Outage Probability Analysis of Dual Hop FSO Convergent with RF-UWOC Hybrid Link for SAGSIN in 6G-IoT Systems

This paper analyses the effectiveness of a novel hybrid communication system designed for a space-air-ground-sea integrated network (SAGSIN) within 6G Internet of Things (6G-IoT) environments. The system employs a dual-hop mechanism, featuring a free-space optical (FSO) link with a Malaga distribution for communication between ground and ships, along with a hybrid Radio Frequency - Underwater Wireless Optical Communication (RF-UWOC) link characterized by Nakagami-m and exponential generalized Gamma distributions for ship-to-underwater Autonomous Vehicle (AUV) communication. In this configuration, the ship serves as a Decode-and-Forward relay, where the RF link bolsters system reliability, and the UWOC link ensures secure communication. To optimize overall performance, the system implements a selection combining technique to identify the best signal from both RF and UWOC links. The paper evaluates the end-to-end cumulative distribution function (CDF) of the channel through the Meijer-G hypergeometric function. It also examines the outage probability of the proposed system across various weather conditions in the FSO channel, the effects of the Nakagami fading parameter m, and variations in salinity in the UWOC link.