Comparison and Analysis of Atmospheric Turbulence in Free Space Optical Communication for Srinagar

Traditional microwave communication systems can no longer support high bandwidth demand. Telecommunications companies in the country are therefore investing huge sums of money in laying underground fiber cables for their backbone network. The challenges these companies face in laying optical fiber cables include inaccessibility in the 4 major cities. These cities have already developed infrastructure i.e. buildings and roads . Therefore digging and laying cables are very difficult if not impossible in some suburbs. In such areas, the companies are forced to depend on microwave links. Again, due to lack of already developed network infrastructure design in the country, underground fiber cables are destroyed during road constructions. An alternative to fiber cables in inaccessible areas could be the use of FSO installation. FSO can be used to provide backup links in the event of fiber cable destruction or as a backbone network. Free Space Optical FSO communication is the transmission of optical signals through the atmosphere. To the best of our knowledge, evaluation of FSO performance in the country has not been investigated to determine its feasibility. This paper seeks to investigate whether FSO communication implementation is feasible in Srinagar. However, turbulent atmospheric conditions have impacts on its performance and therefore hampered its wide spread deployment. In this paper, we investigate the feasibility of FSO in Srinagar. Atmospheric attenuation is estimated based on the atmospheric visibility data. Our results show atmospheric specific attenuation as high as 27.17dB km in the 1550nm window, 29.315dB km in 1300nm window and 35.20dB km in the 850nm window. The probability of encountering different atmospheric attenuation conditions is estimated. Fading loss due to scintillation is investigated using the lognormal statistical model. It is shown that the margin to compensate for losses due to scintillation depends on the power scintillation index and the allowable system outage probability. Tabassum Nisar | Rashmi Raj "Comparison and Analysis of Atmospheric Turbulence in Free Space Optical Communication for Srinagar" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-3 , April 2020, URL: https://www.ijtsrd.com/papers/ijtsrd30317.pdf