Using Information about Weather Conditions to Define Availability and Reliability of FSO Links

This paper contains information about Free Space Optics (FSO) systems and their availability and reliability. FSO systems use infrared laser beams for optical communication between two static points and Line of Sight (LOS) technology is needed. Transmission media of optical signals is air, so weather has main influence on availability and reliability of FSO links. It is important to measure and statistically evaluate a quality of air in places, where the FSO system will operate. Amount of phenomena in the atmosphere such as scattering, absorption and turbulence have a negative effects on receiving optical power. Visibility has the critical influence on quality of the optical transmission channel. In typical continental area, where rain, snow or fog can occur is important to know their values. This article describes a device for measuring density of fog, relative humidity and temperature. From measured data, estimation of availability and reliability of FSO links in Slovakia is made.