Information and Telecommunication Sciences

IMPLEMENTATION OF A MATCHED FILTER FOR LFM SIGNALS USING A SYSTEM-ON-CHIP BASED SDR TRANSCEIVER

2024-06-21T00:22:18+03:00

Background. Creation of communication channels with effective protection against intentional interference is the most urgent task for communication channels of unmanned aerial vehicles (UAVs). An effective solution is the use of signals with spectrum expansion, which allows reducing the impact of intentional interference on control and telemetry channels, thereby increasing the survivability of UAVs. The most optimal is the use of LCM modulation, which became possible with the development of SDR and SoC technologies. The main problem of using LFM modulation is the complexity of implementing matched filters. This requires research to create optimal digital implementations of matched filters.

Objective. The purpose of the paper is to determine the parameters of the LFM signal for the implementation of the communication system using CSS modulation on the SDR transceiver. Optimal implementation of discrete matched filter (correlator) for CSS BOK modulation on FPGA (SoC).

Methods. Analysis of the possibilities of implementing CSS BOK modulation for building a communication system based on SDR transceivers. Analysis of optimal options for building a discrete matched filter (correlator) for CSS BOK modulation on FPGA (SoC) and its implementation. Testing on a laboratory bench.

Results The possibility of creating a communication system based on an SDR transceiver using CSS BOK modulation has been confirmed. The optimal parameters of the LFM signal, which can be implemented, have been studied. An implementation of a discrete matched filter (correlator) for CSS BOK modulation on FPGA has been developed. Testing carried out on a laboratory bench using SDR transceivers AD9361 (AD9364) showed the correctness and effectiveness of the decisions made.

Conclusions The parameters of the LFM signal for the implementation in the communication system using CSS modulation on the SDR transceiver have been studied and determined. It was determined that when using the AD9361 (AD9364) transceiver, it is possible to implement an LFM signal with a band of up to 25 MHz, while the optimal symbol duration will be 16.6667 µsec at 1024 counts and a sampling frequency of 61.44 MHz. It was determined that the best CSS modulation method for creating a communication system is the binary orthogonal manipulation (BOK) method, which allows you to effectively use the advantages of SDR technologies, in particular, the ease of working with quadrature channels and, as a consequence, the ease of implementing phase synchronization. It has been determined that the best method of implementing a matched filter (correlator) on the basis of FPGA (SoC) is the application of fast convolution based on the fast Fourier transform. The developed implementation of a discrete matched filter (correlator) for CSS BOK modulation on FPGA showed the possibility of implementing a communication system with CSS BOK modulation on an SDR transceiver in full accordance with the research results. Experimental studies were carried out on a laboratory bench using SDR transceivers AD9361 (AD9364), which fully confirmed the results of simulation modelling.

ANALYSIS OF ROUTING PROTOCOLS CHARACTERISTICS IN AD-HOC NETWORK

2024-06-21T00:43:41+03:00

Background. Wireless ad-hoc networks are becoming increasingly prevalence in remote areas, in extreme environments, even in military operations, and in scenarios where setting up infrastructure networks is not possible. Research of ad-hoc routing protocols problems allows improving the efficiency of their operation in conditions of high variability in packet loss or instability of network operation when the speed of users changes.

Objective. The purpose of the paper is analysis of packet loss dependency from a network operation time, study of a user speed influence on a network efficiency, and research of network operation efficiency with different routing protocols.

Methods. The method of routing protocols efficiency evaluation is the simulation of their operation in an ad-hoc network on a test data set and research of a network indicators dependency in time under different loads and changing mobility of users.

Results. The conducted research demonstrated that user’s mobility at different speeds significantly affects the network operation as a whole. The instability of users' positions leads to a significant increase in route search time and packet transmission time. Among researched GPSR, DSDV, and AODV protocols, the latter proved to be the best because it has the lowest percentage of data loss and the lowest average time of message send and receive operations.

Conclusions. The work is dedicated to the actual problem of developing and setting parameters of ad-hoc network. Received research results indicate the need to choose the optimal routing protocol depending on specific application conditions, such as user movement speed and network stability. The proposed solutions can be the first stage of complex processing of packets in the mobile network and justify the choice of AODV protocol as a basis for further improvement.

AUTHENTICATION OF WIRELESS SYSTEMS BASED ON A DRONE SWARM AS A COMPONENT OF THE 5G RADIO ACCESS NETWORK ARCHITECTURE

2024-06-21T15:40:32+03:00

Background. When establishing security measures for telecommunication networks involving unmanned aerial vehicles (UAVs), characteristics such as high scalability, device diversity, and high mobility should be considered. Authentication is a fundamental property that allows a UAV network to establish secure communication between its core components. Authentication also protects the UAV network from attackers impersonating legitimate UAVs. UAV authentication can further secure the communication channel by preventing impersonation and replay attacks. The design of UAV access control schemes, such as authorization and authentication mechanisms, remains a challenging research problem in UAV networks. The network becomes even more complicated when it interacts with a multitude of UAVs, called a swarm. A swarm by its very nature has a dynamic structure, and this raises the issue of unreliable constraints on UAVs in its composition. A standardized solution for the authentication of a single drone using the new 5G radio network (NR) is known, but for a swarm of drones, this is an open field of research. Per-UAV authentication key sharing as described in 5G NR does not scale across groups of UAVs.

Objective. The purpose of this work is to conduct an analytical review and consider approaches to creating procedures for the authentication of a swarm of UAVs/drones with wireless equipment on board for the 5G NR network, taking into account the features of swarm formation and the very requirements for 5G authentication.

Methods. Analysis of factors affecting the quality of provision of telecommunication services using UAVs in fifth generation networks. Analysis of well-known publications dedicated to the implementation of 5G networks and the use of drones in them. Comparing the implementation of UAV authentication procedures with on-board wireless equipment in the 5G network.

Results. The widespread use of small UAVs, as well as the large expansion of wireless 5G networks, requires new security measures to prevent unauthorized access to sensitive data.

Identification and Authentication for a mobile operator's network using drones allows for secure communication between its main components. This makes it possible to recognize the very drones that participate in the formation of such a network. Drone authentication often protects the communication channel by preventing replay attacks. The development of drone radio access control mechanisms, such as authorization and authentication mechanisms, remain relevant researches for the construction of promising radio access networks involving UAVs.

It has been confirmed that the introduction of special group procedures for the authentication of a swarm of drones in the 5G network can significantly improve the quality of the provision of telecommunication services.

Conclusions. When working with a swarm of drones, in addition to the usual problems with encryption and authentication (within the swarm and for communication between the swarm and the ground control station), there are additional problems related to the constant change in the composition of the swarm and its hovering position: drones can join or leave a swarm.

Depending on the swarm management structure, a different method of authentication will be needed, which makes it difficult to unify such procedures for a swarm of drones. Authentication procedures for a swarm of drones in 5G can be implemented through the following approaches: individual authentication, when each drone as a member of the swarm undergoes authentication with one NR 5G ground station; you can consider such an approach as authentication of a group of IoT devices, if the traffic of the swarm is very limited; group authentication through a leader drone that communicates with swarm members and the 5G operator's network; group distributed authentication through edge drones.

Group authentication via a drone leader is presented, where authentication is performed through a mechanism based on distributed delegation to reduce the service traffic directed to the 5G operator's core network. Here, legitimate drones are authorized as proxy delegated signers to perform authentication on behalf of the underlying network.

Group distributed authentication through boundary drones is considered, which offers more solutions than the case of authentication through a leader drone. Here, a solution is possible for several cases at once, for example, authentication of new drones (entering the swarm or leaving the swarm) and merging two separate drone swarms.

REMOTE VEHICLE DIAGNOSTIC SYSTEM DEVELOPMENT BASED ON THE INTERNET OF THINGS TECHNOLOGY

2024-06-21T16:03:52+03:00

Background. Advanced artificial intelligence and IoT gateways are working together in the automotive industry to predict potential vehicle problems by analysing sensor data and optimizing quality control processes. Manufacturers can detect anomalies, improve product reliability, and eliminate manufacturing defects or malfunctions in advance. Predictive analytics also lead to improved fuel efficiency, performance and overall vehicle reliability.

Objective. The purpose of this work is to develop a model for remote diagnosis of vehicle faults using a Raspberry Pi model B microcomputer and a SIM7600G-H GSM module. Configure data modules, install the necessary software and configure it, demonstrate step-by-step actions, and perform diagnostics and testing of this module for data transmission.

Methods. A prototype was created on the basis of Raspberry Pi 4. and provides monitoring of machine operation in remote mode using the SIM7600E-H LTE Cat-4 4G/3G module. The design has small dimensions, easy installation, requires only initial adjustment and has a wide range of improvements.

Results. This prototype uses a diagnostic OBD-II car scanner ELM327 with Bluetooth connection support, a Raspberry PI 4 model B microcomputer with 8 GB of RAM, 4 USB connectors (2 ports type USB3 and 2 ports type USB2), a Gigabit Ethernet port, a USB-C power supply port, and two micro HDMI 4K display connectors. On top of the module there are 48 pins (contacts) with which you can connect modules of different types and directions. The SIM7600G-H communication module is connected to these pins. The last element of the prototype is the SIM card of one of the telephone service providers and the micro SD card, which will act as the main memory element on which the operating system will be written and data will be stored.

Conclusions. The article proposes the development of a device model using Internet of Things technologies, which is capable of providing remote diagnosis of car malfunctions. This model is based on the use of the SIM7600G-H module, which provides data transmission through the mobile network.

The developed model allows you to read data from various car sensors, as well as transfer this data to a remote device for further analysis. This makes it possible to quickly detect malfunctions and make timely decisions on their correction.

COMPREHENSIVE ANALYSES OF METHODS OF ENERGY STORAGE SYSTEMS USAGE FOR MICROGRID

2024-06-21T16:21:44+03:00

Background. Energy storage systems (ESS) provide uninterrupted power access to users and aim to minimize energy losses. These systems are extensively utilized in microgrids, facilitating smooth transitions between grid-connected and isolated microgrid operations. ESS devices with high power density must manage fluctuating loads, such as substations and distributed power sources like wind turbines. Despite existing standards for ESS management, these regulations are often limited to specific areas, leading to interoperability challenges due to the absence of unified modeling approaches and data models.

Objective. The purpose of the paper is to explore methods for controlling energy storage systems and enhancing their interoperability. The study focuses on integrating ESS without necessitating changes in consumer control schemes and utilizing interoperable data models for rapid identification and configuration.

Methods. The research involves analysing various methods used in electricity management systems, identifying interaction conflicts, and emphasizing the development of an interoperable network. The study also considers the potential of an ontology-based control system to achieve the desired level of interoperability.

Results. The analysis indicates that most existing electricity management systems experience interaction conflicts, highlighting the need for an interoperable network. The proposed systems offer significant advantages in fault tolerance, reliability, and scalability. These systems ensure a smooth transition between networked and isolated operations in microgrids, allowing for instant reconnection to the grid when normal conditions are restored.

Conclusions. The findings suggest that developing an interoperable ESS is crucial for improving system efficiency and reliability. Future research directions include forming an ontology-based control system to enhance interoperability. This approach is expected to address current interaction conflicts and pave the way for more resilient and scalable energy storage solutions.

METHOD OF THE SERVER HORIZONTAL LOAD BALANCING FOR REDUCING ENERGY CONSUMPTION

2024-06-21T16:47:09+03:00

Background. Server horizontal load balancing is a crucial aspect of modern computing systems, particularly in cloud computing environments. The efficient management of incoming flows of applications is essential to ensure optimal resource utilization and minimize energy consumption. This study focuses on developing a method for managing the incoming flow of applications to reduce energy consumption in server horizontal load balancing.

Objective. The primary objective is to develop a method for managing the incoming flow of applications to reduce energy consumption in server horizontal load balancing. This involves identifying the maximum permissible number of applications that can simultaneously enter the system for service, ensuring that the volume of resources used is close to the total maximum possible amount of resources. The method aims to minimize the variance of the elements of the sequence of maximum allowable numbers of applications and the dispersion of the elements of the sequences of volumes of resources used.

Methods. The method involves several key steps:

Input Load Smoothing Scheme: A static control method is proposed to smooth the incoming load. This involves developing a scheme for smoothing the incoming load, which is a set of values of the maximum allowable number of requests (sequence {ki}) arriving at the system input for a small time interval ∆ti. The sequence is selected to ensure that the volume of resources used is close to the total maximum possible amount of resources.

Genetic Algorithm: The selection of the sequence {ki} is carried out using a genetic algorithm. The algorithm involves crossover, mutation, and selection operations to minimize the variance of the elements of the sequence and the dispersion of the elements of the sequences of volumes of resources used.

Resource Allocation: The method involves allocating resources for the maintenance of a given type of service. The parameters of the server, which are characterized as the resources of the system serving the applications, are usually calculated for the average values of the parameters of the input stream.

Delay Introduction: To manage the application processing process and prevent resource shortages, a delay is introduced for a part of the applications that coincide with a surge in load. The delay time is determined so that delayed applications do not enter the system until the previous burst of load is successfully serviced in the resource-consuming functional block.

Results. The results of the study include the development of a method for managing the incoming flow of applications to reduce energy consumption in server horizontal load balancing. The method involves the use of a genetic algorithm to select the sequence {ki} that minimizes the variance of the elements of the sequence and the dispersion of the elements of the sequences of volumes of resources used.

Conclusions. The study concludes that the proposed method for managing the incoming flow of applications can effectively reduce energy consumption in server horizontal load balancing. The method involves the use of a genetic algorithm to select the sequence {ki} that ensures efficient use of system resources and minimizes the variance of the elements of the sequence and the dispersion of the elements of the sequences of volumes of resources used. The method can be applied in various scenarios where efficient use of system resources is crucial, such as in cloud computing environments.

ANALYSING MALICIOUS SOFTWARE SUPPORTING DDOS ATTACKS ON IOT NETWORKS

2024-06-21T17:05:49+03:00

Background. With the proliferation of Internet of Things (IoT) networks in the digital age, the risk of cyberattacks, especially DDoS attacks, is also increasing. IoT devices such as smart refrigerators, thermostats, webcams and other Internet-connected home appliances are being targeted by attackers who can use them as part of a botnet to conduct DDoS attacks. These devices often have inadequate network security and are rarely updated, making them vulnerable. DDoS attacks can result in significant losses such as lost revenue, reputational damage and costs to restore services. So, the vulnerability of IoT networks to DDoS attacks and the need to develop effective protection measures is a pressing issue.

Objective. The purpose of the paper is to analyse software that supports DDoS attacks in IoT networks. Provide general recommendations to help improve approaches to defence measures in IoT networks against DDoS-enabled malware.

Methods. Five main DDoS attack models are considered: agent-handler model, reflexive model, IRC-based model, web-based model, and P2P-based model. Three most dangerous software capable of DDoS attacks on IoT networks are analyzed: Mirai, XOR.DDoS and Linux.Hydra.

Results. There are many models and methods of DDoS attacks on IoT networks. The most dangerous are Mirai, XOR.DDoS and Linux.Hydra. Each of these software has its own specific characteristics and methods of carrying out attacks. The study also showed that there are several effective measures to counter these attacks, including setting strong passwords, regularly updating software, setting up traffic filters and restricting network access.

Conclusions. Key aspects of DDoS attacks, their models and process steps are considered. The paper focuses on the three most dangerous software used to conduct such attacks and provides recommendations on how to counteract them.

MODEL OF RANDOM-LIKE PLANAR TRAJECTORIES WITH INTERSECTIONS

2024-06-21T17:20:04+03:00

Background. Recently the task of detecting and identifying trajectories of objects whose genuine purposes are uncertain or strike threatening has become extremely important. The known approaches produce insufficiently smooth trajectories.

Objective. The purpose of the paper is to build a model of generating random-like planar trajectories, which would have sufficiently smooth curves. A trajectory may have self-intersections and may intersect other trajectories.

Methods. Preliminarily two starting points on a plane are generated. The distance and angle between these points are calculated, which then are successively updated to calculate new trajectory points using the polar coordinate system. A trajectory of points is generated using values of normally distributed random variables with zero mean and unit variance and four values of -uniformly distributed random variables.

Results. The random-like trajectory generator has the same time complexity as its predecessors, including the direction randomization generator and its modifications. Exemplary trajectories appear very realistic. Self-intersections are important to manoeuvre and confuse the opponent side. The trajectory has four parameters to adjust its heading, scattering of points, and intensity of turns and twists. These parameters serve as magnitudes to amplify the respective properties. The highest influence has the angle-scattering parameter. Four simple conditions can be embedded to fit the trajectory within a rectangular domain.

Conclusions. The suggested model should serve either for generating trajectory datasets to train manoeuvring-object detectors on them or for masking reconnaissance. The model allows balancing the trajectory smoothness and randomness.