Analysis of Outage Probability in Wavelength Diversity Based FSO Link Under Gamma–Gamma Fading with Varying Atmospheric Attenuation

Free space optical (FSO) communication links offers an emerging alternative to RF communication links because of high speed, secure and cost-effective options to provide the last mile connectivity to end-users. They may be deployed for quick network access temporarily during link failure and natural disaster. This paper focusses on the performance of FSO communication link impaired with strong turbulence and atmospheric attenuation added through varying climatic conditions. A closed-form expression for outage probability is derived to evaluate the performance under different levels of atmospheric attenuation and turbulence strengths. The mathematical analysis clearly shows inimical effects added by atmospheric attenuation over the performance of the communication link. The impact of wavelength diversity on the outage probability of such a link is analyzed with three carrier wavelengths 1550 nm, 1310 nm and 850 nm. The simulation results with wavelength diversity for different atmospheric attenuation levels and turbulence are plotted and analyzed.