Michal Márton

Analysis of possibilities for measurement effect of visibility in experimental FSO system

Abstract Nowadays, wireless optical systems are very popular because they offer a a lot of advantages including high speed transmission, high security levels, and low maintenance costs. One of these wireless optical systems is Free Space Optics (FSO). However, their primary drawback relates to the type of transmission medium used. Atmospheric channel is chosen to be the transmission medium for FSO systems. The resulting attenuation relates with all inhomogeneities that occur in the atmosphere. Concentration of water particles represents inhomogeneities which increase the levels of attenuation. Weather conditions are characterized by speciffc concentration of these particles. Visibility is one of the most crucial parameters for FSO communication. It is very important to monitor this parameter in order to switch between primary optical line and backup secondary Radio Frequency (RF) line. The focus of this paper is to analyze and evaluate visibility measurement in FSO system deployed in TUKE (Technical University of Kosice) campus. The measurement of different weather parameters for this system is triggered on TUKE. The Switching method is based on monitoring visibility as the primary parameter. Different measurement approaches provide different processing speeds. Faster and more accurate switching ensures stable system without disruption.

Design of Pyramidal Horn Antenna for 2.45GHz in FEKO for Application in Experimental FSO/RF Hybrid System

Abstract Communication technologies are growing for day to day because demand on data sharing is unstoppable. Users require availability of approach to network at all time. Implementation of smart technologies allows communication of all type of devices. Capacity of data flow have to grow. Video formats HD or 4K require transmit on high data speed. Based on the demands many types of different communication systems which are suitable for these speeds were designed. One of these systems is FSO (Free Space Optics). FSO system is based on transmission of optical beams which carry the information. This system allow high data speed comparable with standard optical fiber in range to 10km. One of drawbacks of this system is LOS (Light of Sight) between communication points. The other drawback is sensitivity to weather changes. Optical beams interfere with water particles and cause attenuation on transmission path. The solution is in implementation using hybrid FSO/RF system which combines optical communication system with RF (Radio Frequency) backup link. We realized FSO communication link on Technical University of Košice. Our research is focused on design of appropriate type of antenna for our RF backup link. Our results in this area were published.