A wireless optical communication system with a quantum key distribution system is demonstrated. It is implemented on the basis of the coupling of the quantum key distribution system developed for the fiber optic communication system with atmospheric optical communication lines terminals. For an atmospheric communication line with a length of 200 m, loss statistics in an open and quantum communication channel was obtained during several weeks of monitoring, on the basis of which an approach for estimating signal attenuation in a quantum channel was developed. The results of studies of the influence of atmospheric phenomena on the transmission of telecommunication data are presented.
A wireless optical communication system with a quantum key distribution system is demonstrated. It is implemented on the basis of the coupling of the quantum key distribution system developed for the fiber optic communication system with atmospheric optical communication lines terminals. For an atmospheric communication line with a length of 200 m, loss statistics in an open and quantum communication channel was obtained during several weeks of monitoring, on the basis of which an approach for estimating signal attenuation in a quantum channel was developed. The results of studies of the influence of atmospheric phenomena on the transmission of telecommunication data are presented.
Subject of study. An optical system, composed of transmitting and receiving telescopes, was designed for quantum key distribution, based on the subcarrier wave modulation method, over an atmospheric channel. Aim of study. The aim of the study was to develop an optical system that allowed the use of single-mode fibers as the input and output of the system, ensured the transmission of an ultralow-power optical signal without introducing additional distortion, and implemented a protocol for distributing a quantum key over an atmospheric optical communication channel at a distance of up to 25 m. Method. An experimental setup with an atmospheric quantum communication channel was developed, which showed stable quantum key distribution without interruptions throughout the measurement process. Radiation propagation simulations were also performed to estimate the insertion loss of the optical signal. Main results. Simulations revealed that the optical losses in the quantum key distribution system amounted to approximately 17 dB. The atmospheric communication channel was studied at distances of 5, 10, and 25 m. Considering all optical elements of the system, including the ferrules of the output and input fibers of the quantum key distribution modules, the attenuation of the optical signal was approximately 8, 13, and 18 dB, respectively. Based on the atmospheric optical losses, the quantum key generation rates were of the order of 500, 350, and 190 bits/s with increasing distance and insertion losses. The probability of a quantum error was in the range of 3% to 5%, which was lower than the threshold of 6%, ensuring the legitimacy of the generated key and excluding the possibility of an attack on the communication channel. Practical significance. The compatibility of the developed optical system with single-mode optical fibers allows its integration into the existing infrastructure of data transmission lines without the need for additional optical radiation converters. Owing to the analyzed characteristics of the optical system for distributing a quantum key over an atmospheric communication channel, it can be applied in communication systems based on the Internet of Things, unmanned vehicles, and other moving objects.
The article considers a communication system including quantum cryptographic equipment implementing quantum key distribution, in which there is a section of atmospheric optical communication line. The methodology and results of an experimental study of the influence of external nature factors on the efficiency of the communication system using an atmospheric optical communication line are discussed. The research method is based on monitoring the key indicators of the telecommunication channel of the communication network, which determine the quality of the communication system as a whole, such as data transfer rate, error rate, percentage of packet losses. The experiment was conducted on a communication system including a section of atmospheric optical communication line and terminals. The results of the study showed a significant influence of weather factors on the characteristics of the atmospheric optical channel. The data obtained emphasize the need to take into account the influence of external factors in the design and operation of communication systems with an atmospheric optical communication line
The possibility of quantum key distribution in the atmosphere has been experimentally demonstrated by coupling commercially available quantum key distribution units designed for fiber-optic communication lines with atmospheric optical communication terminals. For distances up to 3100m, data on losses in a quantum channel on an optical path were obtained and the influence of systems for intelligent adjustment of atmospheric communication terminals on the synchronization system of quantum communication blocks was studied. It has been established that failures of synchronization systems in the case of quantum key distribution in the atmosphere at distances greater than 10m are due to the peculiarities of the algorithm implemented in the quantum communication unit.
Subject of study. This study examined the applicability of quantum key distribution (QKD) technology under free-space atmospheric conditions. Aim of study. The objective was the development of a hardware and software system for investigating the applicability of QKD technology in wireless communication systems based on commercially available modules. The system includes optical blocks for atmospheric optical communication and a training setup for studying QKD in fiber-optic communication lines. Method. The characteristics of a quantum communication channel in free-space conditions were studied through experiments. The channel was formed by the QKD units of the EMQOS 1.0 scientific and educational complex, integrated with optical blocks for atmospheric optical communication. The systems were also upgraded to minimize losses in the quantum channel. Main results. A hardware and software system was developed, within which the transmission of a quantum key through free-space atmospheric conditions over a distance of 180 m was successfully demonstrated. The quantum bit error rate did not exceed 6%. This system enabled the study of the effects of weather conditions on optical losses in the quantum communication channel and the quantum key generation rate. Practical significance. The developed hardware and software system allows the monitoring of the parameters of both classical and quantum communication channels in free space under various weather conditions. Its modular structure enables the integration of other quantum equipment for comparative testing of the performance of quantum communication systems under real atmospheric transmission conditions.
The possibility of quantum key distribution in the atmosphere has been experimentally demonstrated by coupling commercially available quantum key distribution units designed for fiber-optic communication lines with atmospheric optical communication terminals. For distances up to 3100 m, data on losses in a quantum channel on an optical path were obtained and the influence of systems for intelligent adjustment of atmospheric communication terminals on the synchronization system of quantum communication blocks was studied. It has been established that failures of synchronization systems in the case of quantum key distribution in the atmosphere at distances greater than 10 m are due to the peculiarities of the algorithm implemented in the quantum communication unit. Keywords: quantum key distribution, atmospheric optical communication lines, FSO, decoy-state BB84 protocol, polarization coding.
This paper presents a comprehensive analysis of the application of quantum key distribution technology in atmospheric optical communication lines to ensure the information security of transmitted information in urban infrastructure conditions and between critical infrastructure industrial facilities. The necessity of applying quantum key distribution technology in atmospheric optical communication channels is substantiated. The results of numerical modeling of quantum key distribution performance indicators confirm the need for their preliminary numerical analysis taking into account regional meteorological statistical data when designing network segments including atmospheric quantum key distribution systems. The developed software package enables optimization of system parameters for specific climatic conditions and channel topology which increases the efficiency of deploying secure networks including atmospheric optical channels for energy, financial and industrial facilities. The developed software package, implementing a physically based methodology for accounting for cumulative losses in such a communication channel, enables a comprehensive assessment of the effectiveness of quantum key distribution taking into account turbulence, absorption, scattering, geometric losses, meteorological conditions and the characteristics of the detection equipment. The practical significance of the complex lies in the ability to optimize system parameters (wavelength, aperture diameter, transmitter power, etc.) for specific climatic conditions and channel topology, which is critical when designing secure networks that include atmospheric optical channels.