Simulative Analysis of Free Space Optical Transmission System under Different Environmental Conditions

Free space optics is an excellent supplement to fiber optics, capable of handling point to point and point to multipoint connections. It is the broadband wireless solution for connecting the backbone to the users (Last-Mile-Access). FSO links are highly affected by the local atmospheric conditions. In this paper we simulate the FSO system for different  vironmental conditions operating at a bit rate of 2.5, 10 and 20 Gb/s for RZ format with 0.8 duty cycle. The results shows that heavy rain cause very high bit error rate, and they limit maximun link length to 1.1 km for bit rate 2.5Gb/s and link length decreases as the bit rate increases. During heavy haze and moderate rain the link length is upto 2.5 km and 1.8 km, respectively.