# Effects of Atmospheric Turbulence on Optical Wireless Communication in NEOM Smart City
## 2 Literature Review  
FSO communication is a promising emerging technology that can likely satisfy the requirements of next-generation networks. A general overview of FSO was presented in [33] where the author described the evolution of FSO from mirrors to telescopes to most modern wireless communication. This technology is superior to several other wireless technologies, including the microwave (radio frequency) spectrum, in terms of the high data rate, immunity from interference, high security, small size/low weight of the components, low power consumption, unlicensed spectrum, ease of use, and low cost of implementation and maintenance [16]. Moreover, problems associated with optical fiber connectivity, such as the high cost of digging paths and physical link maintenance, can be eliminated. Notably, FSO requires line-of-sight clarity to transmit data through the atmosphere channel. Thus,the performance of the optical signal that carries the information and traverses through air degrades, largely owing to beam scattering, absorption, and atmospheric turbulence. Therefore, one of the most important elements affecting FSO link performance is the local weather. Different studies have been conducted to test optical communication under varying environments, as per the work in [34; 35], mid-infrared wavelengths are found to perform well and are less affected by the environment, and its beam farming and stealth conformance make it a better choice, but it can be applied in an indoor environment. Whereas, the study [36; 37] focuses mainly on the working and evaluation of FSO system under maritime environment. In [36], the authors established a model to measure the link performance by relating incident points with environment parameters. Furthermore, they conducted an experimental study to prove the performance of the proposed system. Whereas, in [37; 38], the authors use both analytical and experiment studies to analyze FSO under maritime conditions. The effect of atmosphere on FSO is evident and area-specific. It is the motivation of this study to foresee the effect of NEOM weather conditions on FSO communication. Similar studies have been conducted around the world to assess the performance of FSO links using meteorological data. Due to the frequent clear sky conditions in the Northeast of Brazil, FSO systems can provide optical communication speed and quality at a very low cost for a wavelength of \(\lambda=780\) nm. With almost 99% availability, distances of 5 km to 8 km are possible. While 98% feasibility of FSO systems are alternatives for links with ranges up to 3.5 km and roughly 90% availability in certain cities in Brazil, southeastern and midwestern regions [21]. Rain and haze are the key limiting factors for FSO in Malaysia, according to [PERSON] et al. [22]. Due to high bit error rate (BER) caused by seasonal heavy rain, the maximum link length is limited to 1 km for a wavelength of 1550 nm [22]. [PERSON] et al. [23] attempt to identify and examine the challenges associated with FSO deployment in Algerian weather conditions. It has been determined that scintillation is one of the most significant issues in the southern region of the country, where temperatures are high almost year-round. In the North of the country, heavy rain and fog were the main problem [23]. Using data from the Libyan National Meteorological Centre, [PERSON] et al. [24] investigated the effects of rain weather conditions on the performance of the FSO link. They found that the maximum link distance is 1.91 km under heavy rainfall weather conditions. [PERSON] et al. [25] investigated the viability of adopting free-space optical communication technology in six locations in South Africa. They found that, under typical conditions, Ermelo has the longest ideal FSO link distance of 7.5 km at an overall atmospheric loss of 2.8 dB, whereas Durban has the smallest optimal FSO link distance of 2.6 km at an overall atmospheric loss of 12 dB under worst-case conditions. [PERSON] et al.