Communication Operations Research Articles

Dual-Mode Conical Horn Antenna with 2-D Azimuthal Monopulse Pattern for Millimeter-Wave Applications.

In this paper, a novel concept of a three-dimensional full metal system including a Dual-Mode Converter (DMC) network integrated with a high-gain Conical Horn Antenna (CHA) is presented. This system is designed for 5G millimeter wave applications requiring monopulse operation at K-band (37.5-39 GHz). The DMC integrates two mode converters. They excite either the TE11cir or the TE01cir modes of the circular waveguide of the CHA. The input of the mode converters is the TE10rec mode of two independent WR-28 standard rectangular waveguide ports. By integrating the DMC with the CHA, the whole system, called a Dual-Mode Conical Horn Antenna (DM-CHA), is formed, radiating the sum (Σ) and difference (Δ) patterns associated to the monopulse operation. To adequately prevent the propagation of higher order modes and mode mutual coupling, this integration procedure is carefully designed and fabricated. To prove the performance of the design, the DMC network was fabricated using subtractive manufacturing by Computer Numerical Control (CNC) technology. The CHA was fabricated using additive manufacturing by Direct Metal Laser Sintering (DLMS) technology. Finally, the simulation and measurement results were exhaustively compared, including return loss, isolation, radiation pattern, and gain of the full DM-CHA structure. It is noteworthy that this system provided up to ±11° per beam in the angular of arrival detection to support the high data rate operation for 5G satellite communications in the millimeter-wave band.

Методика формирования комплексной системы синхронизации и доставки шкалы времени для крупной распределенной системы технологического назначения

Purpose: To develop scientific and technical solutions for constructing a comprehensive synchronization system and delivery of the time scale, which includes subsystems of network clock synchronization (NCS) and unified time (UT), as a unified timekeeping system addressing the challenges of frequency, time, and phase synchronization in large-scale distributed technological purpose systems. Methods: Research methods are based on the fundamental provisions of the theory of systems and the theory of decision-making. Results: A methodology for the formation of a comprehensive synchronization system and the delivery of a time scale is proposed, which is characterized by an integrated approach to building unified time and frequency systems in the communication networks of the technological segment, the independence of the types of generator equipment used and the means of delivery of NCS and UT signals, as well as meeting the requirements of potential consumers of frequency and time services. The proposed methodology for the formation of a comprehensive synchronization system and delivery of a time scale will allow to reasonably approach building systems for delivering unified time and frequency signals in complex heterogeneous communication networks. Practical significance: Solutions based on the presented methodology will allow the provision of an infrastructure independent of external communication operators to ensure the unity of network clock synchronization and unified time. This is necessary for the correct operation of telecommunication equipment of the technological communication network. The methodology will also meet the needs for providing a full range of synchronization and unified time signal services to existing and prospective consumers. Additionally, it will enable a gradual transition of the organization of communication networks from channel-swithching to packet-oriented technologies due to a flexible approach to the routes and transmission systems used for the distribution of synchronization signals and unified time.

Research on a Method of Locating Civil Aviation Radio Interference Sources Based on Time Difference of Arrival and Frequency Difference of Arrival for Four Unmanned Aerial Vehicles.

Monitoring and analyzing radio interference sources play a crucial role in ensuring the safe operation of civil aviation navigation, communication, airport management, and air traffic control. Traditional ground monitoring methods are slow and inadequate for tracking aerial and mobile interference sources effectively. Although flight methods such as helicopters and airships can effectively monitor aerial interference, the flight approval process is time-consuming and expensive. This paper investigates a novel approach to locating civil aviation radio interference sources using four unmanned aerial vehicles (UAVs) to address this issue. It establishes a model for aerial positioning of radio interference sources with the four UAVs and proposes a method for time synchronization and data communication among them. The paper conducts simulations of the four-UAV time-frequency difference positioning method, analyzing the geometric accuracy dilution with different deployment configurations of the UAVs, positioning biases, and root mean square errors (RMSEs) under varying interference source movement speeds. The simulation results provide crucial data to support subsequent experiments.

Duality of averaging of quantum states over arbitrary symmetry groups revealing Schur–Weyl duality

It is a well-established fact in quantum information theory, that uniform averaging over the collective action of a unitary group on a multipartite quantum state projects the state to a form equivalent to a permutation operator of the subsystems. Hence states equivalent to permutation operators are untouched by collective unitary noise. A trivial observation shows that uniform averaging over permutation operators projects the state into a form with block-diagonal structure equivalent to the one of the collective action of the unitary group. We introduce a name for this property: duality of averaging. The mathematical reason behind this duality is the fact that the collective action of the unitary group on the tensor product state space of a multipartite quantum system and the action of the permutation operations are mutual commutants when treated as matrix algebras. Such pairs of matrix algebras are known as dual reductive pairs. In this work we show, that in the case of finite dimensional quantum systems such duality of averaging holds for any pairs of symmetry groups being dual reductive pairs, regardless of whether they are compact or not, as long as the averaging operation is defined via iterated integral over the Cartan decomposition of the group action. Although our result is very general, we focus much attention on the concrete example of a dual reductive pair consisting of collective action of special linear matrices and permutation operations, which physically corresponds to averaging multipartite quantum states over non-unitary SLOCC-type (Stochastic Local Operations and Classical Communication) operations. In this context we show, that noiseless subsystems known from collective unitary averaging persist in the case of SLOCC averaging in a conditional way: upon postselection to specific invariant subspaces.

Comparison Analysis of Nearest Road Calculations on Dijkstra Algorithm and A*(A-Star) Algorithm for Mapping BTS Tower Area

BTS (Base Transceiver Station) is a telecommunications infrastructure in the form of a tower with a transmitting antenna that facilitates wireless communication between communication devices and operator networks. BTS as a signal receiver and transmitter, its existence must be known to a user, such as maintenance staff and BTS tower operation staff to deal with existing problems. So a special system is needed for users to use in determining the closest path between the user and the location of the BTS tower. The purpose of this study is to make it easier for the user to determine the shortest path to the intended BTS tower location and to analyze the Dijkstra algorithm and the A* algorithm in determining the shortest route between the user's location and the location of the Telkomsel BTS tower in Semarang, Central Java. The results obtained from the 82 test data tested with the information system created show that Dijkstra's algorithm is more efficient than the A* algorithm. Validation is carried out by calculating with the system between the user's location and 82 test data or the location of BTS towers in the city of Semarang. The results of the validation carried out explained that the system was running according to the functions made and the results of the calculations carried out by the system were appropriate.

Design and Development of Hydro-Optical Communication-Based Invasive Wireless Sensor Networks

The selection and implementation of a hydro-optical communication connection for real-time position tracking of remotely operated vehicles (ROVs) in underwater settings are the main topics of this research article. For a variety of applications, including pipeline maintenance, environmental research, and undersea infrastructure inspection, effective monitoring and control of ROVs is essential. Due to signal attenuation and interference, conventional communication techniques are difficult to use in aquatic environments. To get over these restrictions, hydro-optical communication, which sends light messages through water, presents a viable option. The paper examines current hydro-optical communication methods and technology, pointing out their benefits and drawbacks. It deals with the technical needs of setting up a trustworthy communication channel for monitoring the real-time location of ROVs. To ensure accurate and timely data delivery, an appropriate communication protocol is created. The research also demonstrates the smooth operation of hydro-optical communication with the ROV's navigation system. The suggested method is put into practise and tested in safe underwater environments in order to assess how well it works at pinpointing the position of ROVs. Among the performance indicators evaluated are data rate, communication range, and energy efficiency. The results of this study help to advance the area of underwater communication and make it easier to monitor and manage ROVs in real-time for a variety of underwater applications.

Violating the Rules of Centralized Management of Technical Means of Counteracting the Threats to Information Security

Objective: to acquire new knowledge about the liability for violating the rules of managing technical means of counteracting the threats to information security; to elaborate theoretical recommendations and proposals for improving legislation and law enforcement.Methods: the methodological basis of the research is a set of scientific cognition methods, including abstract-logic, dogmatic, comparison, etc.Results: based on studying documents and publications, the following conclusions were made: 1) the measures taken at the national level for regulating the relations associated with introduction of technical means of counteracting the threats generally comply with the provisions of the Doctrine on information security of the Russian Federation; 2) one of the main directions of development of the foreign legislation on telecommunications is building a system of public-private interaction, in which communication operators would perceive the information security problem not as their internal task but as an element of the overall security of the state. In this regard, one may clearly trace the statement of the need to efficiently control the activities of communication operators, first of all, in the sphere of the newly introduced standards providing cyber resilience; 3) regulation of relations in the sphere of managing the technical means of counteracting threats in Russia is characterized by their multiplicity, multi-leveledness, hence, rather predictable complexity; 4) the model of communication operators’ liability for violations in the field of exploitation of technical means of counteracting threats, implemented in Article 274.2 Of the Russian Criminal Code, is not optimal. Rather disputable is the approach to describing the administratively prejudicial elements of crime. Despite the significance of the relations, the possibility of a criminal-legal reaction to a particular incident appears not in connection with the occurrence of certain publicly dangerous consequences and not even with the traditional recurrence, but only with the third documented violation. We consider more preferable the model of criminalization of violating the management of technical means of counteracting threats depending on infliction of substantial harm to the rights and legal interests of citizens or organizations, or the legally protected interests of the society or the state.Scientific novelty: the novelty of the research is mainly due to the actual underdevelopment of the issues related to the legal definition and implementation of criminal liability for violating the rules of centralized management of technical means of counteracting the threats to sustainability, security and integrity of functioning of the telecommunication network Internet and the general purpose communication network in the territory of the Russian Federation.Practical significance: the main provisions and conclusions of the research can be used for improving the mechanism of criminal-legal protection of information security, further development of the Russian doctrine of criminal law on liability for crimes in the sphere of computer information.

RAMP: A flat nanosecond optical network and MPI operations for distributed deep learning systems

Distributed deep learning (DDL) systems strongly depend on network performance. Current electronic packet switched (EPS) network architectures and technologies suffer from variable diameter topologies, low-bisection bandwidth and over-subscription affecting completion time of communication and collective operations. We introduce a near-exascale, full-bisection bandwidth, all-to-all, single-hop, all-optical network architecture with nanosecond reconfiguration called RAMP, which supports large-scale distributed and parallel computing systems (12.8 Tbps per node for up to 65,536 nodes). For the first time, a custom RAMP-x MPI strategy and a network transcoder is proposed to run MPI collective operations across the optical circuit switched (OCS) network in a schedule-less and contention-less manner. RAMP achieves 7.6-171× speed-up in completion time across all MPI operations compared to realistic EPS and OCS counterparts. It can also deliver a 1.3-16× and 7.8-58× reduction in Megatron and DLRM training time respectively while offering 38-47× and 6.4-26.5× improvement in energy consumption and cost respectively.

Particle swarm optimization based artificial neural network (PSO-ANN) model for effective k-barrier count intrusion detection system in WSN

Wireless Sensor Networks (WSN) offers an extensive array of possibilities and finds application to nearly every wake of human lifetime. Two of the methods are intrusion detection and monitoring in dangerous environments. Generally, WSN are extremely vulnerable to various kinds of network attacks, lifespan of whole network is reduced by interfering with data transmission and communication operations. A novel approach, provides accurate measurement of several obstacles to achieve rapid identification and avoidance of disruptions. In order to more accurately estimate k-barrier number for efficient intrusion detection and prevention, a Particle Swarm Optimization based Artificial Neural Network (PSO-ANN) is developed. The region's size, sensor's detecting field, area where sensor transmits its signals, several sensors constitute the four important features utilized for learning and evaluating PSO-ANN model. The extraction of the different attributes is achieved with the help of simulation through Monte Carlo. It has been inferred from the research that the approach is accurate in predicting number of invasions, correlation coefficient, root mean square error, accuracy, precision are achieved to be excellent in contrast to the remaining approaches.

Determining the Day-to-Day Occurrence of Low-Latitude Scintillation in Equinoxes at Sanya during High Solar Activities (2012–2013)

Plasma irregularity in the equatorial and low-latitude ionosphere, which leads to ionospheric scintillation, can threaten the operation of radio-based communication and navigation systems. A method for forecasting scintillation activity is still pending. In this study, we examined the performance of ionospheric parameters, including the critical frequency (foF2), peak height of the F2-layer (hmF2), scale height (Hm) and virtual height (h’F), around local sunset from ground-based ionosonde observations, and also the characteristics of Equatorial Ionization Anomaly (EIA) derived from Gravity Recovery and Climate Experiment (GRACE) observations in equinoctial months (March–April and September–October) during high solar activities (2012–2013) at a low-latitude station at Sanya (18.3° N, 109.6° E; dip lat.: 12.8° N), China. Furthermore, the simplified linear growth rate of Rayleigh–Taylor (R–T) instability inferred from ionosonde measurements and EIA strength derived from GRACE observations were used to estimate the day-to-day occurrence of post-sunset scintillation. The results indicate that it is not adequate to determine whether scintillation in a low-latitude region would occur or not based on one ionospheric parameter around sunset. The simplified growth rate of R–T instability can be a good indicator for the day-to-day occurrence of scintillation, especially in combination with variations in EIA strength. An index including the growth rate and EIA variations for the prediction of the post-sunset occurrence of irregularity and scintillation is proposed; the overall prediction accuracy could be about 90%. Our results may provide useful information for the development of a forecasting model of the day-to-day variability of irregularities and scintillation in equatorial and low-latitude regions.

Energy-Efficient Massive MIMO Network

Massive Multiple-Input Multiple-Output (Massive MIMO) is widely regarded as a highly promising technology for the forthcoming generation of wireless systems. The massive MIMO implementation involves the integration of a substantial number of antenna elements into base stations (BSs) to enhance spectral efficiency (SE) and energy efficiency (EE). The energy efficiency (EE) of base stations (BSs) has become an increasingly important issue for telecommunications network operators due to the need to take care of profitability while simultaneously minimizing their detrimental effects on the environment and addressing economic challenges faced by wireless communication operators. In this paper, the EE of massive MIMO networks and the relationship between EE, SE, and other parameters like bandwidth (B), number of antennas (M), circuit power, and number of users’ equipment (K) are discussed and investigated. For a fixed circuit power (PFIX), simulation results showed that the EE could be increased by about 1.12 as the number of antennas was doubled. The findings in this work also indicated an almost linear relationship between maximum EE and optimal SE, with a massive increase in the number of antennas when the power consumed by each antenna (PBS) was included in circuit power. In addition, when considering the power consumed per user’s equipment (PUE) impact, the SE increased with the ratio (M/K), in which SE showed a cubic relationship against M/K. On the other hand, the EE increased with M/K ratio until M/K reached a specific value. The maximum EE (and hence optimum SE) was achieved by massive MIMO, where the number of antennas was three times the number of users. However, EE started degrading after this value, as the number of antennas was considered larger than the users’ and consumed more energy, resulting in EE degradation.

Automotive Radar Optimization Design in a Spectrally Crowded V2I Communication Environment

A main challenge for radar-aided millimeter wave (mmWave) vehicle-to-infrastructure (V2I) communication application, is that it requires mitigating the mutual interference between vehicular radar and communication operating at same frequency bands. This paper considers the joint design of the multiple-input multiple-output (MIMO) transmit waveform and receive filter bank for road side unit (RSU)-mounted radar in a spectrally crowded V2I communication environment. With the criterion of maximizing the average signal-to-interference-plus-noise ratio (SINR), a non-convex problem, which involves the weighted-sum waveform energy over the overlayed space-frequency bands, energy and similarity constraints, is formulated. An iterative algorithm is proposed to solve the joint optimization problem. At each iteration, the transmit waveform is optimized based on the alternating direction method of multipliers (ADMM) method with a significantly lower computational complexity. As a consequence, accurate location information derived from the optimized radar is used to reduce the beam training overhead of V2I communication links. Finally, simulation results display the effectiveness of the devised method in finding feasible and enhanced solutions, importantly outperforming several counterparts.

A 32-GHz Eight-Way Power Amplifier MMIC in 150 nm GaN HEMT Technology

This paper presents a 32 GHz high-power amplifier (HPA) with a design strategy to achieve high-power output with reliable operation for Ka-band deep space satellite communication in 150 nm GaN HEMT technology. The presented Ka-band HPA employs a cascaded two-stage common source amplifier topology, and the output stage comprises an eight-way power combining network in the current mode. The interstage matching network is designed with the bandpass configuration utilizing capacitors and transmission lines to provide better stability at the low-frequency regime. The implemented Ka-band HPA achieved a power gain of 7.3 dB at the input level with the maximum PAE at 32 GHz, and the 3 dB gain bandwidth was 3.5 GHz (31.3~34.8 GHz). The saturated output power at the peak power-added efficiency (PAE) of 19.3% was 38.2 dBm, and the output 1 dB gain compression point (OP1 dB) was 27.4 dBm in the measurement. The designed HPA consumes an area of 19.35 mm2 including RF pads and DC pads.

Literature review: visible light communication system business model scheme for telecommunication business in Indonesia

The telecommunication sector mainly comprises operators, vendors, and regulators. In Indonesia, tele- communications operator companies tend to decrease profits from the first quarter of 2017 to the third quarter of 2018. This condition is due to the tight competition of telecommunication service providers, high operational costs, and digital transformation that does not provide substantial revenue for the company. Telecommunica- tions operators need other service options that can expand target market segmentation. It aims to open up a new blue ocean as a new source of income. The world is getting closer to massive communication technology, so high-speed communication is needed. Therefore, telecommunications operators can open new service options based on the visible light spectrum as their communication resources. This option can be integrated with ambient lighting, a wide spectrum ranging from radio waves, and greater bandwidth, making visible light suitable for IoT- 5G services. This research aims to design a wireless visible light communication business model. Several frame- works are used, such as the magic triangle of St. Gallen, Osterwalder Business Model Canvas, and PESTLE analysis. The business model design results in a business model with B2B market segmentation being the main focus and B2C market segmentation to acquire retail customers.

Interactive visual analytics of parallel training strategies for DNN models

Understanding and optimizing the parallel training strategies in the training of large-scale Deep Neural Network (DNN) models is crucial to enhance training efficiency. Existing works tried to demonstrate the layer-level information of the computational graph to support parallel training strategy selection. Whereas, the overall parallel execution logic is rarely considered by previous methods. In this paper, we proposed a novel visual analytics approach for parallel training strategies, demonstrating the execution logic of the distributed computing from up to bottom via explaining communication operators. Specifically, a computation-communication bipartite construction algorithm is designed for the computational graph visualization. Furthermore, a system is developed to help users easily access the proposed approach and explore the parallel training strategies interactively. With empirical evaluation through a quantitative user study and a qualitative expert interview, the practicality and superiority of the proposed approach is verified.

The impact of resources on digital transformation in energy sector companies. The role of readiness for digital transformation

Energy sector companies operate in a complex environment characterized by restrictive regulations, increasing competition, geopolitical influences and changing stakeholder expectations. To be able to respond dynamically to these changes, ensuring open, automated communication and real-time operation of the energy system, managers need to transform companies digitally. While the digital transformation of energy companies is inevitable, limited access to specific resources can slow down or, in extreme cases, prevent the process of digitalization. Based on studies that combine the resource-based view and the digital transformation concept this paper aims to explain how human, technological, financial, ICT and infrastructure resources impact digital transformation of the energy company sector. Using structural equation modeling to analyze data collected from 110 energy companies, the study provides evidence of the links between organizational resources and digital transformation. This research contributes to a better understanding of the importance of soft aspects of management during digital change, that is digital transformation readiness, which plays a mediating role between organizational resources and digital transformation. In addition, the results reveal the influence of technological and financial resources on readiness for digital transformation, and suggest that there is no statistically significant relationship between ICT and infrastructure resources and digital transformation readiness. The role of digital transformation readiness recognized in the study has specific practical implications, as it suggests to management practitioners that a perspective on soft aspects, including organizational culture and governance, can accelerate and enhance digital transformation.

Emergency Communication Operators: Findings from the National Wellness Survey for Public Safety Personnel

Emergency Communication Operators: Findings from the National Wellness Survey for Public Safety Personnel

DC Microgrids: A Propitious Smart Grid Paradigm for Smart Cities

Recent years have seen a surge in interest in DC microgrids as DC loads and DC sources like solar photovoltaic systems, fuel cells, batteries, and other options have become more mainstream. As more distributed energy resources (DERs) are integrated into an existing smart grid, DC networks have come to the forefront of the industry. DC systems completely sidestep the need for synchronization, reactive power control, and frequency control. DC systems are more dependable and productive than ever before because AC systems are prone to all of these issues. There is a lot of unrealized potential in DC power, but it also faces some significant challenges. Protecting a DC system is difficult because there is no discrete location of where the current disappears. DC microgrid stability that is dependent on inertia must also be considered during the planning stage. The problems that DC microgrids have include insufficient power quality and poor communication. The power quality, inertia, communication, and economic operations of these value streams, as well as their underlying architectures and protection schemes, are all extensively discussed in this paper. This review paper examines the pros and cons of both grid-connected and isolated DC microgrids. In addition, the paper compares the different kinds of microgrids in terms of power distribution and energy management agency, such as the prerequisites for a DC microgrid’s planning, operation, and control that must be met before state-of-the-art systems can be implemented.

Privacy, Confidentiality, and Data Protection: Ethical Considerations in the Use of the Internet

The Internet has had a profound, impact on society, enabling numerous benefits while also presenting significant challenges. While it has revolutionized communication, information access, and business operations, it has also created new ethical challenges, particularly with regards to inappropriate or negative content. Cybercrime, misinformation, disinformation, and user data exploitation are just a few examples of these issues. As the Internet's reach and influence continue to expand, it is critical to recognize and adhere to ethical principles in the digital world. This article aims to explore the importance of ethical principles in Internet use and their role in mitigating negative impacts. To achieve this objective, the paper conducts a literature review towards policy document and analyzes bibliometrics data against scholarly article databases indexed by Scopus and identify key point regarding ethical discourse. The article delves into the ethical implications of the Internet, including privacy concerns, confidentiality, decision-making, and data protection. In conclusion, it posits that the Internet should not be viewed simply as a tool but as a cultural artifact with the potential to shape society for better or worse. Therefore, it is our responsibility as users and stakeholders to understand and uphold ethical standards to ensure the responsible and equitable use of this powerful technology.

A novel reduced instruction set computer-communication processor design using field programmable gate array

In this paper, a novel reduced instruction set computer (RISC)- communication processor (RCP) has been designed with 32-bit operations which access 64-bit instruction format and implemented using field programmable gate array (FPGA). The design of the RISC processor is facilitated with communication operations like basic signals sine, cosine, and square, and modulation schemes like amplitude modulation, amplitude shift keying, analog, and digital quadrature amplitude modulation. Additionally, application-oriented operations like a traffic light, digital clock, and linear feedback shift register are included in the design. The pipeline mechanism is incorporated in the design to enhance the performance characteristics of the processor, hence allowing the execution of the instructions more effectively. Also, the design is implemented with Xilinx Virtex 7 family FPGA. The device utilization analysis of the proposed FPGA along with different FPGA families is evaluated and compared.