International Journal of Wireless and Microwave Technologies @ijwmt
Journal articles - International Journal of Wireless and Microwave Technologies
All articles: 648
Privacy Preserving Similarity Measurement
Scientific article
Data similarity measurement is an important direction for data mining research. This paper is concentrated on the issue of protecting the underlying attribute values when sharing data for the similarity of objects measurement and proposes a simple data transformation method: Isometric-Based Transformation (IBT). IBT selects the attribute pairs and then distorts them with Isometric Transformation. In the process of transformation, the goal is to find the proper angle ranges to satisfy the least privacy preserving requirement and then randomly choose one angle in this interval. The experiment demonstrates that the method can distort attribute values, preserve privacy information and guarantee valid similarity measurement.
Free
Probabilistic Constellation Extension Scheme for PAPR Reduction in OFDM Signals
Scientific article
In this paper, a combinational method is proposed to mitigate the peak-to-average power ratio problem in orthogonal frequency division multiplexing signals. The proposed algorithm is an intelligent combination of the constellation extension and probabilistic techniques. It is shown that proposed technique achieves the significant reduction in peak-to-average power on maintaining sufficient bit error rate with a slight increase in computational complexity compared to conventional schemes.
Free
Scientific article
Beibuwan Economical Zone of Guangxi Province has the necessary basis and conditions to develop the madicine manufacturing industry.It is significant to select products which ficilitate the development of madicine manufacturing industry from the prospective of promoting the development of the industry smoothly. The feature of selection of essential products of medicine manufacturing can be summarized as multi-objectiveness, multi-layer, fuzziness and the interaction and penetration of different objectives. Due to these characteristics, analysis is made through analytic hierarchy process (AHP) by this thesis. The paper put forward the developmental sequence of madicine manufacturing industry in Beibuwan Economical Zone of Guangxi Province by adopting analytic hierarchy process, and pointed out that, among others, the technical competence is the most influnctial factor of a company. The appropriate developmental sequence of the products selected is biological and biochemical products, medicinal chemicals, chemical medicine and preparations. This research is in favor of speeding up the development of competitive products and creating industry competition.
Free
Programming SDNs: A Compass for SDN Programmer
Scientific article
The modern communication networks have evolved from simple-static systems to highly flexible and adaptive systems facilitating dynamic programmability and reconfiguration. This network evolution has influenced the lowest level of packet processing in data plane to highest level of network control and management functions. It has also influenced the overall network design and architecture which is clearly evident from the emergence of SDN and NFV. With the wide-spread acceptance of SDN, a novel networking paradigm, the network programmability has re-appeared as a top research area in networking and numerous programming languages have been proposed. In this paper, we present a systematic review of various state-of-the-art SDN programming languages used to program different network planes. We follow a top-down approach, starting with the high-level or top-tier programming languages followed by the data plane or bottom-tier programming languages. We have provided an in-depth analysis of various top-tier and bottom-tier programming languages and compared them in terms of most prominent features and supported abstractions. In addition to it, we have elaborated various programming models used in different bottom-tier programming languages which provide necessary abstractions for mapping diverse functionalities of data plane algorithms splendidly onto the specialized hardware like ASICs. Lastly, we have highlighted the research challenges in SDN programming languages like cross platform programming, necessary language libraries, support for network verification, NFV, stateful and inline packet processing, which need to be incorporated into existing programming languages to support diverse functions required in next generation networks.
Free
Scientific article
One of the important studies in 6G aerial radio access networks is the propagation channel modeling. The high accurate propagation channel model will save cost and time, and is more effective in the design of the air radio access network system. However, existing channel models are limited to 1 THz, while 6G wireless technology is expected to operate up to 3 THz. In this paper, the propagation channel from 275 GHz to 3 THz is modeled by modifying the Friis equation, and each parameter in the model is described and analyzed analytically. The main factors that contribute to wireless signal attenuation at terahertz, such as atmospheric oxygen and water vapor, rainfall, and cloud factors, are also discussed in detail. Furthermore, the propagation channel calculation App for 6G low-altitude platform access networks application has been built using MATLAB GUI.
Free
Propagation Profile and Signal Strength Variation of VHF Signal in Ekiti State Nigeria
Scientific article
This paper presents the experimental results of a study on radio frequency attenuation path loss conducted in Ekiti State, Nigeria. The objective of the study is to develop a path loss model comparable to the existing path loss models through a real time application of outdoor VHF signal propagation measurements of the Nigeria Television Authority (NTA) Channel 5 and carrier frequency of 175.25 MHz located in Ado-Ekiti, Ekiti State, Nigeria. Experimental measurements were taken in three routes covering the entire state. Analysis of the data collected from the experiments resulted in models which are in agreement with the existing standard models. Root Mean Square Errors were calculated for all the path loss models. Results show that the signal of the station was generally poor along the routes considered as the deviations of the measured path losses from the free space path loss exceed 6 dB in most cases.
Free
Proposed WiMAX hybrid scheduler with split FTP traffic and its performance evaluation
Scientific article
The most promising broadband wireless access technology, Worldwide interoperability for Microwave Access (WiMAX), is the commercial name of IEEE 802.16. It is popular due to its middle range access mobile, high data rates, high scalability and convenient deployment. WiMAX provides Quality of Service (QoS) to various triple-play services (voice, video and data) through five service classes. QoS provisioning to various service classes in WiMAX is achieved by a scheduler at MAC layer. Selection of appropriate scheduler is based on certain design goals, such as attainment of QoS required for variety of applications, fairness to all services, reduced complexity etc. However, in general, File Transfer Protocol (FTP) traffic starves for bandwidth under the presence of high priority real-time traffic. This paper proposes a WiMAX hybrid scheduler that integrates homogeneous schedulers namely Weighted Fair Queuing (WFQ), strict priority and a Round Robin (RR). The unique feature of the proposed scheduler is that it has a splitter for FTP traffic with varying ratio and two stage priority schedulers for providing proper traffic load distribution for packet scheduling. The analytical modelling of proposed scheduler is achieved by Markov Chain and balance equations are solved to derive performance indicators such as mean queue length of packets, mean queuing delay, throughput and inter-class fairness for various triple-play services. The analytical results show that, as compared to recently reported hybrid WiMAX schedulers, proposed hybrid scheduler fulfils QoS requirements of various services and the splitting of FTP traffic has improved fairness among various services.
Free
Providing Useful Data Reliably to Mobile Cloud Users from Random Wireless Sensor Network
Scientific article
The integration of mobile cloud computing and wireless sensor network plays an important role in the field of research and industry. Data fetched from Wireless Sensor Network (WSN) are stored in the cloud and provides it to the mobile cloud users. This integration helps in providing data to users in the form of digitalization. To help the applications involving an integration of Mobile Cloud Computing (MCC)–Wireless Sensor Network, this paper finds the crucial things that influence the sensor data and WSN, and then propose a concept called Time based Priority Sleep Scheduling (TPSS). TPSS is divided into three parts 1. Based on the priority and time, wireless sensor network gateway should transmit the sensed data to cloud and 2. The algorithm used to save the battery consumption of mobile users in fetching data from the cloud is Priority Based Sleep Scheduling (PBSS); this provides data to users request based on the time slot. 3. Location Based Sleep Scheduling (LBSS) algorithm used to provide sensed data based on mobile cloud users location.
Free
Pure-Octet Extraction based Technique for Identifying Malicious URLs based on IP Address Attributes
Scientific article
On the basis of characteristics derived from IPv4 addresses, this paper offers a method for identifying interaction linked with website-based malware and then modelling a machine-learning-based classifier. In this research work, a modified approach is proposed for detecting fraudulent websites and compared with other methods like SVM assessment of IP addresses, octet-based technique, modified extended version of octet-based technique, and bit string-based characteristics. This modified approach is based on the fact that logical addressing is more reliable and consistent than other measures like URLs and DNS. The characteristic sequence which makes up URLs and domain names are more changeable with respect to IP addresses which are less changeable in comparison to URLs or domain names. The IPv4 address length is encoded into 4-byte space. Here, we have evaluated our modified approach with valid IP addresses from Kaggle [11], published on January 16, 2018, have been used to validate the efficacy of their metho.
Free
Scientific article
This Research focuses on cross layer approach to enhance the User Experience and Quality Of Service of video streaming in Long Term Evolution mobile network. During run time channel quality index is observed. Application layer requirement is fulfilled by changing modulation techniques as well as dynamic allocation of resources. This paper proposes a algorithm which improves the End-to-End Delay,Peak Signal to Noise Ratio of transmitted video over Mobile Network. Experimental results show the improvement in end to end delay by 89% and Peak Signal to Noise Ratio by 8%. Simulation in Network Simulator-3 provide credible evidence that this proposed cross-layer algorithm outperforms between earlier algorithm in providing better Quality Of Experience for real time, adaptive video streaming over Long Term Evolution.
Free
QoS-Aware VoIP Support in WMNs via PSO-Based Multi-Level Node Monitoring
Scientific article
Wireless Mesh Networks (WMNs) provide low-cost, self-organizing and self-healing connectivity, but multi-hop interference, hidden-node effects and unbalanced load make delay-sensitive Voice over Internet Protocol (VoIP) communication difficult to support. This paper presents a Particle Swarm Optimization (PSO)-driven node monitoring and traffic scheduling framework for QoS-aware VoIP in WMNs. In the revised method, multi-level monitoring is explicitly defined through three measurable levels: node-state monitoring (identifier, residual energy and queue occupancy), link-quality monitoring (delivery probability, loss, delay and interference), and traffic/QoS monitoring (VoIP classification and priority scheduling). These normalized features are combined in a dimensionally consistent PSO fitness function that jointly maximizes packet delivery ratio and residual energy while minimizing delay, packet loss and hop count. A MATLAB-based discrete-event simulation was conducted for WMNs with 50-300 nodes, bidirectional CBR/UDP VoIP flows, IEEE 802.11 CSMA/CA access and common channel/interference assumptions. Under the modeled conditions, the proposed PSO-MLNM-EPDR method achieved 97.7-98.8% packet delivery ratio, compared with 94.1-95.2% for RAAOR-WMN and 92.7-93.7% for FDOE-WMN, while keeping one-way delay within 7.4-8.6 ms. The study is limited to controlled simulation settings without mobility or field deployment; therefore, future work should validate the method under realistic traffic bursts, mobility and heterogeneous radio environments.
Free
Quantum Computers’ threat on Current Cryptographic Measures and Possible Solutions
Scientific article
Cryptography is a requirement for confidentiality and authentic communication, and it is an indispensable technology used to protect data security. Quantum computing is a hypothetical model, still in tentative analysis but is rapidly gaining traction among scientific communities. Quantum computers have the potential to become a pre-eminent threat to all secure communication because their performance exceeds that of conventional computers. Consequently, quantum computers are capable of iterating through a large number of keys to search for secret keys or quickly calculate cryptographic keys, thereby endangering cloud security measures. This paper’s main target is to summarize the vulnerability of current cryptographic measures in front of a quantum computer. The paper also aims to cover the fundamental concept of potential quantum-resilient cryptographic techniques and explain how they can be a solution to complete secure key distribution in a post-quantum future.
Free
RAFIA: A Game-Theoretic Risk-Based Framework for Insider Threat Mitigation
Scientific article
Insider attacks pose a significant security threat precisely because they originate from individuals with authorized access, making them inherently difficult to detect and prevent; addressing this issue is crucial for preserving the confidentiality, integrity, and availability of organizational systems. This paper contributes to mitigating insider attacks by proposing an approach called RAFIA, which monitors the system, evaluates the risk of insider threats, and blocks malicious actions before unauthorized or high-risk access is granted. The security policy is specified using an enhanced version of Linear Temporal Logic, called Risk-LTL, which evaluates the risk of each new action based on system history, including log files or traces, and a risk evaluation function provided as input. Risk evaluation is based on combining maliciousness probability and impact assessment, enabling quantitative estimation of the risk associated with user actions and action traces. Access decisions are governed by configurable risk thresholds specified within Risk-LTL policies. To strengthen decision-making, the model frames access control as a game between users and the organization. By applying game-theoretic tools, the system analyzes user behavior and makes access decisions that discourage malicious actions and reward honest ones. The objective is to reach a Nash equilibrium, where both players act rationally and securely. The proposed approach aims to improve the effectiveness of access control by reducing dishonest behavior and promoting more stable, risk-aware system interactions. Experimental evaluation using synthetic workloads of up to 10,000 access requests demonstrated the practicality of the proposed framework. RAFIA achieved an average authorization latency of approximately 3.3 ms while improving the F1-score compared with a conventional static-threshold access-control baseline.
Free
RF CMOS Low Noise Amplifier Design-A Case Study
Scientific article
A design methodology of Differential Design of CMOS low noise amplifier (LNA) with source degeneration for Bluetooth frequency is presented. The results show that the proposed topology is effective and can be used to achieve the minimum noise figure at all frequencies of interest. This LNA was realized in 0.18μm CMOS technology using Microwave Office Tool from AWR Inc. The measured noise figure is 2.066 dB and the gain is 20.29 dB.
Free
Scientific article
Distributed Denial of Service (DDoS) attacks have emerged as one of the most critical cybersecurity threats to cloud computing environments, significantly affecting service availability, resource utilization, and operational reliability. The dynamic nature of cloud traffic and the increasing sophistication of attack patterns make accurate and efficient DDoS detection a challenging task. To address this issue, this paper proposes a hybrid feature-selection and classification framework, namely Random Forest-based Oppositional Crow Search Algorithm (RF-OCSA), for intelligent DDoS attack detection in cloud environments. The proposed framework consists of data preprocessing, optimal feature selection using the Oppositional Crow Search Algorithm (OCSA), and attack classification using the Random Forest (RF) classifier. OCSA employs oppositional learning to enhance search diversity and identify the most discriminative features while reducing feature redundancy and computational overhead. The effectiveness of the proposed RF-OCSA model is evaluated using four benchmark datasets, namely CIC-DDoS2019, AISED, TestCloudIDS, and UNSW-NB15. Experimental analysis is conducted using Accuracy, Sensitivity, Specificity, Precision, and F-measure as evaluation metrics, while NS-3 is utilized to emulate representative cloud-network traffic scenarios. The results demonstrate that RF-OCSA consistently outperforms GHLBO, CNN-LSTM, and DeepDefend by achieving superior detection performance across all datasets, with classification metrics exceeding 98% in most cases. The integration of oppositional feature optimization and ensemble learning significantly improves attack detection capability, reduces false alarms, and enhances model robustness. These findings indicate that RF-OCSA is an effective and scalable framework for securing cloud infrastructures against evolving DDoS attacks.
Free
RIS-assisted Coverage Maximization Using Multi-UAVs in LTE Networks
Scientific article
In this paper, in order to improve the coverage and the Quality of Service of end-users on the edge of a cellular network, the use of unmanned aerial vehicles (UAVs) is employed to give them direct line of sight. In addition to that, to improve the performance of the said UAVs, reconfigurable intelligent surfaces (RIS) are introduced to the model, in such a way that will enhance the connection of the UAVs with the base station. An RIS will receive a signal from the base station, modulate it and then the RIS will act as the transmitter, sending the signal towards the UAV. By simulating our proposed approach using MATLAB, we have demonstrated that utilizing RIS-assisted communication maximizes coverage between the Base Station and the UAV, outperforming the simulation results of coverage as a function of height without the use of RIS. The significance of this work lies in its ability to enhance the signal quality and coverage at cell edges by leveraging UAVs as intermediate relays. These UAVs serve the purpose of connecting users with weak or no links, effectively bridging the gap. In our simulation results, we employed RIS to strengthen the backhaul link quality between the UAVs and base stations. While our work successfully addresses the challenges of connectivity and coverage, it is important to note that we have not specifically focused on the cost aspect of these factors.
Free
Scientific article
In the recent years the development in communication systems requires the development of low cost, minimal weight and low profile antenna that is capable of maintaining high performance over a wide spectrum of frequencies. This technological trend has focused much effort into the design of a microstrip patch antenna. The aim of this paper is to design and simulate a triangular microstrip patch array antenna using HFSS software and compare the performance of 2 elements, 4 elements and 8 elements patch arrays with that of a single patch for the same operating frequency. Also comparisons are made between the performance of series, corporate and series-corporate feed network. These arrays are designed to operate at a frequency of 11 GHz. Our goal is to obtain a high directivity with better gain and reduced losses, to be especially used for X band applications such as satellite communication, radar, medical applications, and other wireless systems.
Free
Scientific article
Tin-based perovskites are among the most promising candidates for high performance light-weight and radiation-tolerant space photovoltaics, but their response to energetic proton fluxes is not adequately determined. In this work, integrated SCAPS–SRIM analysis was applied to lead-free MASnI3 perovskite solar cells for space applications in order to correlate device optimization with proton-radiation response. We established a combined SCAPS–SRIM simulation platform to simulate optoelectronic behaviors and radiation tolerance of an Au/Cu2O/MASnI3/TiO2/FTO solar cell under AM0 illumination. Optimal-device calculations demonstrate that device absorber thickness of 0.20–0.30 µm and a TiO2 ETL of 20–50 nm, Cu2O HTL of 50 nm thicknesses result in good carrier collection and minimized recombination losses. Quantum efficiency and J–V measurement illustrate a stable operation under AM0 light, verifying the no extrinsic spectral incompatibility of MASnI3 for the space energy source application. SRIM proton irradiation simulations (10-250 keV, 0° incidence) highlight the most damaging energy range within 50–150 keV for which masked Bragg peak lies in proximity to the MASnI3 absorber and MASnI3/TiO2 interface accompanied by enhanced vacancy density, recoil energy deposition and phonon generation. High-energy protons (>200 keV) which deposit most of their damage in the rear contact stack, minimizing absorber degradation. The results overall indicate that MASnI3 holds a good optoelectronic performance beyond the predictable radiation-damage behavior and thus can be considered as a promising alternative for space photovoltaic technology
Free
Real-Time Animal Location Estimation Using Wearable Sensors and Cellular Mobile Networks
Scientific article
In this article, we propose a novel concept of using an existing cellular network to find the location of animals living in outdoor environments. The proposed method has simplified hardware architecture which can be implemented at a meager cost. Moreover, the sensors communicate with existing cellular networks, which will reduce the implementation cost. The proposed system consists of a SIM 900 GSM module, a BMP280 pleasure sensor, and a battery as a wearable device that can warn the animal. The wearable device will send the real-time pressure values of the animal. In the proposed model, the pressure value, radial distance of transmitter fixed at the animal, and direction of the electromagnetic waves are used to calculate the real-time coordinates of the animals. The received pressure value and the radial distance will be used to calculate the location using this proposed model. The proposed model parameters' error was analyzed and simulated using suitable probability density distributions, and results were presented.
Free
Reconfigurable Origami Antennas: A Review of the Existing Technology and its Future Prospects
Scientific article
Owing to the much-gained popularity and unique properties of origami antenna, a review of some of the important types of these antennas is conducted. Origami is an ancient paper folding technique which has many applications in technical and non-technical fields. With the growing trend of utilizing origami concept, it was integrated with the electromagnetic field to realize reconfigurable antennas. This review contains some of the important applications in which the origami antennas are widely used to make the system more efficient. The development of the antennas over the years and some state-of-the-art designs are discussed along with the future trends in design and manufacturing of origami antennas. Some unique abilities of origami antennas which make them better choice than other antennas are smaller size and volume in addition to being light weight, cost efficient and easily manufacturing. They are widely used to reduce the size of bulky antennas which is very handy in many space and air borne facilities and provide reconfigurable frequency. They are even used to provide mobile range in far off regions which are not accessible with the use of ordinary antennas. The field of antenna design is vast and provides a lot of room for further advancements which are covered in future trends of the paper. This paper provides a detailed review of the different designs of antenna and points towards possible future enhancements and state of the art designs for the fabrication of antenna.
Free
