Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 271-294).

Em telecomunicações é utilizada uma grande variedade de modelos de propagação para prever a intensidade do sinal de recepção num enlace de rádio. Os resultados dos modelos empíricos e dos modelos baseados em simplificações do problema eletromagnético apresentam, em geral, grande discrepância entre si, na análise do fenômeno de propagação. Por exemplo, o modelo de dois raios, que prevê atenuação de enlace com variação de 40 dB/década, na região de campo distante da antena de transmissão, quando colocada a uma certa altura da superfície de um solo condutor perfeito. Já o modelo empírico de Okumura-Hata exibe, para as mesmas condições geométricas, mas para solo de condutividade finita, uma variação da atenuação de enlace de 30 dB/década. Neste trabalho propõe-se uma calibração do modelo de dois raios para aumentar sua aderência aos resultados obtidos por Okumura-Hata num cenário real na faixa de frequências de 450MHz a 1900MHz para comprimentos de enlace entre 1 km e 20 km. Os resultados obtidos com o modelo proposto são comparados com os obtidos através de outros modelos apresentando boa aderência verificada através de uma comparação numérica particularmente com o modelo Okumura-Hata. / In telecommunications, there is a large variety of propagation models in order to predict the intensity of the receiving signal in a communication link. The empirical models and the models based on simplifications of the electromagnetic problem with theoretically obtained results show, in general, a significant disagreement, for the same propagation phenomenon. For example two-ray model predicts a path-loss of 40 dB/decade in the far-field region of a transmission antenna deployed at a certain height of the surface of a perfect conducting soil. On the other hand, the Okumura-Hata empirical model shows, for the same geometrical conditions, bur for a real soil, a path-loss of 30 dB/decade. This work proposes a calibration of the Two-Ray model for better adherence to the results obtained by Okumura-Hata in a real scenario for the frequency range 450MHz to 1900MHz and for a radio link length of 1 km to 20 km. The results obtained with the proposed model are compared with other model results showing good adherence through numeric comparison, in particular with the Okumura - Hata model.

Em telecomunicações é utilizada uma grande variedade de modelos de propagação para prever a intensidade do sinal de recepção num enlace de rádio. Os resultados dos modelos empíricos e dos modelos baseados em simplificações do problema eletromagnético apresentam, em geral, grande discrepância entre si, na análise do fenômeno de propagação. Por exemplo, o modelo de dois raios, que prevê atenuação de enlace com variação de 40 dB/década, na região de campo distante da antena de transmissão, quando colocada a uma certa altura da superfície de um solo condutor perfeito. Já o modelo empírico de Okumura-Hata exibe, para as mesmas condições geométricas, mas para solo de condutividade finita, uma variação da atenuação de enlace de 30 dB/década. Neste trabalho propõe-se uma calibração do modelo de dois raios para aumentar sua aderência aos resultados obtidos por Okumura-Hata num cenário real na faixa de frequências de 450MHz a 1900MHz para comprimentos de enlace entre 1 km e 20 km. Os resultados obtidos com o modelo proposto são comparados com os obtidos através de outros modelos apresentando boa aderência verificada através de uma comparação numérica particularmente com o modelo Okumura-Hata. / In telecommunications, there is a large variety of propagation models in order to predict the intensity of the receiving signal in a communication link. The empirical models and the models based on simplifications of the electromagnetic problem with theoretically obtained results show, in general, a significant disagreement, for the same propagation phenomenon. For example two-ray model predicts a path-loss of 40 dB/decade in the far-field region of a transmission antenna deployed at a certain height of the surface of a perfect conducting soil. On the other hand, the Okumura-Hata empirical model shows, for the same geometrical conditions, bur for a real soil, a path-loss of 30 dB/decade. This work proposes a calibration of the Two-Ray model for better adherence to the results obtained by Okumura-Hata in a real scenario for the frequency range 450MHz to 1900MHz and for a radio link length of 1 km to 20 km. The results obtained with the proposed model are compared with other model results showing good adherence through numeric comparison, in particular with the Okumura - Hata model.

Στην εργασία αυτή γίνεται μια αναφορά αρχικά στα GSM δίκτυα κινητής τηλεφωνίας (χαρακτηριστικά-λειτουργίες). Στη συνέχεια περιγράφεται ο τρόπος υπολογισμού της κυτταρικής ακτίνας με βάση τα μοντέλα Okumura-Hata και Ikegami. Τέλος αναφέρονται παραδείγματα υπολογισμού της ακτίνας των κυττάρων αλλά και διαστασιοποίησης των καναλιών σε αυτά ώστε να εξυπηρετείται συγκεκριμένη τηλεπικοινωνιακή κίνηση. / The purpose of this project is to examine the major steps in cell planning process such as cell coverage, frequency planning and calculations of traffic and channel needs for the given areas.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 271-294). / Also available by subscription via World Wide Web / ix, 294 leaves, bound 29 cm

The dissertation concerns about the path loss calculation of Radio Frequency (RF) propagation models for 4G Long Term Evolution (LTE) Network to prefer the best Radio Frequency propagation model. The radio propagation models are very significant while planning of any wireless communication system. A comparative analysis between radio propagation models e.g. SUI model, Okumura model, Cost 231 Hata Model, Cost 231-Walfisch Ikegami and Ericsson 9999 model that would be used for outdoor propagation in LTE. The comparison and performance analysis has been made by using different geological environments e.g. urban, sub-urban and rural areas. The simulation scenario is made to calculate the lowest path loss in above defined environments by using selected frequency and height of base station antennas while keeping a constant distance between the transmitter and receiver antennas. / Asad Saeed C/O Muhammad Awais Hovslagargatan 47 LGH 1004 19431 Stockholm Sweden Mob: 0046723333734

Aim of this master´s project is to analyse localization possibilities in GSM and GPS wireless networks. Choise of proper module and design location device for both GPS and GSM networks. Design and construction of system, which is able to designate it´s positron, using both GPS and GSM networks. The location informations, are send to Internet server, using GPRS system. Localization techniques in both wireless network are described. The system which is able to get position information was designed and constructed. The module´s driving software and the software, which process the localization informations and controls the database storing process, was designed.