Outage Analysis of Terrestrial FSO Links in Arid Regions

Free-space optical (FSO) communication offers high-capacity wireless connectivity but is highly susceptible to atmospheric impairments in arid and dust-prone environments. This paper presents a closed-form outage analysis for FSO links subject to Beta-distributed random dust fading, Málaga-M atmospheric turbulence, pointing errors, and visibility-dependent deterministic dust attenuation. The cumulative distribution function (CDF) of the received electrical signal-to-noise ratio (SNR) is obtained by averaging the existing Málaga-M/pointing-error CDF over the Beta-distributed dust gain and is expressed in terms of the Meijer-G function for both heterodyne and intensity-modulation/direct-detection (IM/DD) receivers. For fixed visibility and propagation distance, the deterministic dust attenuation is incorporated through an SNR scaling. The analysis is validated by direct numerical evaluation and Monte Carlo simulations. Results show that reduced visibility, stronger turbulence, increased pointing errors, and longer propagation distances degrade link reliability, with IM/DD being more sensitive than heterodyne detection. A visibility-aware transmit-power-control scheme reduces outage by compensating deterministic dust attenuation within the available power margin; its benefit depends on visibility, link distance, and operating SNR, while random fading remains present.