Evaluation of a 1 Gb/s Free Space Optic system in typical Malaysian weather

Abstract

Free Space Optical (FSO) communication is increasingly growing type of communication around the world because it has capability similar to fiber optic in terms of speed and bandwidth. But FSO is more preferred compared to fiber optics communication from the point of view of time and cost of deployment. FSO can transmit data from point to point at speed of light through space and requires no licensing. Since FSO is a line of sight communication so it is vulnerable to atmospheric attenuation, so to overcome this immense problem it is necessary to precisely study the channel characteristics present between the transmitter and receiver, especially for tropical climate region like Johor Bahru (JB) Malaysia, where rain and haze attenuation are the main concern. Many studies have been carried out in the temperate climate region where the attenuation due to snow and fog are the two major problems in the placement of FSO. The study in this paper concentrates on performance of single beam FSO system under heavy rain events for a period of four months from the point of view of attenuation and BER versus link distance L. The study is based on simulation and other atmospheric losses are not included. The results from the analysis have shown that under average of maximum rain rate intensities for the period of four months in typical Malaysian weather, single beam FSO system can successfully operate for a link distance of 830m with 19 dB/km attenuation and BER of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-9</sup> . It is also clear from this study that link distance is inversely proportional to rain intensity.