5G Mobile Communications

In this paper, a novel analytical model for resource allocation is proposed for a device-to-device (D2D) assisted cellular network. The proposed model can be applied to underlay and overlay D2D systems for sharing licensed bands and offloading cellular traffic. The developed model also takes into account the problem of unlicensed band sharing with Wi-Fi systems. In the proposed model, a global system state reflects the interaction among D2D, conventional cellular, and Wi-Fi packets. Under the standard traffic model assumptions, a thresholdbased flow control is proposed for guaranteeing the quality-ofservice (QoS) of Wi-Fi. The packet blockage probability is then derived. Simulation results show the proposed scheme sacrifices conventional cellular performance slightly to improve overlay D2D performance significantly while maintaining the performance for Wi-Fi users. Meanwhile, the proposed scheme has more flexible adjustments between D2D and Wi-Fi than the underlay scheme.

Throughout this study, a novel network model for massive machine-type communications (mMTC) is proposed using a compressive sensing (CS) algorithm and a non-orthogonal multiple access (NOMA) scheme. Further, physical-layer security (PLS) is applied in this network to provide secure communication. We first assume that all the legitimate nodes operate in full-duplex mode; then, an artificial noise (AN) signal is emitted while receiving the signal from the head node to confuse eavesdroppers (Eve). A convex optimization tool is used to detect the active number of nodes in the proposed network using a sparsity-aware maximum a posteriori (S-MAP) detection algorithm. The sensing-aided secrecy sum rate of the proposed network is analyzed and compared with the sum rate of the network without sensing, and the closed-form expression of the secrecy outage probability of the proposed mMTC network is derived. Finally, our numerical results demonstrate the impact of an active sensing algorithm in the proposed mMTC network; improvement in the secrecy outage of the proposed network is achieved through increasing the distance of the Eve node.

With the current discussion in the UK about mobile coverage degradation since the shutdown of the 3G networks, there have been a number of proposals put forward to remedy this situation, from more sites from an MNO perspective, to local authorities sponsoring infill in whatever form that might take, but one approach we are yet to see is a more flexible application of parameters in existing networks, in particular reference signal power (used in combination where appropriate with remote electrical tilt), to better balance site to site PRB utilisation and/or provide coverage infill. We stress that this is an iterative approach that works consistently on the target area and makes one change per day (proposed).
This would serve to give optimal user experience and can reduce/delay the reliance on costly upgrades and/or new infill sites.
This presentation gives an overview of the concept, methodologies and mechanism of action, outcomes and safety measures in place to ensure other performance indicators are not adversely affected.

This book provides an analysis of the problem of high energy consumption of mobile networks and describes methods for improving the energy efficiency of mobile networks. It explores new technologies and strategies that will enable mobile networks to operate with less energy and become more sustainable while not compromising service quality.

Improving the Energy Efficiency of Mobile Networks: Strategies for 5G and 6G Technologies is designed to help readers understand how to optimize energy consumption in mobile networks. It explores technical solutions for reducing the energy consumption with a focus on innovative solutions such as network energy consumption optimization using artificial intelligence (AI) in the management of network resources, energy harvesting (EH), software-defined networking, renewable energy sources, and implementation of advanced techniques and protocols for improving the energy efficiency of mobile networks. The book analyzes how the integration of different advanced technologies, network function virtualization, and non-orthogonal multiple access techniques, along with the implementation of AI, renewable energy sources, and EH, can contribute to the optimizing energy use of mobile networks, without compromising network performance. It offers an overview of concrete solutions, with an insight into future directions of development, which makes it particularly relevant at a time when industry is increasingly moving toward sustainability and the implementation of green technologies.

This book is ideal for researchers, industry professionals, and scholars who want to gain a deeper understanding of the excessive mobile network energy consumption and contribute to the development of energy-efficient and sustainable mobile networks.

This document describes a mechanism to control Service Function access to the Network Service Header (NSH). It addresses the Service Function trust issue and provide a method to enforce predefined access control lists to limit Service Function access to Service Function Chain information in the NSH in NSH-based Service Chaining.

Wireless communication research is currently focused on 5G. On an FR4 substrate, a building-like structure with two slot-based planar multiple input multiple output (MIMO) antenna has been designed. dielectric constant is 4.3, and the substrate thickness is 1.6mm. The proposed antenna is designed and simulated for 5G applications using CST microwave studio and HFSS at 24.25GHz, 29.25GHz, and 32.40GHz. According to the simulated results, the VSWR is lower than 3:1 and the return loss at both ports is-43.27dB,-60.55dB, and-42.61dB at 29.25GHz, 34.20GHz, and 34.075GHz resonating frequencies respectively. Isolation between both ports is better. At 24.25GHz, 29.25GHz, and 32.40GHz the proposed design achieves a gain of 5.1dBi, 5.5dBi, and 3.5dBi respectively. The structure is fabricated and measurement is carried out. The simulated and the measured results shows good agreement.

Türkiye teknoloji alanında 23 yılını kaybetmiş durumda; yapay zekâ ve 5G çağında hâlâ geriden geliyor. Bu durum, gençlerin geleceğe dair umutsuzluğunu artırıyor. İşsizlik ve özellikle “ev genci” (NEET) diye tanımlanan ne eğitimde ne istihdamda olan gençlerin sayısı rekor seviyede olması ve tüm bu sorunların futbol kullanılarak unutturulması üzerine bir deneme.

This paper presents the integration slots and Complementary Split Ring Resonators (CSRRs) in the development of miniaturized, high-gain, dual-band Microstrip Rectangular Patch Antennas (MRPAs) for 5G mobile communication applications. The antennas were designed on a Rogers RT5880 substrate with a thickness of 0.508 mⅿ. Slots and ⅭSRR metamaterial unit cells were integrated into the patch and ground planes, respectively, to achieve size reduction, high gain, and bandwidth enhancement. The design and simulation processes were conducted using ⅭЅΤ Studio Suite 2018. Simulated results of the best-performing antenna showed that integrating CSRRs reduces the MRPA size by approximately 25%, from 330 mm² (16.5 × 20.0 mm²) to 248 mm² (15.5 × 16.0 mm²). The conventional MRPA antenna without slots and CSRRs resonated at 26.59 GHz and 28.0 GHz, offering bandwidths of 0.50 GHz and 0.81 GHz, with corresponding gains of 5.81 dΒ and 9.44 dΒ, respectively. After integrating the slots and CSRRs, the MRPA antenna resonated at 26.75 GHz and 28.0 GHz, with bandwidths increased to 0.52 GHz and 1.10 GHz (enhancements of 4% and 36%), and gains improved to 9.20 dΒ and 11.39 dΒ (enhancements of 58% and 21%), respectively. These enhancements and size reduction make the proposed slotted and CSRR-loaded MRPA antennas suitable for millimeter-wave 5G wireless portable devices.

Power efficiency is a growing concern in softwarized 5G gNBs due to increasing energy costs and carbon emissions. While SmartNICs offer low-power acceleration for packet processing, they struggle with complex operations, often requiring offloading to servers, which raises power usage. This study evaluates the performance and power consumption when dividing 5G gNB data plane tasks between SmartNICs and a DPDK-enabled host, comparing flow-based and function-based task allocation methods. We introduce an adaptive CPU power management strategy that adjusts CPU power states based on traffic. Results show that deploying five SmartNICs with function-based partitioning, which retains packet buffering on the host and offloads header decapsulation, insertion, and lookuptable operations to the SmartNICs, delivers a throughput of 109 MPPS, which is 173% more than a SmartNIC-only setup and reduces latency by 70% compared with a host-only setup. Adaptive power management lowers total power consumption by 12.5% in the optimal partitioning while preserving high throughput and low latency.

The Art and Science of Antenna
Selection: A Practitioner's Guide

Section 5: The Pitfall Prevention Handbook

 Learning Objective: To provide the reader with a practical checklist of critical questions to ask and mistakes to avoid throughout the design process.

 Key Takeaway for the Reader: Upon completing this section, the reader will be able to:
 Identify and avoid common integration errors before they happen.
 Diagnose problems quickly based on known symptoms.
 Apply proven solutions to known failure modes.
 Use the provided checklist to ensure all critical aspects have been covered.

The Art and Science of Antenna Selection: A Practitioner's Guide
Section 0: Executive Summary for Busy Engineers
• Learning Objective: To provide a rapid overview of the guide's core framework and most critical insights, enabling a time-constrained engineer to grasp the essential methodology.
• Key Takeaway for the Reader: Upon completing this section, the reader will be able to:
o Articulate the fundamental challenge of antenna selection (the lab-field gap).
o Describe the three-pillar framework (Technical, Environmental, Commercial).
o Recall the top pitfalls to avoid.
o Identify which subsequent sections are most relevant to their current challenge.

2.1 Executive Summary: The Macro-Cell Challenge
The Product: An Active Antenna Unit (AAU) for 5G Massive MIMO macro-cell base stations, supporting 3.4-3.8 GHz (n78) and 2.3-2.7 GHz (n41) bands with 64 transmit/receive channels, designed for urban coverage and capacity enhancement.

The Core Challenge: Designing a high-efficiency, compact antenna array capable of simultaneous multi-user beamforming while meeting strict weight, wind load, and power consumption constraints for tower-top deployment, all within aggressive cost targets for mass deployment.

The Key Constraints:
• Performance: >65% system efficiency, ±45° electronic downtilt, 256-QAM support
• Environmental: IP67 rating, -40°C to +55°C operational range, 200 km/h wind survival
• Physical: <25 kg weight, <0.8 m² wind load area, <600W power consumption
• Commercial: <$3000 production cost, 10-year service life, <3-year ROI

The Final Architecture: A 64-element dual-polarized array featuring:
• Stacked patch antenna elements with wideband characteristics
• Silicon-based beamforming ICs with integrated calibration
• Hybrid beamforming architecture combining analog and digital domains
• Advanced cooling system using heat pipes and passive cooling fins
• Lightweight composite radome with optimized RF transparency
The study also includes practical examples, problem definitions, causes, solutions, scientific and practical advice, as well as questions, answers, lessons, and expert insights in each section to ensure both scientific and practical benefits.

• The Product: A flagship smartphone requiring global 5G connectivity, including millimeter-wave (mmWave) bands.
• The Core Challenge: Integrating a high-performance mmWave phased array antenna system into an extremely compact, metal-and-glass device, ensuring reliable beamforming despite signal blockage from the user's hand and head.
• The Key Constraint: The antenna must occupy less than 1% of the device's internal volume and operate within strict Specific Absorption Rate (SAR) and regulatory power limits.
• The Final Choice: Multiple distributed sub-arrays (3x) of 4-element patch antennas integrated into the phone's frame, coupled with analog beamforming ICs and advanced blockage detection algorithms.
The study also includes practical examples, problem definitions, causes, solutions, scientific and practical advice, as well as questions, answers, lessons, and expert insights in each section to ensure both scientific and practical benefits.

The evolution of mobile infrastructure in Brazil, from the 3G era to the implementation of 5G, represented one
of the most complex logistical and technical challenges for the telecommunications sector. While major carriers
are recognized by end users, specialized contractors played an essential yet often invisible role in enabling this
digital revolution. This paper analyzes the contributions of subcontracted companies in the adaptation of
antennas, equipment installation, and technical documentation, focusing on the entrepreneurial trajectory of
businessman Hélio Nogueira. The discussion emphasizes the role of technical entrepreneurship and operational
efficiency in driving Brazil’s digital transformation.

The rapid evolution of telecommunication networks is poised to have a profound impact on the complexity of future networks, promising a revolutionary leap in the field of communications. This rapid evolution necessitates the exploration of novel techniques that enable adaptive, flexible, and intelligent decision-making in resource management, orchestration and access control. One promising approach to implementing the network intelligence paradigm is through the adoption of the Network Digital Twin (NDT) paradigm, aiming at modeling the behavior of devices, communication links, operating environments, and applications within complex networking systems. The main objective of this article is to define IDLE, an Intent-based Digital twin LEarning framework that enables the possibility of performing simultaneous What-if Scenario analyses to support decision-making for real-time network management and orchestration. A proof-of-concept (POC) of the proposed architecture is described, targeted to manage horizontal offload inside a Flying Ad-Hoc Network (FANET) providing edge computing to ground devices in remote areas. Some numerical results are presented to demonstrate the gain achieved thanks to the proposed framework.

In this paper, we study the hybrid beamforming design for millimeter-wave (mmWave) massive multiple-input multiple-output (mMIMO) systems. The designing of hybrid beamforming for orthogonal frequency-division multiplexing (OFDM) systems is tasking since its analog beamforming is shared among all subcarriers. We adopt a twostep technique for designing the analog and digital beamforming separately in order to maximize the average achievable energy and spectral efficiency of frequency-selective mmWave mMIMO-OFDM systems. Firstly, the analog beamforming design is based on the viewpoint of subsystems (SS) and the goal is to optimize the array gain and radio frequency chains. Secondly, the digital beamforming design is carried out by using the regularized channel diagonalization (RCD) and block diagonalization (BD) solutions. On the other hand, the BD solution is modified for single-user. Thus, we propose the use of SS-RCD for multiuser and SS-BD for single-user hybrid beamforming designs. The solutions provide interference suppression but differ in low-SNR performance when communicating to many mobile users via data streams. Simulation results present that our hybrid beamforming design outperforms several other designs.

Dynamic Adaptive Streaming over HTTP (DASH) ensures continuous video transmission via Adaptive Bitrate (ABR) algorithms reliant on accurate throughput estimation. Existing methods often falter in unstable network conditions, impacting Quality of Experience (QoE). We address two intertwined issues in mobile HTTP video delivery. First, we present Weighted Harmonic–Exponential Averaging (WHEA), a lightweight hybrid estimator that reduces the next segment throughput prediction error compared to state-of-the-art baselines. Second, we embed WHEA within a new edge-executed adaptation framework, called Extended-EQAH, which leverages the cross-client view available at the edge to coordinate bitrate choices. Experiments on realistic LTE traces show that Extended-EQAH raises the mean quality by 10.74 % and Jain’s Fairness Index (JFI) by 10.98 % compared to its baseline schemes. In higher-variability settings using 5G traces, Extended-EQAH with WHEA yields substantially larger average relative gains about 27.73% in mean quality and 11.11% in JFI over representative baselines. These results demonstrate that combining accurate edge-side forecasting with joint buffer and throughput control is the key to robust video streaming in dynamic wireless networks.

In 5G NR, robust data delivery depends on the joint operation of retransmission mechanisms at Layer 2, specifically RLC ARQ and MAC HARQ. Two key parameters, tPollRetransmit and maxRetxThreshold, govern the RLC AM retransmission behavior. tPollRetransmit defines the timer for retransmission polling, directly affecting how quickly lost PDUs are detected, while maxRetxThreshold sets the maximum number of allowed retransmissions before declaring a radio link failure. Their configuration must be carefully aligned with MAC HARQ processes, which provide faster, physical-layer retransmissions with limited buffer capacity. Improper parameter tuning may lead to excessive retransmissions, spurious RLF triggers, or inefficient radio resource use. Conversely, well-balanced settings minimize delay, optimize packet recovery, and ensure seamless interaction between HARQ and ARQ layers. Simulation and field results indicate that throughput is maximized when RLC timers and retransmission thresholds are harmonized with HARQ round-trip times and scheduler behavior. Ultimately, the correct interplay of tPollRetransmit and maxRetxThreshold is crucial to achieving high throughput, low latency, and reliable 5G network performance.

The incorporation of Artificial Intelligence (AI) has changed the telecom industry in terms of designing, managing, and delivering services by telecom operators. As the industry gears up for 5G and looks toward 6G, AI techniques, such as machine learning, natural language processing, and predictive analytics, are being used to create more intelligent network operations, better customer experience, and more agile service delivery. Telecom operators are working with AI for automating fault detection, rescue allocation, service personalization, and revenue assurance. But on top of it, there is a new layer of challenges introduced: algorithmic transparency, data privacy, AI model biases, infrastructure readiness challenges, and the growing digital skills gap. Further complicating matters are regulatory uncertainties and the steep costs of implementation. This paper delves into how AI is being deployed across key telecom areas and the inherent technological and ethical risks it poses, then outlines future AI trends expected to shape next-generation networks. Using recent case studies, industry reports, and peer-reviewed research, the study explores AI as an enabler of operational change and as a disruptor of strategic change. Within this framework, a multi-layered approach into responsible AI adoption in telecom is proposed that tries to balance innovation and governance. This paper contains five tables and five figures (Python code-generated and conceptual diagrams) portraying the present state of applications, risk matrices, and investment trends in AI. Finally, the paper sets out a seed list of recommendations for telecom operators to scale AI-driven operations efficaciously while fortifying resilience, transparency, and accountability throughout the digital infrastructure.

8. الجيل الخامس  5G وما بعده
8.1 تطور الجيل الخامس: من  4G إلى5G  (Evolution from 4G to 5G)
لا شك أن التطور السريع في شبكات الاتصالات قد أدى إلى تحسين هائل في الأداء والكفاءة. كان الانتقال من شبكات الجيل الرابع 4G إلى شبكات الجيل الخامس خطوة رئيسية نحو دعم متطلبات التطبيقات الحديثة التي تحتاج إلى سرعات عالية وأداء متقدم. يعتبر الجيل الخامس 5G طفرة في عالم الاتصالات اللاسلكية؛ حيث يوفر سرعات تصل إلى 10 أضعاف سرعة شبكات الجيل الرابع، مع تقليل زمن الاستجابة  (Latency) ليصل إلى أقل من 1 ملي ثانية.

الفصل السابع: التطورات المستقبلية بعد UMTS
  (Future Developments Beyond UMTS)
7.1 الانتقال إلى HSPA و LTE (Transition to HSPA and LTE)
في إطار التطور المستمر في تقنيات الاتصالات اللاسلكية، ظهرت الحاجة إلى تحديث الشبكات لتلبية الزيادة الكبيرة في حجم البيانات التي يتم نقلها يوميًا عبر الإنترنت. بينما كانت تقنية UMTS تمثل قفزة كبيرة في تحسين أداء الشبكات اللاسلكية من خلال تقديم خدمات الجيل الثالث، إلا أن تزايد الطلب على البيانات عالية السرعة دفع إلى الحاجة لمعايير جديدة أكثر قدرة على تلبية هذه المتطلبات.
كان الانتقال إلى HSPA (High Speed Packet Access)  و (Long Term Evolution) LTE جزءًا من هذا التطور التكنولوجي الذي يهدف إلى زيادة السرعات وتقليل زمن الاستجابة، وتحسين القدرة على التعامل مع التطبيقات الحديثة مثل الفيديو عالي الدقة، الألعاب عبر الإنترنت، البث المباشر، والعديد من التطبيقات التي تعتمد على الإنترنت السريع.

It is often requested to get an analytical formula for the throughput (i.e. TBS (Transport Block Size)) vs. SINR, MIMO rank, and modulation order, either as drive test results or as an analytical formula.
In this white paper a common way is recommended to use the Shannon-Hartley theorem, which relates capacity to bandwidth and SINR.

3GPP Release 10 introduced advanced MIMO functionality on TM7 & TM8, to enhance the LTE performance by facilitating the beamforming or SU-MIMO Spatial Multiplexing or MU-MIMO capacity enhancements. The in-depth understanding of Transmission Mode 7 & 8 are therefore of fundamental importance for an RF planner or RF optimizer, in order to apply their benefits and advance techniques in principles.

Unlike other technical manuals and documents, this white paper emphasizes on the basic LTE TM7 & TM8 functionality, their technical details and their special performance characteristics to solve several coverage and capacity issues in a mobile network nowadays.

It contains the basic theory followed by practical implementation examples along with some useful coverage and capacity hints. Τhis white paper summarizes with an extensive reference to the techniques and peculiarities of the coverage and capacity design procedure, providing the most useful hints to the 4G and 5G planners/optimizers

It is designed to be a good guide for every RAN engineer, RAN System Architect, Antenna Technician, students and researchers on the field, Academic lecturers and PhD candidates for use in a typical LTE-A presentation. And as such it will be a good companion to each individual’s technology journey and personal endeavor.

Beamforming is the ability to adapt the radiation pattern of the antenna array to a particular direction. Following the history of antenna beamforming it has started as an analog tapper solution with phase shifters (analog tappers), adding also some kind of flexibility with a switching architecture with several phase shifters, each for a different beam pattern.
To understand beamforming we should first of all understand the technology of Uniform Linear (Dipole) Array Antennas (ULA), starting from the dipole radiation pattern.

IoT is not just a technology but it is an ideology or a concept which leads to a new age that is age of machine. IoT is the key to fully digitalize the world. Move towards IoT will revolutionise human life where machine-to-machine communication is emphasized and human interaction is minimized. IoT demands everything on internet and be controlled and managed by machine itself. The goal of this paper is to give an imagination and a Skelton of IoT. This paper also highlights the challenges in IoT implementation and other critical issues. Keywords— IoT, age of machine, smart objects, IoT challenges, automation, architecture, open loop, RFID. INTRODUCTION The term IoT was first coined by Kevin Ashton in 1992 [7]. IoT don’t have any exact or wildly accepted definition. We can explain IoT by saying that ―IoT is a network of things, where thing refers to a smart object. Objects are embedded with electronics, software, sensors, and network connectivity, which enable these objects to collect ...

This short but comprehensive white paper examines the role of Demodulation Reference Signals (DMRS) in 5G channel estimation procedures, emphasizing their function as pivotal pilot signals for difficult radio environments such as the 5G UL Non-Terrestrial Network, 5G UL NTN communication. Following 3GPP AN standards, DMRS are embedded within the 5G waveform, enabling accurate capture of instantaneous channel conditions for efficient signal demodulation (it is also called coherent demodulation). They provide the necessary framework for quantifying both time and frequency coherence, which are essential for robust channel estimation.

This paper analyzes the relationship between throughput performance and CSI Type-I feedback in 5G NR. CSI Type-I, with its coarse feedback granularity, enables reduced overhead but limits beamforming precision. We evaluate how these constraints impact spectral efficiency, highlighting the trade-off between signaling simplicity and achievable throughput in realistic deployment scenarios.

This paper investigates how CSI feedback enables gNBs to optimize beamforming in SU-MIMO and MU-MIMO scenarios. In SU-MIMO, CSI guides precoding to maximize received signal power, while in MU-MIMO it facilitates interference suppression across users. The granularity of CSI feedback (Type-I vs. Type-II) critically impacts how accurately the precoder can be constructed, influencing throughput and spectral efficiency.

Today, advances in technology bring changes to people's lifestyles, and challenging organizations to accompany these advances. Organizational managers and those responsible for the Information Technology (IT) department must evaluate current trends in innovation, and determine how they can boost business, creating new business models, and promoting competitiveness. The objective of these paper is presented a group of technological advances aimed at being the latest digital trends and changing previous trends by producing improvements or updates, the same ones that streamline processes in the field of business intelligence (BI). In this survey paper, current trends in the Internet of Things (IoT) are described, as well as topics related to 5G mobile communication, WiFi 6 technologies, the transformation of the user's technological experience, and Machine Learning (ML). In addition, the support in decision-making process will be analysed as these trends, both personally and at the business level.

In mathematical terms, extrapolation and interpolation are two methods used to estimate values that are not explicitly provided in a given set of data points. or pattern that can be extended or filled in. However, extrapolation is generally riskier than interpolation because it involves making assumptions about the behavior of data beyond the observed range. On the other hand Inference involves drawing conclusions about a population or process based on a sample. It includes estimation of parameters, hypothesis testing, and making predictions. Unlike interpolation, inference may involve uncertainty quantification and does not necessarily restrict the conclusions tobased on a sample, involving uncertainty quantification and does not necessarily restrict the conclusions to within the range of observed data.
Using C* Algebra the overall procedure can be improved with superior performance in 3GPP Release 18 and 19 SON AI/ML algorithms, specially in the CU-DU split architecture

Massive Multiple-Input Multiple-Output (mMIMO) technology represents a significant advancement in wireless communications, particularly within the realm of 5G networks. mMIMO enhances network capacity, coverage, and efficiency by leveraging a large number of antennas at the base station (BS) to simultaneously serve multiple user equipment (UE). Beamforming, a technique integral to mMIMO, directs signals to specific users, optimizing signal strength and minimizing interference. This whitepaper is a short survey for the SRS based beamforming vs. the Codebook based beamforming.

Table of Contents 1. Introduction 2. Background and Literature Review 3. Importance of SINR in CCO 4. Antenna beamwidth adjustments vs. capacity 5. Effective SINR as the main metric in 5G mMIMO environments 6. Effective SINR vs. SSB beamwidth relation 7. Effective SINR vs. SSB beamwidth and user throughput 8. Analysis and Description on the SSB beamwidth adjustments 9. Atoll simulation methodology 10. Atoll charts and use case analysis 11. Atoll simulation results and discussions 12. Cost-Benefit Analysis 13. Future Trends and Directions 14. Conclusion 15. References

This application note gives an overview of the channel estimation strategies used in orthogonal frequency division multiplexing (OFDM) systems. Section 1 describes the protocols associated with OFDM systems and the problems posed by such systems. Section 2 through Section 5 describe the various types of channel estimation methods for use in such systems. The implementation complexity and system performance of the methods are studied and compared in Section 6, measuring performance in terms of symbol error rate (SER).

This paper reviews, discusses, and compiles the works which have not been cited often by other authors, and attempts to give a complete overview of the nutritional and other solutions to counter exposure to wireless radio frequencies and fortify the immune system to mitigate the detrimental effects of radio frequency exposure.

This research work was aimed at determining the seasonal variation of 5G network signal speed and Signal strength over Abuja, North-Central Nigeria. The research involved the measurement of 5G network signal download and upload speeds, the ping and the Reference Signal Received Power (RSRP) in both rainy season and dry season months of 2024, from July 1 to December 31, 2024. The measurements were taken every hour daily from 8:00 am-6:00 pm in a particular experiment site using Speedtest software and Netmonitor application installed on a laptop computer and Infinix Android phone with a Simard of a particular network service provider in Nigeria. The results showed that there were variations in the speed of the download and the upload of the 5G network as well as the signal strength in the study area hourly and seasonally. It was concluded from the results that the average 5G signal strength was higher in dry season compared to the signal strength in rainy season, given that the average RSRP values in dry season and rainy season were-107.9 dBm and-110.3 dBm respectively. It was recommended that the effect of some atmospheric components like rainfall, pressure, temperature on the 5G network signal over Abuja be investigated in future works as they may have some influences on 5G signal in addition to the ping as discovered in this work. This study will inform the infrastructural development strategies and resource allocations in Abuja and other areas.

The International Electrotechnical Commission (IEC) develops and validates methods for assessing radio frequency electromagnetic field (RF EMF) exposure due to base stations (BS). When the assessment is performed in-situ, it is recommended to extrapolate the maximum level of exposure from measurement of stable signals, such as broadcast signal with BS of the 5 th generation (5G) of mobile communication systems (gNodeB). A comparative statistical analysis of extrapolation methods based on nominal antenna pattern (as measured in an anechoic chamber) and effective antenna pattern (as measured in scattering environment) of gNodeB is presented in this paper. This theoretical analysis shows that extrapolation with nominal antenna pattern may lead to significant overestimation of the maximum RF EMF exposure (up to 5.4 dB) in case of scattering environment or non-line-of-sight (NLOS) conditions. This overestimation is expected to be reduced by using effective antenna pattern in order to better represent the actual propagation conditions, such as those found in urban or dense urban areas. Therefore, it is recommended to perform extrapolation of the maximum exposure based on joint modeling of antenna beam pattern and representative value of the angular spread (AS) for the targeted deployment conditions. This conclusion was obtained from the observed consistence between two different approaches for determination of effective antenna gain. The first approach assumes statistical simulations with full three-dimensional (3D) channel model, especially distribution function of AS. The second approach enables simpler calculation of the effective antenna gain in scattering environment or NLOS conditions by considering only representative values from the full range of AS distribution function. The proposed simple method, if used with representative realistic values of AS, could reduce overestimation of RF EMF exposure resulting from an extrapolation factor based on nominal antenna gains of broadcast and traffic beams.

The International Electrotechnical Commission (IEC) develops and validates methods for assessing radio frequency electromagnetic field (RF EMF) exposure due to base stations (BS). When the assessment is performed in-situ, it is recommended to extrapolate the maximum level of exposure from measurement of stable signals, such as broadcast signal with BS of the 5 th generation (5G) of mobile communication systems (gNodeB). A comparative statistical analysis of extrapolation methods based on nominal antenna pattern (as measured in an anechoic chamber) and effective antenna pattern (as measured in scattering environment) of gNodeB is presented in this paper. This theoretical analysis shows that extrapolation with nominal antenna pattern may lead to significant overestimation of the maximum RF EMF exposure (up to 5.4 dB) in case of scattering environment or non-line-of-sight (NLOS) conditions. This overestimation is expected to be reduced by using effective antenna pattern in order to better represent the actual propagation conditions, such as those found in urban or dense urban areas. Therefore, it is recommended to perform extrapolation of the maximum exposure based on joint modeling of antenna beam pattern and representative value of the angular spread (AS) for the targeted deployment conditions. This conclusion was obtained from the observed consistence between two different approaches for determination of effective antenna gain. The first approach assumes statistical simulations with full three-dimensional (3D) channel model, especially distribution function of AS. The second approach enables simpler calculation of the effective antenna gain in scattering environment or NLOS conditions by considering only representative values from the full range of AS distribution function. The proposed simple method, if used with representative realistic values of AS, could reduce overestimation of RF EMF exposure resulting from an extrapolation factor based on nominal antenna gains of broadcast and traffic beams.

The LTE (Long-Term Evolution) eMBMS (evolved Multimedia Broadcast Multicast Service) technology employed in MBSFNs (Multicast Broadcast Single Frequency Networks) has been shown to be capable of considerably increasing the capacity of serving public safety users under group communication scenarios. However, due to its own limitations, a more fine-tuned scheduling approach is needed in order to fully utilize the strengths of eMBMS multicast. In this work, we first identify and analyze several overlooked challenges for scheduling multicast traffic in MBSFNs. Then we develop an effective and efficient dynamic scheduling algorithm for eMBMS multicast in time and frequency varying channel. The proposed algorithm leverages the advantages of both multicast and unicast schemes via user grouping; and through extensive simulations, is shown to be capable of significantly enhancing the mission critical performances under both best effort and guaranteed bit rate delivery models. We also show the resiliency of our proposed algorithm by applying it onto various network and user deployment scenarios. Our consistent results further prove that LTE eMBMS in MBSFN is a key solution in overcoming limitations in near future public safety networks.

The 5G mobile communication cellular networks are expanding rapidly. With the quick development of several new services and mobile applications, there is an anticipated consumption of frequency and bandwidth resources in the upcoming cell phone networks. Therefore, networks suffer from low speed and high latency. Corporative Non-Orthogonal Multiple Access (C-NOMA) is an approach method to meet the various needs of improved user fairness, high reliability, high spectral efficiency (SE), extensive connectivity, raising data rates, high flexibility, low transmission latency, massive connectivity, low delay, higher cell-edge throughput, and superior performance. This paper mainly focuses on power-domain (PD-NOMA), which employs successive interference cancellation (SIC) at the receiver and superposition coding (SC) at the transmitter. Also, this paper compares C-NOMA, NOMA, and OMA for different types of environmental fading. This paper shows how NOMA performance can be improved when combined with numerous confirmed wireless communication network strategies, including cooperative C-NOMA system communications, with the help of optimization. The simulation results demonstrated enhancements in cooperative NOMA compared to non-cooperative NOMA and OMA with the help of MATLAB and NYUSIM simulations. The results also demonstrated that the improvement is valid with the increase in bandwidth frequency signal spectrum for the varying near and far user distances.

A low cost miniaturized ultra-wideband (UWB) microstrip antenna with dual notched band for X band and aeronautical radio navigation (ARN) is presented in this article. The antenna (19×25 mm 2 ) is composed of a half-circular ring as a radiation patch with an incomplete ground plane. The measured results indicate a fractional bandwidth of 112% for 𝑆 11 ≤ -10dB between 3 to 10.6 GHz. The dual notched band has been achieved by incorporating window shaped microstrip closed ring resonators at the rear surface of the designed structure. The first notch band is centered at 7.5 GHz (7-8.1 GHz) to reject interference with X-band downlink (7.25 to 7.74 GHz) and second band centered at 9.1 GHz (8.6-9.4 GHz) to reject interference with ARN (8.7 to 9.2 GHz). The simulated and measured return loss, radiation pattern, and gain shows good agreement which confirms the applicability of the designed antenna for the intended UWB applications.

In this paper, we consider an indoor visible light communication (VLC) system with multiple "white" light emitting diodes serving to form overlapping wireless communication cells. In order to maintain seamless connectivity to mobile users, a handover procedure should be implemented. In particular, practical conditions such as blockages due to obstacles inside the room environment and the mobility of users can affect direct VLC connectivity. The use of reconfigurable intelligent surfaces (RISs) in optical wireless systems allows to exploit non-direct connectivity links, thus providing efficient communication links. In this paper, we present a proactive handover mechanism that exploits the presence of a RIS, in order to redirect the communication links in case of blockages. The proposed approach has been implemented both in hard and soft modes and assessed in terms of achievable data rate and handover latency for a user walking in a given reference room at different user speeds and blockage conditions. Our presented results and comparisons with conventional handover methods (i.e., without RIS) are helpful in showing the superiority of the presented algorithm.

The swift advancement of networking technologies has given rise to Network Function Virtualization (NFV) as a promising avenue for enriching network adaptability, scalability, and cost efficiency. This article delves deeply into the essential endeavour of appraising the effectiveness of NFV infrastructure and drawing a parallel with conventional hardware-based networks. Through the utilization of the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method, the primary objective of this study is to identify possible bottlenecks and prospects for enhancement within both approaches. In recent times, NFV has garnered substantial attention owing to its capability to uncouple network functions from dedicated hardware, allowing their operation within virtualized environments. While this shift offers agility and economic advantages, it simultaneously introduces intricacies necessitating meticulous performance evaluation. On the other hand, traditional hardwarebased networks, while tried and assessed, may encounter constraints in promptly acclimating to dynamic requisites. As a result, an all-encompassing assessment framework becomes indispensable to accurately assess the genuine potential of NFV infrastructure. A robust research approach is utilized in this study, characterized by a quantitative analysis framework. Key performance indicators such as latency, throughput, resource utilization, and scalability are assessed and contrasted between Network Function Virtualization (NFV) infrastructure and conventional hardware networks. The Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) methodology is implemented to pinpoint performance limitations and potential enhancement zones within both paradigms. Evaluation and Alternate parameters taken as in this study, Scalability, Resource Utilization, Latency, and Energy Consumption serve as assessment parameters, while contrasting Traditional Hardware, NFV with Software Acceleration, NFV with GPU Acceleration, NFV with FPGA Acceleration, and Cloud-based NFV configurations. The results presented in the evaluation demonstrate the effectiveness of different Network Function Virtualization (NFV) alternatives using the TOPSIS method. NFV with GPU Acceleration emerges as the top-performing choice, closely followed by NFV with FPGA Acceleration. These alternatives exhibit superior proximity to the ideal solution, as indicated by their high Closeness Coefficient (Ci) values and top ranks. NFV with Software Acceleration ranks third, showcasing favorable performance. Cloud-based NFV and Traditional Hardware secure lower ranks, implying comparatively less optimal performance. The Closeness Coefficient values and ranks provide a clear and concise basis for decision-making, guiding the selection of NFV alternatives with greater alignment to desired outcomes.

Due to the vertiginous increase of the electromagnetic emissions of the modern communication systems and to the affected population's concern, it becomes necessary a more exhaustive control of this type of contamination. There are available different measure devices that make a characterization of the received emissions, but most does not discriminate between the contributions from different systems. Therefore, you cannot identify the systems responsible for the excessive measured levels. Of all the studied devices, the one that better it fulfils the expectations it is the spectrum analyzer, that it allows to characterize the received emissions, separating the different bands of the spectrum, and isolating the frequencies that don't perform the existent norm. To control the spectrum analyzer we have developed a software program that makes the measures according to the procedure exposed in the standard. Finally, another program processes and it represents the results of the measures. In addition, this application can calculate the theoretical level of radiation of different communication systems by simulation approximations and then, to compare with the measurement levels and with the reference level.

In recent years, the use of unmanned aerial vehicles (UAVs), commonly known as drones, has significantly surged across civil, military, and commercial sectors. Ensuring reliable and efficient communication between UAVs and between UAVs and base stations is challenging due to dynamic factors such as altitude, mobility, environmental obstacles, and atmospheric conditions, which existing communication models fail to address fully. This paper presents a multi-ray channel model that captures the complexities of the airspace network, applicable to both ground-to-air (G2A) and air-to-air (A2A) communications to ensure reliability and efficiency within the network. The model outperforms conventional line-of-sight assumptions by integrating multiple rays to reflect the multipath transmission of UAVs. The multi-ray channel model considers UAV flights’ dynamic and 3-D nature and the conditions in which UAVs typically operate, including urban, suburban, and rural environments. A technique that calculates the received power at a target UAV within a networked airspace is also proposed, utilizing the reflective characteristics of UAV surfaces along with the multi-ray channel model. The developed multi-ray channel model further facilitates the characterization and performance evaluation of G2A and A2A communications. Additionally, this paper explores the effects of various factors, such as altitude, the number of UAVs, and the spatial separation between them on the power received by the target UAV. The simulation outcomes are validated by empirical data and existing theoretical models, providing comprehensive insight into the proposed channel modelling technique.