Enhancing Urban IoT Connectivity: Performance Analysis of Free-Space Optical Communication Under Atmospheric Turbulence

Abstract

The explosive growth in the use of the Internet of Things (IoT) devices in cities has aggravated the need to upgrade communication infrastructure to high-capacity, low-latency, and secure infrastructures. Free-Space Optical (FSO) communications have become an interesting proposition as the data rates can be as high as in fiber and communication is secure in nature, and not affected by electromagnetic interference. FSO links are, however, highly susceptible to degrading effects of atmospheric turbulence, particularly in cities where there is a high plenum of sunlight temperature, wind, and building heat emissions. It did assess the performance of FSO communication systems as an option to connect IoT in urban areas under different atmospheric turbulence environments with an aim of finding how turbulence affects the reliability of the link and determine how the sophisticated mitigation techniques withstand the challenge to provide strong and efficient connection. The simulation, as well as the analytical modeling of FSO links in realistic urban turbulence profiles was used to carry out a comprehensive performance analysis. Advanced mitigation techniques were also added to the study such as adaptive optics, which could provide real-time compensation of wavefront error, and power optimization, as well as wavelength division multiplexing (WDM) to achieve higher data throughput. The most relevant performance indicators that were considered included bit error rate (BER), Q-factor, and link margin as per the weak, moderate, and high turbulences conditions. The results prove that atmospheric turbulence has a great impact on the performance of FSO links which are characterized by high BER and low link margin in the case of intense turbulence. However, introduction of the adaptive optics and power optimization method lead to significant enhancement in signal quality and reliability of the link. WDM also increased the capacity of the system so that strong and scalable IoT connectivity became possible. The research also gives a quantitative confirmation that these mitigation measures are able to lower BER to acceptable levels and maintain high data rates even at challenging urban circumstances. To sum it up, FSO communication, in case it is supplied with sophisticated mitigation technologies, can become a robust and a high-performance infrastructure of urban IoT networks. The operational lessons that could be learnt based on this work are helpful in the implementation and enhancement of FSO-based IoT backhaul as a means of expanding the available bandwidth and transmission of real-time information in smart cities. Next lines of research will focus on hybrid FSO/RF networks along with machine learning-based adaptation in order to enhance urban IoT connectivity even more.