Performance Analysis of Free Space Optical Communication System Under Rain Weather Conditions: A Case Study for Inland and Coastal Locations of India

Free space optical communication (FSOC) has emerged as a potential candidate for providing huge bandwidth and solving the problem of spectrum congestion. But the atmospheric conditions limit the performance of FSOC link as the laser signal propagates through the atmospheric channel. This work aims to investigate the performance of FSOC link under average and heavy rainfall weather conditions of India. The meteorological data related to rainfall, over a duration of 4 years, was obtained from the Indian Meteorological Department for six different locations of India, representing the inland and coastal areas. The attenuation coefficient due to rain for all the locations has been calculated using mathematical models. The performance analysis of Wavelength Division Multiplexing based free space optical communication system has been analyzed by incorporating the attenuation due to rain for all considered locations. The inland location of Hyderabad has recorded the minimum attenuation coefficient of 1.91 dB/km due to rain and can support a link range of 5.43 km, corresponding to bit error rate of order of 10−9 under average rain weather conditions. On the other hand, the average rainfall is maximum for the coastal area of Mumbai, resulting in maximum attenuation coefficient of 4.08 dB/km. Moreover, the maximum link range for Mumbai is limited to 3.48 km, corresponding to bit error rate of order of 10–9 under average conditions of rain weather. Similarly, the inland locations of India have delivered a better link performance as compared to coastal areas under heavy rainfall weather conditions also.