Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Long-Term Propagation Statistics and Availability Performance Assessment for Simulated Terrestrial Hybrid FSO/RF System | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2011 Article ID 435262 9 pages doi 2011 435262 Research Article Long-Term Propagation Statistics and Availability Performance Assessment for Simulated Terrestrial Hybrid FSO RF System Vaclav Kvicera 1 Martin Grabner 1 and Ondrej Fiser2 1 Czech Metrology Institute Hvozdanska 3 148 00 Prague 4 Czech Republic 2Institute of Atmospheric Physics The Academy of Sciences of the Czech Republic Bocni II 1401 141 31 Prague4 Czech Republic Correspondence should be addressed to Vaclav Kvicera vkvicera@ Received 1 November 2010 Accepted 7 February 2011 Academic Editor Fabrizio Granelli Copyright 2011 Vaclav Kvicera et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Long-term monthly and annual statistics of the attenuation of electromagnetic waves that have been obtained from 6 years of measurements on a free space optical path 853 meters long with a wavelength of 850 nm and on a precisely parallel radio path with a frequency of 58 GHz are presented. All the attenuation events observed are systematically classified according to the hydrometeor type causing the particular event. Monthly and yearly propagation statistics on the free space optical path and radio path are obtained. The influence of individual hydrometeors on attenuation is analysed. The obtained propagation statistics are compared to the calculated statistics using ITU-R models. The calculated attenuation statistics both at 850 nm and 58 GHz underestimate the measured statistics for higher attenuation levels. The availability performance of a simulated hybrid FSO RF system is analysed based on the measured data. 1. Introduction Free space optical communication systems are becoming a more and more important part of the telecommunication .
