MODELLING TO RAIN ATTENUATION EFECTS IN POINT-TO-POINT AND POINT-TO-MULTIPOINT TERRESTRIAL LINKS / MODELAMENTO DE EFEITOS DE ATENUAÇÃO POR CHUVAS EM ENLACES TERRESTRES PONTO-A-PONTO E PONTO-MULTIPONTO

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

The growing demand for broadband services such as high- speed data, video, audio and multimedia, has lead to the use of point-multipoint radio systems operating in frequencies above of 10 GHz, that are not yet allocated for other services and allow the use of the large bandwidths required by these services. At these frequencies, the main contribution for the propagation losses is due to rain attenuation. The rain directly affects the area coverage and the performance of systems operating at these frequencies. In the present work, an empirical model is developed for predicting the cumulative distribution of rain attenuation prediction, using the ITU-R data base and results of propagation measurements campaigns performed in Brazil. The model provides better results than others currently found in the technical literature and allows the evaluation of the impact of rain attenuation in the coverage of LMDS (Local Multipoint Distribution System/Local Multipoint Communications System). Also, two models were developed for predicting distributions of differential rain attenuation, an essential factor for interference effects and its impact in LMDS performance. Finally, models were developed for the prediction of total and average duration of rain attenuation events, also relevant for systems performance assessment.

ASSUNTO(S)

rain attenuation planning sistemas sem fio atenuacao por chuvas wireless systems planejamento

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