetura também apresenta um mecanismo de descarte seletivo de pacotes especifico para aplicações multimídia. A proposta é avaliada via simulação utilizando-se o ns-2 (Network Simulator) e os resultados de desempenho são apresentados através das métricas de QoS, de QoE e também visualmente através da exibição de frames dos vídeos transmitidos na arquitetura.
Resumo:
Internet access by wireless networks has grown considerably in recent years. However, these networks are vulnerable to security problems, especially those related to denial of service attacks. Intrusion Detection Systems(IDS)are widely used to improve network security, but comparison among the several existing approaches is not a trivial task. This paper proposes building a datasetfor evaluating IDS in wireless environments. The data were captured in a real, operating network. We conducted tests using traditional IDS and achieved great results, which showed the effectiveness of our proposed approach.
Resumo:
Faced with an imminent restructuring of the electric power system, over the past few years many countries have invested in a new paradigm known as Smart Grid. This paradigm targets optimization and automation of electric power network, using advanced information and communication technologies. Among the main communication protocols for Smart Grids we have the DNP3 protocol, which provides secure data transmission with moderate rates. The IEEE 802.15.4 is another communication protocol also widely used in Smart Grid, especially in the so-called Home Area Network (HAN). Thus, many applications of Smart Grid depends on the interaction of these two protocols. This paper proposes modeling, in the traditional network simulator NS-2, the integration of DNP3 protocol and the IEEE 802.15.4 wireless standard for low cost simulations of Smart Grid applications.
Resumo:
Wireless networks are widely deployed and have many uses, for example in critical embedded systems. The applications of this kind of network meets the common needs of most embedded systems and addressing the particularities of each scenario, such as limitations of computing resources and energy supply. Problems such as denial of service attacks are common place and cause great inconvenience. Thus, this study presents simulations of denial of service attacks on 802.11 wireless networks using the network simulator OMNeT++. Furthermore, we present an approach to mitigate such attack, obtaining significant results for improving wireless networks.
Resumo:
This paper discusses some aspects related to Wireless Sensor Networks over the IEEE 802.15.4 standard, and proposes, for the very first time, a mesh network topology with geographic routing integrated to the open Freescale protocol (SMAC - Simple Medium Access Control). For this is proposed the SMAC routing protocol. Before this work the SMAC protocol was suitable to perform one hop communications only. However, with the developed mechanisms, it is possible to use multi-hop communication. Performance results from the implemented protocol are presented and analyzed in order to define important requirements for wireless sensor networks, such as robustness, self-healing property and low latency. (c) 2011 Elsevier Ltd. All rights reserved.