Performance evaluation and fog attenuation modelling of FSO link for hilly regions of India

Free space optics (FSO) is considered as one of the emerging technologies in wireless communication system. In this work, real time data analysis of fog weather condition has been performed for hilly regions of north west region (Nainital, Uttarakhand) and north east region (Imphal, Manipur) of India. Different models have been considered for calculation of fog attenuation considering two specific months (January and February) for six consecutive years from 2016 to 2021. Quality of received signal has been analysed in terms of internal system parameters of an FSO link by incorporating amplitude shift keying, phase shift keying and duobinary return-to-zero modulation techniques at a data rate and transmission wavelength of 40 Gbps and 1550 nm respectively. It has been studied that PSK modulation scheme performs better as compared to other modulation techniques and received signal quality deteriorates below an unacceptable value in case of fog beyond the propagation range of 9000 m.