Search

Wireless medical telemetry systems (WMTSs) are typical radio communication–based medical devices that monitor various biological parameters, such as electrocardiograms and respiration rates. In Japan, the assigned frequency band for WMTSs is 400 MHz. However, the issues accounting for poor reception in WMTS constitute major concerns. In this study, we analyzed the effects of electromagnetic interferences (EMIs) caused by other radio communication systems, the intermodulation (IM) effect, and noises generated from electrical devices on WMTS and discussed their management. The 400-MHz frequency band is also shared by other radio communication systems. We showed the instantaneous and impulsive voltages generated from the location-detection system for wandering patients and their potential to exhibit EMI effects on WMTS. Further, we presented the IM effect significantly reduces reception in WMTS. Additionally, the electromagnetic noises generated from electrical devices, such as light-emitting diode lamps and security cameras, can exceed the 400 MHz frequency band as these devices employ the switched-mode power supply and/or central processing unit and radiate wideband emissions. Moreover, we proposed and evaluated simple and facile methods using a simplified spectrum analysis function installed in the WMTS receiver and software-defined radio for evaluating the electromagnetic environment. [ABSTRACT FROM AUTHOR]

A good understanding of the behavior of the atmosphere is a key factor in radio wave propagation and link's design. This study investigated the influence of refractivity gradient, effective earth radius factor (k-factor) and geo-climatic factor (K-factor) on radio communication over the cities of Kaduna, Katsina and Sokoto, in Northwestern parts of Nigeria. Forty-one year's secondary data (1980–2020) of temperature, pressure and humidity at the surface 12, 100 and 250 m above ground level retrieved from European Centre for Medium-Range Weather Forecasts (ECMRWF) ERA-5 reanalysis were used for the study. The three secondary radio-climatic parameters under investigation were computed and analyzed using latest ITU-R (Rec.P.453-14 (08/2019)) Models. It was observed that secondary radio-climatic variables exhibit seasonal type dependence. The research also reveals that the secondary radio-climatic variables depend on location, with all the study locations having different values. The highest value of refractivity gradient obtained is about −75.06 (N-units / km) in the month of February in Sokoto while the least of about −162.65 (N-units/km) was recorded in Kaduna in September. The value of the refractivity gradient is higher during the dry season compared to the wet season months with Sokoto recording the highest values for more than half of the months, followed by Katsina. Kaduna recorded highest number of lowest values of refractivity gradient. For the geoclimatic factor, it was revealed that Kaduna has an average maximum geoclimatic factor of 14.0000E-5 in September and an average minimum of 9.6677E-05 in February. Furthermore, the obtained values of k factor values for the study areas are higher than the standard value of, 4 3 (1.33). The k-factor in Kaduna ranges from 1.69 to 2.16 with mean value of 1.85 for dry season while for the wet season it ranges from 2.66 to 4.12 with a mean value of 3.74; the overall mean value for Kaduna is 2.80. In Katsina, it ranges from 1.66 to 2.20 with mean value of 1.81 for dry season while for the wet season it ranges from 1.95 to 4.00 with a mean value of 3.27; the overall mean value is 2.54. In Sokoto it ranges from 1.60 to 2.30 with mean value of 1.78 for dry season while for the wet season it ranges from 1.72 to 3.45 with a mean value of 2.59; the overall mean value is 2.19. The interpretation of this is that, radio signal propagation in the Northwest region of Nigeria is super-refractive. The overall findings of this research are essential for estimating location-dependent fade margins, which are useful for the design of wireless communication links for the region. [ABSTRACT FROM AUTHOR]

This article presents an explanation of the incorporation of on-board radio communication as a consequence of the growing concerns for maritime safety. It focuses on the economic, political and social characteristics that influenced its incorporation and evolution, and a legislative change in safety. The article demonstrates how the evolution of radio communication has been very important as the only emerging means to request and provide assistance on the high seas. In addition, the study provides evidence of the technological leap that has improved radio communication, with a new system with a high degree of reliability: the Global Maritime Distress and Safety System. [ABSTRACT FROM AUTHOR]

The quality of short-wave radio communication in the ionosphere depends largely on the state of the ionosphere, but it is uncontrollable and unreliable. The release of gaseous samarium into the ionospheric space can form high-density plasma clouds, which is of great significance for improving the quality of shortwave radio communication. The high temperature and high heat released by the self-propagation high-temperature synthesis reaction can effectively heat and vaporize the samarium. At the same time, this method can effectively avoid the adverse impact of the reaction of individual components of the reaction material on the ionization efficiency of samarium, and greatly improve the ionization efficiency of the samarium. Therefore, self-propagation high-temperature synthesis is an important method for heating and vaporizing samarium. To study the ignition model of self-propagation high-temperature synthesis system for heating and vaporizing samarium, and to design and control the ignition process is the premise for heating and vaporizing samarium. Based on the theory of chemical reaction and heat conduction, the electrothermal ignition process is studied in detail. By analyzing the change of energy distribution in the ignition process, a theoretical model of ignition under the electric energy heating mode is proposed, and a theoretical equation for calculating the ignition time is derived. The model can be used to design and control the ignition system and explain many phenomena in the ignition process. In addition, the electrothermal ignition test was carried out for heating and vaporizing samarium in the self-propagation high-temperature synthesis system to obtain the ignition power and ignition time of different reaction systems under different samarium content and porosity, and further analyze the universality of the calculation model. The results show that the test results are in good agreement with the theoretical calculation results, and the validity of the model is verified, which provides an important support for the design of self-propagation high-temperature synthesis reaction heating and vaporizing samarium ignition system. [ABSTRACT FROM AUTHOR]

Reliability of the communication system with spatial multiplexing has been studied. Increasing the bandwidth of radio communication channels due to spatial multiplexing is one of the most popular and relevant areas of modern research in the field of radio communications. Solving the problem of spatial multiplexing in the time domain with multipath propagation is associated with a significant increase in the dimension of the problem and redundant calculations. Detection in the time domain makes it difficult to take into account the frequency dependence of the amplitude and phase of the received signals, which in turn reduces the probability of correct signal recognition. In multipath propagation, a solution to the problem of spatial multiplexing in the frequency domain is proposed by applying the convolution theorem. The probability of error is estimated when using the proposed detection method. The stability of the solution is estimated depending on the conditionality of the matrix of amplitude-phase parameters. The expression of the estimation of the upper bound of the error probability in the subchannel is derived depending on the number of conditionality of the matrix of amplitude-phase parameters and the spectral density of noise in physical communication channels. An algorithm for adaptive formation of matrices of amplitude-phase parameters has been developed which selects such antennas among an excessive number of receiving antennas allowing to increase the stability of detection by reducing the number of conditionality of the matrix of coefficients of a system of linear equations. The theoretical basis of the spatial multiplexing method in multi-antenna communication systems has been developed. The proposed method makes it possible to increase the efficiency of calculations by reducing the dimension of the detection problem in comparison with the solution in the time domain. It is proposed to solve the detection problem only at frequencies at which a useful signal is expected to be received, which is especially useful for narrow-band frequency and phase, orthogonal and biorthogonal types of modulation often used in multi-antenna digital communication systems. Expressions for estimating the probability of error in the subchannel are derived. An algorithm for adaptive formation of matrices of amplitude-phase parameters has been developed, which makes it possible to increase the stability of the solution of the detection problem. The research results are applicable in the development of multi-antenna communication systems with spatial multiplexing.

Copyright of Revista de Tecnologia Aplicada is the property of Faculdade Campo Limpo Paulista 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.)

When an FIR-Hilbert transformer with an even-numbered filter order of N is used in real-time signal processing, a delay line should be placed in parallel to compensate for the delay time of N/2 arising from the FIR-Hilbert transformer. In general, the FIR-Hilbert transformer possesses a ripple governed by a filter order, a transition bandwidth, among others. In contrast, the delay line does not possess any ripple. Then, an issue regarding the ripple is encountered during signal processing. In this letter, a practical method is proposed to nullify the ripple effect in signal processing. A simple solution is that the same ripple exists on the Hilbert transformer and delay line. Subsequently, two Weaver's modulators for generating the USB signal are placed in parallel, and the real part of one of the two is used for a delay line and the imaginary part of the other of the two is used for a Hilbert transformer. When the same FIR-LPF is introduced into each of the two, the ripple effect can be nullified. [ABSTRACT FROM AUTHOR]

Copyright of Railway Signalling & Communication Engineering is the property of Railway Signalling & Communication 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.)

Copyright of Railway Signalling & Communication Engineering is the property of Railway Signalling & Communication 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.)

In this paper, a new drivers’ warning application through personalized Direct-Sequence Spread Spectrum Code-Division Multiple Access (DSSS-CDMA) transmissions, performed using the FM radio broadcasting infrastructure is presented. The proposed application is designed to simultaneously transmit a maximum of 15 low-resolution image notifications together with standard FM radio broadcasting in different geographical areas. The application is intended to warn drivers of significant driving events in major traffic areas of a country. The proposed solution is low-cost and rapid to put into practice because the modifications, both on the transmission infrastructure and on the receiver’s side, are relatively easy to implement. The transmission of image notifications is performed in subsidiary bands of commercial FM radio systems. The receiver is implemented using the Software-Defined Radio (SDR) paradigm and is able to extract the audio signal (corresponding to the usual FM transmission) and the data component, depending on the geographical area in which the vehicle is located. The receiver is based on a novel implementation of a modified Costas loop using two new nonlinear limiters. Appropriate image notification is selected using a specific decoding key, generated according to the geographical position of the vehicle. The performance of the data transmission system is analyzed by plotting the Bit Error Rate (BER) versus the signal-to-noise ratio of the data signal for different numbers of image notifications simultaneously transmitted. The proposed radio communication system was validated through an experimental setup based on Universal Software Radio Peripheral (USRP) devices driven by MATLAB/Simulink software.

Introduction/purpose: The frequency hopping spread spectrum (FH-SS) technique assumes the carrier generated by the syntesizer to hop from frequency to frequency over a wide bandwidth, according to a pseudonoise code sequence defined by the code sequence generator. The article presents the history, principles and applications of the FH-SS technique. Both military and commercial applications are discussed. Methods: This article presents an overview of data from the technical literature, with appropriate comments. Results: After presenting the history and principles of the FH-SS technique, the article summarizes its use with examples of military and commercial applications. The importance of using FH-SS in the described applications is highlighted. Conclusion: The FH-SS technique has been successfully implemented in many military and commercial technologies due to its high protection against interference, making communication difficult for reconnaissance and eavesdropping, and its ability to provide code division multiple access.

The approach of soft decoding of block codes based on determining the most reliable basis of the generator matrix and applying the differential evolution procedure is proposed. The choice of this search optimization procedure was made as a result of the analysis of the features and limitations of evolutionary optimization procedures. The scheme and the essence of the main stages of the developed method of soft decoding of block codes are presented. At the first stage, a hard decision is formed and the received word syndrome is calculated. After that, the received symbols are ranked by reliability and the generator matrix of the block code is transformed into the corresponding most reliable basis. Next, a differential evolution procedure is applied to search for the most probable transmitted information message and a binary codeword. Decoding is completed by inverse transformation of the found most probable binary codeword by rearranging the corresponding elements. It is shown that the key stage of decoding is the search for the transmitted codeword using the differential evolution procedure, and the formation of the most reliable basis of the generator matrix of block code makes it possible to increase the decoding efficiency. In order to be able to technically implement this decoding method, an appropriate algorithm has been developed and its main steps are given. The results of the work can be used for the implementation of new generation radio communication technologies to improve the reliability of the transmission of service messages. It is also recommended to use the obtained results when solving the problem of decoding other error-correcting code structures that are used in modern telecommunication technologies. [ABSTRACT FROM AUTHOR]

Copyright of Question (1669-6581) is the property of Universidad Nacional de La Plata 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 increase of cyberattacks by using the Internet of Things devices has exposed multiple vulnerabilities not only on devices but also on IoT infrastructures. Now, small devices can affect different networks and their services. This paper presents a review of the vulnerabilities on wireless technologies that gives connectivity to IoT, and the experiences using Software Defined Radio SDR for implementing wireless attacks to IoT technologies are assessed. A systematic literature review was conducted. The types of vulnerabilities and attacks that can affect the wireless technologies that stand the IoT ecosystem and SDR platforms were compared, and recent methods to overcome these attacks were identified. On the IoT reference model, the perception layer was identified as the most vulnerable. Most attacks at this level occur due to hardware limitations, physical device exposure, and heterogeneity of technologies. Future cybersecurity systems based on SDR technologies have notable advantages due to their flexibility and adaptability to new communication technologies and their potential to develop advanced tools. However, the IoT’s cybersecurity challenges are so complex that merging SDR hardware with cognitive and intelligent techniques is highly advisable. Some of these techniques could include deep learning to adapt mitigation systems to rapid technological changes.

The paper is dedicated to the development of hardware and software components for the autonomous water quality monitoring system (WQMS) for fishing farms. The system can measure main water quality parameters, storing and processing data on the remote server. The LoRaWAN technological solutions and infrastructure are utilized, providing the optimal tradeoff between data transmission range and adaptive power consumption. The main implementation and exploitation issues are described, and the proposed solutions are provided.

The article is devoted to the problem of communication in the Ministry of the Russian Federation for Civil Defence, Emergencies and Elimination of Consequences of Natural Disasters (EMERCOM of Russia). There are considered the issues of organization of communication between territorial bodies, institutions of EMERCOM of Russia and subjects of the Russian Federation. Short and ultra-short wave radio communication systems are described. Questions of development and improvement of radio communication system of EMERCOM of Russia are discussed.

The practice of sports has been steadily evolving, taking advantage of different technological tools to improve different aspects such as individual/collective training, support in match development or enhancement of audience experience. In this work, an in-house implemented monitoring system for golf training and competition is developed, composed of a set of distributed end devices, gateways and routers, connected to a web-based platform for data analysis, extraction and visualization. Extensive wireless channel analysis has been performed, by means of deterministic 3D radio channel estimations and radio frequency measurements, to provide coverage/capacity estimations for the specific use case of golf courses. The monitoring system has been fully designed considering communication as well as energy constraints, including wireless power transfer (WPT) capabilities in order to provide flexible node deployment. System validation has been performed in a real golf course, validating end-to-end connectivity and information handling to improve overall user experience. [ABSTRACT FROM AUTHOR]

This text is about an extension project that consists of storytelling on radio. By understanding the scope of radio and how it contemplates various spheres of society, even moving between social classes, the presence of Storytelling at Rádio Excelsior Recôncavo FM has been configured as an fruitful project. In this work, we initially presente the importance of the extension Project as something politically constitutive of the university essence, within a exit perspective. Parallel to this, we situate the radio as a place/bridge between the university and society within one of the oldest cultural practices of humanity, which is Storytelling. The methodology used was a phenomelogical-descriptive nature with the aim of placing a phenomenon in parentheses and situating it within a universe of meanings. [ABSTRACT FROM AUTHOR]

By combining independent component analysis (ICA) with a chaotic dynamical system of orthogonality, it is potential to construct a communication system that enables data transmission and reception at the chip rate, and achieves high speed and potentially large capacity. As ICA communication is a kind of novel digital wireless technology, in this study, we successfully confirmed the transmission of bit data using chaotic spreading sequence at the chip rate. Also further evaluations of its performance by simulation and the comparison of code-division multiple access with the same chaotic spreading sequence are performed. [ABSTRACT FROM AUTHOR]

The continuous observation of flows is required to assess a river's ecological status, to allocate irrigation withdrawals, to provide sustainable hydropower production and to plan actions as well as develop adaptive management plans. Drifters have the potential of facilitating the monitoring and modeling of river behavior at a fraction of traditional monitoring costs. They are floating objects equipped with sensors able to passively follow the movements of water. During their travel, they collect and transmit information about their movement and their surrounding environment. In this paper, we present and assess a low-cost (<150 EUR) customizable drifter developed with off-the-shelf components. The open drifter is capable of handling the majority of use cases defined in the specialized literature and in addition it offers a general river flow characterization toolkit. One of the main goals of this work is to establish an open hardware and software basis to increase the use of drifters in river studies. Results show that the proposed drifter provides reliable surface velocity estimates when compared to a commercial flow meter, offering a lower cost per data point and in contrast to traditional point measurements it can be used to identify and classify large-scale surface flow patterns. The diverse sensor payload of the open drifter presented in this work makes it a new and unique tool for autonomous river characterization. [ABSTRACT FROM AUTHOR]

To date, no natural media is available to derive the "ancient" ionosphere, so the current understanding of ionospheric long‐term trends mainly comes from analyzing ∼70 yr modern measurements supplemented by theoretical simulations. In this study, for the first time, we expanded the ionosphere simulation to the whole Holocene (9455 BCE to 2015 CE) using the Global Coupled Ionosphere‐Thermosphere‐Electrodynamics Model developed at the Institute of Geology and Geophysics, Chinese Academy of Sciences, driven by a realistic geomagnetic field, CO2 level, and solar activity, all of which are a combination of ancient media derivations and modern observations. Through a series of control runs, we found that the ionospheric oscillation of the global mean profile is characterized by a nonlinear variation versus geomagnetic field effect, a decrease (increase) above (below) ∼200 km due to CO2 increase, and violent oscillations in phase with changes in solar activity, with corresponding contributions of approximately 20%, 20%, and 60%, respectively. The CO2 effect became nonnegligible and even more significant after ∼1800 CE. The solar activity effect is marked by a frequently occurring grand solar minimum. The ionospheric characteristics show linear variations versus the dipole moment of the geomagnetic field, the CO2 level, and the F10.7 index, with the growth rate having significant local time and latitude variations. Our prediction shows that a 400 ppm CO2 increase will cause a global mean decrease of 1.2 MHz in foF2, 34 km in hmF2, and 4 tecu in TEC, which will directly influence radio wave communication. Plain Language Summary: The ionosphere (∼60–1,000 km above sea level), which is the ionized part of atmosphere, can influence the radio communication and satellite navigation significantly. Given the increasing human's space activity in near future, this influence will be more important. Our current understanding of the ionosphere is mainly obtained by analyzing measurements made by modern instruments dating back to the 1930s. To date, no natural media is available that can record "ancient" ionosphere, which restrict our prediction of future ionosphere in a longer time scale. In this study, for the first time, we try to reconstruct the paleoionosphere using our own theoretical model driven by realistic geomagnetic field, solar activity, and CO2 level as long as possible (9455 BCE to 2015 CE). Then we analyzed the ionospheric evolution due to the variations of different drivers. Based on the simulation, we further analyzed the variations of ionospheric characteristics (critical frequency, peak height, and total electron content), which are most frequently used in real application, versus different drivers. We then made a prediction of ionosphere during the coming century due to variations of different drivers. Our results are of significances for future ionosphere related applications due to potential CO2 increase and geomagnetic field variations. Key Points: The ionosphere during the Holocene was first simulated using the Global Coupled Ionosphere‐Thermosphere‐Electrodynamics Model developed at the Institute of Geology and Geophysics, Chinese Academy of Sciences driven by realistic indicesThe geomagnetic field, CO2, and solar activity contributed ∼20%, 20%, and 60% of ionospheric variability, respectivelyA rough prediction of ionosphere was made for the following century under several scenarios [ABSTRACT FROM AUTHOR]

In-band full-duplex (IBFD) communications has the potential to nearly double the spectrum efficiency of existing 5G communications. Digital signal processing to mitigate self-interference is one way to realize this full-duplex capability. However, the aggregated wideband nature of 5G coupled with the potential for large delay spreads and short coherence times makes the realistic implementation of such an IBFD processor challenging. In this paper, we address the architectural considerations and describe the practical implementation of a real-time IBFD digital processor and its performance when operating on wideband data collected in a highly dynamic environment.

Introduction/purpose: The frequency hopping spread spectrum (FH-SS) technique assumes the carrier generated by the syntesizer to hop from frequency to frequency over a wide bandwidth, according to a pseudonoise code sequence defined by the code sequence generator. The article presents the history, principles and applications of the FH-SS technique. Both military and commercial applications are discussed. Methods: This article presents an overview of data from the technical literature, with appropriate comments. Results: After presenting the history and principles of the FH-SS technique, the article summarizes its use with examples of military and commercial applications. The importance of using FH-SS in the described applications is highlighted. Conclusion: The FH-SS technique has been successfully implemented in many military and commercial technologies due to its high protection against interference, making communication difficult for reconnaissance and eavesdropping, and its ability to provide code division multiple access. [ABSTRACT FROM AUTHOR]

An appropriate pulse-coding algorithm is the key to achieving an efficient switched-mode power amplification in all-digital transmitters. A five-level RF-PWM method with third and fifth harmonic elimination is proposed to relax the requirements of the filter and to reduce the control complexity of the SMPA for all-digital transmitters. By controlling the pulse width and the center position of three-level sub-pulses, third and fifth harmonic elimination is achieved. Meanwhile, the control complexity of the SMPA is reduced by the decrease in the output-signal-level number. Finally, the feasibility of the method is verified by simulation. For the 16QAM signal with a carrier frequency of 200 MHz, the proposed method can achieve third harmonic suppression of −46.24 dBc and fifth harmonic suppression of −54.05 dBc when coding efficiency reaches 77.51%. [ABSTRACT FROM AUTHOR]

Metal cesium (Cs) vapor, released at an altitude in the upper atmosphere, generates an artificial space plasma cloud with high electron density. It can act as a scatter to realize radio communication across an over-the-horizon distance. A full-life model of radio propagation via an artificial plasma cloud is established based on its space–time evolution in this article. In addition, this model is verified by the sounding data of the rocket release experiment carried out in the United States. The multipath effect of plasma cloud scattering is studied by using ray tracing, and then, the coherent bandwidth is estimated for this spatial channel. Also, the theoretical channel model of artificial plasma cloud is established by using its space–time evolution and atmospheric wind field parameters. Considering common modulation modes and receiver noise levels, the potential communication performance is evaluated by using the proposed channel model, such as the transmission rate, the bit error rate (BER), and the available time for building up and maintaining communication links. It is shown that the maximal communication rate is up to 200 kb/s, BER overall maintains below 10−7, and the available time for a single release is about 30–60 min; for the case of this article, they are release mass of 2–10 kg, communication distances of 400–1200 km, and radio frequencies of 30–70 MHz at the VHF band. This demonstrates that the artificial channel can propagate radio waves at a much higher frequency, wider bandwidth, and higher rate than those of HF communication. Hopefully, it could be a solution to overcome the intolerable shortcoming and adverse effects on HF communication due to ionospheric disturbances especially in cases of maritime, emergency, and minimum communications [ABSTRACT FROM AUTHOR]

The increase of cyberattacks by using the Internet of Things devices has exposed multiple vulnerabilities not only on devices but also on IoT infrastructures. Now, small devices can affect different networks and their services. This paper presents a review of the vulnerabilities on wireless technologies that gives connectivity to IoT, and the experiences using Software Defined Radio SDR for implementing wireless attacks to IoT technologies are assessed. A systematic literature review was conducted. The types of vulnerabilities and attacks that can affect the wireless technologies that stand the IoT ecosystem and SDR platforms were compared, and recent methods to overcome these attacks were identified. On the IoT reference model, the perception layer was identified as the most vulnerable. Most attacks at this level occur due to hardware limitations, physical device exposure, and heterogeneity of technologies. Future cybersecurity systems based on SDR technologies have notable advantages due to their flexibility and adaptability to new communication technologies and their potential to develop advanced tools. However, the IoT's cybersecurity challenges are so complex that merging SDR hardware with cognitive and intelligent techniques is highly advisable. Some of these techniques could include deep learning to adapt mitigation systems to rapid technological changes. [ABSTRACT FROM AUTHOR]

Aircraft operations in the terminal area rely heavily on voice communications between pilots and air traffic controllers. This paper proposes a novel aircraft trajectory simulation framework by guiding the trajectory simulation following the voice command from controllers. Bayesian model selection is used for checking pilot compliances to controller commands with observed trajectories. This framework is named as Voice Communication-Augmented Simulation. The goal of the proposed study is to enable accurate trajectory predictions. The framework can act as a computer assistant for controllers to monitor pilot compliances and ensure safe operations. The proposed method is tested and validated with actual trajectory data from Sherlock Data Warehouse. The tests showed that the proposed framework can accurately simulate and monitor the flight level change of aircraft and update the approach procedure. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Ciencias Sociales (13159518) is the property of Revista de Ciencias Sociales de la Universidad del Zulia Venezuela 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 Internet Engineering Task Force and its Lightweight Authenticated Key Exchange working group have developed a solution that enables public-key-based authenticated key exchange over the most constrained Internet of Things radio communication technologies. [ABSTRACT FROM AUTHOR]

Circular phased array antennas with a quasi-omnidirectional pattern to generate transverse orbital angular momentum (OAM) waves with modes l = 0 and − 1 are designed at the frequency of 4 GHz. Proposed antennas consist of eight substrates integrated waveguide (SIW) H-plane horn elements and microstrip corporate feeding networks. Experimental results show that the mutual coupling between array antennas can be reduced by employing transverse OAM waves with different modes. [ABSTRACT FROM AUTHOR]

In this paper a new application for transmitting image notifications on the FM radio broadcasting infrastructure, dedicated to warn drivers about significant road events and to increase the traffic safety is presented. The paper analyzes different technical solutions suitable for transmitting and receiving real-time image notifications in different scenarios by using the software-defined radio concept. In the first scenario, the image notifications are QPSK modulated and transmitted with 8 kb/s bit-rate by using a mono FM radio channel. In order to increase the speed of data transmission, the second scenario uses the FM subcarrier channels dedicated for broadcasting alternate services. In this case, a stereo FM radio channel is used to transmit data with 40 kb/s, 60 kb/s and 80 kb/s bit-rates, by using QPSK, 8-PSK and 16-PSK modulations, respectively. A new software solution to perform the real-time carrier synchronization for 8PSK/16-PSK modulation based on a decision-directed PLL and non-linear decision block is also presented. The functionality of the proposed application was demonstrated by simulations for both transmission scenarios. Moreover, the first scenario was tested experimentally by using a professional FM transmitter and a simple RTL-SDR dongle as receiver. The customized baseband modulating signal including audio, data (image notification) and RDS signals was generated by using a device built by the authors. The receiver provides the digital signal through a USB interface to a software program, running on a processing unit, for demodulation. An experimental method for plotting the bit error rate vs. Eb/N0 ratio, based on signal-to-noise ratio measured with a software spectrum analyzer is also proposed. This method allows the characterization of the data transmissions performed by using an experimental setup and give hints about the QPSK signal power level compared to the other ones (audio and RDS signals).

The suggested benefits of automated vehicles are plentiful, but many of the benefits depend on connectivity with other vehicles and infrastructure to be useful to the society at large. This paper identifies two main research gaps: first, to identify whether ITS-G5 can be a reliable communication link for V2V communication. Second, to discuss which implications the results have for practitioners working with the future implementation of CAVs. We answer these research gaps by introducing a conceptualization of V2V communication operationalized through controlled experiments with vehicles on a closed runway. In the experiments, onboard ITS-G5 communication devices are used for measuring signal strength and package loss between the vehicles. The results indicate that ITS-G5 technology has some limitations, especially for long range communication (>1500 m), and in cases with other traffic shadowing the signal. We conclude that although ITS-G5 has high risk of reduced radio link in non-line-of-sight situations and in situations where the radio signal is shadowed by other traffic, the latency and operational range would be sufficient for safety critical services in line-of-sight situations. For policymakers and practitioners working with implementing communication for vehicles, the results imply that large-scale piloting is critical for testing the technology in a realistic environment outside of the laboratories. In such environments different stakeholders and disciplines can meet and collaborate to avoid siloed approaches.

Bluetooth has solidified its status as one of the most prominent and versatile wireless communication technologies alongside Wi-Fi. In spite of its widespread usage, contemporary Bluetooth testing technology still has many unaddressed shortcomings and issues. Hardware limitations, computational complexity, and the lack of standardization are some of these longstanding problems. Furthermore, very few systems possess a proven and reliable capability to test both Wi-Fi and Bluetooth. This paper presents the development of an adaptive Bluetooth test-bed framework that can not only overcome limitations with existing systems but can accommodate other technologies and protocols as well. The work presented in this paper includes: a packet processing and logging utility, a promiscuous packet capture subsystem built around a production test engine, and a complementary subsystem that handles encryption and other security mechanisms.

Warehouse management plays a pivotal role to boost the entire supply chain. To increase productivity, enterprises are focusing on different object localization approaches to achieve better accuracy amid high interferences. This helps to reduce the overall time for order taking & perform effective stock management. For this purpose, we propose a cost-effective system to achieve better accuracy for locating objects in indoor spaces with the help of BLE beacons. BLE is the term used for the Bluetooth wireless standard for low power consumption. BLE beacons are used as technology enablers because BLE supports all the major mobile smart devices and tablets. The measurement is performed using Received Signal Strength Indication (RSSI). Also, improved the location accuracy with the help of machine learning algorithms & utilizing neighborhood beacons for real-world use cases of warehouse management. The target object & neighborhood beacons provide the raw data to the system & the mobile device acts as a receiver. Our results show that the proposed work provides high accuracy for finding resources, taking orders & improving the overall stock process in warehouse management.

In this paper an approach is presented, enabling to solve the problem of local navigation of mobile robotic platforms (MRP), based on utilization of wireless networks with mesh topology. Establishment of wireless networks was ensured, based on the set of radio modules, mounted on unmanned aerial vehicles (UAV), comprising a swarm. This paper presents a developed algorithm for establishment of such wireless networks, aided by LoRa-technology, as well as an algorithm for MRP localization, based on analysis of signal level, where the incoming signals are fed from MRP group radio modules to radio modules of wireless data transfer network. An algorithmic model is given for task distribution among UAV and to implement navigational capabilities of MRP swarm. In some experiments descending dependencies of absolute error value, pertinent to MRP, from the number of UAV in action were revealed, as well as of averaged deflection value of MRP positions in motion along their paths from the number of UAV in action. Thereby the averaged value of MRP localization error, depending on the number of UAV in action, was from 8.14 to 17.13 m, and the averaged value of MRP position deflection – from 16.38 to 57.12 m, respectively.

Embedding Artificial Intelligence (AI) in integrated circuits is one of the technology pillars of the so-called digital transformation. Nowadays, the vast majority of electronic devices benefits from digital signal processing to implement more and more functionalities, which can be further enhanced by the action of AI algorithms and artefacts. Moreover, as the analog/digital interfaces are moving closer and closer to the point where the information is either acquired or transmitted, the so-called AI-managed data converters are becoming key building blocks in an increasingly number of interconnected cyberphysical systems–made up of both software and hardware components. Software Defined Radio (SDR) and Cognitive Radio (CR) systems intended for 5G/6G communications are good examples which can benefit from an early digitization managed by AI engines. [ABSTRACT FROM AUTHOR]

Copyright of Esferas is the property of Esferas 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 Railway Signalling & Communication Engineering is the property of Railway Signalling & Communication 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.)

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny 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.)

This paper describes the results measured with a radio evaluation system using under-sampling when the frequency difference between carrier and local signals changes continuously. In addition, we show the correction performance by estimating the frequency difference before and after correction. As a result, the phase fluctuation within the correction range could be corrected. Meanwhile, it was clarified that the element of the fluctuating frequency difference affects the signal evaluation and that there is a residual frequency difference after correction. [ABSTRACT FROM AUTHOR]

The aim of this article is to present an architecture to support reconfigurable multimedia services for a practical emergency environment use case of rescue operations. Specifically, radio communication and video surveillance services are provided by means of a small device carried by a mobile vehicle. This solution is validated by implementing a digital mobile radio (DMR) standard radio hotspot and a video streaming server in an unmanned aerial vehicle (UAV) that conveys a device with scarce resources in order to minimize power consumption. To achieve a fast and flexible deployment of the envisioned services, a virtualization-based approach is proposed. Namely, a Kubernetes orchestrator is used to manage the life-cycle of services deployed on a small resource device, endowing the architecture with scalability and management flexibility. This article describes the executed performance tests that measured key parameters such as deployment time and recovery time after disconnection. Highly promising results were obtained, showing that the proposed architecture can be deployed in less than 4 minutes and can recover from network disconnections in less than 10 seconds. Thus, the performance, reliability and flexibility of the overall solution are demonstrated.