Authors : Tunde Afolabi; Eseosa Omorogiuwa

Volume/Issue : Volume 11 - 2026, Issue 1 - January

Google Scholar : https://tinyurl.com/2dwfve5f

Scribd : https://tinyurl.com/342mejp3

DOI : https://doi.org/10.38124/ijisrt/26jan308

Note : A published paper may take 4-5 working days from the publication date to appear in PlumX Metrics, Semantic Scholar, and ResearchGate.

Abstract : Free Space Optical (FSO) communication has emerged as a viable alternative for addressing the last-mile connectivity challenge in fifth-generation (5G) networks, particularly in regions where fibre deployment is economically or logistically impractical. This paper presents the modelling and simulation of an FSO communication link for 5G last-mile applications under atmospheric conditions representative of Nigeria. The system is modelled using the Beer–Lambert attenuation law, geometric loss formulation, and turbulence-induced fading models. Simulations are carried out in OptiSystem 21.0 with link distances ranging from 0.5 km to 5 km, optical transmit power between –3 dBm and +10 dBm, and an operating wavelength of 1550 nm. Performance metrics including received power, signal-to-noise ratio (SNR), and bit error rate (BER) are evaluated under clear air, haze, and fog conditions. Results indicate that reliable FSO transmission with BER below 10−9 is achievable up to 2 km under moderate visibility conditions, confirming the suitability of FSO for 5G last-mile connectivity in Nigeria. The study provides design guidelines for practical deployment of FSO systems in tropical environments.

Keywords : Free Space Optics, 5G Last-Mile, Optical Wireless Communication, Atmospheric Attenuation, BER, SNR.

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