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Search Results (176)

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Keywords = multi-radio access

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32 pages, 3549 KB  
Article
BeamSecure-AI: AI-Driven Beam-Level Attack Detection in mmWave RAN
by Faris Alsulami
Electronics 2025, 14(23), 4642; https://doi.org/10.3390/electronics14234642 - 25 Nov 2025
Viewed by 458
Abstract
Millimeter-wave radio access networks have a high level of security risks due to the vulnerability of having security threats at the beam level as hackers can exploit this by breaking network integrity and user privacy. This paper proposes BeamSecure-AI, an artificial intelligence-based framework [...] Read more.
Millimeter-wave radio access networks have a high level of security risks due to the vulnerability of having security threats at the beam level as hackers can exploit this by breaking network integrity and user privacy. This paper proposes BeamSecure-AI, an artificial intelligence-based framework that allows locating beam-level attacks and overcoming them in mmWave RAN networks in real-time. The proposed system combines deep reinforcement learning and explainable AI modules to enable it to dynamically detect threats and be transparent about the operations of the decision-making processes. We mathematically formulate the dynamic beam alignment patterns covering the multi-dimensional feature extraction through space, time, and spectral space. Experimental results validate the effectiveness of the proposed method across a range of attack scenarios, where significantly higher improvement in detection rates (96.7%) and response latency of 42.5 ms, with false-positive rates below ≤2.3%, are observed as compared to other methods. The framework can detect complex attacks such as beam stealing, jamming, and spoofing while maintaining low false-positive rates and consistent performance across urban, suburban, and rural deployment scenarios. Full article
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36 pages, 4374 KB  
Review
Spectrum Sensing in Cognitive Radio Internet of Things: State-of-the-Art, Applications, Challenges, and Future Prospects
by Akeem Abimbola Raji and Thomas O. Olwal
J. Sens. Actuator Netw. 2025, 14(6), 109; https://doi.org/10.3390/jsan14060109 - 13 Nov 2025
Viewed by 1325
Abstract
The proliferation of Internet of Things (IoT) devices due to remarkable developments in mobile connectivity has caused a tremendous increase in the consumption of broadband spectrums in fifth generation (5G) mobile access. In order to secure the continued growth of IoT, there is [...] Read more.
The proliferation of Internet of Things (IoT) devices due to remarkable developments in mobile connectivity has caused a tremendous increase in the consumption of broadband spectrums in fifth generation (5G) mobile access. In order to secure the continued growth of IoT, there is a need for efficient management of communication resources in the 5G wireless access. Cognitive radio (CR) is advanced to maximally utilize bandwidth spectrums in the radio communication network. The integration of CR into IoT networks is a promising technology that is aimed at productive utilization of the spectrum, with a view to making more spectral bands available to IoT devices for communication. An important function of CR is spectrum sensing (SS), which enables maximum utilization of the spectrum in the radio networks. Existing SS techniques demonstrate poor performance in noisy channel states and are not immune from the dynamic effects of wireless channels. This article presents a comprehensive review of various approaches commonly used for SS. Furthermore, multi-agent deep reinforcement learning (MADRL) is proposed for enhancing the accuracy of spectrum detection in erratic wireless channels. Finally, we highlight challenges that currently exist in SS in CRIoT networks and further state future research directions in this regard. Full article
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11 pages, 18450 KB  
Article
Design of Multi-User Collaborative Anti-Jamming System Under Sensing Heterogeneity
by Shiqi Gao, Yingxin Huang, Nan Qi, Xiaonan Mu, Luliang Jia and Daolong Wu
Electronics 2025, 14(21), 4264; https://doi.org/10.3390/electronics14214264 - 30 Oct 2025
Viewed by 361
Abstract
Dynamic spectrum access enables efficient anti-jamming in cognitive radio systems. However, in a multi-user distributed decision scenario, differences in spectrum states make collaboration among users a major challenge, especially when the sensing devices are heterogeneous. In order to solve this issue, we propose [...] Read more.
Dynamic spectrum access enables efficient anti-jamming in cognitive radio systems. However, in a multi-user distributed decision scenario, differences in spectrum states make collaboration among users a major challenge, especially when the sensing devices are heterogeneous. In order to solve this issue, we propose a collaborative anti-jamming cognitive radio system architecture based on historical jamming knowledge. Devices exhibiting high sensing performance support those exhibiting low sensing performance. An online reinforcement learning algorithm is used to learn the jamming patterns in real time. Finally, a multi-user collaborative anti-jamming system is developed using a software-defined radio platform. The anti-jamming performance of the system is verified experimentally under both internal communication jamming and external malicious jamming scenarios, achieving a jamming probability below 0.1. Full article
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15 pages, 1493 KB  
Article
Energy-Efficient User Association with Multi-Objective Optimization for Full-Duplex C-RAN Enabled Massive MIMO Systems
by Shruti Sharma and Wonsik Yoon
Electronics 2025, 14(21), 4197; https://doi.org/10.3390/electronics14214197 - 27 Oct 2025
Viewed by 399
Abstract
In this study, we developed an energy-efficient multi-user-associated optimization method involving a massive multi-input multi-output (M-MIMO) system-enabled Cloud Radio Access Network (C-RAN) in Full-Duplex (FD) mode. Maximization of energy efficiency (EE) was achieved with user association. We compose the non-convex multi-objective optimization (MOO) [...] Read more.
In this study, we developed an energy-efficient multi-user-associated optimization method involving a massive multi-input multi-output (M-MIMO) system-enabled Cloud Radio Access Network (C-RAN) in Full-Duplex (FD) mode. Maximization of energy efficiency (EE) was achieved with user association. We compose the non-convex multi-objective optimization (MOO) problem for resource allocation and user association in C-RAN. The resultant non-convex MOO problem is non-deterministic polynomial (NP) hard. To tackle this complexity, we find a trade-off between achievable rate and energy consumption. We first reaffirm the problem as an MOO targeting high throughput and minimizing energy consumption instantaneously. By using the epsilon (ε)-constraint method, we transform MOO to an equivalent single objective optimization (SOO) problem by majorization–minimization (MM) approach that enables the transformation of binaries into continuous variables. Further, we propose a multi-objective resource allocation algorithm to obtain a Pareto optimal solution. The simulation results show a significant gain in EE of C-RAN achieved through our proposed MOO algorithm. Our results also show remarkable trade-offs between EE and spectral efficiency (SE). Full article
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20 pages, 1343 KB  
Article
Hybrid CDN Architecture Integrating Edge Caching, MEC Offloading, and Q-Learning-Based Adaptive Routing
by Aymen D. Salman, Akram T. Zeyad, Asia Ali Salman Al-karkhi, Safanah M. Raafat and Amjad J. Humaidi
Computers 2025, 14(10), 433; https://doi.org/10.3390/computers14100433 - 13 Oct 2025
Cited by 1 | Viewed by 1607
Abstract
Content Delivery Networks (CDNs) have evolved to meet surging data demands and stringent low-latency requirements driven by emerging applications like high-definition video streaming, virtual reality, and IoT. This paper proposes a hybrid CDN architecture that synergistically combines edge caching, Multi-access Edge Computing (MEC) [...] Read more.
Content Delivery Networks (CDNs) have evolved to meet surging data demands and stringent low-latency requirements driven by emerging applications like high-definition video streaming, virtual reality, and IoT. This paper proposes a hybrid CDN architecture that synergistically combines edge caching, Multi-access Edge Computing (MEC) offloading, and reinforcement learning (Q-learning) for adaptive routing. In the proposed system, popular content is cached at radio access network edges (e.g., base stations) and computation-intensive tasks are offloaded to MEC servers, while a Q-learning agent dynamically routes user requests to the optimal service node (cache, MEC server, or origin) based on the network state. The study presented detailed system design and provided comprehensive simulation-based evaluation. The results demonstrate that the proposed hybrid approach significantly improves cache hit ratios and reduces end-to-end latency compared to traditional CDNs and simpler edge architectures. The Q-learning-enabled routing adapts to changing load and content popularity, converging to efficient policies that outperform static baselines. The proposed hybrid model has been tested against variants lacking MEC, edge caching, or the RL-based controller to isolate each component’s contributions. The paper concludes with a discussion on practical considerations, limitations, and future directions for intelligent CDN networking at the edge. Full article
(This article belongs to the Special Issue Edge and Fog Computing for Internet of Things Systems (2nd Edition))
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15 pages, 1529 KB  
Article
Peak Age of Information Optimization in Cell-Free Massive Random Access Networks
by Zhiru Zhao, Yuankang Huang and Wen Zhan
Electronics 2025, 14(13), 2714; https://doi.org/10.3390/electronics14132714 - 4 Jul 2025
Viewed by 677
Abstract
With the vigorous development of Internet of Things technologies, Cell-Free Radio Access Network (CF-RAN), leveraging its distributed coverage and single/multi-antenna Access Point (AP) coordination advantages, has become a key technology for supporting massive Machine-Type Communication (mMTC). However, under the grant-free random access mechanism, [...] Read more.
With the vigorous development of Internet of Things technologies, Cell-Free Radio Access Network (CF-RAN), leveraging its distributed coverage and single/multi-antenna Access Point (AP) coordination advantages, has become a key technology for supporting massive Machine-Type Communication (mMTC). However, under the grant-free random access mechanism, this network architecture faces the problem of information freshness degradation due to channel congestion. To address this issue, a joint decoding model based on logical grouping architecture is introduced to analyze the correlation between the successful packet transmission probability and the Peak Age of Information (PAoI) in both single-AP and multi-AP scenarios. On this basis, a global Particle Swarm Optimization (PSO) algorithm is designed to dynamically adjust the channel access probability to minimize the average PAoI across the network. To reduce signaling overhead, a PSO algorithm based on local topology information is further proposed to achieve collaborative optimization among neighboring APs. Simulation results demonstrate that the global PSO algorithm can achieve performance closely approximating the optimum, while the local PSO algorithm maintains similar performance without the need for global information. It is especially suitable for large-scale access scenarios with wide area coverage, providing an efficient solution for optimizing information freshness in CF-RAN. Full article
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18 pages, 6082 KB  
Article
Metamaterial-Enhanced MIMO Antenna for Multi-Operator ORAN Indoor Base Stations in 5G Sub-6 GHz Band
by Asad Ali Khan, Zhenyong Wang, Dezhi Li, Atef Aburas, Ali Ahmed and Abdulraheem Aburas
Appl. Sci. 2025, 15(13), 7406; https://doi.org/10.3390/app15137406 - 1 Jul 2025
Cited by 3 | Viewed by 1607
Abstract
This paper presents a novel, four-port, rectangular microstrip, inset-feed multiple-input and multiple-output (MIMO) antenna array, enhanced with metamaterials for improved gain and isolation, specifically designed for multi-operator 5G open radio access network (ORAN)-based indoor software-defined radio (SDR) applications. ORAN is an open-source interoperable [...] Read more.
This paper presents a novel, four-port, rectangular microstrip, inset-feed multiple-input and multiple-output (MIMO) antenna array, enhanced with metamaterials for improved gain and isolation, specifically designed for multi-operator 5G open radio access network (ORAN)-based indoor software-defined radio (SDR) applications. ORAN is an open-source interoperable framework for radio access networks (RANs), while SDR refers to a radio communication system where functions are implemented via software on a programmable platform. A 3 × 3 metamaterial (MTM) superstrate is placed above the MIMO antenna array to improve gain and reduce the mutual coupling of MIMO. The proposed MIMO antenna operates over a 300 MHz bandwidth (3.5–3.8 GHz), enabling shared infrastructure for multiple operators. The antenna’s dimensions are 75 × 75 × 18.2 mm3. The antenna possesses a reduced mutual coupling less than −30 dB and a 3.5 dB enhancement in gain with the help of a novel 3 × 3 MTM superstrate 15 mm above the radiating MIMO elements. A performance evaluation based on simulated results and lab measurements demonstrates the promising value of key MIMO metrics such as a low envelope correlation coefficient (ECC) < 0.002, diversity gain (DG) ~10 dB, total active reflection coefficient (TARC) < −10 dB, and channel capacity loss (CCL) < 0.2 bits/sec/Hz. Real-world testing of the proposed antenna for ORAN-based sub-6 GHz indoor wireless systems demonstrates a downlink throughput of approximately 200 Mbps, uplink throughput of 80 Mbps, and transmission delays below 80 ms. Additionally, a walk test in an indoor environment with a corresponding floor plan and reference signal received power (RSRP) measurements indicates that most of the coverage area achieves RSRP values exceeding −75 dBm, confirming its suitability for indoor applications. Full article
(This article belongs to the Special Issue Recent Advances in Antennas and Propagation)
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26 pages, 2415 KB  
Article
RL-SCAP SigFox: A Reinforcement Learning Based Scalable Communication Protocol for Low-Power Wide-Area IoT Networks
by Raghad Albalawi, Fatma Bouabdallah, Linda Mohaisen and Shireen Saifuddin
Technologies 2025, 13(6), 255; https://doi.org/10.3390/technologies13060255 - 17 Jun 2025
Viewed by 654
Abstract
The Internet of Things (IoT) aims to wirelessly connect billions of physical things to the IT infrastructure. Although there are several radio access technologies available, few of them meet the needs of Internet of Things applications, such as long range, low cost, and [...] Read more.
The Internet of Things (IoT) aims to wirelessly connect billions of physical things to the IT infrastructure. Although there are several radio access technologies available, few of them meet the needs of Internet of Things applications, such as long range, low cost, and low energy consumption. The low data rate of low-power wide-area network (LPWAN) technologies, particularly SigFox, makes them appropriate for Internet of Things applications since the longer the radio link’s useable distance, the lower the data rate. Network reliability is the primary goal of SigFox technology, which aims to deliver data messages successfully through redundancy. This raises concerns about SigFox’s scalability and leads to one of its flaws, namely the high collision rate. In this paper, the goal is to prevent collisions by switching to time division multiple access (TDMA) from SigFox’s Aloha-based medium access protocol, utilizing only orthogonal channels, and eliminating redundancy. Consequently, during a designated time slot, each node transmits a single copy of the data message over a particular orthogonal channel. To achieve this, a multi-agent, off-policy reinforcement learning (RL) Q-Learning technique will be used on top of SigFox. In other words, the objective is to increase SigFox’s scalability through the use of Reinforcement Learning based time slot allocation (RL-SCAP). The findings show that, especially in situations with high node densities or constrained communication slots, the proposed protocol performs better than the basic SCAP (Slot and Channel Allocation Protocol) by obtaining a higher Packet Delivery Ratio (PDR) in average of 60.58%, greater throughput in average of 60.90%, and a notable decrease in collisions up to 79.37%. Full article
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59 pages, 4517 KB  
Review
Artificial Intelligence Empowering Dynamic Spectrum Access in Advanced Wireless Communications: A Comprehensive Overview
by Abiodun Gbenga-Ilori, Agbotiname Lucky Imoize, Kinzah Noor and Paul Oluwadara Adebolu-Ololade
AI 2025, 6(6), 126; https://doi.org/10.3390/ai6060126 - 13 Jun 2025
Cited by 4 | Viewed by 6280
Abstract
This review paper examines the integration of artificial intelligence (AI) in wireless communication, focusing on cognitive radio (CR), spectrum sensing, and dynamic spectrum access (DSA). As the demand for spectrum continues to rise with the expansion of mobile users and connected devices, cognitive [...] Read more.
This review paper examines the integration of artificial intelligence (AI) in wireless communication, focusing on cognitive radio (CR), spectrum sensing, and dynamic spectrum access (DSA). As the demand for spectrum continues to rise with the expansion of mobile users and connected devices, cognitive radio networks (CRNs), leveraging AI-driven spectrum sensing and dynamic access, provide a promising solution to improve spectrum utilization. The paper reviews various deep learning (DL)-based spectrum-sensing methods, highlighting their advantages and challenges. It also explores the use of multi-agent reinforcement learning (MARL) for distributed DSA networks, where agents autonomously optimize power allocation (PA) to minimize interference and enhance quality of service. Additionally, the paper discusses the role of machine learning (ML) in predicting spectrum requirements, which is crucial for efficient frequency management in the fifth generation (5G) networks and beyond. Case studies show how ML can help self-optimize networks, reducing energy consumption while improving performance. The review also introduces the potential of generative AI (GenAI) for demand-planning and network optimization, enhancing spectrum efficiency and energy conservation in wireless networks (WNs). Finally, the paper highlights future research directions, including improving AI-driven network resilience, refining predictive models, and addressing ethical considerations. Overall, AI is poised to transform wireless communication, offering innovative solutions for spectrum management (SM), security, and network performance. Full article
(This article belongs to the Special Issue Artificial Intelligence for Network Management)
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19 pages, 691 KB  
Article
Implementation of LoRa TDMA-Based Mobile Cell Broadcast Protocol for Vehicular Networks
by Modris Greitans, Gatis Gaigals and Aleksandrs Levinskis
Information 2025, 16(6), 447; https://doi.org/10.3390/info16060447 - 27 May 2025
Cited by 3 | Viewed by 1268
Abstract
With increasing vehicle density and growing demands on transport infrastructure, there is a need for resilient, low-cost communication systems capable of supporting safety-critical applications, especially in situations where primary channels like Wi-Fi or LTE are unavailable. This paper proposes a novel, real-time vehicular [...] Read more.
With increasing vehicle density and growing demands on transport infrastructure, there is a need for resilient, low-cost communication systems capable of supporting safety-critical applications, especially in situations where primary channels like Wi-Fi or LTE are unavailable. This paper proposes a novel, real-time vehicular network protocol that functions as an emergency fallback communication layer using long-range LoRa modulation and off-the-shelf hardware. The core contribution is a development of Mobile Cell Broadcast Protocol that is implemented using Long-Range modulation and time-division multiple access (TDMA)-based cell broadcast protocol (LoRA TDMA) capable of supporting up to six dynamic clients to connect and exchange lightweight cooperative awareness messages. The system achieves a sub-100 ms node notification latency, meeting key low-latency requirements for safety use cases. Unlike conventional ITS stacks, the focus here is not on full-featured data exchange but on maintaining essential communication under constrained conditions. Protocol has been tested in laboratory to check its ability to ensure real-time data exchange between dynamic network nodes having 14 bytes of payload per data packet and 100 ms network member notification latency. While focused on vehicular safety, the solution is also applicable to autonomous agents (robots, drones) operating in infrastructure-limited environments. Full article
(This article belongs to the Special Issue Advances in Telecommunication Networks and Wireless Technology)
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31 pages, 1214 KB  
Article
Intra-Technology Enhancements for Multi-Service Multi-Priority Short-Range V2X Communication
by Ihtisham Khalid, Vasilis Maglogiannis, Dries Naudts, Adnan Shahid and Ingrid Moerman
Sensors 2025, 25(8), 2564; https://doi.org/10.3390/s25082564 - 18 Apr 2025
Viewed by 957
Abstract
Cooperative Intelligent Transportation Systems (C-ITSs) are emerging as transformative technologies, paving the way for safe and fully automated driving solutions. As the demand for autonomous vehicles accelerates, the development of advanced Radio Access Technologies capable of delivering reliable, low-latency vehicular communications has become [...] Read more.
Cooperative Intelligent Transportation Systems (C-ITSs) are emerging as transformative technologies, paving the way for safe and fully automated driving solutions. As the demand for autonomous vehicles accelerates, the development of advanced Radio Access Technologies capable of delivering reliable, low-latency vehicular communications has become paramount. Standardized approaches for Vehicular-to-Everything (V2X) communication often fall short in addressing the dynamic and diverse requirements of multi-service, multi-priority systems. Conventional vehicular networks employ static parameters such as Access Category (AC) in IEEE 802.11p-based ITS-G5 and Resource Reservation Interval (RRI) in C-V2X PC5 for prioritizing different V2X services. This static parameter assignment performs unsatisfactorily in dynamic and diverse requirements. To bridge this gap, we propose intelligent Multi-Attribute Decision-Making algorithms for adaptive AC selection in ITS-G5 and RRI adjustment in C-V2X PC5, tailored to the varying priorities of active V2X services. These adaptations are integrated with a priority-aware rate-control mechanism to enhance congestion management. Through extensive simulations conducted using NS3, our proposed strategies demonstrate superior performance compared to standardized methods, achieving improvements in one-way end-to-end latency, Packet Reception Ratio (PRR) and overall communication reliability. Full article
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11 pages, 4877 KB  
Proceeding Paper
Leveraging RFID for Road Safety Sign Detection to Enhance Efficiency and Notify Drivers
by Dhanasekar Ravikumar, Vijayaraja Loganathan, Pranav Ponnovian, Vignesh Loganathan and Bharanidharan Sivalingam
Eng. Proc. 2025, 87(1), 53; https://doi.org/10.3390/engproc2025087053 - 15 Apr 2025
Viewed by 766
Abstract
Road safety signboards are now difficult to see due to pollution and harsh weather elements such as snow and fog, which has resulted in more accidents. The problem is especially common in Western countries where snow can block these critical signs. An approach [...] Read more.
Road safety signboards are now difficult to see due to pollution and harsh weather elements such as snow and fog, which has resulted in more accidents. The problem is especially common in Western countries where snow can block these critical signs. An approach addressing this issue involves a system that uses Radio Frequency Identification (RFID) and Internet of Things (IoT). The real-time alerts that this system sends to drivers improve driver safety in complex environments. For this purpose, an RFID reader is placed in the vehicle, and passive RFID tags are attached to road safety signboards. The reader picks up the signal as a vehicle comes within range, and the warning for the vehicle is sent to the driver. It helps to reduce the number of accidents resulting from poor visibility. In addition, because its multi-lingual audio alerts the drive through speakers and visual warnings displayed on a display screen, the system is accessible to drivers from various regions. To make the system more sustainable, we added some solar panels to the system to cut costs as far as energy efficiency is concerned. The system combines GPS and GSM modules to provide the vehicle position in real time in the cloud. It gives better warnings and helps avoid accidents. In addition to improving road safety, the system offers support for the environment, by limiting emissions and waste of resources caused by accidents. Traffic patterns can thus be studied with the data, creating more efficient and ecofriendly transportation systems. This solution enables a smarter vehicle network that is safer and more sustainable with quick, accurate alerts. Full article
(This article belongs to the Proceedings of The 5th International Electronic Conference on Applied Sciences)
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16 pages, 910 KB  
Article
An Application of Explainable Multi-Agent Reinforcement Learning for Spectrum Situational Awareness
by Dominick J. Perini, Braeden P. Muller, Justin Kopacz and Alan J. Michaels
Electronics 2025, 14(8), 1533; https://doi.org/10.3390/electronics14081533 - 10 Apr 2025
Viewed by 1847
Abstract
Allocating low-bandwidth radios to observe a wide portion of a spectrum is a key class of search-optimization problems that requires system designers to leverage limited resources and information efficiently. This work describes a multi-agent reinforcement learning system that achieves a balance between tuning [...] Read more.
Allocating low-bandwidth radios to observe a wide portion of a spectrum is a key class of search-optimization problems that requires system designers to leverage limited resources and information efficiently. This work describes a multi-agent reinforcement learning system that achieves a balance between tuning radios to newly observed energy while maintaining regular sweep intervals to yield detailed captures of both short- and long-duration signals. This algorithm, which we have named SmartScan, and system implementation have demonstrated live adaptations to dynamic spectrum activity, persistence of desirable sweep intervals, and long-term stability. The SmartScan algorithm was also designed to fit into a real-time system by guaranteeing a constant inference latency. The result is an explainable, customizable, and modular approach to implementing intelligent policies into the scan scheduling of a spectrum monitoring system. Full article
(This article belongs to the Special Issue Machine/Deep Learning Applications and Intelligent Systems)
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24 pages, 736 KB  
Article
5G New Radio Open Radio Access Network Implementation in Brazil: Review and Cost Assessment
by Eduardo Fabricio Notari and Xisto Lucas Travassos
Telecom 2025, 6(2), 24; https://doi.org/10.3390/telecom6020024 - 8 Apr 2025
Cited by 2 | Viewed by 3683
Abstract
With the advances of Radio Access Networks, the Open RAN introduced the concept of virtualization and openness to the mobile network elements. These characteristics allow multi-vendor implementations in commercial out-of-shelf hardware with open radio interfaces beyond flexibility and scalability, permitting bringing the data [...] Read more.
With the advances of Radio Access Networks, the Open RAN introduced the concept of virtualization and openness to the mobile network elements. These characteristics allow multi-vendor implementations in commercial out-of-shelf hardware with open radio interfaces beyond flexibility and scalability, permitting bringing the data processing to the network edge and easy network element escalation. In Brazil, Radio Access Networks comprise distributed and centralized architectural topology types, which do not meet the requirements of the 5G New Radio wireless mobile network. To reach the 5G needs, an upgrade in the existing network is necessary, revealing some challenges over the existing scenario. This study shows the state-of-art, political, and economic factors that challenge the implementation of Open RAN in Brazil, analyzing the actual regulatory and political facts that can make the technology affordable and possible to introduce quickly to the market. Full article
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20 pages, 5129 KB  
Article
Multi-Band Analog Radio-over-Fiber Mobile Fronthaul System for Indoor Positioning, Beamforming, and Wireless Access
by Hang Yang, Wei Tian, Jianhua Li and Yang Chen
Sensors 2025, 25(7), 2338; https://doi.org/10.3390/s25072338 - 7 Apr 2025
Cited by 2 | Viewed by 1310
Abstract
In response to the urgent demands of the Internet of Things for precise indoor target positioning and information interaction, this paper proposes a multi-band analog radio-over-fiber mobile fronthaul system. The objective is to obtain the target’s location in indoor environments while integrating remote [...] Read more.
In response to the urgent demands of the Internet of Things for precise indoor target positioning and information interaction, this paper proposes a multi-band analog radio-over-fiber mobile fronthaul system. The objective is to obtain the target’s location in indoor environments while integrating remote beamforming capabilities to achieve wireless access to the targets. Vector signals centered at 3, 4, 5, and 6 GHz for indoor positioning and centered at 30 GHz for wireless access are generated centrally in the distributed unit (DU) and fiber-distributed to the active antenna unit (AAU) in the multi-band analog radio-over-fiber mobile fronthaul system. Target positioning is achieved by radiating electromagnetic waves indoors through four omnidirectional antennas in conjunction with a pre-trained neural network, while high-speed wireless communication is realized through a phased array antenna (PAA) comprising four antenna elements. Remote beamforming for the PAA is implemented through the integration of an optical true time delay pool in the multi-band analog radio-over-fiber mobile fronthaul system. This integration decouples the weight control of beamforming from the AAU, enabling centralized control of beam direction at the DU and thereby reducing the complexity and cost of the AAU. Simulation results show that the average accuracy of localization classification can reach 86.92%, and six discrete beam directions are achieved via the optical true time delay pool. In the optical transmission layer, when the received optical power is 10 dBm, the error vector magnitudes (EVMs) of vector signals in all frequency bands remain below 3%. In the wireless transmission layer, two beam directions were selected for verification. Once the beam is aligned with the target device at maximum gain and the received signal is properly processed, the EVM of millimeter-wave vector signals remains below 11%. Full article
(This article belongs to the Section Communications)
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