# Effects of Atmospheric Turbulence on Optical Wireless Communication in NEOM Smart City
## 2 Literature Review
[26] studied the OFDM-FSO system performance under various weather conditions for a wavelength of 1550 nm using data from the Bangladesh Meteorological Department. They found that severe fog is the worst weather condition for the OFDM-FSO system, with a maximum feasible link of 0.4 km and a BER in the order of \(10^{-3}\). Under the condition of light rain, the greatest link range achievable at 40 Gbps is 3.5 km at BER in the order of \(10^{-3}\). In Lahore, Pakistan, [PERSON] et al. [27] investigate the impact of dust and rain on FSO performance for wavelength 1550 nm. Their simulation revealed that the maximal attenuations for dust and rain rate are 8.1 dB/km and 11.59 dB/km, respectively. This also indicates that FSO communication at 10 Gbps across a link distance of up to 2 km is very much possible with a high SNR and a low BER. Using average meteorological measurements from the Egyptian Meteorological Unit, [PERSON] et al. [28] studied the performance of FSO in Alexandria, Egypt, under various weather conditions. The laser source used in this investigation had operating wavelengths of 750, 850, 950, 1310, and 1550 nm. The most difficult factors, according to the findings, were sandstorms and fog. In the presence of dense sandstorms, QAM-OFDM techniques improved the data rate by 17% when compared to standard QAM. The effect of atmospheric turbulence on FSO systems is a considerable challenge. Such turbulence can produce beam scintillation, spreading, and wandering, resulting in a significant reduction in BER performance and the inability to use the communication link. Using the Hufnagel Valley model, [PERSON] et al. [30] investigated the effect of scintillation on the performance of FSO lines in Yemen for wavelengths of 850, 1000, and 1550 nm. The report concluded that the FSO system performed admirably during the harshest conditions in Yemen. In addition, to achieve a BER of \(10^{-9}\) utilizing the wavelength of 1550 nm during air turbulence, the distance between transmitter and receiver should be 2600 m. The effects of turbulence and refractive index fluctuation owing to temperature and pressure were investigated experimentally under different weather conditions in Pakistan [31], for an 8 GB data FSO data link over propagation distances ranging from 100 to 1500 m and 980 nm operation wavelength. It has been discovered that Pakistan, south region, is particularly ideal because it is naturally free of the majority of channel impairments that reduce the performance of traditional FSO links. This is because changes in temperature are very minor, and the refractive index that results is suitable for transmission [31]. Based on data from the Tanzania Meteorological Agency (TMA), the author of [32] explores the effect of scintillation on FSO in the two Tanzanian cities of Dar es Salaam and Dodoma. The attenuation due to scintillation was calculated using the Hufnagel Valley and Rytov models for wavelengths of 1550 nm. Dar es Salaam has a larger FSO attenuation than Dodoma, according to the case study. It has also been established that the weather conditions in Dodoma are better for FSO communication than those in Dar es Salaam. The study characteristics reveal that one can transmit over a distance of 8 km for Dar es Salaam and more than 12 km for Dodoma. According to a comparison of the two-modulation technique, non-return-to-zero (NRZ) and return to zero (RZ), NRZ is the best modulation scheme for the two cities, while October is the best month for transmission in Dodoma [32]. According to the literature reviewed, a weather analysis of the deployment location, NEOM, is required before the installation of FSO connections to help in determining the system parameters of the FSO system to achieve the desired link performance.