Unmanned systems' first-person view control requires transmitting the video stream from the unmanned system to its operator. The quality of the transmitted video stream directly affects the external pilot's assessment of the current flight situation and the formation of appropriate and timely control commands. The paper investigates the dependence of the unmanned system's operational objective achievement probability on the objective video stream quality metrics (SSIM, PSNR). Relevance of this work is based on the necessity to determine the unmanned system FPV control video coding system parameters depending on the specified unmanned system’s operational objective achievement probability.

Methods used. When processing the results of natural experiments, methods of statistical analysis, experimental design theory and probability theory were used.

Results. Quantitative values of video stream quality metrics requirements are justified when using standard video codecs for a given operational objective achievement probability in unmanned systems FPV control for various purposes.

Novelty of the results is that the requirements for the transmitted video stream quality metrics are determined not by experts, but by experiments based on the analysis of the transmitted video stream quality, which allowed to develop the unmanned system control that achieved its operational goals.

Practical significance. The required values of FPV video stream quality metrics have been determined, at which FPV control is possible with a given unmanned system’s operational objective achievement probability.

Relevance. Modern business processes critically depend on the continuous availability of data, while the frequency of data loss incidents due to ransomware attacks, equipment failures, and administrative errors is steadily increasing.

The purpose of the study is to develop and validate a comprehensive approach to building centralized data backup systems that minimize recovery time and maximize the likelihood of successful recovery from catastrophic failures of various types.

Methods. The methodological basis of this study is a systems approach to backup architecture design, quantitative risk analysis methods, and comparative analysis.

Solution (Results). A comprehensive architectural approach based on a centralized pull-oriented backup system has been developed. A methodology for choosing between full disk backup and granular file backup has been formulated. The scientific novelty lies in the justification of a comprehensive centralized data backup system that combines snapshot-oriented backup, a multi-tiered storage architecture, and a pull model with a physically and logically isolated server.

The theoretical significance lies in the development of a scientific and methodological framework for ensuring business process continuity by formalizing criteria for selecting backup modes and architectural solutions, taking into account resource limitations and data heterogeneity.

The practical significance of the work lies in the development of specific architectural requirements and recommendations for building backup systems.

The relevance The Information-Centric Network (ICN) is a promising concept for describing and modeling modern information and telecommunications. In an ICN, information interaction is considered conditionally independent of the telecommunications technologies used, and it is carried out on the basis of named data objects. In Industry 4.0 digital systems, including the Internet of Things, rapid situational awareness across a network of interacting objects requires disseminating essential information. It is necessary to objectively analyze the overall dynamics of sensor information distribution in the form of up-to-date data during information processing at ICN nodes. The current status of the data enables effective decision-making regarding the management of objects and information flows. To increase speed, sensor data is stored in the semantic cache memory of ICN network nodes. This paper presents an approach to studying the distribution of up-to-date data in ICNs based on information diffusion using deterministic models based on epidemic simulation. Obtaining data on the current status of a significant event from the source node is analogous to the conditional infection of ICN nodes. This approach enables us to estimate the rate at which ICN nodes update information from the current source and make management decisions based on the exchange of operational knowledge in the form of sensor information.

The aim of this study: improving the efficiency of information flow control in the ICN network for the propagation of sensor data.

Methods: analytical review of scientific publications, numerical methods, simulation modeling.

Solution: An analytical model of data propagation with topical status in the ICN network was developed based on a system of nonlinear ordinary differential equations that describe the diffusion processes of the SIR model. The results of the independent discrete-event modeling of the propagation of ICN sensor data in the ns-3 simulator are presented. The modeling algorithm is based on applying a deterministic epidemic model.

Scientific novelty lies in the authors' proposed approach to analyzing and displaying the dynamics of content distribution in an ICN network during a significant event, as well as estimating the maximum distribution rate of topical data.

The practical significance consists of assessing the intensity of changes in situational awareness in sensory networks when topical information is disseminated.

Relevance: Modern intra-facility information and telecommunication systems include subsystems utilizing Ethernet technology. These include IP telephony, Wi-Fi access points, video surveillance systems, access control and management systems, smart environment sensor systems comprising Internet of Things sensors and actuators, etc. Power for many subsystems can be supplied centrally from Ethernet switches and injectors using Power over Ethernet (PoE) technology. PoE repeaters or extenders are used to increase the distance to terminal devices.

Problem Statement. When designing an intra-facility communication line whose segments are interconnected via PoE repeaters, it is necessary to determine its maximum length. A methodology for calculating the maximum length of a line with PoE repeaters is not presented in known sources.

Objective: To develop an engineering method for determining the maximum length of an intra-facility communication line using PoE repeaters. The input parameters are the loop resistance of the twisted pair, the source voltage, the self-consumption power of the repeater, and the power consumption of the powered terminal device. Individual segments of such a structure are considered identical, and constraints from the IEEE 802.3af and IEEE 802.3at specifications apply regarding linear path parameters and active equipment used.

Novelty: A mathematical model of serially connected sections of an intra-facility communication line, interconnected via PoE repeaters, has been developed.

Practical Significance: The limitations of PoE repeaters are determined, and the influence of their self-consumption power on the maximum line length is shown. The developed calculation method can be used for designing components of intra-facility information and telecommunication systems. The proposed model, calculation methodology, and its investigation can be used in the educational process at SPbSUT and other telecommunications universities.

Relevance. Digitalization of industrial production and the transition to the concept of predictive maintenance pose the challenge for developers of monitoring systems to ensure high accuracy and timeliness of diagnostics of the state of autonomously operating equipment. Acoustic fault detection based on sound signal analysis is becoming an effective tool for non-invasive monitoring. However, the practical implementation of such systems in conditions of limited computing and network resources is associated with the problems of assessing their probability-time characteristics and selecting the best operating modes. The purpose is to develop a formalized model that makes it possible to estimate delays and the probability of timely delivery of acoustic data packets in order to identify anomalies in the operation of equipment under various parameters of the system architecture. 

Methods. A two-phase model of a queuing system with controlled access is proposed to describe the data transmission process. The paper uses analytical methods, including queuing theory, Laplace ‒ Stieltjes transformations, and Poisson flow models. 

Results. Expressions are obtained for calculating the average time of delivery and processing of acoustic data packets, as well as the probability of their timely delivery and analysis. The analysis of the influence of the system parameters on the probabilistic-temporal characteristics of the process is carried out. 

The novelty lies in the introduction of a parameterized traffic prioritization mechanism and complex modeling of the architecture of an acoustic data processing system under stochastic conditions. The proposed model takes into account the specifics of industrial applications and makes it possible to predict the behavior of the system. 

The theoretical significance is determined by the expansion of the mathematical apparatus for analyzing data transmission and processing processes based on queuing theory and stochastic modeling. 

The practical significance lies in the possibility of using the model to design and configure monitoring systems to meet the specific requirements of critical infrastructure facilities.

Ensuring the noise immunity of radio engineering systems operating under severe power and spectral constraints constitutes a pressing scientific and technical problem, particularly in the presence of impulsive noise with a non-Gaussian distribution. This paper considers the application of signal-code constructions based on Trellis Coded Modulation as an effective solution for enhancing noise immunity without bandwidth expansion.

The objective of this research is a comprehensive evaluation of the impact of statistical parameters of channels described by Bernoulli – Gaussian and Middleton Class A models on the system's Bit Error Rate, as well as the establishment of an analytical relationship between these models across various operating regimes.

The research methodology is based on theoretical analysis utilizing the apparatus of mathematical statistics, with result verification performed via simulation in the MATLAB environment.

The scientific novelty lies in conducting a generalized stability analysis of the Trellis Coded Modulation system under a wide variation of noise parameters and, specifically, in the development of a methodology for determining model equivalence boundaries. The proposed approach enables a justifiable transition from the computationally complex Middleton model to simpler approximations (Bernoulli – Gaussian or Gaussian), thereby ensuring the simplification of the system's mathematical description while maintaining the required accuracy of the results.

Simulation results demonstrate that increasing the power ratio between the Gaussian and impulsive components consistently improves the system's noise immunity for both modulation types: 8-Phase Shift Keying and 16-Quadrature Amplitude Modulation. Regarding the verification of model equivalence boundaries, it has been established that approximation by the Bernoulli – Gaussian model is valid at an impulsive index value of  for both for both modulation types. At the same time, convergence to the Gaussian model is achieved at different threshold values:  for 8-Phase Shift Keying and  for 16-Quadrature Amplitude Modulation, which is attributed to the difference in signal constellation density.

The article investigates methods of spatio‑temporal encoding of signals in MIMO-OFDM systems during transmission in non‑stationary frequency‑selective channels. The limitations of traditional approaches (STBC, SFBC) at high levels of Doppler shift and frequency selection are considered. The relevance of the study is due to the need to increase the spectral efficiency and stability of wireless communication systems to intersymbol interference and Doppler distortion.

Methods used. The article proposes the structure of a combined spatial encoding algorithm WHSTBC‑CC based on combined suppression and Walsh‑Hadamard transformation. Mathematical models of transmitting and receiving signals are constructed, taking into account the influence of channel distortions and additive white Gaussian noise. To analyze the effectiveness, modeling methods were applied taking into account the normalized values of the Doppler shift and the coefficients of time and frequency correlation.

Results. It is shown that the use of WHSTBC‑CC provides an increase in transmission stability and a reduction in the probability of errors at fdT < 0.01. The energy gain coefficient of the method is 5-12 dB compared with the classical STBC and is practically independent of the frequency abundance of the channel. The modification of spatial coding developed in the work using the Walsh-Hadamard transform and the conjugate suppression algorithm partially compensates for these disadvantages, increasing the stability of the system and providing an energy gain of up to 12 dB compared with the classical STBC. Experimental measurements on a mobile SDR platform have confirmed the operability of the proposed approach in a real radio environment, including scenarios with and without direct visibility.

The novelty of the work lies in the development of an adaptive spatial coding algorithm that integrates various schemes (STBC, SFBC) depending on the channel parameters.

Practical significance. The results obtained can be used in the design and optimization of MIMO‑OFDM systems for mobile communications and broadband access networks, as well as in specialized radio networks operating in conditions of high instability and exposure to electronic jamming.

Relevance. Despite the development of 5G technologies, the use of 4G remains relevant. Moreover, the LTE radio interface parameters underlie NR, making the results obtained for LTE applicable to NR. Positioning in LTE networks is based on ToA signal arrival time measurements. Non-line-of-sight conditions in a multipath channel cause significant ToA estimation errors, requiring the development of compensation methods to improve positioning accuracy.

The aim of this work is to improve the accuracy of ToA measurements in non-line-of-sight conditions by researching and developing methods for joint maximum-likelihood (JML) ToA estimation in a multipath channel.

Results. The 2D-JML method is shown to be more effective than 1D-JML, especially in scenarios with closely spaced multipath components typical of small-bandwidth signals. This improvement is achieved through a scientifically justified selection of the number of signal samples at the multipath channel output. It was found that in the EPA, EVA, and ETU models at C/N₀ = 85 dB∙Hz, after interference elimination, the ranging accuracy of 2D-JML measurements with a hybrid sampling model ranges from 26 to 60 m for a 1.4 MHz bandwidth and less than 4 m for 20 MHz.

Novelty. For the first time, a comprehensive scientific justification of the bandwidth and number of samples for the joint maximum-likelihood ToA estimation method in a multipath channel is presented in typical LTE device positioning scenarios to achieve meter-level accuracy of ranging measurements.

The theoretical significance. The theoretical foundations for signal arrival time estimation in multipath LTE channels are refined. The proposed JML ToA estimation method expands on the classical maximum likelihood method by taking into account the channel structure and allowing for closer approximation to the CRLB. The results can be used in the further development of OFDM-based positioning theory.

The practical significance. The JML method can be implemented in existing LTE/LTE-A devices to improve positioning accuracy without changing the network infrastructure. The results obtained are also applicable to the development of positioning algorithms for future 5G networks.

Relevance. The organization of long-span fiber-optic communication lines (for example, DWDM) using traditional erbium amplifiers requires their placement in populated areas for the purpose of power supply and routine maintenance. This affects the increase in the length of sections, the number of amplification points and the accumulation of noise, which leads to an increase in the cost of the network and the need to install regenerators. An alternative is Remote Booster Pumping (ROPA) technology. However, its implementation requires addressing the issues of maximum pumping power, its effect on the information signal in different modulation formats, and the optimal length of the amplification section. Research in this area needs in-depth analysis and verification. Research in this area requires in-depth analysis and verification of previously obtained results by other scientists.

The purpose of the work is to analyze schemes for building long-span communication lines based on ROPA amplifiers in order to systematize and expand theoretical aspects in the field of research, determine the parameters of the pump signal and the optimal configuration of the line.

The methods of system analysis, analytical review of literature, generalization, as well as analytical calculation of pumping power and length of the amplification section are applied in the work.

Result. It is shown that a 350 km long line with two ROPA amplifiers requires a 2-Watt pumping source using a dedicated ITU-T G.652B fiber. For a 500 km section, it is recommended to use ITU-T G.652B and ITU-T G.654E fibers, as well as hybrid amplifiers (Raman and erbium) at the ends of the line, with the transmission of an information signal and a pump signal over a single fiber. It is noted that such a concept can cause nonlinear distortions that require additional research.

The scientific novelty lies in the comparative analysis of two remote pumping schemes and in the hypothesis of an increase in nonlinear effects and errors during the joint transmission of a powerful pumping signal and an information signal over a single fiber.

Practical significance. The results can be applied in the design of DWDM backbone networks with a length of up to 500 km for telecommunications and energy companies.

Theoretical significance. The work systematizes and summarizes knowledge in the field of remote EDF fiber pumping, allowing a more accurate assessment of the limits and prospects of the technology.