Telecommunication Systems Research Articles

Telesurgery: humanitarian and surgical benefits while navigating technologic and administrative challenges.

Telesurgery, the remote execution of surgical procedures through telecommunication and robotic systems, has witnessed substantial growth in recent years, promising to address global healthcare disparities and enhance surgical expertise. This paper explores the humanitarian and surgical benefits of telesurgery, emphasizing its potential to provide expert surgical care to underserved regions. Despite its transformative potential, telesurgery faces significant technologic challenges, including issues of data transmission, latency, and the need for advanced robotic platforms. The advent of 5G networks and innovative robotic systems provides a promising technological landscape, yet global disparities in 5G coverage remain a concern. Ethical considerations, ranging from preserving the surgeon-patient relationship to addressing patient vulnerability and conflicts of interest, are pivotal aspects that demand attention. The paper underscores the importance of clear regulatory frameworks and international collaboration to navigate legal complexities and ensure ethical standards. As telesurgery progresses, integrating artificial intelligence, augmented reality, and haptic feedback technologies holds promise for further advancements. Despite these challenges, telesurgery has the potential to achieve equitable access to expert surgical care; however, it requires a collective effort to overcome its intricate technologic and administrative hurdles.

The Efficiency Assessment of the Blockchain Networks Adaptive Algorithm as Part of a Multi-Consensus System on Communication Networks

The relevance of the approaches and solutions proposed in the work is due to the desire for distributed computing and decentralization of system modules using blockchain technology in order to increase the autonomy, security and independence of system components. The implementation of blockchain technology for decentralization is hampered by the lack of flexibility in terms of the algorithm for making a single decision in the asynchronous system ‒ consensus, which affects the amount of generated network traffic and the requirements for the hardware component. Due to the changing nature of the transmitted traffic, the load on the communication channel, the time of day of traffic transmission, the equipment, and the network protocols used, the development of a single universal consensus algorithm is not possible, since it depends on a very wide range of variable and specific parameters characteristic of different tasks. The introduction of adaptation mechanisms to current network conditions and a change in the consensus algorithm without losing information and with a satisfactory level of delays would provide sufficient flexibility for further implementation in existing telecommunication systems. The purpose of this paper is to evaluate the effectiveness of the proposed adaptive algorithm for choosing a consensus for blockchain networks.The essence of the presented algorithm is to change the consensus algorithm on a section of the blockchain network upon reaching certain network conditions, which allows regulating the amount of generated load on the communication network to reduce the loss of transaction blocks and the subsequent delay in their processing. The proposed efficiency assessment model is based on mathematical modeling methods, differential equation analysis, queueing theory and network graphs. The analysis of the results showed the efficiency of the proposed model when comparing the results of the analytical calculation and the experiment. The scientific novelty of the proposed approach is to developing an adaptive consensus selection algorithm, as opposed to developing a universal consensus algorithm, and the efficiency assessment model of the proposed algorithm on the communication network, taking into account a number of parameters characterizing the devices and the section of the communication network.The theoretical significance is in the universality of the proposed efficiency assessment model for calculating the synchronization speed of all nodes of the blockchain network with specified network parameters.The practical significance of the proposed algorithm and efficiency assessment method lies in the formation of new approaches and opportunities for integrating blockchain technology into modern communication networks, abstracting from the problem of consensus selection in changing conditions of the communication network section.

Delay drift compensation of an optoelectronic oscillator over a large temperature range through continuous tuning

Phase noise reduces target sensitivity in radar and increases bit error rate in telecommunications systems. Optoelectronic oscillators are known for using optical fibre technology to realise the large delay required to attain superior phase noise performance compared to conventional microwave source technology. However, the long fibre is vulnerable to environmentally induced phase perturbations, while conventional phase shifters have insufficient range to compensate for the phase drift over the operational temperature range without the use of a temperature-controlled enclosure. Here we introduce a vector modulator controlled by a Stuart-Landau integrator, as a solution to non-efficient tuning for the phase shift. The concept is verified by simulation and experimentally demonstrated using an optoelectronic oscillator phase-locked to a system reference. Phase lock is maintained over four free spectral ranges equivalent to a tuning phase range of 1440° when the optoelectronic oscillator is cycled over a 10 °C to 85 °C temperature range. These demonstrations highlight the practical potential of our continuous tuning method.

Linear and nonlinear coupling of light in twin-resonators with Kerr nonlinearity

Nonlinear effects in microresonators are efficient building blocks for all-optical computing and telecom systems. With the latest advances in microfabrication, coupled microresonators are used in a rapidly growing number of applications. In this work, we investigate the coupling between twin-resonators in the presence of Kerr nonlinearity. We use an experimental setup with controllable coupling between two high-Q resonators and discuss the effects caused by the simultaneous presence of linear and nonlinear coupling between the optical fields. Linear-coupling-induced mode splitting is observed at low input powers, with the controllable coupling leading to a tunable mode splitting. At high input powers, the hybridized resonances show spontaneous symmetry breaking (SSB) effects, in which the optical power is unevenly distributed between the resonators. Our experimental results are supported by a detailed theoretical model of nonlinear twin-resonators. With the recent interest in coupled resonator systems for neuromorphic computing, quantum systems, and optical frequency comb generation, our work provides important insights into the behavior of these systems at high circulating powers.

Guest Editorial: Techno-Economic Analysis of Telecommunications Systems

Guest Editorial: Techno-Economic Analysis of Telecommunications Systems

A split ring resonator slot based fabricated crescent microstrip patch antennas for UWB wireless system applications

This paper clarifies significant bandwidth and optimum gain for a split ring resonator slot based fabricated microstrip patch antenna for ultra wide band (UWB) wireless telecommunication system applications. The antenna has a circular slot partially cut into a circular patch and radiates in the UWB frequency range. The design system features a steady radiation pattern and an impedance bandwidth of 3.3 to 10.96 GHz. The proposed UWB notch antenna is at 4.6 GHz, 7.29 GHz, and 9.36 GHz, with an impedance bandwidth of 3.3 to 10.96 GHz. The UWB notch antenna offers linear phase response and a group delay of fewer than 1 ns. It is practical for UWB applications due to less group delay and stable radiation patterns. FR4 material with a 4.4 relative permittivity. The reported antenna is measured following the manufacturing of the prototype design using HFSS simulations. The suggested fabricated antenna minimizes return loss. The findings demonstrate that when combined with VSWR 2, the reflection coefficient covers the band ranges from 3.3-10.96 GHz.

STATE POLICY ON THE PROTECTION OF NATIONAL INTERESTS OF UKRAINE IN THE INTERNET ENVIRONMENT

The article deals with the problem of protecting Ukraine’s national interests in the context of the Russian-Ukrainian war. The Internet is seen as a space for free expression of opinions, but often turns into a battlefield in the information war. The article analyses the processes of informatisation of society and the increase in the number of Internet users. The impact of the Russian-Ukrainian war on the leading Internet providers and their political position is analysed. Today, Ukraine enjoys great support from leading campaigns in this area, but the aggressor country is heavily funding war propaganda. Attention is drawn to the results of statistics on cyberattacks on state institutions and the public by the Russian Federation. It is emphasised that today state institutions, business and society in Ukraine have united to counteract the negative information influence of Russia. The structure of Ukraine’s national interests, priorities and directions of their protection are defined. Attention is focused on the fact that the Russian Federation attracts teenagers to extremist and radical activities on the Internet. This additionally threatens the national interests of Ukraine. Prevention of extremism is based on raising the legal, political and general culture of citizens, and shaping a positive image of the state. Therefore, it is justified to take effective measures to develop a powerful ideological corpus, a national idea and to adhere to the state’s strategy for European integration. It is important to establish systematic training of specialists in the field of protecting national interests in the Internet space, enhancing the preventive role of the media and institutional support for analytical, educational, propaganda and information work. The author proposes to develop a powerful system of countering manipulations on the Internet, which will include technological developments, methodology, ideological component, legal and educational measures. The author substantiates the necessity of Ukraine’s integration into the global and regional European information space; integration into international information and telecommunication systems and organisations; modernisation and certain changes in the information policy; improvement of legislation on harmonisation of national legislation with international standards; introduction of modern information and communication technologies into public administration processes, etc.

How inaccurate offshore wind observations impact the quality of operational numerical weather prediction

AbstractAt Norwegian offshore platforms, wind speed is observed at heights between approx. 35 and approx. 150 m a.s.l. These observations are used to estimate 10‐m wind speed, by a power law with a constant wind shear coefficient. The resulting 10‐m wind speed is then distributed to the Global Telecommunication System (GTS) and used for assimilation and verification purposes by the meteorological community. However, multiple methods with varying results exist for the reduction of wind speed from the original measurement height to 10 m. The resulting estimate of 10‐m wind speed is therefore sensitive to the choice of method. The use of such observations may therefore be suboptimal in forecast analysis and make the forecast verification difficult to interpret. This study investigates how the use of these observations impacts forecasts from the operational regional forecast system used at MET Norway and the Global Integrated Forecast System operated by ECMWF for the period 2017–2023. Both forecast systems assimilated the observations over major parts of the period and the presented results indicate that the use of these observations increased the initial errors in the forecasts. This is confirmed in a data denial experiment over a shorter period of time. The verification results show that both forecast systems underestimate the wind speed at the original measurement heights, while the results for 10‐m verification vary with the interpolation method between original sensor height and 10 m. The forecasts show in general more wind than the GTS‐distributed estimates and are in better agreement with more advanced interpolation methods. The verification results show a strong dependency on the vertical stability of the atmosphere. The major differences between the forecast systems are that the regional system shows less bias, while the standard deviations of the errors are slightly lower in the global system.

Complex signals parameters optimization on the base of linear approximations using the gradient method and Newton’s method

The article examines the effectiveness of the gradient descent and Newton methods for optimizing the parameters of ensembles of complex signals. Algorithms have been developed and implemented that increase the accuracy of setting parameters and ensure reasonable optimization of spectral, temporal and statistical characteristics of signals. The effectiveness of the application of the methods was confirmed experimentally on the example of reducing the error and increasing the level of immunity. The obtained results substantiate the improvement of the parameters of complex signals, which proves the efficiency of use for wireless telecommunication systems in order to ensure stable and reliable operation in conditions of dynamic changes in the environment and a high level of interference.The article compares the mathematical methods of optimization, namely the gradient method and Newton's method, proposes mathematical models and constructs algorithms that empirically prove the effectiveness of the application of the studied mathematical methods in the specified scientific area - for optimizing the parameters of ensembles of complex signals. Scientific works [1-6, 9, 12] present algorithms based on the gradient method and Newton's method, but they do not consider in detail the comparative analysis of the effectiveness of these methods for optimizing the parameters of ensembles of complex signals for implementation in various scientific and practical tasks. The effectiveness of the algorithms proposed in the article was confirmed experimentally, which made it possible to reduce the error and improve the characteristics of ensembles of complex signals.As a result of the experiments using the methods of gradient descent and Newton, a significant reduction of the error and an improvement of the stability of the signals were achieved. Newton's method reduced the error from 0.1 to 0.0027, justifying the high accuracy of setting the signal parameters. The gradient descent method provided a stable reduction of the gradient norm from 12.75 to less than 1.23, effectively reducing the interference level, i.e. increasing the interference immunity.

A Survey of Phase Shifters for Microwave Phased Array Systems

ABSTRACTPhased Array Systems (PASs) are extensively used in radar and telecommunication systems for diverse applications, including military surveillance and wireless broadband communication. Besides, they are becoming increasingly indispensable in modern applications such as multi‐function phased array radars for weather monitoring and aircraft tracking or high‐throughput satellite systems, which aim to provide fast broadband connectivity in remote areas. Despite the numerous advantages of phased array systems with RF phase shift, including high signal‐to‐noise and signal‐to‐interference ratios, as well as low complexity, they present a few limitations, including high cost and large chip areas. The cost and size of PASs are mainly dependent on the RF phase shifters, which are essential to their operation. This article describes the different types of phase shifters (mechanical, ferromagnetic/magnetic, electromechanical, and electronic). It compares their performance metrics, highlighting that electronic phase shifters are the most common type used in modern PASs. In this regard, a comparative study of different subcategories of electronic phase shifters, such as the switched‐type, reflective‐type, loaded‐transmission line, and vector‐sum phase shifters, are explored along with their advantages, drawbacks and state‐of‐art techniques used to address their limitations. Therefore, this article may serve as a reference for research milestones on RF phase shifters.

Optimizing Key Value Indicators in Intent-Based Networks through Digital Twins aided service orchestration mechanisms

For many years, the orchestration of network resources and services has been addressed by considering homogeneous communication infrastructures and simple Service Level Agreements (SLAs), generally defined through a list of traditional Key Performance Indicators (KPIs). Unfortunately, state-of-the-art solutions risk being quite ineffective for future telecommunication systems. Beyond 5G networks, for instance, are emerging as complex and heterogeneous ecosystems where resources belonging to diverse network domains with evolving capabilities can be dynamically exposed to support much more complex and cross-domain services and applications. At the same time, SLAs will be defined by also considering novel performance demands, including security, economic, and environmental needs. Based on these premises, this work proposes a novel orchestration strategy designed to fulfill service requirements expressed through Key Value Indicators (KVIs), while combining the potentials of both Network Digital Twins and Intent-Based Networking. Leveraging insights from Network Digital Twins, multiple service orchestration options are explored to optimize resource utilization. Simultaneously, Intent-Based Networking is adopted to streamline network management via intents, specifying Beyond 5G requirements through KPIs and KVIs. An optimal orchestration scheme has been conceived through a multi-criteria decision-making algorithm and a many-to-many matching game between domains and service requests mapped into intents, aiming to minimize SLA violations over time. The performance of the conceived solution has been investigated through computer simulations in realistic scenarios. The obtained results clearly highlight its effectiveness and demonstrate that it is able to reduce SLA violations (related to latency, throughput, costs, and cyber risk requirements) by up to 22.44% compared to other baseline techniques.

Implementing a Secure Cloud-Based System to Safeguard Sensitive Medical Data for Healthcare

In most developed countries, the medical healthcare system is experiencing rapid development from the stage of clinical information to the stage of information dissemination. In all of these countries, it is undeniable that the Internet of Medical Things (IoMT) technologies have contributed in order to develop information medical healthcare. In reality, the development of smart medical healthcare has been hindered by the protection of medical privacy, according to research and acceptance. This is especially true as telecommunications systems continue to expand and wireless sensor networks (WSN) develop, as well as ways to penetrate those checks that have become increasingly difficult. In the smart healthcare system, protecting users’ information remains an outstanding issue. IoMT features and the protection of privacy and security have led to the development of an extended privacy homomorphism algorithm based on scrambling matrixes, an encryption algorithm enhanced by Modified RSA (mRSA), and a method of encrypted data compression that ensures data confidentiality. For the above purpose, we built a prototype system on a demo temporary domain using both hardware and software. According to the results, the proposed scheme protects E-healthcare from potential threats by providing stakeholders with a secure interface and preventing unauthorized users from accessing the mCloud, thus ensuring privacy. E-healthcare services based on cloud technology are protected by the proposed scheme because it is simple and robust.

First-principal analysis and design of TaPO5-based waveguides for photonic circuitry

With the rapid development of telecommunication systems, supercomputers, and large data centers, there is a growing need for advanced photonic materials to overcome the limitations of traditional photonic circuitry. This paper introduces monoclinic TaPO5, an indirect-bandgap semiconductor material, as a compact platform for photonic integrated circuits. TaPO5, with a bandgap of 2.148 eV, is analyzed for its structural, vibrational, thermodynamic, and optical properties using pseudo-potential plane waves within the density functional theory (DFT) framework. Our analysis reveals that TaPO5's thermodynamic properties, such as entropy, internal energy, and heat capacity, increase with temperature, while Helmholtz's free energy decreases. The materials demonstrate favorable optical characteristics, including a refractive index (n) of 2.11, an extinction coefficient (k) of 1.2 × 10⁻⁵, and a dielectric function with a real part of 4.45 and an imaginary part of 5.1 × 10⁻⁵ at a wavelength of 1.55 μm. TaPO5 exhibits promising performance metrics for photonic applications. Specifically, a proposed 1 × 2 multimode interference (MMI) splitter demonstrates 0.03 dB excess loss, a compact footprint of 4 × 18 μm2, and a 50:50 splitting ratio at 1.55 μm. These findings indicate that TaPO5 is a viable material for next-generation photonic integrated circuits, offering theoretical and practical advantages for various applications in photonic technology.

Broadband low-loss polarization-insensitive graphene-integrated photonic crystal fiber modulators in the near-infrared range

The amplitude modulator with the function of converting electric signal to optical amplitude modulation is a key component in high-speed optical communication links. In this paper, we demonstrate a variety of two-dimensional graphene-integrated photonic crystal fiber modulators for efficient near-infrared amplitude modulation with ultra-low insertion loss. Taking the advantages of the perfect total internal reflection of the porous photonic crystal fiber and flexible tunability of the graphene conductivity, the modulation depth of 0.075 dB μm−1 with a low optical loss of 2.13 × 10−4 dB μm−1, a long propagation length of ∼20 mm and polarization-insensitive characteristics in a wide wavelength of 1.3 to 1.8 μm can be achieved. This high-performance modulator may have great potential applications in various high-speed telecommunication, interconnection, and graphene-based integrated photonic systems.

Real-FlexE: Real-time Flexible channel Emulator

In digital communications, accurately modeling and replicating the channel effects between a transmitter and receiver is essential to assess their impact on transmitted data. Access to a real-time channel emulator is therefore crucial in the development of telecommunication systems. This paper presents a configurable, flexible, and high-performance FPGA-based channel emulator that supports multiple channel models, including Doppler, AWGN, and multi-path Fading. We explore bit-width precision in the components and present trade-offs between quality and resource utilization. Our exploration demonstrates ∼25%–∼45% savings in various resources while maintaining the accuracy of the channel effects and operating at a high throughput of 500 Msps.

Artificial Neural Network Approach for Analysis and Prediction of Solar Radiation and Wind Speed in Telecommunication Systems

The use of renewable energy sources in the power grid is essential for maintaining economic growth, especially for many African countries. Therefore, these countries can also install advanced artificial intelligence technology in their airport’s power system to capture renewable energy. The paper aims to propose a real-time power management algorithm for a distributed hybrid renewable energy grid. It continues with the network modeling with the integration of solar and wind power. A multi-objective approach is proposed for the maximization of the spatial spectral efficiency and the energy efficiency as a function of the number of wind turbines and solar photovoltaic panels. Radio parameters for a Mobile Wireless inter-operability Medium Access (WiMAX) technology are considered for the simulation in MATLAB software. The results are quite mitigated but theoretically promising for the integration of green energy into the current telecommunication systems

Optimizing The Pump Power and Frequencies of Raman Amplifiers for Gain Flatness

The Internet has become an indispensable part of daily life, accessible to anyone with coverage via smartphones or computers. Extending internet coverage to remote areas necessitates long-distance transmission, which requires optical amplifiers to combat signal degradation and dispersion between the transmitter and receiver. This challenge restricts the reach and bandwidth of long-distance telecommunications. Among optical amplifiers, the Raman amplifier (RA) stands out due to its lower noise gain advantage compared to other amplifiers. The RA shows promise in overcoming the limitations of long-distance telecommunications. Its gain can be controlled by adjusting the pump power or wavelength. This paper investigates the performance optimization of RA with the objective of enhancing its effectiveness in long-distance telecommunication systems. Using the Optiwave simulation tool, we conducted a series of experiments to optimize RA performance by varying pump power and frequency. The results, analyzed through a spectrum analyzer, demonstrate significant improvements in gain flatness post-optimization, with an observed enhancement of 1-1.5 dB. A comparative analysis of gain flatness before and after optimization highlights the RA's potential in mitigating long-distance communication limitations. These findings suggest that optimized RA can significantly improve bandwidth and signal quality, offering a viable solution for current and future telecommunication challenges.

Design of an Anti-interference long-range acoustic Communication System Based on optimal length segment coding

Abstract With the increased demand for unmanned vehicles in marine development, the development of underwater acoustic communication technology has received much attention. One of the key technologies in the research of long-range underwater acoustic communication technology is the use of underwater acoustic channels for efficient and stable data transmission. The harsh environment of the underwater acoustic channel has a significant impact on the rate and quality of underwater acoustic communication, making it a challenging research direction to achieve high-speed and reliable telecommunication systems underwater. In this paper, a high-speed remote command-based communication system is investigated, and a long-range acoustic communication system with good adaptability to sudden and continuous interference is designed based on a remote unmanned platform. A method for encoding the communication message in segments of optimal length is proposed in this paper. This coding method can enhance the anti-sudden interference capability of the communication system which has a certain degree of communication confidentiality, and the performance of this anti-interference communication system is verified by laboratory tests and field tests. The verification results show that the proposed telecommunication system based on optimal length segment coding has better performance in anti-sudden interference and continuous interference, which can make the communication system performance more stable and increase the success rate of command-based communication significantly.

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.