Performance Analysis of Triple Hop RF-RIS Convergent with FSO and UWOC System

Abstract

This paper proposes a hybrid communication system for integration within the space-air-ground-sea network (SAGSIN) architecture, tailored for 6G Internet of Things (6GIoT) applications. The system employs a triple-hop link combining Reconfigurable Intelligent Surface (RF-RIS), Free Space Optics (FSO), and Underwater Wireless Optical Communication (UWOC), facilitating communication between a base station, a lighthouse, a ship, and Underwater Aerial Vehicles (UWAVs). The architecture, using differential phaseshift keying, is ideal for Underwater Optical Wireless Sensor Networks (UOWSNs) and Internet of Underwater Things (IoUT). Performance analysis models RF-RIS with Nakagamim distribution, the FSO link with the Malaga distribution, and the UWOC link using the Exponential Generalized Gamma (EGG) distribution. The system's end-to-end cumulative distribution function (CDF) is evaluated via the Meijer-G function, while outage probability is examined under varying conditions, including atmospheric turbulence, fading parameters, and salinity levels. This system shows promise for coastal environments with changing weather conditions like rain, haze, and fog. © 2025 IEEE.