Made available in DSpace on 2016-04-04T18:31:22Z (GMT). No. of bitstreams: 1 Gildevane Aparecido Ferreira.pdf: 3776872 bytes, checksum: 2024d74a9d885d3bc67ca267094d9d6c (MD5) Previous issue date: 2008-02-25 / This MSc. thesis presents new results of activities with the development and characterization on RF devices operating on the 2,4 GHz channel, which has been done using a flat fast fading emulator. This RF emulator has been developed with the use of electronic circuits between them, and the presence of an attenuator which can be controlled by software and another one controlled by a power supply. The performance and characterization of the emulator has been done with some tests of video streaming links. The essential purpose is to present a simple and efficient approach to implement a testbed emulation of flat fast fading that can allow the RF signal to be confined inside a coaxial cable, where there is a controlled ambient whose permits to investigate the performance over all wireless networks. We perform also in this work some comparison to evaluate the behavior of both the 802.11b and 802.11g standards in flat fast fading channel through a video transmission and a further analysis of the jitter in many different power levels of the signal by assuming that the emulator has a perfect control of the system. / An?lise comparativa do desempenho das redes locais sem fio (WLANs), padr?o IEEE 802.11b e 802.11g, na transmiss?o de fluxo cont?nuo de v?deo, tamb?m conhecido como streaming de v?deo, simulando caracter?sticas de uma transmiss?o de v?deo em formato IPTV, com o intuito de identificar qual dos dois padr?es tem melhor desempenho na transmiss?o desse tipo de tr?fego. Esse trabalho foi motivado pela necessidade de implanta??o da segunda fase do projeto Exibe da TV PUC Campinas, que prev? a distribui??o da programa??o do canal universit?rio, em formato IPTV, atrav?s de redes IP sem fio. Para simula??o desse sistema de distribui??o de v?deo, foram feitas an?lises das caracter?sticas de distribui??o, transmiss?o e formatos do v?deo transmitido. As transmiss?es foram realizadas com o uso de um emulador de R?dio Freq??ncia que disp?e de dois atenuadores, um controlado por software e outro por uma fonte de tens?o. O emulador pode proporcionar um ambiente controlado, onde todas as transmiss?es puderam ser realizadas utilizando os dois padr?es de rede, garantindo uma correta identifica??o do canal, controle das atenua??es e acompanhamento dos fen?menos de propaga??o.