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This study proposes a compact, low-profile, four-port dual-band monopole multiple-input-multiple-output (MIMO) antenna array for unmanned aerial vehicle (UAV) communication systems. Each monopole antenna of the array features a modified T-shaped radiator configuration and is printed on a Rogers RT5880 substrate with compact dimensions of 134.96 mm × 134.96 mm × 0.8 mm. A four-element square MIMO configuration with sequential 0°, 90°, 180°, and 270° rotations was integrated smoothly into the UAV body. A prototype of the MIMO array was fabricated and experimentally evaluated, with measured results showing a close correlation to simulated results. The proposed dual-band monopole antenna demonstrated one of the widest impedance bandwidths of 46.15% at 2.4 GHz (2.04 to 3.25 GHz) IEEE 802.11b and 31.85% at 5.8 GHz (5.37 to 7.38 GHz) IEEE 802.11a on a thin 0.0064 λo substrate while achieving high transmission efficiency. The isolation of the proposed four-port MIMO design was measured at 23 dB at 2.4 GHz and 19 dB at 5.8 GHz. The MIMO array's total efficiency of each monopole antenna was measured at 96% at 2.4 GHz and 89% at 5.8 GHz. The design has measured diversity parameters such as an ECC below 0.01 and a DG of approximately 10. Based on these results, the proposed design suits the UAV communication system. [ABSTRACT FROM AUTHOR]

This study examines the high‐power microwave (HPM) jamming effect on software‐defined radio (SDR). Following theoretical analysis and formula derivation of the single‐tone jamming, the HPM jamming effect is validated using an SDR platform. Jamming is relatively easily achieved when the jamming signal falls within the communication system's frequency band. For out‐of‐band signals, a higher jamming signal ratio is needed, with the receiving front‐end device's nonlinearity causing the jamming. This study highlights the susceptibility of broadband receivers to HPM jamming, demonstrating that even out‐of‐band threats cannot be disregarded in wideband receiver designs for strong signals such as HPM. [ABSTRACT FROM AUTHOR]

The article addresses the issue of current and critical protections for applications for 4G and 5G mobile phones. The objective of the article is to provide an overview of the threats to 4G and 5G mobile communication networks and to analyze the variables used in conjunction with core and security methods. The research work uses a review of the literature to provide an overview of the threats to 4G and 5G mobile communication networks. The research also analyzed the variables used in conjunction with core and security methods. The research presents an overview of the threats to 4G and 5G mobile communication networks, including privacy attacks, behavioral attacks, space attacks, and authentication attacks. The authors also provide an overview of three types of cases, including road signs, officers, and road signs. The analysis of variables used in conjunction with core and security methods is unclear, often summarizing security. The authors conclude that there is a need for improved protections for applications for 4G and 5G mobile phones. They also suggest that further research is needed to better understand the variables used in conjunction with core and security methods. [ABSTRACT FROM AUTHOR]

End of 2019 had seen global spread of the deadly coronavirus (SARS-CoV-2) pandemic, which kills people, puts a large portion of the world in danger, and poses a serious threat to all of the world's nations. Leading medical professionals are working extremely hard to identify the virus, develop treatments for it, and create the vaccines that are required to stop and limit its spread. This study intends to develop a low-cost electronic health system to observe patients with covid infections and lessen the work required of clinicians. An enhanced approach for remote health monitoring in hospitals or detention facilities is offered by the internet of things (IoT). The IoT keeps and displays the patient's medical data via a web browser or through specialized apps that offer remote treatment once the sensors collect it. When a patient is in danger, the system offers immediate action to send alarms by email and SMS and to rapidly provide drugs to the patient. Doctors will be updated on each patient's condition thanks to this message. [ABSTRACT FROM AUTHOR]

This manuscript presents an experimental study of Quadrature Chaos Shift Keying (QCSK) as a means to tighten the physical layer security of Internet of Things (IoT) communication. Our study examines the characteristics and operational aspects of chaos oscillators, prioritizing low-power functionality, resilient chaotic oscillations, and resistance to parameter variations and noise. This study emphasizes the key role of chaos oscillators in enhancing IoT security, showcasing their potential to ensure data integrity. The findings elucidate the dynamics and synchronization stability of the selected oscillators, providing insights into their suitability for secure communication systems. This comprehensive analysis contributes to advancing secure communication methodologies for the expanding landscape of wireless sensor networks in the Internet of Things, underscoring the significance of chaos oscillators in ensuring robust and secure data transmission. [ABSTRACT FROM AUTHOR]

The requirement for a secure emergency communication system has become imperative in tandem with the industrial revolution. Additionally, the development of technology has led to increasingly robust penetration techniques that pose a threat to communication system security, leaving data vulnerable to unwanted third parties. This paper introduces a novel, powerful security approach that ensures a secure emergency communication system. Moreover, this research focuses on several cryptographic techniques among various symmetric and asymmetric ciphers, including advanced encryption standards, substitution, and transposition. The article presents an affordable and secure communication system that can transmit data over long distances with low power consumption using long-range technology. This system features a unique function that transmits updated locations, directing rescuers to the designated location. [ABSTRACT FROM AUTHOR]

Copyright of HiSTOReLo: Revista de Historia Regional y Local is the property of Universidad Nacional de Colombia, Centro Editorial Facultad de Ciencias Humanas y Economicas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Athenaeum: Polskie Studia Politologiczne is the property of Faculty of Political Science & Security Studies Nicolaus Copernicus University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mastering real-time and accurate downhole information is crucial for ensuring drilling safety, improving drilling efficiency, and maximizing economic benefits. In recent years, logging while drilling (LWD) technologies, represented by mud pulse telemetry (MPT), achieved significant success. However, they still face challenges such as a large amount of downhole information conflicting with low information transmission rates, severe channel distortion, strong noise interference, and weak surface receiving signals. Therefore, this review collects and updates the papers, patents, and conference articles in the relevant field over the past ten years. Starting from the basic structure of communication systems, the downhole signal coding and modulation technologies of the MPT system are discussed. The attenuation reflection brought by the mud channel and various noise interferences in the system are described. The surface noise cancellation, channel equalization, synchronization, and decoding are studied in detail. By analyzing the theoretical principles, development breakthroughs, and relevant challenges that can improve the development of LWD technologies, this review aims to assist researchers in the field in obtaining the latest references and strategies. [ABSTRACT FROM AUTHOR]

The 5G communication system requires an antenna as a receiving device that has high performance including wide bandwidth and high gain. Microstrip antennas have advantages such as low cost, suitable for high frequencies and easy to integrate with other devices. One of the disadvantages of microstrip antennas is their narrow bandwidth and low gain. Therefore, microstrip antennas with wide bandwidth and high gain are especially needed to support 5G communication systems. This paper provides a solution by proposed a wide bandwidth and high gain microstrip antenna operating at a resonant frequency of 3.5 GHz for a 5G communication system. The proposed antenna was developed in four stages starting from a single element, a two-element series array, a 4-element series array and a 4×2-element planar series array. A series planar array technique is proposed to increase the gain and bandwidth of the microstrip antenna simultaneously. In this paper, simulations and measurements from the proposed antenna are displayed and compared comprehensively to show the performance improvement from each stage of the development of the proposed model. Based on the measurement results, the designed antenna has an impedance bandwidth (IBW) of 0.6 GHz and fractional bandwidth (FBW) of 17.14 % with a frequency range of 3.11–3.71 GHz and maximum gain of 12.2 dB at a resonant frequency of 3.5 GHz. The bandwidth and gain of the antennas increased by 205 % and 99.03 % compared to single element antennas, respectively. Therefore, the proposed antenna can be recommended to be used as a receiving antenna for 5G communication systems. [ABSTRACT FROM AUTHOR]

For a safe and effective commuting experience in the near future, autonomous vehicles are a growing technology. 85% or more of traffic accidents could potentially be avoided with the use of autonomous vehicles. Drivers could also skip boring tasks and enjoy their rides. Because of these benefits, "57% of customers worldwide trust autonomous cars - much more so in emerging nations," according to Cisco's survey. Self-driving cars, or autonomous vehicles, are able to communicate with everything around them. This communication environment lacks security and contains a number of weaknesses. Trustworthiness, correctness, and security of received and broadcasted data in the communication channel are the main problems in autonomous vehicle (AV) communication. Automobile communication systems, which electronically relay road conditions, are crucial components of autonomous vehicles. Conventional wireless technologies immediately show their incapability when data traffic expands dramatically due to their limited capacity. Researchers have attempted to make driving simpler and more convenient, but they risk complicated accident investigations. Car manufacturers have made great efforts to meet consumer needs. This paper examines recent technological developments enabling peer-to-peer communication in autonomous cars. [ABSTRACT FROM AUTHOR]

A helicopter in flight can be considered an unstable dynamic system with many unwanted vibrations originating from multiple sources, such as the operation of the engines and individual components. These vibrations cause the degradation of the structural and functional components of a helicopter, thereby generally reducing the utility and technical efficiency of the aircraft. During the analysis of frequently recurring errors of medium-heavy helicopters, partial damage to antenna elements with vertical polarisation was detected. These damages provided the basis for the presented research, based on which supplementary vibrations caused by unwanted electromagnetic oscillations were revealed. These oscillations were detected in the process of communication between the helicopter crew and the ground ATC (air traffic control) station. This phenomenon's existence and negative influence were confirmed via measurements and modal analysis, based on which an exact synergy between harmonic frequencies of the helicopter's normal vibrations was discovered. The obtained results serve as a theoretical and practical basis for the future monitoring of this phenomenon, especially in the process of determining the "health status" of medium-heavy helicopters. [ABSTRACT FROM AUTHOR]

Through the theoretical frameworks of the media system dependency model and uses and gratifications theory, this study examined the uses of social media by Syrian refugees in Jordan and Turkey. A mixed-methods approach was used to increase the credibility and validity of the study's findings by combining a qualitative method with quantitative data. The findings show that there were some factors that affected the Syrian refugees' use of social media before seeking refuge in Jordan and Turkey, which were mainly its ban due to the regime's censorship and a bad Internet connection due to the bad infrastructure. The absence of these two factors led to an increase in their social media dependency after seeking refuge. There are variances in which social media sites Syrian refugees use the most and why. The majority relied on Facebook for various reasons, and this dependency had varying repercussions on individuals. Furthermore, many immigrants were acquainted with new platforms, implying that refugees became social-media-literate and participated in the updates of the new platforms, even if such sites were not well known to the general public. The Syrian refugees' dependency on social media varies from person to person due to differences in personal goals, social status, locations, living characteristics, and easy access to the Internet. Furthermore, this dependency on social media has different effects on them according to the media system dependency model. The refugees become increasingly dependent on social media to satisfy their needs and, because of that, social media dependency will become more important in their lives and will increase its influence and effects on them. Furthermore, the study found that the Syrian refugees depended on social media for various gratifications, such as educational, work, and business; information access; cultural and social aspects; connecting with networks and families; establishing friendships; learning new skills; self-expression; making business; and finding work, in addition to reaching routes and contacting smugglers to help them leave the country. [ABSTRACT FROM AUTHOR]

In this research, we proposed a protocol for information transmission in a communication system. The protocol consists of three parts: Publisher, Broker, and Subscriber. The main problem in the transmission is the reliability of the broker. It is very difficult to get the status of the broker whether it is active or not. Secondly, we also worked on the part of security. Here by employing a Watchdog timer to determine whether the broker is active or not. To make the system more secure AES algorithm is incorporated into it. To validate the suggested protocol hardware setup is built and performance is tested in various conditions. Performance tests show that our proposed system outperforms the current system when compared to the existing system. The suggested system architecture's temporal and spatial complexity are also presented in this research. [ABSTRACT FROM AUTHOR]

Communication is pervasive, it helps us to know ourselves better, and those around us; it is a perfect interrelationship system between people and it "builds" mutually beneficial relationships, giving efficiency to any activity, regardless of the field. [ABSTRACT FROM AUTHOR]

Featured Application: The proposed speech communication system can be used in mechanical antenna-based low-frequency communications. Low-frequency electromagnetic waves have strong penetration and low attenuation performance, making them widely used in long-wave communication areas such as underwater communication and earthquake prediction. Mechanical antennas are seen as a promising alternative to traditional low-frequency resonant antennas, as they offer the potential for miniaturization and low power consumption. However, existing communication systems using mechanical antennas are usually rudimentary, incompatible, and inconvenient to use. To address these problems, a novel speech communication system based on a piezoelectric electret mechanical antenna was proposed. This communication system includes a hardware system, a communication protocol for mechanical antennas, and a software system with a modular structure. This system includes hardware, a communication protocol, and a modular software system. The results of the experiments showed that this communication system provides real-time speech communication with a user-friendly design, high compatibility with different communication devices, and easy customization to meet specific requirements. This design holds great potential for applications in mineral detection, seismic research, submarine communication, industrial RF control, and other related mechanical antenna applications. [ABSTRACT FROM AUTHOR]

The current work is devoted to chaos oscillator employment in digital communication systems for IoT applications. The paper presents a comparative performance analysis of two different chaos data transmission systems: frequency-modulated chaos shift keying (FM-CSK) and quadrature chaos phase-shift keying (QCPSK), and a comparison to their non-chaotic counterparts: frequency-shift keying (FSK) and quadrature amplitude modulation (QAM). For both chaotic communication systems, the Vilnius oscillator and substitution method of chaotic synchronization are chosen due to simple circuitry implementation and low power consumption properties. The performance of the systems in the fading channel with additive white Gaussian noise (AWGN) is evaluated. Also, the systems' performance in the case phase noise is investigated, and the benefits of chaotic waveforms employment for data transmission are demonstrated. [ABSTRACT FROM AUTHOR]

It has been observed that the use of UAVs in search and rescue (SAR) operations is very advantageous. When, all of a sudden, a crisis strikes, UAV technology is incredibly helpful and works more effectively to identify the entire region of a disaster and identify victims trapped in the region. The deployment of a UAV network with a high battery lifespan and complete coverage of the disaster region is the primary emphasis of this article. For the efficient communication of UAVS, we suggested the intelligent cluster-based multi-unmanned aerial vehicle (ICBM-UAV) protocol. In order to discover victims swiftly and rescue those who are trapped in the afflicted region as soon as possible, ICBM-UAV uses the clustering technique smartly, which helps conserve drone batteries and performs some of the useful computations within the CH and hence helps to lessen workload on network congestion. Dividing the CMBM-UAV into two parts, the information gathering and the user equipment location identification, improves network life and makes the search and rescue operation more efficient and successful. After going to through vigorous result calculation, it is deduced that the proposed scheme has outperformed the existing state-of-the-art protocols such as AODV, OSLR and flocking mechanisms in terms of throughput, PDR, and coverage area probability by considering each scenario with and without the presence of obstacles. Hence, by delivering an exploitable estimate before reaching the victim, the proposed approach could drastically minimize the search and rescue time to save valuable lives. [ABSTRACT FROM AUTHOR]

After summarizing and evaluating works on system reliability, various models and results for predicting and evaluating system reliability have been introduced. However, we have not seen a study conducted to assess the reliability of communication systems in an underground mine. Underground mining operations are normally dependent on communication system reliability. The main purpose of this work is to study the failure of a theoretical underground mine communication system, propose a method to improve its reliability, and predict the results of the suggested method using system dynamic modeling. This study contributes to improving the reliability of communication systems in underground mines. In the case of a single nonredundant system, three options were implemented: doubling corrective maintenance, increasing preventative maintenance by 50%, and combining both measures. These three options were modeled by combining Markov modelling with system dynamic modelling methodology and were confirmed by experiments and simulation results. This combination of modelling constitutes the novelty of this study. In this paper, actual system component failure data was used for simulation for the single nonredundant system, after doubling corrective maintenance, increasing preventative maintenance by 50%, and combining in the case of implementing simultaneously both maintenance changes, but not for developing single and dual standby system models. Therefore, these models should be suitable for practical use, as they are based on actual working systems. Modelling confirmed that placing a communication system in each shaft of the theoretical underground mine increases the reliability of the communication system. The degree of availability of the communication system with single standby device shows the result of 62.38% while the communication system with two standby devices and three parallel communication systems' availability rating shows a result of 85.18%. [ABSTRACT FROM AUTHOR]

A software-defined radio (SDR) system is a radio communication system which uses software for the modulation and demodulation of radio signals. An SDR performs significant amounts of signal processing in a general purpose computer, or a reconfigurable piece of digital electronics. SDR can talk and listen to multiple channels at the same time, also it can be quickly and easily upgraded with enhanced features. In fact, the upgrade could be delivered over-the-air In the long run, SDR is expected to become the dominant technology in radio communications. [ABSTRACT FROM AUTHOR]

In daily life, the most direct and important way of human communication is voice. With the rise of the Internet and the development of communication technology, the proportion of non voice signals such as image and data in communication system is increasing. However, in most communication systems, voice transmission function is generally required, so it is still one of the necessary functions for many communication systems to transmit voice information effectively. With the rapid development of the Internet, especially the recent 5G technology commercial and future civil, human–computer interaction will become more and more intelligent in the future, which also poses a greater challenge to speech recognition as a human–computer interface. Noise interference is one of the biggest obstacles to the practical application of speech system. Although a large number of noisy data based on deep learning can solve part of the noise robustness problem, non-stationary noise interference is still a great challenge for speech recognition system in very low SNR complex scenes. In addition, in the multi information fusion communication system, there are many kinds of data to be transmitted, and there are high requirements for bandwidth and storage space. Hence, this paper studies the construction of voice signal communication system based on the artificial intelligence and 5G technology. The model is designed and implemented considering the complex scenarios. The performance is validated through the simulations compared with the state-of-the-art methods. [ABSTRACT FROM AUTHOR]

The use of Yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) in medicine has rapidly expanded over the past decade, driven by its advantageous properties, showing potential to overcome titanium alloy in implant fabrication. The release of metal ions and the aesthetic problems of titanium alloy implants are the main reasons for this trend. In addition to meeting expectations regarding its properties, an implant must possess intrinsic capacities such as auto-diagnostic and auto-treatment. Thus, based on the concept of smart implants, this work proposes a hybrid approach for printing a part of the communication system of a zirconia implant by resorting to laser technology, aiming to endow the implant with intrinsic capacities. Therefore, the antenna was designed and then printed on the zirconia surface. The laser was applied as a versatile tool, whether for preparing the surface of the material in a subtractive way, by creating the micro-cavity, or for printing the silver-based antenna in an additive way through laser technology. The silver powder was used as the conductor material of the antenna. The results revealed that the antenna is capable of communicating from inside the body with the outside world without needing to have an exterior antenna attached to the skin. [ABSTRACT FROM AUTHOR]

Modulation signal classification in communication systems can be considered a pattern recognition problem. Earlier works have focused on several feature extraction approaches such as fractal feature, signal constellation reconstruction, etc. The recent advent of deep learning (DL) models makes it possible to proficiently classify the modulation signals. In this view, this study designs a chaotic oppositional satin bowerbird optimization (COSBO) with bidirectional long term memory (BiLSTM) model for modulation signal classification in communication systems. The proposed COSBO-BiLSTM technique aims to classify the different kinds of digitally modulated signals. In addition, the fractal feature extraction process takes place by the use of Sevcik Fractal Dimension (SFD) approach. Moreover, the modulation signal classification process takes place using BiLSTM with fully convolutional network (BiLSTM-FCN). Furthermore, the optimal hyperparameter adjustment of the BiLSTM-FCN technique takes place by the use of COSBO algorithm. In order to ensure the enhanced classification performance of the COSBO-BiLSTM model, a wide range of simulations were carried out. The experimental results highlighted that the COSBO-BiLSTMtechnique has accomplished improved performance over the existing techniques. [ABSTRACT FROM AUTHOR]

The traditional fixed-point operation robot of natural gas pipeline uses cable as the medium to realise the through-wall communication. However, with the increase of working distance, problems such as increasing cable weight or friction force with the pipeline wall will prevent the work from continuing and have a high potential risk. In order to solve this problem, this paper puts forward an overall design of the through-wall communication using the extremely low-frequency (ELF) electromagnetic wave with strong penetration ability. Firstly, a model of the solenoid transmitting coil is established using the Maxwell finite element simulation module to simulate the distribution of the extremely low-frequency electromagnetic field. Then, the influence of different factors such as environment and medium on magnetic field intensity are analysed. With STM32F405 as the main control chip and AD9959 as the transmitting signal source, the hardware circuit of the communication system is built. At the same time, an experimental test of the ELF communication system is carried out and the experimental results show that the designed through-wall communication system can achieve good communication inside and outside the tube. The communication distance along the radial direction of the tube can reach 140 cm, which can meet the communication needs of fixed-point operation of the robot in the tube. [ABSTRACT FROM AUTHOR]

The current paper presents the experimental study of the frequency-modulated chaos shift keying (FM-CSK) communication system. The proposed system has the potential to enhance the security aspects of the physical layer to meet the needs for safe data transmission in wireless sensor networks (WSN). Compared to common digital FM-DCSK, the studied analog FM-CSK communication system provides a more straightforward design. As chaos oscillators are the core elements of the FM-CSK communication system, the paper investigates the selected oscillators' properties, including the implementation aspects—the impact of reactive element value deviations on dynamics and synchronization stability. Chaotic dynamics are evaluated with the mean-square-displacement-based 0–1 test, while correlation analysis is used to evaluate synchronization. The impact of the different chaos oscillators' employment on FM-CSK communication system performance is examined, and the bit error ratio is used for noise immunity evaluation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Communication plays a huge role in the operation of modern power systems. It permits a real-time monitoring coordination and control of the transmission, generation and distribution of electrical energy. As the modern grid grows towards an increased reliance on communication systems for the protection, metering and monitoring for as well as data acquisition for planning; there is a need to understand the challenge in the powers' system communication and their impact on the uninterrupted supply of electrical energy. Communication delays are one of the challenges that might affect the performance of the power system and lead to power losses and equipment damage, it is important to investigate the causes and the mitigation options available. Thus, this paper the state of arts on the cause, the effect and mitigation of communication delays in the power system. Furthermore, in this paper an analysis of different causes of the delays for different network configurations and communication systems used; a comparative analysis of different latency mitigation methods and system performance simulations of a given compensation algorithm is tested against the existing methods. The pros and cons of these control strategies are illustrated in this paper. The summary and assessment of those methods of control in this review offer scholars and utilities valuable direction-finding to design superior communication energy control systems in the future. [ABSTRACT FROM AUTHOR]

Internet of Things(IoT) is a communication technology that collects information of object remotely and controls the function of object by adding a communication function to object that does not have a communication function. For the IoT, various communication technologies such as Wi-Fi, 3GPP, and Bluetooth are available, and Long Range(LoRa) is communication technologies specialized in the IoT concept. LoRa is a communication technology that support long-distance, low-power, and low-speed communication, and is suitable for collecting information generated form object in remote equipment and controlling equipment. Because of these characteristics, it is used in many application field, and various performance improvement studies are in progress. This paper intends to propose an ultra-long-range LoRa communication module that can be used in a wider range of applications. We design and implement hardware, firmware, and application software for testing to develop ultra-long-range LoRa communication modules. The implemented module will be tested in a real environment to verify its performance and to check its utilization. [ABSTRACT FROM AUTHOR]

A broadband, high radiation efficiency graphene‐based reconfigurable square spiral antenna for terahertz communication is proposed. The main part of the antenna is the graphene‐based square spiral microstrip patch. The proposed antenna is built and simulated using high‐frequency structure simulator (HFSS). By applying different combinations of chemical potentials on the graphene layer, the operating frequency of the antenna can be varied from 0.1 to 2 THz. The tuning range of frequency and beam direction with same and different chemical potentials applied to the two graphene sheets are also studied. When the antenna is applied with different chemical potentials, the required bias voltages are much lower to achieve the same frequency tuning range, and the tuning range of beam direction is about 2.5 times that of same chemical potentials. The realized beam reconfiguration of the proposed antenna is over a wide range up to 74°, and the calculated maximum radiation efficiency of the proposed antenna at 1.48 THz is 85.06%. Therefore, the proposed reconfigurable antenna makes it extremely promising for terahertz communication system. [ABSTRACT FROM AUTHOR]

For communication systems there is a recent trend towards shifting functionalities from the physical layer to higher layers by enabling software-focused solutions. Having obtained a (physical layer-based) description of the communication channel, such approaches exploit this knowledge to enable various services by subsequently processing it on higher layers. For this it is a crucial task to first find out in which state the underlying communication channel is. This paper develops a framework based on Turing machines and studies whether or not it is in principle possible to algorithmically solve such classification tasks, i.e., to decide in which state the communication system is. Turing machines have no limitations on computational complexity, computing capacity and storage, and can simulate any given algorithm and therewith are a simple but very powerful model of computation. They characterize the fundamental performance limits for today’s digital computers. It is shown that there exists no Turing machine that takes the physical description of the communication channel as an input and solves a non-trivial classification task. Subsequently, this general result is used to study communication under adversarial attacks and it is shown that it is impossible to algorithmically detect denial-of-service (DoS) attacks on the transmission. Jamming attacks on ACK/NACK feedback cannot be detected as well and, in addition, ACK/NACK feedback is shown to be useless for the detection of DoS on the actual message transmission. Further applications are discussed including DoS attacks on the Post Shannon task of identification, and on physical layer security and resilience by design. [ABSTRACT FROM AUTHOR]

The optimization of several practical large-scale engineering systems is computationally expensive. The computationally expensive simulation optimization problems (CESOP) are concerned about the limited budget being effectively allocated to meet a stochastic objective function which required running computationally expensive simulation. Although computing devices continue to increase in power, the complexity of evaluating a solution continues to keep pace. Ordinal optimization (OO) is developed as an efficient framework for solving CESOP. In this work, a heuristic algorithm integrating ordinal optimization with ant lion optimization (OALO) is proposed to solve the CESOP within a short period of time. The OALO algorithm comprises three parts: approximation model, global exploration, and local exploitation. Firstly, the multivariate adaptive regression splines (MARS) is adopted as a fitness estimation of a design. Next, a reformed ant lion optimization (RALO) is proposed to find N exceptional designs from the solution space. Finally, a ranking and selection procedure is used to decide a quasi-optimal design from the N exceptional designs. The OALO algorithm is applied to optimal queuing design in a communication system, which is formulated as a CESOP. The OALO algorithm is compared with three competing approaches. Test results reveal that the OALO algorithm identifies solutions with better solution quality and better computing efficiency than three competing algorithms. [ABSTRACT FROM AUTHOR]

Due to the lack of data in active distribution networks, employing new accurate measurement devices like phasor measurement units (PMUs) and micro-PMUs with a high reporting rate becomes an inevitable choice for the future vision of distribution systems. As a result, different algorithms have been presented to optimally place PMUs cost-effectively based on the estimation errors of the distribution state estimation (DSE) results. However, any component failure in measurement devices or communication links between sending ends and monitoring system of the distribution management system can significantly affect the DSE results. In response, this study introduces the reliability of satisfying accuracy constraints (RSACs) as an important requirement in the DSE problem. This reliability index along with the estimation errors of the DSE results are then used as two performance indices for determining the optimal number and location (configuration) of PMUs. Finally, the performance of the proposed algorithm in comparison with traditional approaches in different topologies and operating conditions of two considered ADNs is evaluated. The results proved that employing the RSACs in the optimal PMU placement problems leads to a PMU configuration with the optimum RSACs and also the cost and latency of the communication system between all configurations which have the same measurement cost and satisfy accuracy constraints of DSE results. [ABSTRACT FROM AUTHOR]

Satellite based communication either in GEO or LEO based system are prominently employed for voice, video, data communication. Demand of more traffic necessitates the data rate of satellite to be enhanced which can be implemented by the proper choice of modulation scheme. Presently ground systems are also wireless based which include direct broadcast satellite (DBS),television service, wireless local area networks (WLANs), global positioning satellite (GPS), radio-frequency identification systems which is either point-to-point or point-to-multipoint. Modern day communication systems are digital; based rather than analog to have better noise immunity. Further with the limited spectrum availability the choice of modulation scheme plays an important role for faithful transmission of the signal. The digital communication can be categorized as Amplitude Shift Keying (ASK), Frequency Shift Keying (FSK), Phase Shift Keying (PSK) whereas for higher bit data rate Phase Shift Keying (PSK) such as BPSK, QPSK and OQPSK are employed. This article overview of various modulation schemes which are employed in satellite communication apart from its selection criteria along with the concept of bit error rate. [ABSTRACT FROM AUTHOR]

Summary: Underwater wireless sensor networks (UWSNs) contain quite a lot of components such as vehicles and sensors that are deployed in a specific acoustic area to perform collaborative monitoring and data collection errands. These networks are adopted interactively between diverse nodes and ground‐based stations. Currently, UWSNs face problems and challenges that pertain to limited bandwidth, media access control, high propagation delay, 3D topology, spectrum sensing, resource utilization, routing, and power constraints. This proposal deals with the intelligent spectrum sensing in underwater cognitive sonar communication networks (CSCN). Here, the improved performance of spectrum sensing in underwater communication is attained by optimizing the cooperative spectrum sensing and data transmission. The parameters of system like subchannel allocation and transmission power is optimized by a new hybrid meta‐heuristic algorithm by integrating the concepts of deer hunting optimization algorithm (DHOA) and lion algorithm (LA) termed as lion‐enabled DHOA (L‐DHOA). The main intention of optimizing these parameters is to maximize the spectrum efficiency (SE) and energy efficiency (EE) of the underwater channel communication system. From the analysis, with respect to convergence rate, minimum detection probability, and local sensing time, it is proved that the novel hybrid optimization algorithm keeps a great role in making the trade‐off between the SE and EE in underwater channel modeling. [ABSTRACT FROM AUTHOR]

This article presents a framework for mapping digital communication systems and thereby analyzing how and why structural conditions differ across national contexts. Following the 'turn to infrastructure' in Internet studies, we conceptualize communication systems as made of infrastructural, market, and policy structures that enable and constrain mediated communication in a given society. As opposed to media system analyses that typically focus on legacy media institutions, we take individual Internet users as our theoretical point of departure and ask how their communicative capabilities are regulated. In order to exemplify the application of the framework, we describe the methodological steps in a mapping of the components of the Danish communication system. In conclusion, we discuss the overall findings that the method uncovers and its implications for future comparative research. [ABSTRACT FROM AUTHOR]

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The IoT based Power management system requires data from the feeder in the grid. Sufficient power supply with demand is a significant challenge for several countries around the world. RaPID growing demand for power supply requires power quality enhancement to get higher reliability in the smart grid. This smart power system sensor equipped that measures grid power capacity and update to the organization on a consistent schedule. Energy supplies to the specific region indicated by power install capacity in the grid; use a global system for mobile communications (GSM) messaging service to notify customers of power generation and power supply time. The IoT based wireless Sensor network (WSN) is a revolutionary system for smart monitoring. In this article propose a system demonstrate for the progress and implementation of WSN-based communication systems for smart monitoring and automated control in the electric grid. This work allows for the improvement of grid sharing for maintaining power quality. The dynamic controller has controlled the event of Power quality problem and voltage rise. Appropriate systems and controllers have been demonstrated and analyzed for control performance of a monitoring system in the smart grid. [ABSTRACT FROM AUTHOR]

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The power amplifier is an important device in the communication system, and its non-linear characteristics will lead to serious distortion of the output signal, reducing the performance of the communication system. In order to solve the problem of non-linearity in a power amplifier, this study proposes an adaptive learning algorithm based on a digital pre-distortion structure, which combines direct learning and indirect learning structure. It improves the accuracy of pre-distorter parameter and has the faster convergence speed. The pre-distortion device parameters are constantly modified to achieve a good linear effect by using the recursive least square adaptive algorithm. The simulation results show that this structure effectively compensates the output signal distortion of the power amplifier, improves the linearisation degree of the power amplifier and reduces the in-band distortion and adjacent channel leakage ratio. [ABSTRACT FROM AUTHOR]

Nowadays, the use of renewable generations, energy storage systems (ESSs) and microgrids (MGs) has been developed due to better controllability of distributed energy resources (DERs) as well as their cost-effective and emission-aware operation. The development of MGs as well as the use of hierarchical control has led to data transmission in the communication platform. As a result, the expansion of communication infrastructure has made MGs as cyber-physical systems (CPSs) vulnerable to cyber-attacks (CAs). Accordingly, prevention, detection and isolation of CAs during proper control of MGs is essential. In this paper, a comprehensive review on the control strategies of microgrids against CAs and its defense mechanisms has been done. The general structure of the paper is as follows: firstly, MGs operational conditions, i.e., the secure or insecure mode of the physical and cyber layers are investigated and the appropriate control to return to a safer mode are presented. Then, the common MGs communication system is described which is generally used for multi-agent systems (MASs). Also, classification of CAs in MGs has been reviewed. Afterwards, a comprehensive survey of available researches in the field of prevention, detection and isolation of CA and MG control against CA are summarized. Finally, future trends in this context are clarified. • Microgrid (MG) control as a cyber-physical system (CPS) against cyber-attacks (CAs) is one of the concerns of researchers. • CAs include deception attacks, denial of service (DoS) attacks and replay attacks. • Defense mechanisms against CAs consist of prevention, detection and isolation of CAs and resilience control of MG. • Future trends in the context include new methods of CAs prevention, detection and isolation, new resilient control methods. • Retrofitting existing equipment and/or accommodating advanced technologies into networks enhance resilience of MG. [ABSTRACT FROM AUTHOR]

This work presents the approaches used in the process of design of a system with the purpose to transmit the measurements sampled at certain space coordinates along with the exact sampling position, biological data, provide information about certain events happening in the area of the interest. The aim is to obtain an optimal design solution in order to implement stable and reliable hardware platform based on the current design. This paper is the first of series of two papers that present the creation of a system from a conceptual design to working equipment. [ABSTRACT FROM AUTHOR]

An omnidirectional antenna with a compact size is presented. The diameter of the proposed antenna is 100 mm and the height is ∼0.1λL (12 mm). It consists of two dipoles and four shorting pins. With this configuration, the impedance bandwidth of the proposed antenna covers 2.4–2.6 GHz. Within the bandwidth, the proposed antenna has a stable bidirectional radiation pattern in the E-plane and the omnidirectional radiation pattern in the H-plane. The geometry of the antenna is investigated and optimised by the ANSYS high-frequency structure simulator. The fabricated antenna is compact enough to be integrated into a communication system. Measured and simulated results are also obtained and compared at the end of this work. [ABSTRACT FROM AUTHOR]

Integrated radar and communication system can significantly enhance the work efficiency and considerably occupy less hardware resources. However, the integrated systems have limited supply resources, where a proper scheduling scheme is needed to meet the requirement of systems. Here, the authors propose a task-scheduling scheme based on the greedy algorithm, where each arrangement is the result of selecting the minimum shift time compared with the expected time. By guaranteeing the best result of each task, the minimum average time shift ratio (ATSR) of the whole tasks is obtained. Simulation results show that when the number of the tasks is quite large, the proposed scheme has more advantages than the traditional scheme based on time pointer algorithm. Authors' proposed scheme can significantly reduce the average offset time of tasks while maintaining a satisfactory successful scheduling rate (SSR), which shows more advantages in the integrated systems. [ABSTRACT FROM AUTHOR]

Every wireless communication system comes with an innate problem of multipath propagation, which results in spreading the resultant symbols on a time scale and thus causes the symbols to overlap and end up in Inter-symbol Interference (ISI). The overall signal is distorted and the receiver is unable to recover the original signal. ISI from the signal must be removed and the signal must be brought back to its original form as it was sent or as close to it as possible; and process of equalization is used in all wireless communication system for this purpose. Two types of equalization processes are common in modern wireless communication systems. Training based equalization requires the sender block of communication system to constantly send a pilot/training signal in order to update the receiver about the original signal. The receiver removes the ISI and extracts the unadulterated signal. The second equalization process is called blind equalization and it does not require any pilot signal. The receiver only needs to know the type of constellation scheme used in modulation and then the original signal is extracted based on that information. In this paper we have thoroughly reviewed four equalization algorithms, two from each type of equalization for 16-QAM constellation and 64-QAM constellation. We came up with constellation diagrams for each equalization algorithm and comparison of BER, residual ISI and MSE for 16-QAM and 64-QAM is done through simulations. In case of LMS and RLS algorithm for 16 QAM, the performance of RLS gets slightly better than LMS at 6 dB, however, at around 12–14 dB and onwards the BER of RLS leads and there is a significantly better BER than LMS. In future, we will compare these algorithms in order to figure out the best algorithms for the current and upcoming 5G and 6G communication technologies. [ABSTRACT FROM AUTHOR]

With the rapid development of information technology, frequency of electronic devices is increasing. As an important part of the communication system, the design of the microwave circuit is very important. In the design, the microwave circuit and the communication system are considered together, which will he helpful to optimize the system architecture and coordinate the index allocation between the baseband and the radio frequency system, from the perspective of system design. Using the simulation software-SystemVue and ADS, it is possible to design microwave circuits to meet the needs of the system under the premise of system simulation. This experimental teaching method, which takes into account the baseband signal processing and RF transceiver system’ s indicators, is conducive to students’ further understanding of the system architecture, the microwave circuits’ principle and their roles in the system, which develops students’ comprehensive design, research and innovation capabilities. [ABSTRACT FROM AUTHOR]

Disaster recovery from underwater earthquake, plane crashes into the sea, and monitoring underwater cables or piping for energy purpose are underwater missions for Remotely Operated Underwater Vehicle (ROV) in ASEAN MATE 2018 Competition. Two essentials factor to perform successfully in this ROV competition are design of an efficient communication protocol system and a low-cost communication hardware. In this research, an optimal communication system between RS-232 serial communication transmission and RS-485 serial communication transmission is developed to obtain the optimal solution. Both communication system is tested in Tech_SAS ROV-Telkom University Indonesia, a microcontroller underwater ROV based which used single microcontroller to control actuator, sensor and communication, and measured the Quality of Services (QoS) for end-to-end delay and packets loss. From the the experiment and evaluation for the two schemes, shows 12.57 ms end-to-end delay, 0% data packet error and $6 RS-485 communication system are the optimal solution for Tech_SAS ROV. [ABSTRACT FROM AUTHOR]

A review of noise cancellation in communication systems based on adaptive filter algorithms is presented. The modifying of signal characteristics in noise cancellation is relatively fast which involves the utilization of adaptive algorithms for quick coverage. The LMS and RLS algorithms play a vital role in noise cancellation to increase the convergence rate. Current communication applications require reducing the computational complexity in real-time implementation. The category of adaptive filters is automatically changing the parameters of its algorithms according to the input signal. Many adaptive filters are digitally executed to update the algorithm parameters. The original applications of an adaptive filter in numerous fields including system recognition and noise cancellation can be modeled by MATLAB simulator. The input signal of an adaptive filter is with the mixed algorithms and noise signal in the specific design of MATLAB to remove the noise from the original data and produce reliable data at the output port. The filter implementation shows the strength of the suggested structure and the capabilities of the proposed algorithms have been investigated and analyzed. The performance of the filter is promising to support the current and future communication systems in terms of noise cancellation. [ABSTRACT FROM AUTHOR]

The current transformation scenario in power distribution networks forecasts the need for alternative solutions in communication systems employed in the process of making them intelligent. As a premise, these alternatives should be easy to implement and affordable to allow their adoption in rural distribution networks, where, often, the use of technologies, such as mobile, is not available. This Letter proposes a new communication architecture with mesh topology, based on LoRa technology. The architecture adapts packet prioritisation and MIMO mechanisms to ensure the communication requirements necessary for the services. In this sense, several applications and protocols of a smart grid can coexist in the same communication system. The deployment of the architecture gave rise to a routing protocol adapted to the limitations of the radio technology used. The benefits of the proposed architecture can be observed when compared to the use of traditional low power wide area network networks and cellular technologies. The robustness of the system has been proven with average latency measurement within the acceptable range for DNP3 Modbus and NBR14522 applications. The results have shown its potential employment in the management of intelligent rural distribution systems. [ABSTRACT FROM AUTHOR]