Cellular Mobile System
Mostrando 1-12 de 34 artigos, teses e dissertações.
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1. Optically controlled reconfigurable antenna for 5G future broadband cellular communication networks
Abstract This paper presents an optically controlled reconfigurable antenna for millimetre-wave frequency range. Silicon switches are used to control the optical reconfiguration, modifying the frequency response and radiation pattern of the antenna design. Therefore, the system can switch between the lightly licensed 28 GHz and 38 GHz frequency bands, useful
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-03
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2. COVERAGE AND CAPACITY PLANNING OF LTE BROADBAND ACCESS NETWORKS / PLANEJAMENTO DE COBERTURA E CAPACIDADE DE REDES DE ACESSO EM BANDA LARGA COM TECNOLOGIA LTE
At the moment, the cellular networks are being used as an option to provide broadband services in places that have not yet been covered by the fixed networks, mainly in underdeveloped countries like Brazil. The employed technologies now in Brazil, GSM (Global System is Mobile) and UMTS (Mobile Universal Telecommunications System), they were not developed to
Publicado em: 2010
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3. Segurança em sistemas de comunicação pessoal : um modelo de arquitetura de protocolos para a interconexão de sistemas heterogêneos / Security in personal communications systems. one model of protocol architecture for the interworking of heterogeneous systems
A evolução dos sistemas de comunicação sem fio ou wireless apresentam até agora três gerações em menos de duas décadas. Fazendo parte desta evolução estão os sistemas de telefonia celular e os emergentes Sistemas de Comunicação Pessoal ou PCS (Personal Communications Systems). Este trabalho visa apresentar duas questões importantes na evoluç�
Publicado em: 2010
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4. DISTRIBUTED RECOGNITION FOR CONTINUOUS SPEECH IN LARGE VOCABULARY BRAZILIAN PORTUGUESE / RECONHECIMENTO DISTRIBUÍDO DE VOZ CONTÍNUA COM AMPLO VOCABULÁRIO PARA O PORTUGUÊS BRASILEIRO
This Thesis aims at exploring several approaches for performance improvement of the Automatic Speech Recognition System with large vocabulary for the Brazilian Portuguese when applied in a distributed scenario (Distributed Speech Recognition). With this purpose, a speech database for continuous speech recognition for the Brazilian Portuguese with 100 speaker
Publicado em: 2009
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5. Analysis of the expression profile and distribution of EFHC1 gene transcript during rodent brain development and in the adult animal / Analise da expressão e localização do transcrito do gene EFHC1 no cerebro de roedores durante o desenvolvimento e no animal adulto
Epilepsy is a frequent condition that affects around 1.5% of general population and is considered worldwide as a public health problem. The term epilepsy refers to a group of chronic neurological disorders with different etiologies and prognostics. However, a common characteristic of all epilepsies is the recurrence of seizures. Juvenile myoclonic epilepsy (
Publicado em: 2009
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6. Interoperabilidade dos dispositivos móveis / Interoperabilidade dos dispositivos móveis / Device móbiles interoperability / Device móbiles interoperability
The concept of sharing computing resources among WEB participants, has been gradually extended to support scenarios in wireless world, networks, mobile devices which introduce a variety possible uses. Wireless devices become a key of sharing information among peoples. In this point of view we present the main challenges in pervasive/ubiquitous concepts for w
Publicado em: 2008
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7. Localização de usuários usando o sistema celular. / Users localization using cellular system.
The mobile location technique using the cellular system received a special attention from the telecommunication manufacturers and operators, regarding the need of accomplishing the established demands by the emergency service calls and other commercial ones. This study analyzes the main location methods proposed in the literature, including, in each one, the
Publicado em: 2007
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8. AvaliaÃÃo da Qualidade de Voz do ServiÃo VoIP em Sistemas HSDPA / Evaluation of the quality of voice of the VoIP service in systems HDSPA
In recent years, we can observe the development and fast dissemination of VoIP services, being integrated by the present market, beside conventional telephony and cellular networks. For being a technological alternative that contributes to minimize costs, we see an increasing preference for voice transmission through IP networks. HSDPA, as a cellular system,
Publicado em: 2007
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9. AvaliaÃÃo de dependabilidade de sistemas com mecanismos tolerantes a falha: desenvolvimento de um mÃtodo hÃbrido baseado em EDSPN e diagrama de blocos
In current days, we observe a vertiginous advance of technology and a larger dependence of the society on computational systems. A massive use of computerized devices, fixed and mobile, inside a concept of ubiquitous computation, and the increasing pervasiveness of computers and services networks, have been turning systems extremely complex and dynamic. This
Publicado em: 2007
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10. Simulador para servidor habilitador de localizaÃÃo em plataforma LBS
Since XIX centuryâs end, the telephony suffered to constant technological evolution. In the 70âs, a new need was looked for: mobility. So, it began the age of the mobile communications. The increasing integration between cellular systems and computer science made possible the development of new technologies and services to the mobile networks. Currently, t
Publicado em: 2006
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11. Application of artificial intelligence techniques for dynamic channel allocation on wireless networks. / Aplicação de técnicas de inteligência artificial na alocação dinâmica de canais em redes sem fio.
In the last years, mobile networks became more important for communication systems infrastructure. One area of great growth is mobile computation, which is performed through radio signals. The amount of available channels rarely is enough to attend the increasing demand. This work presents a solution for the channel allocation topic, a challenging topic in
Publicado em: 2006
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12. Avaliação dos modelos de predição de propagação para telefonia móvel celular na cidade do Natal
The development of wireless telecommunication in the last years has been great. It has been taking academics to conceive new ideas and techniques. Their aims are to increase the capacity and the quality of the systems services. Cells that are smaller every time, frequencies that are every time higher and environments that get more and more complex, all those
Publicado em: 2006