Long term availability analysis of experimental free space optics system

This paper deals with Free Space Optics (FSO) systems. Availability and reliability of FSO is taken under the scope. FSO links transmit data within the infrared wavelength region. Lasers are used to create medium to carry informational stream. FSO systems need Line of Sight (LOS) technology in order to maintain connection between two points. Weather conditions have quite significant impact on FSO operation in terms of availability and reliability because of free space transmission. It is necessary to evaluate the air quality at the actual geographical location where FSO link is located. It is important to determine the impact of a light scattering, absorption, turbulence and receiving power at the particular FSO link. Visibility has one of the most critical impacts on the quality of an optical transmission channel. Moreover, it is very helpful to monitor and store the information about rain, snow and fog values. This paper introduces a device which measures all mentioned weather indicators such as a fog density, a relative humidity and the temperature. FSO availability and reliability estimation is made from measured data. These results evaluate weather conditions for Kosice, Slovakia in term of FSO operation.