Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2009. / Texto liberado parcialmente pelo autor. Conteudo liberado: resumo e abstract. / Submitted by Tania Milca Carvalho Malheiros (tania@bce.unb.br) on 2009-08-18T11:24:42Z No. of bitstreams: 1 2009_Paulo_Henrique_Sales_Wanderley.pdf: 996078 bytes, checksum: 40c4bfb537aa8864821736f69c312743 (MD5) / Rejected by Guimaraes Jacqueline(jacqueline.guimaraes@bce.unb.br), reason: on 2009-08-18T12:02:00Z (GMT) / Submitted by Tania Milca Carvalho Malheiros (tania@bce.unb.br) on 2009-08-18T12:09:46Z No. of bitstreams: 1 2009_Paulo_Henrique_Sales_Wanderley.pdf: 996103 bytes, checksum: 510ca49ce9abdb583257d9981e426b45 (MD5) / Approved for entry into archive by Guimaraes Jacqueline(jacqueline.guimaraes@bce.unb.br) on 2009-08-18T16:21:50Z (GMT) No. of bitstreams: 1 2009_Paulo_Henrique_Sales_Wanderley.pdf: 996103 bytes, checksum: 510ca49ce9abdb583257d9981e426b45 (MD5) / Made available in DSpace on 2009-08-18T16:21:50Z (GMT). No. of bitstreams: 1 2009_Paulo_Henrique_Sales_Wanderley.pdf: 996103 bytes, checksum: 510ca49ce9abdb583257d9981e426b45 (MD5) Previous issue date: 2009-05 / Com o aumento da utilização do sistema de telefonia celular, houve um crescimento notável no número de Estações Rádio-Base instaladas em localidades povoadas. Neste contexto, este trabalho pretende mostrar como as Estações Rádio-Base do sistema celular disseminam sua energia no ambiente que as circundam, e através da análise da propagação dessa energia, utilizando simulações computacionais, verificar se as emissões destes sistemas estão de acordo com a regulamentação vigente deste tipo de propagação. Para análise das perdas no caminho de propagação será utilizado o modelo de propagação de Ikegami-Walfisch. Neste trabalho se destaca também a utilização de modelos de antenas reais para realização destas simulações. Esta análise de perdas e a utilização de antenas reais aproximam as simulações da condição real do ambiente de propagação que será simulado. Nos casos em que as emissões destes sistemas não estejam em conformidade com a regulamentação vigente, este trabalho também analisa os fatores que geram estas inconformidades do ponto de vista dos parâmetros do sistema. _____________________________________________________________________________________ ABSTRACT / With the increase in the use of cellular telephony, an explosive growth in the number of radio-base stations installed in populated localities is observed. In this context, this work aims to show how the radio-base stations of cellular system spread its energy in the surrounding environment, and analyze the propagation of this energy, using computer simulations to verify whether the emission of these systems follows the current rules specified for this kind of propagation. The propagation model used for evaluation of losses in the propagation path is COST 231 of Ikegami-Walfisch. This work also emphasizes the use of real models of antennas to carry out the presented simulations. This analysis of losses and the use of real antennas approximates the simulations with the conditions of the real environment of propagation that is simulated. In the cases that the emissions from these systems are not in accordance with the current regulations, this work also examines the factors that generate these shortcomings in terms of the parameters of the cellular system.

Large scale path loss modeling plays a fundamental role in designing both fixed and mobile radio systems. Predicting the radio coverage area of a system is not done in a standard manner. Wireless systems are expensive systems. Therefore, before setting up a system one has to choose a proper method depending on the channel environment, frequency band and the desired radio coverage range. Path loss prediction plays a crucial role in link budget analysis and in the cell coverage prediction of mobile radio systems. Especially in urban areas, increasing numbers of subscribers brings forth the need for more base stations and channels. To obtain high efficiency from the frequency reuse concept in modern cellular systems one has to eliminate the interference at the cell boundaries. Determining the cell size properly is done by using an accurate path loss prediction method. Starting from the radio propagation phenomena and basic path loss models this thesis aims at describing various accurate path loss prediction methods used both in rural and urban environments. The Walfisch-Bertoni and Hata models, which are both used for UHF propagation in urban areas, were chosen for a detailed comparison. The comparison shows that the Walfisch-Bertoni model, which involves more parameters, agrees with the Hata model for the overall path loss.

<p>Large scale path loss modeling plays a fundamental role in designing both fixed and mobile radio systems. Predicting the radio coverage area of a system is not done in a standard manner. Wireless systems are expensive systems. Therefore, before setting up a system one has to choose a proper method depending on the channel environment, frequency band and the desired radio coverage range. Path loss prediction plays a crucial role in link budget analysis and in the cell coverage prediction of mobile radio systems. Especially in urban areas, increasing numbers of subscribers brings forth the need for more base stations and channels. To obtain high efficiency from the frequency reuse concept in modern cellular systems one has to eliminate the interference at the cell boundaries. Determining the cell size properly is done by using an accurate path loss prediction method. Starting from the radio propagation phenomena and basic path loss models this thesis aims at describing various accurate path loss prediction methods used both in rural and urban environments. The Walfisch-Bertoni and Hata models, which are both used for UHF propagation in urban areas, were chosen for a detailed comparison. The comparison shows that the Walfisch-Bertoni model, which involves more parameters, agrees with the Hata model for the overall path loss.</p>