Area Network System Research Articles

The Flipped Classroom Approach via the M-Learning Model: Impact on Student Learning and Motivation

Over the past decade, there has been a growing emphasis on integrating modern technology into educational systems, particularly in the form of new information and communication technologies (NICT), including mobile technologies. Mobile learning (M-Learning) is an advanced form of e-learning that allows learners to access educational materials and knowledge sources through intelligent digital electronic devices in a flexible mobile environment. This study explores the impact of applying the flipped classroom pedagogical approach via the M-Learning model on learners' motivation. To investigate this, an experiment was conducted on a group of 86 learners in the Operating System and Local Area Network course, where M-Learning was adopted as the teaching model. The experimental group was compared with a control group, and the obtained results showed that the experimental group had a significant improvement in learning outcomes and remarkable motivation according to the ARCS model. The findings indicate that the experimental group demonstrated improved learning and remarkable motivation according to the ARCS model. This suggests that incorporating M-Learning into the flipped classroom approach can be an effective way to enhance learners' motivation and engagement in the learning process. Keywords : flipped classroom, m-learning, ARCS model, motivation. https://doi.org/10.55463/issn.1674-2974.50.4.18

Multichannel non-blocking system area network with direct channels

An unblockable non-blocking self-routing network with direct channels has been developed, in which packet conflicts are resolved at the entrance to the network by the procedure of connecting sources to the first cascade of the network , providing a packet duality. Packets blocked during conflict resolution are retransmitted by sources with minimal delays. Within the network, the occurrence of conflicts is prevented by means of parallelization of the network itself. The network is designed in 2-, 4- and 8-stage versions with scaling of the number of channels from several hundred to many millions, keeping the same network performance. The network can provide 1- or 2-channel fault tolerance at the same link rate. The overhead cost of achieving these properties is higher complexity of the network, that becomes comparable to the complexity of the theoretical non-blocking Clos switch, which has no known practical implementation.The purpose of the proposed networks is photonic networks with routing information transmission in packet headers represented as one-time-use binary numbers. The proposed networks are made in an extended circuit basis, consisting of switches and separate multiplexers and demultiplexers. The paper presents the characteristics of the constructed networks with the specified method of presenting routing information.

A Formal Modeling and Verification Scheme with an RNN-Based Attacker for CAN Communication System Authenticity

To enhance the attack resistance of the Controller Area Network (CAN) system and optimize the communication software design, a comprehensive model that combines a variable attacker with the CAN bus (VACB) is proposed to evaluate the bus communication risk. The VACB model consists of a variable attacker and the CAN bus model. A variable attacker is a visualized generation of the attack traffic based on a recurrent neural network (RNN), which is used to evaluate the anti-attack performance of the CAN bus; the CAN bus model combines the data link layer and the application layer to analyze the anomalies in CAN bus data transmission after the attack message. The simulation results indicate that the transmission accuracy and successful response rate decreased by 1.8% and 4.3% under the constructed variable attacker. The CAN bus’s authenticity was promoted after the developers adopted this model to analyze and optimize the software design. The transmission accuracy and the successful response rate were improved by 2.5% and 5.1%, respectively. Moreover, the model can quantify the risk of potential attacks on the CAN bus, prompting developers to avoid it in early development to reduce the loss caused by system crashes. The comprehensive model can provide theoretical guidance for the timing design of embedded software.

A Novel Single-Fed Dual-Band Dual-Circularly Polarized Dielectric Resonator Antenna for 5G Sub-6GHz Applications

In this research article, a single-fed dual-band circular polarized (CP) dielectric resonator antenna (DRA) for dual-function communication, such as GPS and WLAN, was made. Initially, the proposed design process was initiated by designing a linearly polarized singly fed-DRA. To attain CP fields, the cross-shape conformal metal strip was optimized to excite the fundamental and the high-order mode in the two frequency bands. The metallic strip (parasitic) was utilized on top of the rectangular DRA to improve and widen the impedance and axial ratio (AR) bandwidth. This step led to a 2.73% improvement on the lower band and an impact of 6.5% on the upper band while on the other side a significant improvement was witnessed in the AR bandwidth in both frequency bands. A prototype was designed and fabricated in order to validate its operations. The measurement outcomes of the proposed antennas authenticated wideband impedance bandwidths of 6.4% and 25.26%, and 3-dB axial ratios (AR) of 21.26% and 27.82% respectively. The prototype is a decent candidate for a global positioning system (GPS) and wireless local area network (WLAN).

Detection and Mitigation of Sensor and CAN Bus Attacks in Vehicle Anti-Lock Braking Systems

For a modern vehicle, if the sensor in a vehicle anti-lock braking system (ABS) or controller area network (CAN) bus is attacked during a brake process, the vehicle will lose driving direction control and the driver’s life will be highly threatened. However, current methods for detecting attacks are not sufficiently accurate, and no method can provide attack mitigation. To ensure vehicle ABS security, we propose an attack detection method to accurately detect both sensor attack (SA) and CAN bus attack in a vehicle ABS, and an attack mitigation strategy to mitigate their negative effects on the vehicle ABS. In our attack detection method, we build a vehicle state space equation that considers the real-time road friction coefficient to predict vehicle states (i.e., wheel speed and longitudinal brake force) with their previous values. Based on sets of historical measured vehicle states, we develop a search algorithm to find out attack changes (vehicle state changes because of attack) by minimizing errors between the predicted vehicle states and the measured vehicle states. In our attack mitigation strategy, attack changes are subtracted from the measured vehicle states to generate correct vehicle states for a vehicle ABS. We conducted the first real SA experiments to show how a magnet affects sensor readings. Our simulation results demonstrate that our attack detection method can detect SA and CAN bus attack more accurately compared with existing methods, and also that our attack mitigation strategy almost eliminates the attack’s effects on a vehicle ABS.

Flexible Wearable Composite Antennas for Global Wireless Communication Systems.

Although wearable antennas have made great progress in recent years, how to design high-performance antennas suitable for most wireless communication systems has always been the direction of RF workers. In this paper, a new approach for the design and manufacture of a compact, low-profile, broadband, omni-directional and conformal antenna is presented, including the use of a customized flexible dielectric substrate with high permittivity and low loss tangent to realize the compact sensing antenna. Poly-di-methyl-siloxane (PDMS) is doped a certain proportion of aluminum trioxide (Al2O3) and Poly-tetra-fluoro-ethylene (PTFE) to investigate the effect of dielectric constant and loss tangent. Through a large number of comparative experiments, data on different doping ratios show that the new doped materials are flexible enough to increase dielectric constant, reduce loss tangent and significantly improve the load resistance capacity. The antenna is configured with a multisection microstrip stepped impedance resonator structure (SIR) to expand the bandwidth. The measured reflection return loss (S11) showed an operating frequency band from 0.99 to 9.41 GHz, with a band ratio of 146%. The antenna covers two important frequency bands, 1.71–2.484 GHz (personal communication system and wireless body area network (WBAN) systems) and 5.15–5.825 GHz (wireless local area network-WLAN)]. It also passed the SAR test for human safety. Therefore, the proposed antenna offers a good chance for full coverage of WLAN and large-scale development of wearable products. It also has potential applications in communication systems, wireless energy acquisition systems and other wireless systems.

Joint Timing and Frequency Synchronization Using Convolutional Neural Network in WLAN Systems

In wireless communication systems, the performance of the receiver is very sensitive to time and frequency offsets. In particular, orthogonal frequency division multiplexing (OFDM) systems are highly vulnerable to those offsets due to inter-carrier interference (ICI) and inter-symbol interference (ISI). To solve this problem, wireless local area network (WLAN) systems transmit a preamble for synchronization. In this paper, we propose a joint time and frequency offsets estimation technique based on convolutional neural network (CNN) for WLAN systems. In the proposed technique, the correlation between the received signal and the transmitted preamble is performed first. Then the frequency offset is coarsely compensated by several hypothesized offsets. The compensated signals are inputted to the proposed CNN and the CNN predicts the time and frequency offsets. The estimation performance is examined through computer simulation. According to the results, the proposed time offset estimator shows 3 dB to 6 dB performance gain, and the frequency offset estimator shows much lower root mean square error (RMSE) performance than the conventional technique at low SNRs

Secure and Efficient Cloud-based IoT Authenticated Key Agreement scheme for e-Health Wireless Sensor Networks

With the advancement and innovations in mobile and wireless communication technologies including cloud computing and Internet of Things, the paradigms of dispensing heath-based services have massively transformed. The telecare medical information system (TMIS) or wireless body area networks technology frameworks facilitate patients to remotely receive medical treatment from physicians through the Internet without paying a visit to the hospital. In order to ensure the medical privacy of the patients and the verification of authenticity of all entities in TMIS-based system before exchange of sensitive credentials and diagnosis reports, many TMIS-based authentication protocols have been presented so far; however, there is a still need of more efficient and secure key agreements. Recently, Karthegaveni et al. demonstrated a remote health care monitoring protocol with the use of elliptic curve cryptography crypto-primitives. However, we discover many drawbacks in their protocol including replay attack, denial of service attack, lacking mutual authenticity between the client and server. Moreover, the scheme has several technical limitations. We propose an efficient and secure TMIS-based protocol employing lightweight symmetric key operations. The contributed model is proven by rigorous formal security analysis, while its security features are also validated under automated ProVerif tool. The proposed scheme supports 38% more security features on average than compared schemes. The performance evaluation also depicts that the demonstrated and comparative findings are in the favour of the proposed model.

Multi-terminal Experimental System Based on Wireless Local Area Network

Aiming at the problems of single experimental data display, difficult data recording, poor human-computer interaction and low security for an experimental system, a multi-terminal experimental system based on Android operating system and wireless local area network was designed. Based on the Android operating system and wireless LAN, the system combines MySQL database, Web server, and LabVIEW software, and adopts modular design, realizes real-time collection and recording of experimental data during the experiment, and multi-parameters cross hardware display, good human-computer interface and remote status monitoring.

New intelligent network approach for monitoring physiological parameters: the case of Benin

Benin health system is facing many challenges as: (i) affordable high-quality health care to a growing population providing need, (ii) patients’ hospitalization time reduction, (iii) and presence time of the nursing staff optimization. Such challenges can be solved by remote monitoring of patients. To achieve this, five steps were followed. 1) Identification of the Wireless Body Area Network (WBAN) systems’ characteristics and the patient physiological parameters’ monitoring. 2) The national Integrated Patient Monitoring Network (RIMP) architecture modeling in a cloud of Technocenters. 3) Cross-analysis between the characteristics and the functional requirements identified. 4) Each Technocenter’s functionality simulation through: a) the design approach choice inspired by the life cycle of V systems; b) functional modeling through SysML Language; c) the communication technology and different architectures of sensor networks choice studying. 5) An estimate of the material resources of the national RIMP according to physiological parameters. A National Integrated Network for Patient Monitoring (RNIMP) remotely, ambulatory or not, was designed for Beninese health system. The implementation of the RNIMP will contribute to improve patients’ care in Benin. The proposed network is supported by a repository that can be used for its implementation, monitoring and evaluation. It is a table of 36 characteristic elements each of which must satisfy 5 requirements relating to: medical application, design factors, safety, performance indicators and materiovigilance.

A CSRR DGS Loaded Dual-Frequency Microstrip Antenna in Ground Plane for Application in PCS and WLAN Communication System

In this paper, a rectangular microstrip antenna which is inset-fed by the microstrip line with a complementary split ring resonator (CSRR) defected ground structure (DGS) cell in the ground plane just below the microstrip line (substrate present in between) for the dual frequency operation at 1.92 GHz and 5.22 GHz is presented, which are the operation bands of personal communication system (PCS) and wireless local area network (WLAN) respectively. The fundamental mode TM10 and one strongly activated higher order mode are excited which are responsible for the dual-band operation. Smaller broadside radiation and same polarization planes are the characteristics of these modes.

Compact reconfigurable triple notch ultra-wideband bandpass filter for cognitive radio system

This paper introduces a compact ultra-wideband (UWB) bandpass filter (BPF) with two switchable external notch structures which avoids the interference between the UWB communication with worldwide interoperability for microwave access (WiMAX) and wireless local area network (WLAN) systems, suitable for cognitive radio (CR) applications. The first external notch structure is modified C-shaped structure which generates a sharp rejection at 3.5 GHz to avoid interference with WiMAX system and second external notch structure is back to back T-shaped structure which creates sharp rejection notch bands at 5.2 GHz and 5.8 GHz frequencies for WLAN systems. The filter reconfiguration is achieved by varying the conductance of microstrip line. The response of the proposed structure shows sharp rejections at one WiMAX and two WLAN bands. The bandpass filter covers frequency of UWB system from 3.1 to 10.7 GHz having very low passband insertion loss. The proposed UWB BPF is designed, simulated, fabricated and tested to validate the results. A good agreement is achieved between simulation and experimental results.

Quality of Service in bandwidth adapted hybrid UMTS/WLAN interworking network

Integration of Universal Mobile Telecommunications System (UMTS) and Wireless Local Area Network (WLAN) result in ubiquitous connection for end users. In the integrated network, ensuring the quality of service to users and enhancing capacity of network are prominent issues. Bandwidth adaptation technique is one of the solutions to overcome these issues. Bandwidth adaptation based on per flow and per class schemes were proposed for loosely coupled interworking network. In this paper, hybrid coupled UMTS and WLAN interworking network is analyzed with bandwidth adaptation based on per flow and per class schemes and the performances have been compared. Simulation result shows that the proposed hybrid coupled interworking network with bandwidth adaptation based on per class scheme performs better with enhanced quality of service and network capacity.

Conflict-Free Self-Routing for a Three-Dimensional Complete Multiring

The system-area network is proposed in the form of a non-blocking three-dimensional complete multiring. The structure of a multiring is developed and the algorithm is suggested of a conflict-free laying out direct paths between its nodes by means of dynamic local self-routing in them.

Direct Sequence and Frequency Hopping Signals Classification Based on Co-Occurrence Matrix and Clustering Techniques

Spread Spectrum techniques (SS) were first developed for military applications, but currently, they have commercial applications. SS provides secure communication and allows multiple accesses for same radio spectrum. So, most Wireless Local Area Network (WLAN) systems use it, as do Cognitive Radios (CR), space systems and Global Positioning Systems (GPS). Direct Sequence Spread Spectrum (DSSS) and frequency hopped spread spectrum (FHSS) are the two most-used techniques today. Nowadays radio spectrum has become very crowded and so now there is a need for spectrum efficiency. Automatic SS classification presents a rather difficult problem, especially if the parameters, such as the signal power, carrier frequency, etc., are unknown. This research takes a new direction; it deploys the Gray Level Co-occurrence Matrix (GLCM) to capture statistical features of SS signals. Using GLCM, 22 features are extracted for each vector of signal. Analyzing the signals is done in the time domain which measures the variation of amplitude of signals with time. Therefore, the main contribution is to apply and show how GLCM improves the identification accuracy of the two signals in presence of noise. The proposed model achieves considerably accurate results even with a low SNR. GLCM features help classifiers to achieve average accuracy 84% and reach 100% signal identification at a zero SNR. To prove the superiority of these features, a variety of clustering methods are applied, such as centroid, connectivity, model-based and message-passing models. Clustering performance results based on GLCM features are compared With Principal Components Analysis (PCA), Kernel-based Principal Components Analysis (KPCA) and fast Independent Components Analysis (Fast-ICA). Clustering results are evaluated with external and internal validity indices. The accuracy was tested over 26 levels of Signal-to-Noise Ratios (SNR).

A Comparison of System Area Networks: Generalized Extended Multiring vs Flattened Butterfly

The paper suggests a system area network of supercomputers with an increased number of nodes and different paths between them, which is called a generalized extended multiring. We compare the characteristics of the suggested network and Flattened Butterfly network with the same dimensions of network nodes and diameters.

Implementation of envelope detection based Wake-Up Receiver for IEEE 802.15.4 WPAN from off-the-shelf components

Abstract. Power consumption in wireless networks is crucial. In most scenarios the transmission time is short compared to the idle listening time for data transmission, the most power is consumed by the receiver. In low latency systems there is a need for low power wake-up receivers (WuRx) that reduce the power consumption when the node is idle, but keep it responsive. This work presents a WuRx designed out of commercial components to investigate the needs of a WuRx when it is embedded in a Wireless Personal Area Network (WPAN) system in a real environment setup including WLAN and LTE communication and considering interferer rejection. The calculation necessary for the attenuation of those interferers is explained in detail. Furthermore, a system design is presented that fulfills the requirements for this environment and is build from off-the-shelf components.

Small-diameter system area network composed of small-port routers

This paper considers the design issues of large system area networks of small diameter based on routers with small port count. We suggest a basic structure of a 2D–4D generalized hypercube with sparse dimensions that are implemented as a non-blocking multiring of unit diameter. All designs employ Angara series routers developed in Russia.

Multiple alignment analysis on phylogenetic tree of the spread of SARS epidemic using distance method

Multiple Alignment (MA) is a particularly important tool for studying the viral genome and determine the evolutionary process of the specific virus. Application of MA in the case of the spread of the Severe acute respiratory syndrome (SARS) epidemic is an interesting thing because this virus epidemic a few years ago spread so quickly that medical attention in many countries. Although there has been a lot of software to process multiple sequences, but the use of pairwise alignment to process MA is very important to consider. In previous research, the alignment between the sequences to process MA algorithm, Super Pairwise Alignment, but in this study used a dynamic programming algorithm Needleman wunchs simulated in Matlab. From the analysis of MA obtained and stable region and unstable which indicates the position where the mutation occurs, the system network topology that produced the phylogenetic tree of the SARS epidemic distance method, and system area networks mutation.

Boosting performance of multidimensional tores

This paper suggests a speed boosting technique for system area networks in massive parallel multiprocessor computers by decreasing the diameter and increasing the throughput of a pair of opposite simplex rings (a duplex ring), a couple and quadruple of such rings. The result is achieved through replacing a duplex ring with a pair of minimal switched multidimensional rings with different steps in each ring. The decreased diameter and increased throughput of rings appreciably reduce packet delivery delays in system area networks based on the pairs of such rings.