Submitted by Tatiana Lima (tatianasl@ufba.br) on 2016-04-07T21:37:48Z No. of bitstreams: 1 Costa, Marcio Andrade.pdf: 885780 bytes, checksum: cce004ad16c68dce35c0c4003cb3f439 (MD5) / Approved for entry into archive by Tatiana Lima (tatianasl@ufba.br) on 2016-04-19T18:26:14Z (GMT) No. of bitstreams: 1 Costa, Marcio Andrade.pdf: 885780 bytes, checksum: cce004ad16c68dce35c0c4003cb3f439 (MD5) / Made available in DSpace on 2016-04-19T18:26:14Z (GMT). No. of bitstreams: 1 Costa, Marcio Andrade.pdf: 885780 bytes, checksum: cce004ad16c68dce35c0c4003cb3f439 (MD5) / O presente trabalho tem por objetivo analisar como a regulação do Serviço Móvel Pessoal (SMP), implementada pela Anatel em 2001, alterou a estrutura do mercado e as estratégias das operadoras do setor de telefonia móvel no Brasil, entre 2002 e 2007. Para tanto, foi realizada uma pesquisa qualitativa em torno do tema com a construção de um estudo de caso múltiplo (YIN, 2003) acerca das maiores operadoras que atuam no setor – Vivo, Tim, Claro e Oi – considerando a participação histórica dessas operadoras na base de clientes móveis em operação no Brasil. O referencial teórico utilizado foi a análise estrutural da indústria (PORTER, 1980). As técnicas de coleta dos dados seguiram as recomendações de Patton (2002) na realização da pesquisa documental, entrevistas e observações não-participantes. A conclusão da pesquisa é que o Serviço Móvel Pessoal representa as mudanças ocorridas no arcabouço regulatório do setor de telefonia móvel, alterando deliberadamente a estrutura desse mercado, reduzindo as barreiras de entrada no setor, elevando a intensidade da concorrência entre as operadoras que nele se encontram e estabelecendo integrações verticais entre estas e as operadoras de telefonia fixa. A conclusão a respeito das estratégias implementadas pelas operadoras, diante da estrutura do mercado, após o SMP, é que as operadoras analisadas – Vivo, Tim, Claro e Oi - adotaram uma estratégia de liderança em custos, competindo em um mercado típico de commodities até o lançamento de serviços que caracterizam a convergência fixa-móvel (CURWEN, 2006) pela Oi, mudando seu posicionamento estratégico no setor, adotando uma estratégia de diferenciação. Em decorrência, a competição no setor de telefonia móvel foi alterada, dividindo o setor em dois grupos estratégicos: o primeiro grupo formado pelas operadoras que mantiveram uma estratégia de custos – Vivo, Tim e Claro, e o segundo grupo formado por uma operadora que adotou uma estratégia de diferenciação – a Oi. This work analysis how the regulation named Serviço Móvel Pessoal (SMP), edited by Anatel, in 2001, modified the mobile cellular market structure and the Brazilian mobile companies strategies during the 2002-2007 period. In order to answer this question, a qualitative research and a multi-case study (YIN, 2003) were developed on the biggest Brazilian mobile companies – Vivo, Tim, Claro and Oi – based on their market share historical indexes. The theoretical framework used was the structural analysis of industry attractiveness (PORTER, 1980). The data collecting techniques followed Patton’s (2002) recommendations on doing documental research, interviewing and non-participant observations. This research concludes that the ‘Serviço Móvel Pessoal’ means the changes in the mobile cellular market regulation, modifying its market structure in a deliberated process, reducing entry barriers, increasing mobile cellular companies’ rivalry and introducing vertical integration between them and fixed-wired companies. The conclusion around the strategies implemented by mobile cellular companies, based on this market structure, after SMP, is that all the operators analyzed by this research - Vivo, Tim, Claro and Oi – implemented a cost leadership strategy, competing in a commodities typical market until the introducing of fixedmobile convergence services (CURWEN, 2006) by Oi company, changing its strategic position, adopting a differentiation strategy. As a consequence, the competition in the mobile cellular market structure was modified, separating this sector into two strategic groups: the first one, composed by the companies who maintained a cost leadership strategy - Vivo, Tim and Claro, and the second one, composed by a company which adopted a differentiation strategy – Oi.

Made available in DSpace on 2016-08-17T14:52:45Z (GMT). No. of bitstreams: 1 Carlos Araujo Melo.pdf: 2692092 bytes, checksum: 602dda0e5531e90be3e278cbf784bffe (MD5) Previous issue date: 2002-10-03 / In this work a system is proposed to minimize the time of search of possible flaws in messages ISUP. The entrance of the proposed system is represented by files containing messages of user's part ISDN, they can be from ACM (Address completes) to USR (User-to-user information). the exit of the proposed system is exhibited through another file containing the reads message and all your meaning, as well as an analysis of the translation. The results obtained show that the time for decoding is extremely reduced. The consideration presented generates taking of decision demonstrating the applicability of the proposed system. / Neste trabalho é proposto um sistema para minimizar o tempo de busca de possíveis falhas em mensagens ISUP. A entrada do sistema proposto é representada por arquivos contendo mensagens da parte de usuário ISDN, que podem ser desde a ACM (Address complete) até a USR (User-to-user information). A saída do sistema proposto é exibida através de um outro arquivo contendo a mensagem lida e todo o seu significado, assim como uma análise da tradução. Os resultados obtidos mostram que o tempo para decodicação é extremamente reduzido. A consideração apresentada gera tomada de decisão demonstrando a aplicabilidade do sistema proposto.

[pt] O rápido desenvolvimento tecnológico que ocorreu na área de comunicações móveis e o surpreendente interesse por parte dos usuários geraram um crescimento da demanda maior que o esperado. A necessidade de atender essa demanda e de suportar novos serviços como áudio, vídeo e multimídia, vem motivando o estudo de novas tecnologias. Atualmente, um dos objetivos principais é o aumento da capacidade da interface rádio. Visando este objetivo, diversos métodos de acesso vêm sendo propostos. Neste trabalho será feita uma análise de três protocolos de acesso proposta para tecnologia TDMA: o PRMA (Packet Reservation Multiple Access), o RAMA (Resource Auction Multiple Access). Resultados numéricos comparando o desempenho dos protocolos RAMA e TRAMA não estavam disponíveis na literatura e serão apresentados. Baseando-se nestes resultados será proposta uma variação do RAMA, o F-RAMA (Fair Resource Auction Multiple Access). O desempenho do protocolo para transmissão de voz bem como a comparação com os outros protocolos serão apresentados. Será visto que o F-RAMA é um excelente candidato à transmissão de voz e bastante promissor para a tecnologia multimídia no ambiente móvel celular. / [en] The fast technological development that occurred in the mobile communications sector and the outstanding interest showed by the users resulted in na unexpected huge demand. The need to sypply this demand and to support new services such as audio, video and multimedia have motivated the study of new technologies. Nowadays, one of the greatest challenge is to increase the radio interface capacity. To meet this goal many access methods have been proposed. This work will analyse three access protocols proposed to TDMA technology: PRMA ( packet Reservation Multiple Access), RAMA (Resource Auction Multiple Access) and TRAMA ( Tree-search Resource Auction Multiple Acess), Numerical results comparing RAMA and TRAMA that were so far unavailable in the literature will be presented here. Based upon these results a variation of RAMA, F-RAMA ( Fair Resource Auction Multiple Access), will be proposed. The protocol perfomance for voice transmission and a comparison among the three will also be presented herein. The effect of the multimedia transmission over F-RAMA will be discussed. It will be show that F-RAMA is an excellent candidate for voice trasmission and a promising candidate for multimedia transmission in the mobile communication environment.

No description available.

[pt] O dimensionamento de enlaces digitais de comunicação e realizado com base em objetivos de desempenho a serem satisfeitos por determina- dos parâmetros, considerando o comportamento aleatório das fontes de degradação do sinal. Em sistemas de comunicação móvel por satélite, o de- sempenho pode ser fortemente afetado pelo erro de apontamento da antena provocado pelo movimento da plataforma. Neste estudo,é apresentada uma metodologia para a caracterização estatística da degradação conjunta por erro de apontamento e por atenuação por chuvas, e avaliado o efeito dessas fontes de degradação nos diversos parâmetros de desempenho. A metodolo- gia proposta permite dimensionar o sistema de comunicações móveis por satélite, e determinar restrições a serem impostas ao comportamento es- tatístico do erro de apontamento da antena. / [en] The design of digital communication links is based on performance objec- tives to be satisfied by certain link parameters. In mobile satellite com- munication systems, performance can be strongly affected by the antenna pointing error due to the platform motion. This study presents a method- ology for the statistical characterization of the joint degradation due to pointing error and to rain, and evaluates the effect of these degradation sources on the various performance parameters. The proposed methodology allows for the design of the mobile satellite communication systems, and for the determination of constrains to be imposed on the statistical behavior of the antenna pointing errors.

[pt] O desempenho de sistemas de comunicações modernos que utilizam técnicas de modulação multiportadora como, por exemplo, o OFDM (Orthogonal frequency division multiplexing), é altamente sensível às distorções não lineares geradas principalmente por amplificadores de alta potência (HPAs). De modo a caracterizar completamente estas distorções, os efeitos de memória destes dispositivos têm que ser considerados. Estes efeitos tornam-se mais importantes à medida que a largura de banda do sinal aumenta. Por outro lado, o aumento na duração do símbolo dos sistemas multiportadora torna-o mais sensível às variações de tempo dos canais móveis. Em particular o efeito doppler tende a prejudicar a ortogonalidade entre as sub-portadoras, gerando interferências entre sub-portadoras (Inter-Carrier Interference - ICI). Assim, torna-se importante o estudo dos efeitos de não-linearidades e canais variantes no tempo em sistemas OFDM, principalmente em sistemas de comunicações móveis. Os trabalhos atualmente disponíveis na literatura se limitam a avaliar os efeitos de não linearidades invariantes no tempo ou o efeito de canais lineares variantes no tempo. Assim, no presente trabalho são desenvolvidas expressões matemáticas que permitem avaliar o efeito conjunto de não-linearidades e canais variantes no tempo sobre sinais OFDM. A investigação deste efeito é realizada em dois níveis: efeito sobre o espectro do sinal OFDM e efeito sobre o desempenho do sistema. As expressões analíticas obtidas para ambos os níveis de investigação consideraram a modelagem do canal não-linear variante no tempo por uma Série de Volterra. Resultados numéricos que avaliam o espalhamento espectral e o impacto sobre a taxa de erro de bits em situações específicas são apresentados. / [en] The performance of modern communications systems that use multicarrier modulation techniques such as, for example, OFDM(Orthogonal frequency division multiplexing), is highly sensitive to nonlinear distortions generated mainly by high power amplifiers (HPAs). In order to fully characterize these distortions, the memory effects of these devices must be considered. These effects become more important as the signal bandwidth increases. On the other hand, the increase in symbol duration makes multicarriers systems more sensitive to time variations as those in mobile channels. In particular, the Doppler effect tends to impair the orthogonality between sub-carriers, resulting in inter-carrier interference (ICI). Therefore, the study of the effects of nonlinearities and time-varying channels on OFDM systems performance becomes important, mainly in mobile communications systems. The studies currently available in the literature are limited to evaluating the effects of time invariant non-linearities or the effects of linear time varying channels. In this work, mathematical expressions are developed to evaluate the joint effect of nonlinearities and time-varying channels on OFDM systems. The investigation of these effects is performed at two levels: the effect on the spectrum of OFDM signal and effect on the system s performance. In deriving the analytical expressions related to both levels of investigation the time-varying non-linear channel was modeled by a Volterra Series. Numerical results, obtained for specific situations, illustrate the resulting impact on the OFDM spectrum (spreading) and on the system s bit error rate performance.

Diploma work on the theme Content Analysis of advertisements' in mobile communication concerned by research work of mobile operators and mobile phone makes. First part of the research work focuses on characteristics of Koktejl magazine, where from I have picked the advertisements', descriptions of market operators and descriptions of used research technique. In next part the research work is being processed. This research work was done by content analysis of advertisements' in Koktejl magazine. It was done from all advertisements' of mobile communication, which were published since 1997 to the present. Research outcome is to find out how the printed communication in mobile world had changed and how had changed the communication of operators in moments, when they were becoming a part of transnational company.

Diploma thesis is focused on an analysis of radio conditions of indoor LTE-A mobile networks. Measurements of the Huawei LTE-A radio access network were performed using the R&S TSMW spectral analyser. Results have been processed and discussed. The practical part of diploma thesis also consists of a development of a program for processing the data sets obtained from R&S TSMW spectral analyzer.

The fifth generation (5G) of mobile communication networks is envisioned to enable a variety of novel applications. These applications demand requirements from the network, which are diverse and challenging. Consequently, the mobile network has to be not only capable to meet the demands of one of these applications, but also be flexible enough that it can be tailored to different needs of various services. Among these new applications, there are use cases that require low latency as well as an ultra-high reliability, e.g., to ensure unobstructed production in factory automation or road safety for (autonomous) transportation. In these domains, the requirements are crucial, since violating them may lead to financial or even human damage. Hence, an ultra-low probability of failure is necessary. Based on this, two major questions arise that are the motivation for this thesis. First, how can ultra-low failure probabilities be evaluated, since experiments or simulations would require a tremendous number of runs and, thus, turn out to be infeasible. Second, given a network that can be configured differently for different applications through the concept of network slicing, which performance can be expected by different parameters and what is their optimal choice, particularly in the presence of other applications. In this thesis, both questions shall be answered by appropriate mathematical modeling of the radio interface and the radio access network. Thereby the aim is to find the distribution of the (end-to-end) latency, allowing to extract stochastic measures such as the mean, the variance, but also ultra-high percentiles at the distribution tail. The percentile analysis eventually leads to the desired evaluation of worst-case scenarios at ultra-low probabilities. Therefore, the mathematical tool of queuing theory is utilized to study video streaming performance and one or multiple (low-latency) applications. One of the key contributions is the development of a numeric algorithm to obtain the latency of general queuing systems for homogeneous as well as for prioritized heterogeneous traffic. This provides the foundation for analyzing and improving end-to-end latency for applications with known traffic distributions in arbitrary network topologies and consisting of one or multiple network slices. / Es wird erwartet, dass die fünfte Mobilfunkgeneration (5G) eine Reihe neuartiger Anwendungen ermöglichen wird. Allerdings stellen diese Anwendungen sowohl sehr unterschiedliche als auch überaus herausfordernde Anforderungen an das Netzwerk. Folglich muss das mobile Netz nicht nur die Voraussetzungen einer einzelnen Anwendungen erfüllen, sondern auch flexibel genug sein, um an die Vorgaben unterschiedlicher Dienste angepasst werden zu können. Ein Teil der neuen Anwendungen erfordert hochzuverlässige Kommunikation mit niedriger Latenz, um beispielsweise unterbrechungsfreie Produktion in der Fabrikautomatisierung oder Sicherheit im (autonomen) Straßenverkehr zu gewährleisten. In diesen Bereichen ist die Erfüllung der gestellten Anforderungen besonders kritisch, da eine Verletzung finanzielle oder sogar personelle Schäden nach sich ziehen könnte. Eine extrem niedrige Ausfallwahrscheinlichkeit ist daher von größter Wichtigkeit. Daraus ergeben sich zwei wesentliche Fragestellungen, welche diese Arbeit motivieren. Erstens, wie können extrem niedrige Ausfallwahrscheinlichkeiten evaluiert werden. Ihr Nachweis durch Experimente oder Simulationen würde eine extrem große Anzahl an Durchläufen benötigen und sich daher als nicht realisierbar herausstellen. Zweitens, welche Performanz ist für ein gegebenes Netzwerk durch unterschiedliche Konfigurationen zu erwarten und wie kann die optimale Konfiguration gewählt werden. Diese Frage ist insbesondere dann interessant, wenn mehrere Anwendungen gleichzeitig bedient werden und durch sogenanntes Slicing für jeden Dienst unterschiedliche Konfigurationen möglich sind. In dieser Arbeit werden beide Fragen durch geeignete mathematische Modellierung der Funkschnittstelle sowie des Funkzugangsnetzes (Radio Access Network) adressiert. Mithilfe der Warteschlangentheorie soll die stochastische Verteilung der (Ende-zu-Ende-) Latenz bestimmt werden. Dies liefert unterschiedliche stochastische Metriken, wie den Erwartungswert, die Varianz und insbesondere extrem hohe Perzentile am oberen Rand der Verteilung. Letztere geben schließlich Aufschluss über die gesuchten schlimmsten Fälle, die mit sehr geringer Wahrscheinlichkeit eintreten können. In der Arbeit werden Videostreaming und ein oder mehrere niedriglatente Anwendungen untersucht. Zu den wichtigsten Beiträgen zählt dabei die Entwicklung einer numerischen Methode, um die Latenz in allgemeinen Warteschlangensystemen für homogenen sowie für priorisierten heterogenen Datenverkehr zu bestimmen. Dies legt die Grundlage für die Analyse und Verbesserung von Ende-zu-Ende-Latenz für Anwendungen mit bekannten Verkehrsverteilungen in beliebigen Netzwerktopologien mit ein oder mehreren Slices.

When considering the addition of a mobile presentation channel to an existing web-based application, a key question that has to be answered even before development begins is how the mobile channel's characteristics will impact the user experience and the cost of using the application. If either of these factors is outside acceptable limits, economical considerations may forbid adding the channels, even if it would be feasible from a purely technical perspective. Both of these factors depend considerably on two metrics: The time required to transmit data over the mobile network, and the volume transmitted. The PETTICOAT method presented in this paper uses the dialog flow model and web server log files of an existing application to identify typical interaction sequences and to compile volume statistics, which are then run through a tool that simulates the volume and time that would be incurred by executing the interaction sequences on a mobile channel. From the simulated volume and time data, we can then calculate the cost of accessing the application on a mobile channel, and derive suitable approaches for optimizing cost and response times.