A Survey on Free-Space Optical Communication with RF Backup: Models, Simulations, Experience, Machine Learning,...

Area of Science:

• Wireless communication networks
• Optical and wireless technologies

Background:

• Sensor technology integration demands increased network capacity.
• Radio frequency (RF) communication faces limitations like bandwidth congestion and interference.
• Free-space optical (FSO) communication offers high data rates but is susceptible to atmospheric conditions.

Purpose of the Study:

• To review hybrid FSO/RF systems for enhanced network reliability.
• To explore theoretical models and real-world applications of hybrid systems.
• To categorize hybrid FSO/RF mechanisms and discuss multi-platform applications.

Main Methods:

• Examination of theoretical models for hybrid FSO/RF systems.
• Categorization of hybrid systems into hard switching, soft switching, and relay-based mechanisms.
• Presentation of graphical models for improved understanding.

Main Results:

• Hybrid FSO/RF systems effectively combine the strengths of both technologies.
• Three distinct categories of hybrid systems (hard switching, soft switching, relay-based) are proposed.
• Multi-platform applications including UAVs, HAPs, and satellites are discussed.

Conclusions:

• Hybrid FSO/RF systems offer a robust solution for dynamic urban communication environments.
• Further research is needed to address key challenges and advance hybrid communication networks.