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Keywords = radioelectric spectrum

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28 pages, 19540 KiB  
Article
Cooperative Multiband Spectrum Sensing Using Radio Environment Maps and Neural Networks
by Yanqueleth Molina-Tenorio, Alfonso Prieto-Guerrero, Rafael Aguilar-Gonzalez and Miguel Lopez-Benitez
Sensors 2023, 23(11), 5209; https://doi.org/10.3390/s23115209 - 30 May 2023
Cited by 7 | Viewed by 2100
Abstract
Cogitive radio networks (CRNs) require high capacity and accuracy to detect the presence of licensed or primary users (PUs) in the sensed spectrum. In addition, they must correctly locate the spectral opportunities (holes) in order to be available to nonlicensed or secondary users [...] Read more.
Cogitive radio networks (CRNs) require high capacity and accuracy to detect the presence of licensed or primary users (PUs) in the sensed spectrum. In addition, they must correctly locate the spectral opportunities (holes) in order to be available to nonlicensed or secondary users (SUs). In this research, a centralized network of cognitive radios for monitoring a multiband spectrum in real time is proposed and implemented in a real wireless communication environment through generic communication devices such as software-defined radios (SDRs). Locally, each SU uses a monitoring technique based on sample entropy to determine spectrum occupancy. The determined features (power, bandwidth, and central frequency) of detected PUs are uploaded to a database. The uploaded data are then processed by a central entity. The objective of this work was to determine the number of PUs, their carrier frequency, bandwidth, and the spectral gaps in the sensed spectrum in a specific area through the construction of radioelectric environment maps (REMs). To this end, we compared the results of classical digital signal processing methods and neural networks performed by the central entity. Results show that both proposed cognitive networks (one working with a central entity using typical signal processing and one performing with neural networks) accurately locate PUs and give information to SUs to transmit, avoiding the hidden terminal problem. However, the best-performing cognitive radio network was the one working with neural networks to accurately detect PUs on both carrier frequency and bandwidth. Full article
(This article belongs to the Special Issue Cognitive Radio Networks: Technologies, Challenges and Applications)
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10 pages, 1293 KiB  
Brief Report
Improving Functional Abilities in Children and Adolescents with Autism Spectrum Disorder Using Non-Invasive REAC Neuro Psycho Physical Optimization Treatments: A PEDI-CAT Study
by Arianna Rinaldi, Márcia C. Marins Martins, Ana C. De Almeida Martins Oliveira, Salvatore Rinaldi and Vania Fontani
J. Pers. Med. 2023, 13(5), 792; https://doi.org/10.3390/jpm13050792 - 5 May 2023
Cited by 5 | Viewed by 3422
Abstract
Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder that affects communication, social interaction, and behavior. Non-invasive neuromodulation techniques, such as radioelectric asymmetric conveyer (REAC) technology, have gained attention for their potential to improve the endogenous bioelectric activity (EBA) and neurobiological processes underlying [...] Read more.
Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder that affects communication, social interaction, and behavior. Non-invasive neuromodulation techniques, such as radioelectric asymmetric conveyer (REAC) technology, have gained attention for their potential to improve the endogenous bioelectric activity (EBA) and neurobiological processes underlying ASD. Neuro Postural Optimization (NPO) and Neuro Psycho Physical Optimization (NPPO) treatments are non-invasive and painless neuromodulation treatments that utilize REAC technology and have shown promising results in improving the symptoms of ASD. This study aimed to evaluate the effects of NPO and NPPO treatments on functional abilities in children and adolescents with ASD using the Pediatric Evaluation of Disability Inventory-Computer Adaptive Test (PEDI-CAT). The study consisted of 27 children and adolescents with ASD who underwent a single session of NPO followed by 18 sessions of NPPO treatment over a period of one week. The results showed significant improvements in the children’s and adolescents’ functional abilities across all domains of the PEDI-CAT. These findings suggest that NPO and NPPO may be effective treatments for improving functional abilities in children and adolescents with ASD. Full article
(This article belongs to the Section Epigenetic Therapy)
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26 pages, 2622 KiB  
Review
Projections of IoT Applications in Colombia Using 5G Wireless Networks
by Alexis Barrios-Ulloa, Dora Cama-Pinto, Johan Mardini-Bovea, Jorge Díaz-Martínez and Alejandro Cama-Pinto
Sensors 2021, 21(21), 7167; https://doi.org/10.3390/s21217167 - 28 Oct 2021
Cited by 9 | Viewed by 5580
Abstract
Wireless technologies are increasingly relevant in different activities and lines of the economy, as well as in the daily life of people and companies. The advent of fifth generation networks (5G) implies a promising synergy with the Internet of Things (IoT), allowing for [...] Read more.
Wireless technologies are increasingly relevant in different activities and lines of the economy, as well as in the daily life of people and companies. The advent of fifth generation networks (5G) implies a promising synergy with the Internet of Things (IoT), allowing for more automations in production processes and an increase in the efficiency of information transmission, managing to improve the efficiency in decision-making through tools such as big data and artificial intelligence. This article presents a description of the 5G implementation process in Colombia, as well as a revision of opportunities when combining with IoT in featured sectors of the departmental development plans, such as agriculture, tourism, health, the environment, and industry. Results shows that the startup of 5G in Colombia has been a slow process, but there are comparisons with similar procedures in other developed countries. Additionally, we present examples of 5G and IoT applications which can be promoted in Colombia, aimed at improving the quality of life of their habitants and promoting economic development. Full article
(This article belongs to the Collection Applications of Internet of Things Networks in 5G and Beyond)
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21 pages, 16917 KiB  
Article
Real-Time Implementation of Multiband Spectrum Sensing Using SDR Technology
by Yanqueleth Molina-Tenorio, Alfonso Prieto-Guerrero and Rafael Aguilar-Gonzalez
Sensors 2021, 21(10), 3506; https://doi.org/10.3390/s21103506 - 18 May 2021
Cited by 16 | Viewed by 5627
Abstract
In this work, a novel multiband spectrum sensing technique is implemented in the context of cognitive radios. This technique is based on multiresolution analysis (wavelets), machine learning, and the Higuchi fractal dimension. The theoretical contribution was developed before by the authors; however, it [...] Read more.
In this work, a novel multiband spectrum sensing technique is implemented in the context of cognitive radios. This technique is based on multiresolution analysis (wavelets), machine learning, and the Higuchi fractal dimension. The theoretical contribution was developed before by the authors; however, it has never been tested in a real-time scenario. Hence, in this work, it is proposed to link several affordable software-defined radios to sense a wide band of the radioelectric spectrum using this technique. Furthermore, in this real-time implementation, the following are proposed: (i) a module for the elimination of impulsive noise, with which the appearance of sudden changes in the signal is reduced through the detail coefficients of the multiresolution analysis, and (ii) the management of different devices through an application that updates the information of each secondary user every 100 ms. The performance of these linked devices was evaluated with encouraging results: 95% probability of success for signal-to-noise ratio (SNR) values greater than 0 dB and just five samples (mean) in error of the edge detection (start and end) for a primary user transmission. Full article
(This article belongs to the Special Issue Cognitive Radio Applications and Spectrum Management)
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14 pages, 2855 KiB  
Article
A Cluster-Based Channel Assignment Technique in IEEE 802.11 Networks
by Jose Manuel Gimenez-Guzman, David Crespo-Sen and Ivan Marsa-Maestre
Telecom 2020, 1(3), 228-241; https://doi.org/10.3390/telecom1030016 - 30 Nov 2020
Cited by 2 | Viewed by 3091
Abstract
Channel assignment has become a critical configuration task in Wi-Fi networks due to the increasing number and density of devices which use the same frequency band in the radioelectric spectrum. There have been a number of research efforts that propose how to assign [...] Read more.
Channel assignment has become a critical configuration task in Wi-Fi networks due to the increasing number and density of devices which use the same frequency band in the radioelectric spectrum. There have been a number of research efforts that propose how to assign channels to the access points of Wi-Fi networks. However, most of them ignore the effect of clients (also called stations or STAs) in channel assignment, instead focusing only on access points (APs). In this paper, we claim that considering STAs in the channel assignment procedure yields better solutions in comparison with those obtained when STAs are ignored. To evaluate this hypothesis we have proposed a heuristic technique that includes the effect of interferences produced by STAs. Results show that taking STAs into account clearly improves the performance of the solutions both in terms of the achieved utility and in terms of the variability of results. We believe that these results will be useful to the design of future channel assignment techniques which consider the effect of STAs. Full article
(This article belongs to the Special Issue Wireless Communication Networks)
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18 pages, 5765 KiB  
Article
Linear Algorithms for Radioelectric Spectrum Forecast
by Luis F. Pedraza, Cesar A. Hernandez, Ingrid P. Paez, Jorge E. Ortiz and E. Rodriguez-Colina
Algorithms 2016, 9(4), 82; https://doi.org/10.3390/a9040082 - 2 Dec 2016
Cited by 3 | Viewed by 4431
Abstract
This paper presents the development and evaluation of two linear algorithms for forecasting reception power for different channels at an assigned spectrum band of global systems for mobile communications (GSM), in order to analyze the spatial opportunity for reuse of frequencies by secondary [...] Read more.
This paper presents the development and evaluation of two linear algorithms for forecasting reception power for different channels at an assigned spectrum band of global systems for mobile communications (GSM), in order to analyze the spatial opportunity for reuse of frequencies by secondary users (SUs) in a cognitive radio (CR) network. The algorithms employed correspond to seasonal autoregressive integrated moving average (SARIMA) and generalized autoregressive conditional heteroskedasticity (GARCH), which allow for a forecast of channel occupancy status. Results are evaluated using the following criteria: availability and occupancy time for channels, different types of mean absolute error, and observation time. The contributions of this work include a more integral forecast as the algorithm not only forecasts reception power but also the occupancy and availability time of a channel to determine its precision percentage during the use by primary users (PUs) and SUs within a CR system. Algorithm analyses demonstrate a better performance for SARIMA over GARCH algorithm in most of the evaluated variables. Full article
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22 pages, 412 KiB  
Article
Automated Negotiation for Resource Assignment in Wireless Surveillance Sensor Networks
by Enrique De la Hoz, Jose Manuel Gimenez-Guzman, Ivan Marsa-Maestre and David Orden
Sensors 2015, 15(11), 29547-29568; https://doi.org/10.3390/s151129547 - 24 Nov 2015
Cited by 27 | Viewed by 6984
Abstract
Due to the low cost of CMOS IP-based cameras, wireless surveillance sensor networks have emerged as a new application of sensor networks able to monitor public or private areas or even country borders. Since these networks are bandwidth intensive and the radioelectric spectrum [...] Read more.
Due to the low cost of CMOS IP-based cameras, wireless surveillance sensor networks have emerged as a new application of sensor networks able to monitor public or private areas or even country borders. Since these networks are bandwidth intensive and the radioelectric spectrum is limited, especially in unlicensed bands, it is mandatory to assign frequency channels in a smart manner. In this work, we propose the application of automated negotiation techniques for frequency assignment. Results show that these techniques are very suitable for the problem, being able to obtain the best solutions among the techniques with which we have compared them. Full article
(This article belongs to the Section Sensor Networks)
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