Telecom, Volume 6, Issue 2 (June 2025) – 9 articles

Free space optics (FSOs) is an emerging technology offering solutions for secure and high data rate transmission in dense urban areas, back haul link in telecommunication networks, and last mile access applications. It is important to investigate the performance of the FSO link as a result of aggregate attenuation caused by different weather conditions in a region. In the present work, empirical models have been derived in terms of visibility, considering fog, haze, and cloud conditions of diverse geographical regions of Delhi, Washington, London, and Cape Town. Mean square error (MSE) and goodness of fit (R squared) have been employed as measures for estimating model performance. The dual polarization-quadrature phase shift keying (DP-QPSK) modulation technique has been employed with hybrid mode and the wave division multiplexing (MDM-WDM) scheme for analyzing the performance of the FSO link with two Laguerre Gaussian modes (LG00 and LG 01) at 5 different wavelengths from 1550 nm to 1554 nm. The performance of the system has been analyzed in terms of received power and signal to noise ratio with respect to the transmission range of the link. Minimum received power and SNR values of −52 dBm and −33 dB have been obtained over the observed transmission range as a result of multiple impairments. Random forest (RF), k-nearest neighbors (KNN), multi-layer perceptron (MLP), gradient boosting (GB), and machine learning (ML) techniques have also been employed for estimating the SNR of the received signal. The maximum R squared (0.99) and minimum MSE (0.11), MAE (0.25), and RMSE (0.33) values have been reported in the case of the GB model, compared to other ML techniques, resulting in the best fit model. Full article

It is well known that existing empirical models cannot fit perfectly into environments other than those they were formulated in due to differences in terrain and climate. The Okumura–Hata family of models are gaining acceptability over the VHF/UHF channels. However, it is imperative to investigate their reliability and to use the one most suited to each environment. This study investigated the reliability of the Okumura–Hata, COST-231, ECC-33, and Ericsson models over digital UHF channels in Ikorodu and Akure, Southwestern Nigeria. The drive test protocol was used for data collection at intervals of 1 km along different routes from the experimental stations up to maximums of 10 and 16 km in Ikorodu and Akure, respectively. This was carried out for both wet and dry season months using a digital Satlink meter with a spectrum (WS-6936), GPS Map 78s and a field vehicle. The uniqueness of this study is that it used real-world data with a seasonal scope, and the mean values were employed in the analysis to strengthen the reliability of the results. The measured path loss (MPL) and predicted path loss (PPLM) were computed, with error margin analysis carried out between them. The results reveal a mean MPL of 110.42 dB in Ikorodu, while the PPLMs were 121.90, 123.55, 158.42, and 291.01 dB for the Hata, COST-231, Ericsson, and ECC-33 models, respectively. In Akure, the mean MPL was 123.157 dB, while the PPLMs were 121.922, 130.179, 198.979, and 313.494 dB. The results further indicate that the Hata model had the best performance with the lowest RMSE of 10.812 in Ikorodu, while COST-231 had the best performance in Akure, with the lowest RMSE of 9.877. The optimized Hata and COST-231 models were developed with improved RMSEs of 5.895 and 7.815 for the Ikorodu and Akure environments, respectively. The optimized models had higher degrees of reliability and will provide a valuable approach to wireless communication planning in tropical urban and suburban environments for achieving quality of transmission and reception (QoTnR) over UHF channels in Nigeria and similar environments in Africa. Full article

As the discussions on sixth-generation (6G) wireless networks progress at a rapid pace, various approaches have emerged over the last few years regarding new architectural concepts that can support the 6G vision. Therefore, the goal of this work is to highlight the most important technological efforts in relation to the definition of a 6G architectural concept. To this end, the primary challenges are first described, which can be viewed as the driving forces for the 6G architectural standardization. Afterwards, novel technological approaches are discussed to support the 6G concept, such as the introduction of artificial intelligence and machine learning for resource optimization and threat mitigation, cell-free deployments, and novel physical layer techniques to leverage high data rates. In the same context, open-access protocols for flexible resource integration, security, and privacy protection in the 6G era, as well as the digital twin concept, are discussed as well. Finally, recent research efforts are analyzed, with an emphasis on the combination of the aforementioned aspects towards a unified 6G architectural approach. To this end, limitations and open issues are highlighted as well. Full article

In this paper, we present recent advancements in transmitter and receiver technologies for Optical Wireless Communication (OWC). OWC offers very wide license-free optical spectrum which enables very high capacity transmission. Additionally, beam-steered OWC is more power-efficient and more secure due to low divergence of light. One of the main challenges of OWC is wide angle transmission and reception because law of conservation of etendue restricts maximization of both aperture and field of view (FoV). On the transmitter side, we use Micro Electro-Mechanical System cantilevers activated by piezoelectric actuators together with silicon micro-lenses for narrow laser beam steering. Such design allowed us to experimentally demonstrate at least 10 Gbps transmission over 100° full angle FoV. On the receiver side, we show the use of photodiode array, and Indium-Phosphide Membrane on Silicon (IMOS) Photonic Integrated Circuit (PIC) with surface grating coupler (SGC) and array of SGC. We demonstrate FoV greater than 32° and 16 Gbps reception with photodiode array. PIC receiver allowed to receive 100 Gbps WDM with single SGC, and 10 Gbps with an array of SGC which had 8° FoV in the vertical angle and full FoV in the horizontal angle. Our results suggest that solutions presented here are scalable in throughputs and can be adopted for future indoor high-capacity OWC systems. Full article

The Internet plays a vital role in the exchange of information in society. Maintaining the security and robustness of the Internet anomaly detection in Border Gateway Protocol (BGP) traffic is very important so that stable routing services can be ensured. The existing solutions are based on the classical machine learning (ML) models, which need to be advanced. In this study, a revolutionary technique that utilizes the Extreme Learning Machine (ELM) to enhance the detection of anomalies in the dynamic environment of the Border Gateway Protocol (BGP), particularly when faced with highly imbalanced class distributions, was used. The combination of imbalanced class distribution and BGP’s dynamic nature often leads to the suboptimal performance of classifiers. Our proposed solution aims to address this imbalance issue by dividing the dominant classes into multiple sub-classes. This division is achieved through optimal partitioning (OP), which involves segmenting the samples from the majority class into different segments to approximate the size of the minority class. As a result, diversified classes are created to train the ELM classifier. In order to assess the effectiveness of the proposed (OP-ELM) model, the RIPE and BCNET datasets were utilized. These trace files were processed using MATLAB to extract and organize the necessary features, thereby generating suitable datasets for analysis, which are referred to as Dataset-1 and Dataset-2. The experimental findings exhibit noteworthy improvements in performance when contrasted with prior methodologies, thereby highlighting the efficacy of our innovative approach in tackling the obstacles associated with anomaly detection in BGP networks. Full article

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

The potential consequences of interference on communication networks are one of the main challenges in the nature and efficiency of wireless communication links. The interruption is seen as additional noise to the device, which can have a major impact on the efficiency of the connection. The rapid expansion of broadband wireless networks and the increasing congestion of the radio frequency spectrum due to shared usage by terrestrial and satellite networks have heightened concerns about potential interference. To optimize spectrum utilization, multiple terrestrial and satellite networks often coexist within the same frequency bands allocated for satellite communications services. Spectrum interference in wireless networks is a topic of much interest in the current scenario as it can present a lot of challenges. This article provides a critical review of the coexistence and spectrum sharing in wireless networks. Along with this, mitigation techniques to avoid interference have also been discussed in detail. The article aims to give a detailed discussion on the challenges and opportunities in this field by reviewing significant recent works in this field. Full article

The design of wideband multi-port multiple-input multiple-output (MIMO) antennas and their optimization are very important for next-generation smartphones with the increase in massive connectivity. This paper offers the design, simulation, measurement, and specific absorption rate (SAR) analysis of a Pi-shaped ten-element MIMO antenna system for use in the upper mid-band, covering LTE 46 (5.15–5.925 GHz), LTE 47 (5.855–5.925 GHz), and n102 (5.925–6.425 GHz), thus meeting a good fractional bandwidth of 32.7% with a maximum peak gain of 2.89 dBi. Hence, it is well suited for high-isolation (<−10 dB), compactness, and wideband (4.7–6.5 GHz) applications suitable for the current communication system needs. The overall size of the proposed system is 125 mm × 70 mm, with a planar dielectric material Rogers RT/5880. Designing the proposed antenna with multiple units entails the preservation of the spatial features of the antenna alongside the reduction of the mutual coupling for adjacent elements by using a decoupling structure. Due to the high accuracy of the positioning elements and precise geometric transformations, the antenna system provides high-performance analysis based on reflection coefficients, radiation patterns, and each antenna’s averaged efficiency values (76.12–91.57%). Full article

Advances in telecommunications and artificial intelligence (AI) are reshaping modern educational spaces. Drawing upon diverse resources, this systematic literature review examines how these new advances including 5G, Internet of Things (IoT), and AI-based analytics can transform conventional classrooms into adaptive, secure, and highly interactive environments. Real-time data collection and personalized feedback systems are found to significantly enhance engagement and accessibility for diverse learner populations. Furthermore, emerging security architectures, such as zero-trust frameworks and AI-driven intrusion detection, mitigate cyber threats and strengthen data confidentiality. Nevertheless, it is found that broader adoption is limited due to practical hurdles, which include budget allocation, professional development, and regulatory compliance. In response, strategic recommendations are provided to guide the planning and implementation of intelligent telecommunications in different educational contexts while noting the need for responsible data governance and equitable access. By illustrating how AI-assisted connectivity can enhance personalized instruction while safeguarding learner privacy, this study offers a forward-looking perspective on modern pedagogical approaches which can balance technological innovation with ethical considerations. Full article