Orientador: Heloisa Vieira da Rocha / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-06T23:50:55Z (GMT). No. of bitstreams: 1 Nemer_AmarilisCanhada_M.pdf: 3000977 bytes, checksum: 07495bf3e42cd276238a03af7c80c133 (MD5) Previous issue date: 2006 / Resumo: Está havendo uma rápida convergência de tecnologias no que diz respeito ao telefone móvel. A primeira geração de dispositivos móveis foi desenvolvida para satisfazer a mesma necessidade do usuário das linhas telefones fixos: fazer e receber chamadas. Um aumento do número das funções tem ocorrido, tais como mensagem texto/voz/multimídia, conexão Internet, tocador de música, filmadora, câmera, agenda, Bluetooth; se estendendo a uma infinidade de funcionalidades nunca antes imaginadas a esses pequenos dispositivos que estão evoluindo na direção dos telefones inteligentes. Este estudo objetiva analisar a usabilidade tomando como ponto de partida convergência de tecnologias, a multiplicidade de aplicações existentes para telefones celulares e a abrangência em termos de usuários. Buscamos obter respostas sobre alguns problemas que estão se impondo ao usuário a partir dessa convergência, como a complexidade dos dispositivos; a atual dificuldade das funcionalidades existentes e novas em relação à usabilidade / Abstract: lt is happening a fast convergence of technologies regarding mobile phones. The first mobile phone generation was developed to satisfy the users to make and receive calls similarly to fixed phones. However, new functionalities such as messaging, multimedia, internet connection, sound player, video, camera, Bluetooth are being added into these devices, which are becoming smart phones. This study aims to contribute to analysis of the mobile phones usability, considering the convergence of technologies, the variety of functionalities into mobile phones and the vast number of different users. lt aims to reach answers regarding complexity, difficulties in handling existing and new functionalities of the mobile phones / Mestrado / Engenharia de Computação / Mestre em Ciência da Computação

No presente trabalho são aplicadas ferramentas estatísticas quantitativas clássicas no setor de telefonia móvel brasileiro a fim de comparar os seus resultados. Uma metodologia é proposta para a aplicação destas ferramentas de um modo prático em uma de uma operadora de telefonia celular brasileira. Após são aplicados os métodos de previsão às séries históricas de demanda de acessos da telefonia móvel brasileira, estratificadas de acordo com as tecnologias utilizadas (TDMA, CDMA e GSM), no período de agosto de 2002 a julho de 2007. De acordo com o desempenho, são obtidos os modelos de cada método estatístico proposto. Entre estes, se escolheu aquele que melhor descreveu cada série e previsões foram geradas. Os modelos ARIMA apresentaram o melhor desempenho dentre os métodos aplicados nas séries estudadas. / The activity of planning ahead their systems in an appropriate manner is fundamental to telecommunication sector agents in order to manage the resources allocation and to meet the quality requirements in the provision of mobile telephony services. As the networks and production systems deployment takes time, there is the need of a service demand forecast. Therefore, in this study, classical quantitative statistics tools are applied to the Brazilian mobile telephony sector to compare their results. A methodology for the application of such tools in a practical way within a business environment of this sector is proposed. Afterwards, forecasting methods are applied to the time series referred to Brazilian mobile telephony demand, stratified according to the technologies (TDMA, CDMA and GSM) in the period from August 2002 to July 2007. The models of each statistical method proposed, based on the performance results, are obtained and, among these methods, it is chosen a model that best described each time series. The ARIMA model had the best performance among the methods applied in the time series studied and forecasts were made.

No presente trabalho são aplicadas ferramentas estatísticas quantitativas clássicas no setor de telefonia móvel brasileiro a fim de comparar os seus resultados. Uma metodologia é proposta para a aplicação destas ferramentas de um modo prático em uma de uma operadora de telefonia celular brasileira. Após são aplicados os métodos de previsão às séries históricas de demanda de acessos da telefonia móvel brasileira, estratificadas de acordo com as tecnologias utilizadas (TDMA, CDMA e GSM), no período de agosto de 2002 a julho de 2007. De acordo com o desempenho, são obtidos os modelos de cada método estatístico proposto. Entre estes, se escolheu aquele que melhor descreveu cada série e previsões foram geradas. Os modelos ARIMA apresentaram o melhor desempenho dentre os métodos aplicados nas séries estudadas. / The activity of planning ahead their systems in an appropriate manner is fundamental to telecommunication sector agents in order to manage the resources allocation and to meet the quality requirements in the provision of mobile telephony services. As the networks and production systems deployment takes time, there is the need of a service demand forecast. Therefore, in this study, classical quantitative statistics tools are applied to the Brazilian mobile telephony sector to compare their results. A methodology for the application of such tools in a practical way within a business environment of this sector is proposed. Afterwards, forecasting methods are applied to the time series referred to Brazilian mobile telephony demand, stratified according to the technologies (TDMA, CDMA and GSM) in the period from August 2002 to July 2007. The models of each statistical method proposed, based on the performance results, are obtained and, among these methods, it is chosen a model that best described each time series. The ARIMA model had the best performance among the methods applied in the time series studied and forecasts were made.

No presente trabalho são aplicadas ferramentas estatísticas quantitativas clássicas no setor de telefonia móvel brasileiro a fim de comparar os seus resultados. Uma metodologia é proposta para a aplicação destas ferramentas de um modo prático em uma de uma operadora de telefonia celular brasileira. Após são aplicados os métodos de previsão às séries históricas de demanda de acessos da telefonia móvel brasileira, estratificadas de acordo com as tecnologias utilizadas (TDMA, CDMA e GSM), no período de agosto de 2002 a julho de 2007. De acordo com o desempenho, são obtidos os modelos de cada método estatístico proposto. Entre estes, se escolheu aquele que melhor descreveu cada série e previsões foram geradas. Os modelos ARIMA apresentaram o melhor desempenho dentre os métodos aplicados nas séries estudadas. / The activity of planning ahead their systems in an appropriate manner is fundamental to telecommunication sector agents in order to manage the resources allocation and to meet the quality requirements in the provision of mobile telephony services. As the networks and production systems deployment takes time, there is the need of a service demand forecast. Therefore, in this study, classical quantitative statistics tools are applied to the Brazilian mobile telephony sector to compare their results. A methodology for the application of such tools in a practical way within a business environment of this sector is proposed. Afterwards, forecasting methods are applied to the time series referred to Brazilian mobile telephony demand, stratified according to the technologies (TDMA, CDMA and GSM) in the period from August 2002 to July 2007. The models of each statistical method proposed, based on the performance results, are obtained and, among these methods, it is chosen a model that best described each time series. The ARIMA model had the best performance among the methods applied in the time series studied and forecasts were made.

Orientador: Celso de Almeida / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-04T17:31:16Z (GMT). No. of bitstreams: 1 Ramos_RodrigoPereira_D.pdf: 950853 bytes, checksum: f7285f4019c5e070e6dc3c92e1e16464 (MD5) Previous issue date: 2005 / Resumo: o desempenho dos sistemas de comunicações móveis baseados na técnica de acesso múltiplo CDMA é limitado pela interferência. Nesta tese, propomos um algoritmo de escolha de seqüências com comprimento fixo para a redução de interferência em sistemas CDMA em canais com desvanecimento seletivo em freqüência, que se baseia na minimização da probabilidade de erro de bit média do sistema. Dentre as classes de seqüências abordadas, podemos citar a de Walsh, a de Gold, a de comprimento máximo e também um novo tipo de seqüência de espalhamento baseado nas seqüências de comprimento máximo. Analisamos o desempenho de sistemas CDMA com arranjo de antenas na recepção e técnicas de diversidade de transmissão, mais especificamente codificação espaço-temporal. Desenvolvemos um limitante superior para a probabilidade de erro de bit média para estes sistemas. Também apresentamos a generalização do algoritmo proposto, para o caso com múltiplas antenas de transmissão e recepção. Com o objetivo de tornar o algoritmo de escolha mais efetivo no enlace reverso, é proposta uma sincronização dos usuários neste enlace / Abstract: The performance of mobile communication systems based on the CDMA technique is limited by interference. In this thesis, we propose a selection algorithm of spreading sequences with fixed length for interference mitigation on CDMA systems over frequency-selective fading channels, that is based on the minimization of the overall mean bit error probability of the system. The classes of sequences considered are Walsh, Gold, maximum length, and a new type of spreading sequences based on the maximum length sequences. We analyse CDMA systems performance with antenna array at the reception and diversity transmission techniques, specifically space-time coding. An upper-bound for the mean bit error probability of those systems is obtained. We also present a generalization of the proposed algorithm for multiple transmission and reception antennas. With the objective of making the selection algorithm more effective on the reverse link, it is proposed synchronization of the users on this link / Doutorado / Telecomunicações e Telemática / Doutor em Engenharia Elétrica

Rural telephony has historically been a recurring subject of concern for most large developing countries. It is generally considered that rural telephone users do not generate the same level of telephone traffic and, thus, revenue as urban users, lowering the incentives to invest in rural telecommunications. The financial implications of wiring a vast area for low telephone traffic causes most telephone service providers to ignore or delay offering telephone service to those regions. Still, it is known that telecommunications are essential to the economic development of a region, and that traffic increases rapidly as soon as the service is available. A satellite-based telephone network can provide efficient long distance telephone service to remote rural communities at a lower cost than land-based wired networks in most cases. Mobile satellite systems already provide this service, but are limited in capacity and charge high per- minute fees for the satellite link. Small earth stations and GEO satellites can provide this service more efficiently and at lower cost. A methodology to optimize the network performance has been developed. A set of economic models to evaluate different combinations of network topologies and multiple access techniques have been implemented, and a technical-economic assessment has been performed for the different technologies under different traffic scenarios. Traffic intensity, network size and per-minute user costs have been optimized to achieve the network's economic break-even point under different conditions and constraints. The general behavior of fixed-assignment Single Channel per Carrier SCPC), fixed-assignment Multiple Channel per Carrier (MCPC) and demand-assignment SCPC star networks, as well as demand-assignment SCPC mesh networks has been analyzed. Important parameters have been identified in order to improve the process of effective and cost-efficient satellite rural telephone network design. / Ph. D.

Esta tesis contribuye a varios campos del conocimiento. Primero, en ella se estudia el efecto ambiguo que la tecnología de Internet tiene en la estructura de costes de transacción en el caso de las ventas al por menor. En segundo lugar, esta tesis estudia empíricamente que factores determinan la adopción de la tecnología de Internet y la telefonía celular a nivel mundial desde 1980. Se demuestra que las diferencias entre países están determinadas en gran medida por el clima de inversión que afecta los incentivos de adoptar tecnologías basadas en activos específicos. Finalmente de desarrolla y pone a prueba una teoría que relaciona los sistemas electorales y las configuraciones de gobierno con la protección de los derechos de propiedad. Se propone un modelo, que establece una relación negativa entre el número de instituciones de toma de decisión consensual y el grado de protección de los derechos de propiedad. / This research contributes to several fields of knowledge. It studies the ambiguous effects that the Internet has on the transaction costs structure in the case of retailing. Next, it presents an empirical study of the determinants of worldwide Internet and cellular phone penetration levels since 1980. It is shown that cross-country differences in the use of information and communication technologies (ICT) are to a considerable extent due to differences in investment climate, which determines the incentives to adopt technologies based on site-specific assets. Finally, this thesis develops and tests a theory regarding the effect that electoral formats and government configurations have on the degree of property rights protection. A formal model is presented, which establishes a negative relationship between the number of institutions of consensual collective decision-making and the degree of property rights protection.

Made available in DSpace on 2015-05-14T12:36:46Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3033244 bytes, checksum: e99c06debab1ade6a603c593035a9da1 (MD5) Previous issue date: 2014-01-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / With the economic growth experienced in recent years, many brazilian cities have also encountered problems such as population growth, congestion of vehicles and violence. At the same time, the purchasing power of the population has grown, allowing many of them to purchase new equipment, such as mobile phones, with Brazil surpassed the barrier of a cell phone per inhabitant. This study aimed to examine the feasibility of using computer simulation systems, using data from the mobile telephone network, aiming a system of urban monitoring usig vehicles. The results showed that the higher was the number of vehicles on public streets, most will hit rate with the data from the cellular network using the methodology of Erlang. / Com o crescimento econômico vivido nos últimos anos, muitas cidades brasileiras têm também se deparado com problemas como o aumento populacional, congestionamento de veículos e a violência. Ao mesmo tempo, o poder aquisitivo dos habitantes tem crescido, permitindo que muitos pudessem adquirir novos equipamentos, como os telefones celulares, tendo o Brasil ultrapassado a barreira de um telefone celular por habitante. Esse trabalho objetivou a analise de viabilidade do uso de sistemas de simulação computacional, utilizando dados da rede de telefonia móvel celular, visando um sistema de monitoramento urbano com veículos. Os resultados mostraram que, quanto maior foi o número de veículos em circulação nas vias públicas, maior será a taxa de acerto com os dados oriundos da rede de telefonia celular utilizando a metodologia de Erlang.

Αντικείμενο της παρούσας διπλωματικής εργασίας είναι η μελέτη των μεθόδων βελτιστοποίησης της ποιότητας των παρεχομένων υπηρεσιών των δικτύων κυτταρικής τηλεφωνίας τρίτης γενιάς σε διαλειπτικό περιβάλλον. Αρχικά γίνεται μια σύντομη ιστορική αναδρομή στην εξέλιξη των συστημάτων κινητών επικοινωνιών και παρουσιάζεται το σημαντικότερο πρότυπο τρίτης γενιάς, το UMTS και τα ιδιαίτερα τεχνικά χαρακτηριστικά του. Στην συνέχεια αναλύεται το LTE το οποίο αποτελεί την τελευταία εξέλιξη των δικτύων τρίτης γενιάς και αναμένεται να αντικαταστήσει το UMTS στο άμεσο μέλλον αποτελώντας στην πραγματικότητα τον πρόδρομο των συστημάτων τέταρτης γενιάς. Στην συνέχεια εστιάζουμε στα διαλειπτικά κανάλια αναλύοντας τα φαινόμενα που παρατηρούνται σε αυτά και τα στατιστικά μοντέλα μέσα από τα οποία περιγράφονται. Παράλληλα διερευνάται η επίδραση των φαινομένων αυτών (θετική ή αρνητική) στο QoS των δικτύων τρίτης γενιάς βάσει των χαρακτηριστικών τους (όπως παρουσιάστηκαν στο κεφάλαιο 1) και οι δυνατότητες για περαιτέρω βελτιστοποίηση κατα τον σχεδιασμό των δικτύων και την σωστή εκμετάλλευση των χαρακτηριστικών του περιβάλλοντος όδευσης. Ιδιαίτερη αναφορά γίνεται στα μοντέλα εσωτερικού χώρου λόγω του μεγάλου φορτίου κίνησης που καλούνται να εξυπηρετήσουν. Στο τελευταίο μέρος παρουσιάζεται η διαδικασία παραμετροποίησης κάποιων σημαντικών μοντέλων και τα αποτελέσματα των εξομοιώσεων που έγιναν στον χώρο του κτηρίου των Ηλεκτρολόγων Μηχανικών. / The subject of this diploma thesis is the study of the optimization techniques of the quality of service for third generation cellular telephony networks in fading enviroment. After a short presentation of the evolution of the systems of wireless telecommunications, it is discussed UMTS the most important third generation system which dominated the european market and its technical features. LTE is also introduced, the system which is expected to replace UMTS in the near future while being the predecessor of the fourth generation systems. Then we focus on the fading channels analysing the phenomena wich are related to them and analysing the statistical models that describe them. It is also studied the effect (positive or negative) of these phenomena on the QoS of the third generation networks and the optimization methods which can be applied during the network designing process with special reference to the indoor propagation models because of the big amount of traffic load that they are asked to serve. At the last chapter of the thesis there is a presentation of the parameter setting procedure for some important models and the outcomes of the simulation that took place in the building of Electronic Engineering.

Orientador: Shusaburo Motoyama / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-17T02:39:28Z (GMT). No. of bitstreams: 1 Marques_LeandroBentoSena_D.pdf: 3039404 bytes, checksum: 84c76813ec2349c45ae1c49f833c31d4 (MD5) Previous issue date: 2010 / Resumo: Este trabalho apresenta um estudo de desempenho dos enlaces diretos dos sistemas CDMA 1xEVDO RA, UMTS/HSDPA e WiMAX com ênfase em escalonadores de dados e nos novos critérios de aceitação de tráfego handoff horizontal e vertical para redes 3G e 4G. Estes novos critérios de aceitação de tráfego handoff horizontal e vertical levam em conta a ocupação do enlace, a ocupação do buffer, a potência do sinal recebido (RSS) e o tamanho do quantum (DRR) como parâmetros para a decisão do processo de handoff. Além disso, o estudo considera os escalonadores de dados Max C/I (Maximum Carrier Interference), DRR (Deficit Round Robin), PF (Proportional Fair), Pr (Prioritário) e a nova proposta Pr/PF (Priority Proportional Fair). Os critérios combinados aos escalonadores são avaliados pormeio de métricas de QoS em função da chegada de tráfego HTTP interno ou em handoff. Os resultados mostraram que conforme o critério e o escalonador adotados, podem assegurar a QoS dos sistemas móveis e ainda aceitar uma boa quantidade de tráfego handoff. O estudo é baseado em simulações computacionais através da ferramenta de software Matlab / Abstract: This work presents a performance study of the forward links of CDMA 1xEV-DO RA, UMTS/HSDPA and WiMAX systems with emphasis on data schedulers and new criteria for horizontal and vertical handoff traffic acceptance in the 3G and 4G networks. These new criteria for horizontal and vertical handoff traffic acceptance take into account the link occupation, the buffer occupation, the received signal strength (RSS) and the size of quantum (DRR) as inputs for decision of handoff process. Moreover, the study considers the data schedulers Max C/I (Maximum Carrier Interference), DRR (Deficit Round Robin), PF (Proportional Fair), Pr (Priority) and the new proposal Pr/PF (Priority Proportional Fair). The criteria combined with the data schedulers are evaluated using QoS metrics in function of internal HTTP traffic or handoff traffic. The results showed that depending on the chosen criterion and scheduler, it is possible to assure the QoS of mobile systems and still accept a good amount of handoff traffic. The study is based on computer simulations through Matlab software tool / Doutorado / Telecomunicações e Telemática / Doutor em Engenharia Elétrica