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A novel-shaped THz MIMO antenna with high bandwidth for advanced 6G wireless application

10.12928/telkomnika.v23i4.26559
Kamal Hossain; Daffodil International University Nahin , Jamal; Daffodil International University Hossain Nirob , Md. Ashraful; Daffodil International University Haque , Narinderjit Singh; INTI International University Sawaran Singh , Redwan Al Mahmud; Daffodil International University Bin Asad Ananta , Md. Kawsar; Daffodil International University Ahmed , Md. Sharif; Daffodil International University Ahammed , Liton; Pabna University of Science and Technology Chandra Paul
This article presents an industrial and innovation highly efficient drone shaped slotted graphene-based multiple input multiple output (MIMO) antenna with improved isolation, designed for high-speed short-range communication, video rate imaging, medical imaging, and explosive detection in the THz band. The proposed antenna is constructed on an 88×244 μm2 polyimide substrate. Key performance parameters such as reflection coefficient, gain, directivity, radiation pattern, and antenna efficiency are evaluated at the resonating frequencies of 1.7 THz, 3.35 THz, and 5.31 THz, covering a wide bandwidth of 4.88 THz with a reflection coefficient of less than -10 dB. The antenna achieves a maximum gain of 13.92 dB and a radiation efficiency of 95.77% within the resonating band. The MIMO design parameters include an envelope correlation coefficient (ECC) of 0.00015, a diversity gain (DG) of 9.9992, and an isolation of less than -31.55 dB between its elements across the entire bandwidth. The outcomes from CST simulations were verified by designing and simulating a similar resistance-inductance-capacitance (RLC) circuit in advanced design system (ADS), with both simulators producing comparable reflection coefficients. These features underscore the potential of the proposed antenna, utilizing simulations and an equivalent RLC circuit model, as a robust candidate for THz band applications in 6G wireless communication.
Volume: 23
Issue: 4
Page: 847-856
Publish at: 2025-08-01

Energy scavenging-aided NOMA uplink communications: performance analysis

10.12928/telkomnika.v23i4.26822
Huu; Industrial University of Ho Chi Minh City Q. Tran , Khuong; Ho Chi Minh City University of Technology (HCMUT) Ho-Van
Energy scavenging-aided nonorthogonal multiple access (NOMA) networks significantly ameliorate energy-and-spectral efficiencies thanks to superimposing a multitude of user signals for concurrent transmission and harvesting radio frequency energy. Practically, energy harvesters possess non-linear characteristic and their efficiency is enhanced considerably with deployment of multiple antennas. Moreover, communication reliability and harvested energy are directly influenced by wireless propagation which induces simultaneous effects of shadowing, path loss, and fading. Accordingly, the current paper assesses analytically outage probability and throughput of energy scavenging (ES)-aided NOMA uplink communications (eNOMAu) taking into account the above-addressed realistic factors (κ − µ shadowed fading, multi-antenna deployment, ES nonlinearity). The results reveal considerable performance degradation caused by ES non-linearity and wireless propagation. Additionally, desired system performance can be reached flexibly with appropriate specification selection. In addition, accreting a quantity of antennas drastically mitigates the outage probability of eNOMAu, which can be minimized with optimal ES time selection. Furthermore, the proposed eNOMAu is considerably superior to its eOMAu counterpart.
Volume: 23
Issue: 4
Page: 918-931
Publish at: 2025-08-01

Modified electro-optical modulator based bipolar optical code division multiple access for free-space optics

10.12928/telkomnika.v23i4.26727
Eddy; Universitas Kristen Krida Wacana Wijanto , Kevin; Universitas Kristen Krida Wacana Sutanto
This study introduces a modified electro-optical modulator (EOM) to enhance bipolar optical code division multiple access (OCDMA) in free-space optical (FSO) communication. The proposed system improves signal quality, spectral efficiency, and resilience to atmospheric turbulence. Unlike conventional dual EOM techniques, the modified EOM enables simultaneous transmission of ‘0’ and ‘1’ chip values, reducing multiple access interference (MAI) and enhancing system robustness. This approach optimizes bandwidth utilization and ensures stable performance in varying environmental conditions. Simulations were conducted in an additive white Gaussian noise (AWGN) channel using three spectral amplitude coding (SAC) schemes: modified M sequence, Walsh-Hadamard, and random diagonal (RD) codes. Results indicate that the modified EOM scheme significantly improves FSO system performance, achieving an average 47.1% lower minimum log of bit error rate (BER) in normal weather and 43.3% lower in extreme weather, ensuring superior noise suppression and signal integrity across varying environmental conditions. Additionally, the system maintains superior performance over longer distances, demonstrating its suitability for high-speed, long-range FSO applications. These findings highlight the potential of the modified EOM based bipolar OCDMA system in advancing next-generation optical wireless networks, offering a more efficient, interference-resistant, and high-capacity communication solution for future technologies such as 6G and beyond.
Volume: 23
Issue: 4
Page: 857-870
Publish at: 2025-08-01

An extensive framework for assessing the quality of websites

10.12928/telkomnika.v23i4.26374
Sasi; CMR College of Engineering and Technology Bhanu Jammalamadaka , Bala Krishna; MLR Institute of Technology Kamesh Duvvuri , Sastry Kodanda; Koneru Laksmaiah Education Foundation University Rama Jammalamadaka , Vishnu; Koneru Laksmaiah Education Foundation University Priya Biyyapu
The quality of the website is quite important in generating customer satisfaction and loyalty. A website’s quality depends on several factors, features, and characteristics. Several computational methods are necessary to evaluate the quality of each factor and subsequently determine the overall quality of the entire website. Each factor does not contribute to the same level of quality required by the end users and thus requires a weighting system. Expert systems, which are either manually defined or learnt using artificial intelligence (AI), are to be modelled for assessing the quality of a factor/sub-factor or characteristics of a sub-factor. The quality of a website varies depending on the context. Context-based quality assessment of the websites is required. There is a need to generate example sets to assess the quality of websites and to establish relationships between web-related quality factors, subfactors, and characteristics. In this paper, a comprehensive framework is presented that caters to parametric structure building and mapping, parsers for computing characteristic values, context assessment, building expert systems, and learning models for assessing the quality of websites and weighing the factors that have specific significance on the quality of the website.
Volume: 23
Issue: 4
Page: 986-999
Publish at: 2025-08-01

Grid search vs Bayesian optimization for intensity scoring classification and channel recommendation prediction

10.12928/telkomnika.v23i4.26341
Kelly; Universitas Multimedia Nusantara Mae , Dinar; Universitas Multimedia Nusantara Ajeng Kristiyanti
Technological advancement has spurred financial technology growth, transforming traditional financial operations into digital. Peer-to-peer (P2P) lending is a key fintech solution offering online loans, though it struggles with repayment issues due to customer financial instability. To overcome these challenges, XYZ is a startup that focuses on enhancing the efficiency of collections and communication with customers. XYZ necessitates the implementation of a collection intensity scoring (CIS) model and a prediction model for interaction on recommended communication channels in order to optimize the collection process. This study evaluates the performance of grid search and Bayesian optimization on random forest (RF) classification models and K-nearest neighbors (KNN) regressor prediction models. RF and KNN regressor algorithms optimization are necessary to enhance their performance in CIS classification and channel recommendation prediction. The research stages follow the cross industry standard process-data mining (CRISP-DM) framework, which consists of business understanding, data understanding, data preparation, modeling, and evaluation. The model performance is assessed by accuracy and mean absolute error (MAE). The results of this study show that Bayesian optimization surpasses grid search, enhancing the accuracy of the RF model to 98.34% and reducing the MAE of the KNN regressor model to 0.24530.
Volume: 23
Issue: 4
Page: 1020-1031
Publish at: 2025-08-01

Design of a soft circular patch antenna operating in the 60 GHz band for 5G/6G applications

10.12928/telkomnika.v23i4.26722
Salah-Eddine; Sidi Mohamed Ben Abdellah University Didi , Imane; LSEED Laboratory Halkhams , Abdelhafid; Sidi Mohamed Ben Abdellah University Es-Saqy , Mohammed; Sidi Mohamed Ben Abdellah University Fattah , Said; Sidi Mohamed Ben Abdellah University Mazer , Moulhime; Sidi Mohamed Ben Abdellah University El Bekkali
5G/6G technologies require higher-performance antennas in terms of bandwidth, gain, radiation, compact size, efficiency, and low cost. At the same time, fewer natural disturbances, such as rain and snow, and fewer non-natural disturbances. This is the challenge facing scientific research into antenna design and manufacture. In addition, in this paper we study and design a flexible circular microstrip patch antenna operating in the 60 GHz band for 5G/6G applications. This antenna is based on a biosourced substrate for industrial, scientific, and medical applications. For this study, we will use two techniques: one concerns the deformation of the ground plane deformation of the ground plane and substrate to improve the electrical performance of a proposed antenna. At the same time, the other is the parametric study of the appropriate position of a coaxial feed probe. This technique has the advantage of requiring no radiation contrition on the part of the coaxial probe. Next, specialized high-frequency structure simulator (HFSS) simulation software is used to design this antenna; it has a wide bandwidth above 3 GHz, a gain of 7.41 dB, a directivity of 7.53 dB, a radiated power of 13.55 dBm, an accepted power of 13.67 dBm, an incident power of 15.08 dBm, a radiation efficiency of 97.29 % and an efficiency of 98.4 %.
Volume: 23
Issue: 4
Page: 1120-1127
Publish at: 2025-08-01

Enhancing realism in hand-drawn human sketches through conditional generative adversarial network

10.12928/telkomnika.v23i4.26856
Imran; REVA University Ulla Khan , Depa Ramachandraiah; REVA University Kumar Raja
This research focuses on enhancing the realism of hand drawn human sketches through the use of conditional generative adversarial networks (cGAN). Addressing the challenge of translating rudimentary sketches into highfidelity images, by leveraging the capability of deep learning algorithms such as cGANs. This is particularly significant for applications in law enforcement, where accurate facial reconstruction from eyewitness sketches is crucial. Our research utilizes the Chinese University of Hang Kong Face Sketches (CUFS) dataset, a paired dataset of hand drawn human faces sketches and their corresponding realistic images to train the cGAN model. Generator network produces realistic images based on input sketches, where as discriminator network evaluates authenticity of these generated images compared to the real ones. The study involves careful preprocessing of the dataset, including normalization and augmentation, to ensure optimal training conditions. The model performance assessed through both quantitative metrics, such as frechet inception distance (FID), and qualitative evaluations, including visual inspection of generated images. The potential applications of this research extend to various fields, such as agencies of law enforcement for finding suspects and locating missing persons. Future work exploring advanced techniques for further realism, and evaluating the model’s performance across diverse datasets.
Volume: 23
Issue: 4
Page: 976-985
Publish at: 2025-08-01

An IoT-based approach for microclimate surveillance in greenhouse environments

10.11591/ijict.v14i2.pp717-727
Irfan Ardiansah , Sophia Dwiratna Nur Perwitasari , Roni Kastaman , Totok Pujianto
As the demand for efficient and cost-effective greenhouse microclimate surveillance has increased, we developed a microclimate surveillance system using microcontroller technology that automatically collects temperature and relative humidity data and transmits it to a cloud server for remote surveillance and data analysis. 1971 microclimate data points were acquired over a 20-day evaluation period, providing insights into greenhouse environmental conditions with a negative linear regression between air temperature and relative humidity within the greenhouse and an R-squared of 0.73. This illustrates the system’s ability to record and quantify environmental conditions data. Additionally, we derived a predictive model to manage microclimate conditions using the regression formula y = -6.12X + 238.33, where X represents the air temperature and y represents the relative humidity. All the results show that the acquired data can be used to make decisions to optimize plant growth. The prototype we developed can be an alternative option for small and medium-sized farms that need a greenhouse surveillance system to improve operational efficiency and reduce surveillance costs. The system can be further developed by implementing additional sensors to monitor light intensity, wind speed, or soil moisture and further data analysis models to optimize greenhouse management.
Volume: 14
Issue: 2
Page: 717-727
Publish at: 2025-08-01

Energy-efficient certificateless signcryption for secure data transfer in wireless sensor networks

10.12928/telkomnika.v23i4.26241
Paruvathavardhini; Avinashilingam Institute for Home Science and Higher Education for Women Jaganthan , Sargunam; Avinashilingam Institute for Home Science and Higher Education for Women Balusamy
Wireless sensor networks (WSN) have gained high popularity in the realm of technological innovation and have a prime responsibility of transferring the data safely to the sink despite the vulnerable situation presiding around the network. There needs to be a compromise made between energy consumption and the intricate network security system because they are inversely correlated. To create a safe and effective data transfer between the communicating nodes, a new censored regressive jaccard indexed certificateless signcryption (CEJICS) technique is suggested. Initially, the Gaussian likelihood censored regression is applied to identify the energy efficient node which supports enhancing the network lifetime. The security is implemented using the rabin cryptographic jaccard indexive certificateless signcryption (RCJICS). To create a signcryption system with the characteristics of digital signature and ciphertext authenticity, the proposed work focuses on certificateless cryptography. The NS-2 simulator is used for the simulation, and performance metrics are used to evaluate it. According to the observed quantitative results, the suggested CEJICS method outperforms the other conventional methods by improving the packet delivery ratio (PDR) by 93%, achieving a minimum drop of 7%, reducing delay by 22%, reducing overhead to 17%, minimizing energy consumption by 15%, and ultimately extending the network lifetime by 10%.
Volume: 23
Issue: 4
Page: 1084-1096
Publish at: 2025-08-01

Graphene-based high-gain MIMO antenna for enhanced 6G wireless communication systems

10.12928/telkomnika.v23i4.26568
Narinderjit Singh; INTI International University Sawaran Singh , Md. Ashraful; Daffodil International University Haque , Jamal; Daffodil International University Hossain Nirob , Kamal; Daffodil International University Hossain Nahin , Md. Kawsar; Daffodil International University Ahmed , Md. Sharif; Daffodil International University Ahammed , Redwan; Daffodil International University A. Ananta , Liton; Pabna University of Science and Technology Chandra Paul
This paper presents a novel design and analysis of a high-performance multiple-input multiple-output (MIMO) terahertz (THz) antenna intended for next-generation sixth-generation (6G) wireless communication systems. The proposed antenna operates over a wide frequency range of 1 THz to 4.9 THz, achieving a broad bandwidth of 3.9 THz with three distinct resonant frequencies at 2.05 THz, 3.9 THz, and 4.52 THz, each exhibiting excellent return loss characteristics. The antenna features a graphene-based patch with a copper ground plane, etched on a polyimide substrate with a dielectric constant (εr) of 3.5 and a thickness of 10 micrometers (μm). Key performance metrics, including a high gain of 15.9 decibels (dB), an efficiency of 95.95%, an envelope correlation coefficient (ECC) of 0.0005, and a diversity gain (DG) of 9.997 dB, indicate outstanding performance. The measured isolation between the two antenna elements is -31.91 dB, signifying excellent isolation. An equivalent resistor-inductor-capacitor (RLC) circuit model is developed using advanced design system (ADS), validated by comparing S11 results from both computer simulation technology (CST) and ADS simulations. The proposed MIMO antenna’s wide operating range and robust performance demonstrates great potential for high-speed THz wireless communication, imaging, spectroscopy, sensing, and offers valuable contributions to industry and innovation.
Volume: 23
Issue: 4
Page: 837-846
Publish at: 2025-08-01

Archimides multiband micro ribbon spiral antenna for energy harvesting

10.12928/telkomnika.v23i4.25702
Edison Andrés; Metropolitan Technological Institute Zapata Ochoa , Vanessa; Metropolitan Technological Institute García Pineda , Alejandro; Universidad de Los Lagos Valencia Arias , Francisco Eugenio; Metropolitan Technological Institute López Giraldo
The current need to conserve natural resources and find new ways to advance without damaging the environment has led to the search for different energy sources. In this sense, the availability of radio frequency (RF) energy is found as a favorable option for new energy sources. This work describes the design of a microstrip antenna for the collection of radiofrequency energy in the megahertz band. Using the automatic optimization software computer simulation technology (CST) Studio, a circular spiral antenna is simulated using the low-cost FR4 substrate with a thickness of 1.57 mm and copper as the conductive material with a thickness of 0.035 mm. The proposed design presents resonance frequencies in multiple bands from 550 MHz to 1900 MHz, with bandwidths between 15 MHz and 150 MHz. The antenna design is based on the resonant cavity model and presents circular polarization due to its design coil type, with modified geometry using symmetrical orthogonal slots to generate multiple working bands. The design of this antenna can capture the power emitted by the frequency bands used in mobile telephony, radio communications, broadcasting, and television.
Volume: 23
Issue: 4
Page: 882-895
Publish at: 2025-08-01

Interoperability in healthcare: a critical review of ontology approaches and tools for building prescription frameworks

10.11591/ijict.v14i2.pp366-381
Eunice Chinatu Okon , Tshiamo Sigwele , Malatsi Galani , Tshepiso Mokgetse , Hlomani Hlomani
Efficient healthcare interoperability is pivotal for delivering high-quality patient care. This research article presents a critical review of ontology based approaches and tools in the development of ontology-based electronic prescriptions (e-prescription), with a focus on enhancing healthcare interoperability. The investigation encompasses two major domains: ontology overview and healthcare interoperability using semantic e-prescription. In the ontology overview, we scrutinize various aspects of ontology development, including the methodologies, languages, tools, and evaluation metrics adopted from literature. Notable comparisons between ontologies and databases are explored. Additionally, we delve into the challenges associated with ontology development and provide a comprehensive summary of methodologies, languages, tools, and evaluation approaches. Healthcare interoperability using semantic e-prescription undertakes a detailed review of e-prescription systems, emphasizing their critical role in healthcare interoperability. A thorough examination of frameworks facilitating semantic e-prescription is presented, offering a nuanced perspective on their contributions and limitations. The section concludes with a concise summary of the key findings from the e-prescription framework review. The article further addresses challenges in healthcare interoperability, including data standardization and system integration issues. To direct continuing research efforts that integrate cutting-edge technologies and interdisciplinary collaborations, future directions and emerging trends are outlined.
Volume: 14
Issue: 2
Page: 366-381
Publish at: 2025-08-01

Factors influencing blockchain adoption intention in Philippine small and medium enterprises

10.12928/telkomnika.v23i4.26744
Victor James; Chung Yuan Christian University C. Escolano , Wei-Jung; Chung Yuan Christian University Shiang , Alexander; Lyceum of the Philippines University A. Hernandez , Darrel; Bohol Island State University A. Cardaña
As an emerging technology, blockchain has huge potential for transforming various industries, such as small and medium enterprises (SMEs). Despite its promising impact, its application in the supply chains of SMEs in developing countries is still in its infancy. This study analyzes the key factors of blockchain adoption intention in Philippine SMEs through an integrated technology-organization-environment (TOE) and technology acceptance model (TAM) with external variables. The data were obtained through a survey of 465 SME practitioners in the national capital region (NCR), Philippines, and analyzed using partial least squares and structural equation modeling (PLS-SEM). In terms of technology dimensions, relative advantage (RLA) had a positive influence on perceived usefulness (PUS) while compatibility (COM) had a positive influence on perceived ease of use (PEU), which both subsequently led to blockchain adoption intention. As regards organization, top management support (TMS) had a significant influence on the adoption intention of blockchain among SMEs. In terms of environment, only competitive pressure (CMP) had significant influence on blockchain adoption intention. In general, most of the hypothesized relationships are significant; thus, SMEs have a positive interest in adopting blockchain technology. Finally, the study serves as baseline evidence of blockchain adoption intention among SMEs in the Philippines.
Volume: 23
Issue: 4
Page: 965-975
Publish at: 2025-08-01

Deep learning-based image super-resolution using generative adversarial networks with adaptive loss functions

10.12928/telkomnika.v23i4.26105
Hani Q.; Mutah University R. Al-Zoubi
This study investigates deep learning based single image super-resolution (SISR) and highlights its revolutionary potential. It emphasizes the significance of SISR, and the transition from interpolation to deep learning driven reconstruction techniques. Generative adversarial network (GAN)- based models, including super-resolution generative adversarial network (SRGAN), video super-resolution network (VSRResNet), and residual channel attention-generative adversarial network (RCA-GAN) are utilised. The proposed technique describes the loss functions of the SISR models. However, it should be noted that the conventional methods frequently fail to recover lost high-frequency details, which signify their limitations. The current visual inspections indicate that the suggested model can perform better than the others in terms of quantitative metrics and perceptual quality. The quantitative results indicate that the utilised model can achieve an average peak signal-to-noise ratio (PSNR) enhancement of X dB and an average structural similarity index (SSIM) increase of Y. A range of improvements of 7.12-23.21% and 2.75-10.00% are obtained for PSNR and SSIM, respectively. Also, the architecture deploys a total of 2,005,571 parameters, with 2,001,475 of these being trainable. These results highlight the model’s efficacy in maintaining key structures and generating visually appealing outputs, supporting its potential implications in fields demanding high-resolution imagery, such as medical imaging and satellite imagery.
Volume: 23
Issue: 4
Page: 1032-1045
Publish at: 2025-08-01

Bolstering image encryption techniques with blockchain technology - a systematic review

10.11591/ijict.v14i2.pp594-604
Narmadha Annadurai , Agusthiyar Ramu
Multimedia data plays a momentous role in present world. With the advancements in various fields of research like internet of things (IoT), industrial IoT (IIoT), cloud computing, medical image processing, and many more technologies, the digital images have already encroached the multimedia eon. The major challenge lies in providing a tamper proof image with higher level of security and confidentiality while being transmitted through a public network. Image encryption techniques are considered to be the predominant method to anticipate security from any unauthorized user access. This has indeed provoked the researchers to create new diverse and hybrid algorithms for encrypting the images. At present blockchain has been the most prevalently discussed method for security and the next level of security can be foreseen using the blockchain encryption techniques. This paper identifies the literature which mainly focuses on assorted image encryption techniques with blockchain technology applied on digital images from heterogeneous sources. An overview has been proposed to discuss on these techniques.
Volume: 14
Issue: 2
Page: 594-604
Publish at: 2025-08-01
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