Made available in DSpace on 2014-06-12T15:04:21Z (GMT). No. of bitstreams: 2 arquivo1112_1.pdf: 1031240 bytes, checksum: 02753136ced35de8f0a4387436937135 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2008 / As mudanças na forma de comunicação estão estreitamente associadas a saltos evolutivos na história da humanidade e, conseqüentemente, das organizações. Dentre essas transformações, destacam-se as decorrentes dos recentes e vertiginosos avanços proporcionados pelo uso da tecnologia de informação e comunicação, principalmente da Internet. Esse profícuo ambiente à troca de informações e conhecimentos das organizações é, atualmente, a principal plataforma das aplicações empresariais por se apresentar como o mais eficiente, de baixo custo e ilimitado meio para o desenvolvimento dessas soluções. Destaca-se, dentre estas, a tecnologia de voz sobre o protocolo da Internet (VoIP), por flexibilizar a comunicação mediada por computador, permitindo a conjugação de recursos comunicacionais através de um único meio, reduzindo custos. Apesar do uso da tecnologia VoIP ter crescido consideravelmente com o objetivo de reduzir a conta telefônica e interligar escritórios sem custo, sua utilização na comunicação interna das organizações ainda é pouco conhecida, o que dificulta um melhor aproveitamento de seu enorme potencial. Nesse contexto, o objetivo do presente estudo é proporcionar um maior entendimento das motivações dos gestores ao implantar a tecnologia VoIP na comunicação interna das organizações. Para elaborar o modelo de pesquisa, numa perspectiva exploratória, foi empreendido um estudo de caso

Made available in DSpace on 2016-04-18T21:39:45Z (GMT). No. of bitstreams: 4 Antonio Carlos GIANOTO1.pdf: 620239 bytes, checksum: aa779772dff23531ab717870d36823d3 (MD5) Antonio Carlos GIANOTO2.pdf: 1522259 bytes, checksum: 928d1a566cc9977b69a13b358fe13a50 (MD5) Antonio Carlos GIANOTO3.pdf: 2036577 bytes, checksum: 4ef7b886a0d20792d494deb085435041 (MD5) Antonio Carlos GIANOTO4.pdf: 1519186 bytes, checksum: cce13633bbc1cf7d5714a8dd727dd008 (MD5) Previous issue date: 2006-06-29 / Fundo Mackenzie de Pesquisa / The aim of this elaboration is to present a study of the migration process involved transforming the digital PBX (Private Branch Exchange), TDM (Time Division Multiplex), SPC (Stored Program Control) based platforms of corporate communications on technology to converged IP (Internet Protocol) systems supported by the TCP/IP (Transmission Control Protocol/Internet Protocol) protocol. This proposal analyzes the necessary interventions in order to preserve the investments made in these platforms, integrating them to existent data networks. Beside other benefits presented in this work, one key advantage is the possibility to transport voice over an existing data infrastructure, optimizing usage of carrier connections. / O objetivo desta dissertação é o de apresentar um estudo do processo de migração de plataformas de voz PABX (Private Automatic Branch Exchange) TDM (Time Division Multiplex) de comunicações corporativas baseadas na tecnologia CPA-T (Controle por Programa Armazenado estágio de comutação temporal digital), para sistemas convergentes suportados pelo protocolo TCP/IP (Transmission Control Protocol/Internet Protocol). São analisadas as intervenções necessárias para esta migração, preservando ao máximo os investimentos efetuados nestas plataformas, integrando-as as redes de dados existentes. Dentre outras vantagens apresentadas no texto, destaca-se a otimização dos acessos fornecidos pelas operadoras de telecomunicações pelo compartilhamento da infra-estrutura da rede de dados para o tráfego de sinais de voz.

The Space Mobile Network (SMN) is NASA’s next generation architecture concept for communications services between ground and space-based assets. The SMN calls for a paradigm shift in space communications. The transition will move from an approach based on static, preplanned communications over point-to-point channels to a dynamic, event-driven, and network-based approach that facilitates service-oriented communications. In doing so, the SMN is able to leverage some concepts and technologies present in today’s terrestrial wireless networks, while others must be extended or adapted to the space communications domain. This paper provides background on key SMN architectural concepts and an evaluation of the suitability of terrestrial wireless network modeling tools to be used and applied for proving out SMN concepts.

The distribution of television is currently dominated by three technologies: over-the-air broadcast, cable, and satellite. The advent of IP networks and the increased availability of broadband access created a new vehicle for the distribution of TV services. The distribution of digital TV services over IP networks, or IPTV, offers carriers flexibility and added value in the form of additional services. It causes therefore no surprise the rapid roll-out of IPTV services by operators worldwide in the past few years. IPTV distribution imposes stringent requirements on both performance and reliability. It is therefore challenging for an IPTV operator to guarantee the quality of experience expected by its users, and doing so in an efficient manner. In this dissertation I investigate some of the challenges faced by IPTV distribution network operators, and I propose novel techniques to address these challenges. First, I address one of the major concerns of IPTV network deployment: channel change delay. This is the latency experienced by users when switching between TV channels. Synchronisation and buffering of video streams can cause channel change delays of several seconds. I perform an empirical analysis of a particular solution to the channel change delay problem, namely, predictive pre-joining of TV channels. In this scheme each Set Top Box simultaneously joins additional multicast groups (TV channels) along with the one requested by the user. If the user switches to any of these channels next, switching latency is virtually eliminated, and user experience is improved. The results show that it is possible to eliminate zapping delay for a significant percentage of channel switching requests with little impact in access network bandwidth cost. Second, I propose a technique to increase the resource and energy efficiency of IPTV networks. This technique is based on a simple paradigm: avoiding waste. To reduce the inefficiencies of current static multicast distribution schemes, I propose a semi-dynamic scheme where only a selection of TV multicast groups is distributed in the network, instead of all. I perform an empirical evaluation of this method and conclude that its use results in significant bandwidth reductions without compromising service performance. I also demonstrate that these reductions may translate into significant energy savings in the future. Third, to increase energy efficiency further I propose a novel energy and resource friendly protocol for core optical IPTV networks. The idea is for popular IPTV traffic to optically bypass the network nodes, avoiding electronic processing. I evaluate this proposal empirically and conclude that the introduction of optical switching techniques results in a significant increase in the energy efficiency of IPTV networks. All the schemes I present in this dissertation are evaluated by means of trace-driven analyses using a dataset from an operational IPTV service provider. Such thorough and realistic evaluation enables the assessment of the proposed techniques with an increased level of confidence, and is therefore a strength of this dissertation.

Through the use of early iNET-prototype IP Transceiver technology, Kawasaki Heavy Industries, Ltd. (KHI) has been able to communicate with a flight test vehicle. This technology provides a two-way high-capacity communication that has not been achieved with conventional telemetry. KHI has been authorized to use S-band IP Transceivers since 2014 in Japan. Then various communication tests have been performed. Last year we presented the result of the performance test of initial iNET-like RF network using a tethered aerostat at ITC. As the next phase, we have a plan of the test using a helicopter. The test is going to be conducted in September. We will present the results at ITC. This paper describes plans of the test which includes improved data backfill techniques.

No description available.

Master’s thesis describes creating of virtual reality in VRML Language with use of VRML Pad editor and VRealm Builder. The thesis consists of the described objects in Simulink 3D Animation Library which are used for 3D Virtual scenes and connection of dynamics from Matlab/Simulink. Dynamics is created in Matlab/Simulink and connected by TCP/IP protocol to system PLC S7-1500. In the PLC is program for control of technology process. Process is visualized by HMI by Siemens AG and supplied by basic setting of connected communication and technology process.

This Diploma thesis describes the procedure of setting the parameters of communication blocks and functions in PLC and PC, so that it is possible to remotely control part of the production process. TCP / IP protocol is used for communication between devices. Part of the production technology is represented by the created 3D model, which serves for three-dimensional interpretation of the simulation of the mathematical model of this part of the process. Part of this work is the design of this model and description of its dynamics.

This work investigates the interface and properties of an ionization radiation detector with the PhPix chip, which is the basis of a future large-scale detector for use in nuclear medicine. In the next stage, an IP core for communication between the processor system and the PhPix chips on the Zynq platform is designed. Furthermore, software for video transmission over Ethernet interface is developed.

The aim of this work is to give information about the structure and elements of the IP Multimedia Subsystem, using signaling protocol and transferring messages between the terminal and elements of IMS. Create model, which implements messages transfer between terminal and IMS elements, by environment tools OPNET Modeler. This work describes system function IMS, its architecture, basic elements, architecture of using signaling protocol SIP and its elements, SIP and SDP messages format and the way of ensuring Quality of Services. There is a project of model terminal registration and reservation data flow by terminal in the IMS. These models were realized in a simulation environment called OPNET Modeler by using tools: project editor, node editor and process editor. In the last part of this work, the method of verification correct function of realized models was created by simulation tools called Debbuger. This tool is one of the environment tools OPNET Modeler.