Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

In recent years there have been significant changes in the way of teaching in universities; the Covid 19 pandemic accelerated several processes in providing remote access to training and incorporating virtual teaching with a central role. Fortunately, the technological maturity that we had as a society when this epidemic began allowed us to continue with our university education goals and led us through practice to discover the advantages of virtual teaching that it is logical to preserve once the epidemic ends. The advancement of software tools, in particular simulators, and the improvement in access to them are other critical tools in changing the paradigms of teaching and research. In subjects such as Radiofrequency (RF), using these simulators and software tools to teach virtual classes offers an excellent opportunity to provide quality training in the area without geographical or even time limitations. In a virtual course, the distance from the student to the educational center does not have the impact it has always had in the case of face-to-face education. From the point of view of student and teacher time management, the possibility of recording classes in a very simplified way and with good quality allows students to take courses asynchronously (watching the class video) when they can't attend this one. The recording of classes also facilitates the teacher's work, allowing them to resort to these recordings in case of need or convenience. This new reality shows us the possibility of sharing quality training globally and significantly expanding our academic collaboration networks. This work analyzes these changes and the opportunities they imply, particularly in the RF topics. A mixed modality of Face-to-Face/Virtual courses allows the preservation of both advantages and does not have to be challenging to implement.

In the world there are 1.15 billion people, including adults and children, with some functional diversity; and on the other hand, population aging, which only in Cuba reaches 20%, means that devices are needed to assist them, and systems for their care in health institutions; this has stimulated professionals in the area of electronics to develop devices and systems that support these people; that is why in the work two case studies of prototype designs are presented, which in addition to constituting home automation implementations, help individuals with visual and motor difficulties such as: the intelligent electronic cane, the use of voice commands for electrical drives and data acquisition; all these applications are associated with systems with wireless sensors and Android devices; the smart cane uses ultrasonic sensors for obstacle detection and notifies the individual with voice messages; the voice command system for drives uses voice recognition, present in Android devices with an operating system with versions greater than 4.1, to convert voice to text and send a command, through the Bluetooth standard, to a microcontroller to carry out the drive.

In the field of telecommunications, real-time processing of multipurpose information flows, such as video processing, is required. To achieve the effectiveness of these complex processes, effective management of the used computational infrastructure is necessary to conduct real-time monitoring and analysis of data resulting from the nodes involved in the processing. There are many tools; both paid and free of cost, developed to perform monitoring. Still, a more straightforward, generic, scalable, and fast design is required to ensure the proper functioning of these highly complex applications. In this work, we have developed a real-time monitoring system based on the integration of Shell scripts and modules programmed in the C++ programming language on Linux operating systems. This solution performs the capture, storage, and analysis of data associated with computing nodes in high-performance applications executed in parallel or distributed compute nodes. The validation of the system operation solution was performed based on the analysis of the acquired data, the execution times of each of the modules, and the execution sequences. This solution is extensible to a wide range of computing solutions that must operate uninterruptedly.

Licensed Primary Users (PU) spatial location awareness by Cognitive Radios(CR) can positively impact the Cognitive Radio Networks(CRN) spectral sensing and sharing process. PU generally doesn't cooperate with secondary users who make its location process a real challenge. One of CRN's most effective PU location methods is based on its signal's Direction of Arrival (DoA) estimation using antenna arrays. Although the theoretical foundations of these techniques are widely disclosed, this is not the case for the implementation variants in real scenarios. This work proposes the practical implementation of a DoA estimation system for CRN with integrated microwave transceivers connected to an Intel FPGA development board. Based on the combined use of programmable logic and software executed in an embedded processor, the design allows for solving the DoA estimation problem in antenna arrays. The experimental verification with accurate PU signals provides for verifying the correct operation of the system in practical scenarios. The implemented design constitutes a feasible way to obtain practical CRN as a solution to increasing spectral saturation. It can be extended to other applications, such as wireless sensor networks or the deployment of 6G, in which CRN constitutes a key technology.

Nowadays, users demand increasingly specialized services and applications (augmented reality, virtual reality, remote surgery, among others), which has affected the rapid growth and development such smart devices and Internet of Things sensors (IoT). Consequently, network requirements have become more demanding, critical, and dynamic to achieve high data transfer rates, massive connectivity, ultra-low latencies, and high reliability. New generation networks (5G/B5G) handle many parameters that make it difficult to manage with the traditional model. It is still insufficient with the help and implementation of technologies such as Software Defined Networks (SDN), Network Functions Virtualization (NFV), and Network Segmentation (NS), which considerably improve network performance by focusing on services. In the client-telecommunications service provider relationship, the latter must comply with the Service Level Agreements (SLA) and have an automated management mechanism at all levels. This article summarizes the 5G network's main characteristics and the technologies that support it. In addition, we present a proposal to achieve an automated management scheme that allows a better distribution (provisioning) of resources in the network.

This paper proposes an economic Automatic Packet Reporting System (APRS), that don’t require an internet connection and employ Global Positioning System (GPS) receivers, radio equipment, and a computer’s sound card. It’s necessary to design a coupler interface between the transceiver and computer-based VOX coupling circuit functioning principle. The article describes the design and demonstrates the efficacy system with realized test results. The investigation employed existent equipment, for example, AMEC hardware and ICOM radios. Still, it can be substituted by a similar economics kit during the application of the control system applicable, including maritime traffic.

The ever-increasing traffic demands of wireless networks and the saturation of the lower bands of the radio spectrum have led the industry to adopt the use of ever-higher frequency bands. One of those bands is the 60 GHz band that has been incorporated into the Wi-Fi network standards within the IEEE 802.11 group in the past decade. In this work, the design of an antenna for use with beamforming techniques in the 60 GHz band is presented. The operating standards in the band are reviewed, from which requirements and criteria for the design are obtained. Simulations are performed and compared with the theoretical design, making adjustments and improvements to the original design. Techniques are applied to reduce secondary lobes, and the antenna is evaluated with multi-user transmission techniques to increase spectral efficiency.

Virtual machines, during the virtualization process of the services they deploy, make inefficient use of the hardware resources that are previously assigned to them. In virtualization, the Docker virtual container platform allows greater efficiency; Thanks to the requirement of less hardware and human resources for the deployment and maintenance of the services, the costs are lower. In this project, a study of the virtual machine and container technology is carried out. Subsequently, several valuable platforms for the deployment of virtual containers are analyzed. It ends with implementing the OpManager telecommunications data network management and operation tool in a Docker container. This research lays the theoretical foundations to optimize the hardware resources used by virtual machines during the virtualization process; this is achieved by migrating a large volume of services to the virtual container infrastructure. Docker is a platform that allows you to create applications in software containers that are lightweight and portable; statistics indicate that Docker is the next step in virtualization technologies.

The radio communications systems are affected by abnormal refractive conditions of propagation, which cause affectations to their availability. The regularity of appearance of the previously mentioned phenomena in our climatic area is very high, as well as the incidence of the degradation of mobile communications services. The objective of the present work consists of the possibility of detection of anomalies in the gradient of the refractive index of the troposphere using RTWP (Receive Total Wide Band Power) data is founded. The analysis is based on a statistical correlation study between the maximum daily level of interferences in RTWP base stations, reported by UMTS (Universal Mobile Telecommunications System) technology cells, and two sources of tropospheric duct parameters. In the first case, Key West's sounding station reports are used; in the second place, the data of re-analyses the ERA5 system. In the same way, these results correlate with the reports of the detection of external operator's signals compiled by the National Center of Spectrum Control. The results of the comparison of interference signals received, and tropospheric ducting detection are satisfactory and prove the capacity of the network to reflect the phenomenon under investigation.

In this work, a Digital Signaling application is implemented that, at the hardware and software level, allows centralized, dynamic, and secure control of multiple screens in a single interface. It can be inserted into an IoT ecosystem through the MQTT protocol, which allows it to react to certain situations detected by sensors or other devices, dynamically changing the content displayed on the screens. In addition, IoT platforms are deployed that allow the management and monitoring of the screens, both within the local network (edge) and based on the cloud. Its operation is demonstrated with a case study where the screen changes the image shown when a motion sensor detects people and turns on the lights of the premises that remain off. At the same time, there were no people in it. This way, energy is used efficiently since it is only activated when necessary.