Telecommunication Systems Research Articles

Outlier Detection in Streaming Data for Telecommunications and Industrial Applications: A Survey

Streaming data are present all around us. From traditional radio systems streaming audio to today’s connected end-user devices constantly sending information or accessing services, data are flowing constantly between nodes across various networks. The demand for appropriate outlier detection (OD) methods in the fields of fault detection, special events detection, and malicious activities detection and prevention is not only persistent over time but increasing, especially with the recent developments in Telecommunication systems such as Fifth Generation (5G) networks facilitating the expansion of the Internet of Things (IoT). The process of selecting a computationally efficient OD method, adapted for a specific field and accounting for the existence of empirical data, or lack thereof, is non-trivial. This paper presents a thorough survey of OD methods, categorized by the applications they are implemented in, the basic assumptions that they use according to the characteristics of the streaming data, and a summary of the emerging challenges, such as the evolving structure and nature of the data and their dimensionality and temporality. A categorization of commonly used datasets in the context of streaming data is produced to aid data source identification for researchers in this field. Based on this, guidelines for OD method selection are defined, which consider flexibility and sample size requirements and facilitate the design of such algorithms in Telecommunications and other industries.

Efficiency Measurements of Energy Harvesting from Electromagnetic Environment for Selected General Purpose Telecommunication Systems

The results of measurements of the efficiency of energy harvesting from commonly available general-purpose telecommunications systems, divided into typical bands available under European conditions, have been presented in this paper. Specially designed harvesters were used, dedicated to powering autonomous semi-passive Radio Frequency Identification (RFID) tags. For the assumed resistive loads, the achievable output voltage values of the harvesters were measured across a wide spectrum of electromagnetic field strengths, simulating real conditions. The performance and dynamics of the energy storage process with fixed parameters were studied at an intermediate stage, before the energy conditioning process. The harvesters were treated as typical energy sources with unknown but variable parameters, so their dynamic parameters and instantaneous energy supply were also analyzed. These activities will enable the final development of a power supply system with parameters acceptable for the planned applications and whose efficiency will be maximized under the given conditions. For this purpose, the energy harvesting systems were designed, a suitable laboratory stand was built, and the elaborated circuits were measured to determine the expected parameters of energy harvesting.

Opening of bankruptcy proceedings at the initiative of the creditor

In cases where a debtor in an obligation becomes unable to pay “on account” any more, the only way left to the creditor or creditors of such debtor to protect their financial interests is to open bankruptcy proceedings against such debtor. However, in practice, not everything is so simple, which makes it necessary to study this issue. The purpose of the article is to reveal relevant issues that arise during the opening of bankruptcy proceedings at the initiative of the creditor, to study the problems that arise in this area and to formulate proposals for improving Ukrainian bankruptcy legislation. The creditor’s appeal to the court with an application to open bankruptcy proceedings against his debtor is one of the manifestations of the right of the initiating creditor to judicial protection. It is emphasized that the possibility of the creditor to apply to the debt repayment mechanisms of his insolvent debtor through bankruptcy procedures is provided only for those creditors who have monetary claims against legal entities. If the debtor of the creditor is a natural person, then such a creditor is limited in the ability to protect his rights through bankruptcy procedures, and can use all the tools offered by the legislation in this area, only in the event that the debtor himself – a natural person shows a desire to initiate proceedings in an insolvency case against himself. It is proposed to provide in the legislation of Ukraine the right of a creditor to initiate bankruptcy proceedings against a debtor who is an individual entrepreneur. The conditions for opening bankruptcy proceedings at the creditor’s request have been studied. The presence of a legal dispute as a reason for refusing to open bankruptcy proceedings was analyzed, and judicial practice in this area was studied. The provisions of the bankruptcy legislation regarding the ability of the initiating creditor to submit a proposal for the nomination of an arbitration manager to perform the powers of a property manager or a restructuring manager before the day of the start of operation of the Unified Judicial Information and Telecommunication System in the application for opening proceedings in the bankruptcy case have been analyzed.

Information on operational sea ice products and current and future activities of the German ice service

The ice service at the German Federal Maritime and Hydrographic Agency and its predecessors has been committed to the safety and easiness of ship navigation for more than 100 years. Within this paper, an overview of the operational products issued by the German ice service on a daily to weekly basis throughout the northern hemisphere winter season is given. These comprise written reports, ice charts, NAVTEX messages, and messages via the Global Telecommunication System to inform about the sea ice situation in German coastal waters, the Baltic Sea, and worldwide. Furthermore, the ice service has systematically collected ice observation data along the German North Sea and Baltic Sea coast since the winter of 1896/1897. The history of the German ice service is presented to put the sea ice data into context of the observation technologies used in the course of the existence of the ice service. These long-term observations enable climatological analyses of the sea ice cover in German coastal waters necessary for the safe operation of offshore infrastructure. An evaluation of the data shows a recent decline in sea ice occurrence in the Baltic Sea and German Bight. Current work is ongoing to preserve more of the historic data in digital form and also to transform the products to conform to modern standards in digital technologies and interactive solutions for the customers.

Coherent manipulation of bright and dark solitons of reflection and transmission pulses through sodium atomic medium

Abstract The coherent manipulation and control of bright and dark solitons through sodium atomic medium have been investigated in this manuscript. Dark soliton is reported for reflection and bright soliton is reported for transmission pulses with variation in position and driving field parameters through sodium atomic medium. Further the transmission pulse is periodic dark and bright solitonic behaviors and reflection pulse is periodic bright solitonic behavior with variation in the incident angle and Rabi frequency of the control field. Elliptical dark and bright solitons as well as breather types solitons are also investigated for reflection and transmission pulses. The dark soliton in reflection is due to slow light propagation and bright soliton is obtained due to fast light propagation of transmission through the medium. The modified results of the dark and bright solitons are useful for telecommunication and ultra-fast signal routing system.

Acceleration of Service Life Testing by Using Weibull Distribution on Fiber Optical Connectors

The service life assessment of previous fatigue stress has a fundamental role in estimating the reliability of products like fiber optical connectors, and should replicate use in severe environments in telecommunications systems. However, the vibration prediction models used in the literature present limitations in vibration life prediction. In this paper, we propose using the insertion loss fatigue life and including it in the Weibull distribution to determine the Weibull parameters ƞ and β to evaluate fiber optic connector reliability R(t) under environmental and mechanical testing stress. We analyzed the failure data of a standard telecommunication fiber optical connector under a program of service life stress testing against that of a fiber optical connector under only mechanical vibration stress testing. The fiber connectors were monitored during the vibration testing to review the transient change of the optical signal. Their results showed that the reliability of the fiber connectors submitted to the service life program was Rt=0.694, while that of the fiber connectors submitted to mechanical vibration only was Rt=0.970. In addition, the analysis showed that the service life testing consumed 70.2% of the product’s lifetime. We present in Numerical Validation the steps to determine the acceleration factors of the vibration test developed.

Bismuth-Doped Fiber Lasers and Amplifiers Operating from O- to U-Band: Current State of the Art and Outlook

The development of unique optical materials that provide amplification and lasing in new wavelength ranges is a major scientific problem, the solution of which is becoming the basis for the emergence of new optical technologies, which are primarily targeting the expanding of operating wavelengths in silica glass. In fact, one of the notable advances in the field of fiber optics over the past two decades has been the production of a new type of laser-active fibers (namely bismuth-doped fibers), which has made it possible to cover previously inaccessible (for rare-earth-doped fibers) spectral ranges, in particular O-, E-, S-, and U-telecom bands. The advance in this direction has led to further growth of the technological capabilities in the telecom industry for amplification and generation of optical radiation in various wavelength bands, which will result in the near future to overcoming the problem known as “capacity crunch” by means of expanding the data transmission range. Recently, bismuth-doped fibers have been actively studying in order to improve their characteristics, which would allow for efficient implementation of optical devices based on bismuth-doped fibers (BDFs) with deployed telecommunications systems. This is one of the dynamically developing areas, where progress has already manifested in form of emergence of new achievements, in particular commercially available various types of BDFs, as well as a series of novel fiber-optic amplifiers for the O- and E-bands. In this review, a number of scientific studies that have already led to a noticeable progress in the field of optical properties of BDFs and the practical implementation of optical devices (lasers and amplifiers) based on them are presented and discussed, with much attention to the achievements of recent years.

Improving Typhoon Muifa (2022) Forecasts with FY-3D and FY-3E MWHS-2 Satellite Data Assimilation under Clear Sky Conditions

This study investigates the impacts of assimilating the Microwave Humidity Sounder II (MWHS-2) radiance data carried on the FY-3D and FY-3E satellites on the analyses and forecasts of Typhoon Muifa in 2022 under clear-sky conditions. Data assimilation experiments are conducted using the Weather Research and Forecasting (WRF) model coupled with the Three-Dimensional Variational (3D-Var) Data Assimilation method to compare the different behaviors of FY-3D and FY-3E radiances. Additionally, the data assimilation strategies are assessed in terms of the sequence of applying the conventional and MWHS-2 radiance data. The results show that assimilating MWHS-2 data is able to enhance the dynamic and thermal structures of the typhoon system. The experiment with FY-3E MWHS-2 assimilated demonstrated superior performance in terms of simulating the typhoon’s structure and providing a prediction of the typhoon’s intensity and track than the experiment with FY-3D MWHS-2 did. The two-step assimilation strategy that assimilates conventional observations before the radiance data has improved the track and intensity forecasts at certain times, particularly with the FY-3E MWHS-2 radiance. It appears that large-scale atmospheric conditions are more refined by initially assimilating the Global Telecommunication System (GTS) data, with subsequent satellite data assimilation further adjusting the model state. This strategy has also confirmed improvements in precipitation prediction as it enhances the dynamic and thermal structures of the typhoon system.

Adaptive Radio Access Technology Selection Algorithm for Heterogeneous Wireless Networks

In Heterogeneous Wireless Networks (HWNs), Radio Access Technologies (RAT) can only consider the situation of one particular Radio Resource Management (RRM) which is unsuitable for managing multiple RATs. This study deployed an adaptive RAT selection scheme model to allocate users to the best RAT with the use of the cost function variable. The adopted model uses different input criteria like signal strength, network loads, service type and QoS requirement for the best access network selections. The adaptive RAT selection algorithm was executed in different service mixes (voice and data service) to access model suitability for users in Global System for Mobile Communications with Enhanced Data Rates for Global Evolution Radio Access Network (GERAN) and Universal Mobile Telecommunications System Radio Access Network (UTRAN). The proposed algorithm resulted in the call blocking probability reduction by 0.03 for GERAN and 0.14 for UTRAN as validated with the existing algorithm based on load balancing, service-based and priority-based. The drop implied an increased probability of ensuring session stability and high quality of the active service, leading to a high load distribution.

Electromagnetic Interference Shielding and Joule Heating Properties of Flexible, Lightweight, and Hydrophobic MXene/Nickel-Coated Polyester Fabrics Manufactured by Dip-Dry Coating and Electroless Plating.

High-performance electromagnetic interference (EMI) shielding materials with high flexibility, low density, and hydrophobic surface are crucial for modern integrated electronics and telecommunication systems in advanced industries like aerospace, military, artificial intelligence, and wearable electronics. In this study, we present flexible and hydrophobic MXene/Ni-coated polyester (PET) fabrics featuring a double-layered structure, fabricated via a facile and scalable dip-dry coating process followed by electroless nickel plating. Increasing the dip-dry coating iterations up to 10 cycles boosts the MXene loading content (∼31 wt %) and electrical conductivity (∼86 S/cm) of MXene-coated PET fabrics, while maintaining constant porosity (∼95%). The addition of a Ni layer enhances hydrophobicity, achieving a high water contact angle of ∼114° compared to only MXene-coated PET fabrics (∼49°). Furthermore, the 30 μm thick MXene/Ni-coated PET fabric demonstrates superior electrical conductivity (∼113.8 S/cm) and EMI shielding effectiveness (∼35.7 dB at 8-12 GHz) compared to only MXene- or Ni-coated PET fabrics. The EMI shielding performance of the MXene/Ni-coated PET fabric remains more stable in an air environment than only MXene-coated fabrics due to the outer Ni layer with excellent hydrophobicity and oxidation stability. Additionally, the MXene/Ni-coated PET fabric exhibits impressive Joule heating performance, swiftly converting electrical energy into heat and reaching high steady-state temperatures (32-92 °C) at low applied voltages (0.5-1.5 V).

Fly-around-the-World Near-Space Picosatellite for Cost-Effective School Space Projects

This research presents the design and development of a near-space picosatellite platform intended to operate at high altitudes between 20–40 km above sea level. These picosatellites function similarly to orbital satellites but float and travel with the wind in the atmosphere instead of orbiting the Earth. The platform utilizes a super-pressure balloon to provide buoyancy, allowing the picosatellite to remain airborne and operational for several days to months, capable of flying around the world multiple times. This study focuses on the cost-effective design of high-altitude platforms, telecommunication systems, and energy consumption for the picosatellite, enabling it to communicate with ground stations from anywhere in the world while consuming low power. The use of common COTS (Commercial Off-The-Shelf) equipment aims to enhance accessibility for educational applications. This research gathered data from our previous studies for over 20 high-altitude platform flights, analyzed the necessary factors for whole system design, and developed a new prototype that has been successfully built and tested.

Securing Your Eggs in Multiple Baskets — Assuring a Resilient and Secure Supply Chain

AbstractThe global supply chain is a complex system of systems made up of and relying on other complex systems of systems (SoS) to achieve its goals. To take a typical example, Enterprise A is supplied essential parts on a regular basis to manufacture its products. To place the order requires global financial systems, integrated email systems, the internet, multiple telecommunications systems, and supply software provided by large companies. To deliver the parts may require air and maritime transportation systems, the rail network, interstate highway systems, road haulage companies, state and local transportation systems and so forth. When any of these complex systems fail, the impact can be global, and the results catastrophic. Recent examples include the shortage of Personal Protective Equipment (PPE) during the COVID pandemic, computer chip shortages delaying the assembly and sales of cars, and, most recently, the baby formula shortage. These were due to disruptions in the supply chain caused by an overreliance on single sourced suppliers who failed to deliver, transportation disruptions, outsourcing of critical parts, supplies, medicines to distant countries, and/or an overreliance on “Just In Time” for inventory management. This is the case of placing too many eggs in too few baskets, and often just one basket. Counterfeit or substandard parts and products can enter the supply chain via graft, breaks in chain of custody, or carelessness. This has included critical mechanical parts on aircraft, chips containing spyware, and substandard or out of date medicines substituted for the real thing resulting in serious illness and death. This complex SoS needs to be examined, studied, and understood in the same way as a mission critical system; threats, vulnerabilities, and risks need to be identified and mitigated and assurance cases defined to ensure a solid and reliable supply chain. This paper will look at the supply chain of an example factory system to determine how some of these problems can be predicted, prevented, mitigated, and solved using the UAF, RAAML and assurance case techniques.

Methodology for the design of a nanosatellite telecommunication system in S-Band based on Software for Digital Mission Engineering

Abstract A trend in the development of nanosatellite platforms for technology demonstration has increased in both private industry and academic projects. Communication link design plays a crucial role in the success of space missions, enabling efficient and reliable data transmission between satellites and ground stations. In this context, the use of advanced tools such as System Tool Kit (STK) has gained significant importance by enabling a comprehensive analysis of the technical and operational aspects of the communication link. In an effort to make the future design of the communications subsystem payload on a nanosatellite more efficient and accessible, this paper shows a methodology for the efficient use of STK to perform link analysis.

FEATURES OF THE TACTICS OF INTERROGATION OF THE ACCUSED IN THE INVESTIGATION OF CRIMES IN THE FIELD OF COMPUTER INFORMATION

The subject of the study is the tactics of interrogation as a key element of the investigation of crimes in the field of computer information. The purpose of the article is to find and choose the right interrogation tactics in the investigation of crimes in the field of computer information, which allows you to effectively collect and analyze data, obtain evidence necessary for the investigation, protect the rights of all participants in the process and save time during the investigation. Methodology. In the course of the work, the following methods of scientific research were used: analysis and synthesis, induction and deduction, dialectical, comparative and formal logical methods. The results of the study. The tactical actions necessary for the effective investigation of crimes in the field of computer information have been identified. It has been established that a particularly important factor in the investigation is the availability of sufficient skills and knowledge of the investigator in the field of information and telecommunications technologies, which allows the most productive way to obtain the necessary information for the investigation. During the interrogation of the suspect, it should be clarified how he gained access to the information and telecommunications system, what specific actions he committed, whether he worked independently or was a member of a group. Scope of application of the results: the results of this work can be applied in the educational process, as well as by investigative authorities in the investigation of crimes in the field of computer information, these materials can be especially useful for novice investigators. The novelty of the study lies in the fact that special attention is paid to the technical component when constructing interrogation tactics. Conclusions. It is concluded that it is technical training that is the key feature of interrogation tactics in the investigation of crimes in the field of computer information, since without this component, in some situations, investigative actions are ineffective.

A study on the prediction of service reliability of wireless telecommunication system via distribution regression

The reliability of wireless telecommunication service has become a major concern for the operation and maintenance (O&M) departments of the major telecommunication service providers. Consequently, reliability prediction has assumed a pivotal role for O&M department to furnish dependable services while simultaneously curtailing operational costs. However, predicting the service reliability is a challenging issue mainly attribute to the mobility characteristics of the end-users in the network. In tandem with the formulation of service reliability metrics, this study introduces a linear distribution regression model under Gaussian distribution and a kernel-based distribution regression model tailored for bimodal scenarios. The empirical validation of these proposed metrics and methodologies is substantiated through case studies employing both simulated data and real-world datasets derived from a wireless telecommunication system within an urban district. The outcomes of these case studies demonstrate the efficacy and applicability of the proposed metrics and methods.

Nonlinear RF impairments modeling with OFDM symbol-based parallel Wiener–Hammerstein structure

In the paper, a novel orthogonal frequency division multiplexing (OFDM) symbol-based parallel Wiener–Hammerstein structure is proposed to deal with the problem of nonlinear radio frequency (RF) impairments modeling for a cyclic prefix OFDM (CP-OFDM) waveform in telecommunication systems. The aforementioned structure is an equivalent linear-in-parameters representation of the parallel Wiener–Hammerstein structure in the considered problem. The structure is formally derived enabling the usage of identification algorithms compared with the artificial neural network (ANN) approach. The solution is compliant with current telecommunication standards.

Material Attribute Estimation as Part of Telecommunication Augmented Reality, Virtual Reality, and Mixed Reality System: Systematic Review

The integration of material attribute estimation (MAE) within augmented reality, virtual reality, and mixed reality telecommunication systems stands as a pivotal domain, evolving rapidly with the advent of the Tactile Internet. This unifying implementation process has the potential for improvements in the realism and interactivity of immersive environments. The interaction between MAE and the haptic Internet could lead to significant advances in haptic feedback systems, enabling more accurate and responsive user experiences. This systematic review is focused on the intersection of MAE and the Tactile Internet, aiming to find an implementation path between these technologies. Motivated by the potential of the haptic Internet to advance telecommunications, we explore its potential to advance the analysis of material attributes within AR, VR, and MR applications. Through an extensive analysis of current research approaches, including machine learning methods, we explore the possibilities of integrating the TI into MAE. By exploiting haptic and visual properties stored in the materials of 3D objects and using them directly during rendering in remote access scenarios, we propose a conceptual framework that combines data capture, visual representation, processing, and communication in virtual environments.

Post-Earthquake Damage Assessment: Field Observations and Recent Developments with Recommendations from the Kahramanmaraş Earthquakes in Türkiye on February 6th, 2023 (Pazarcık M7.8 and Elbistan M7.6)

ABSTRACT This study investigates the effects of the February 6, 2023, earthquakes in Türkiye, measuring 7.8 and 7.6 magnitudes (Mercalli intensities XI and X). It comprehensively assesses their impact, along with the subsequent Hatay earthquake (Mw 6.4), on various structures, including residential RC buildings, commercial, industrial, and strengthened structures, as well as critical lifeline components such as roads, bridges, power, and telecommunication systems, and areas affected by soil failures. Immediate field observations were conducted to assess changes and gather insights. The findings will contribute to the development of recommendations for future seismic damage prevention and mitigation strategies.

Actual methods of realization of orbital angular moments of photons in scientific and technical systems

The article discusses several highly effective methods for realizing the orbital angular momentum of photons in laser beams, including the use of phase plates, metasurfaces and injection into a fiber. These methods provide effective compensation for turbulence aberrations in wireless telecommunications systems.

Detection of phase modulation disorder when processing a sequence of ultra-wideband quasi-radio signals against a background of white Gaussian noise

In conditions of a complex electromagnetic environment in communication and data transmission systems, a change in the type of modulation occurs when one or more signal parameters change abruptly, therefore the task of determining the type of signal modulation can be reduced to the task of detecting a disorder, that is, detecting the fact of a change in the type of modulation of the signal and estimation of the disorder time. The purpose of the work is to synthesize an algorithm for detecting phase modulation disorder when processing a sequence of ultra-wideband quasi-radio signals with unknown amplitude and initial phase against a background of white Gaussian noise and to analyze the effectiveness of the resulting algorithm based on the results of statistical modeling. The work synthesizes an algorithm for detecting a phase modulation disorder of a received sequence of ultra-wideband quasi-radio signals against a background of white Gaussian noise. To analyze the effectiveness of the resulting algorithm, statistical modeling of algorithm for detecting a phase modulation disorder is carried out. The dependences of the probability of detection of a disorder on the signal-to-noise ratio and the length of the sequence of received signals at a fixed moment of disorder are obtained. A comparison of the detection characteristics of phase modulation disorder of ultra-wideband quasi-radio signals and narrowband radio signals is made. It is shown that when a low-order phase modulation disorder is detected, the required values of the probability of detection are achieved at low signal-to-noise ratios, while with an increase in the modulation order and the use of its modifications, the efficiency indicators of the algorithm will deteriorate. The introduction of algorithms for detecting a disorder in radio engineering applications will allow optimizing synchronization algorithms and adaptation to interference conditions with a concomitant change in the type of modulation, as well as reducing the amount of transmitted service information in telecommunication systems.