International Journal of Wireless and Microwave Technologies @ijwmt
Journal articles - International Journal of Wireless and Microwave Technologies
All articles: 648
A QoS Multicast Routing in TDMA-Based MANET Using Directional Antennas
Scientific article
In this paper, a quality of service (QoS) multicast routing protocol in mobile ad hoc networks (MANET) using directional antennas has been presented. Many important applications, such as audio/video conferencing, require the quality of service guarantee. Directional antenna technology provides the capability for considerable increase in spatial reuse, which increases the efficiency of communication. This paper studies TDMA-based timeslot allocation and directional antennas, and presents an effective algorithm for calculating bandwidth of a multicast tree. We also propose a novel DSR-based QoS multicasting routing agrotithm. The simulation result shows the performance of this routing protocol in terms of call success rate.
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Scientific article
The directed routing protocol ends in failure when it faces a situation of the destination node with a very low velocity in a sparse ad hoc network so that none of nodes exist in its forwarding zone. Illuminated by BFDREAM and ZONER, the paper firstly proposes a novelty routing protocol that is fairly immune to forwarding failure through projecting the present source node on the boundaries of convex baffle holes of underwater acoustic networks in deep sea. Compared with DREAM and BFDREAM, the experimental results show our protocol achieves a great improvement in decreasing the propagation delay and reducing quantities of the non-effect information. So the new protocol may have a bright application prospect in deep sea acoustic networks.
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A Rectangular Microstrip Patch Antenna for Wireless Communications Operates in Dual Band
Scientific article
A single layer substrate compact dual band rectangular micro-strip patch antenna with transmission line feeding is designed for Wireless Local Area Networks (WLAN) implementation. The desired antenna consists of a rectangular patch having two I-slots and a dielectric material with dielectric constant of 2.4. The use of cavity model with transmission line feed has the favor of low profile, high gain and wide bandwidth of the antenna. The antenna has overall size of 46.9 mm by 38.01 mm and gives bandwidth of about 90 MHz at resonance frequency of 2.45 GHz and that of 115 MHz at 4.1 GHz frequency with Defected Ground Structure (DGS). The antenna with DGS has return losses -21.25 dB at 2.45 GHz and -27.5 dB at 4.1 GHz where the gains are 6.70 dB for 2.45 GHz and 6.80 dB for 4.1 GHz. Finally the designed antenna has been simulated using Computer Simulation Technology (CST) microwave studio 2009 and it is comparable with manual computation results which are found to be suitable for WLAN applications.
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Scientific article
Probabilistic parametric functions such as density and distribution functions modeled to depict certain stochastic behaviour are used to express the fundamental theories of reliability engineering. In the existing works of literature, a few probability distribution functions have been well reported. However, selecting and identifying the most suitable distribution functions to reliably model and fit datasets remain. This work examines the application of three different methods for selecting the best function to model and fit measured data. The methods comprise the parametric maximum likelihood estimation, Akaike Information Criteria and the Bayesian Information Criteria. In particular, these methods are implemented on Signal Interference to Noise Ratio (SINR) data acquired over an operational Long Term Evolution (LTE) mobile broadband networks in a typical built-up indoor and outdoor campus environment for three months. Generally, results showed a high level of consistency with the Kolmogorov-Semirnov Criteria. Specifically, the Weibull distribution function showed the most credible performance for radio signal analysis in the three study locations. The explored approach in this paper would find useful applications in modeling, design and management of cellular network resources.
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A Robust Autofocusing Approach for Estimating Directions-of-Arrival of Wideband Signals
Scientific article
In this paper, we introduce a robust method for wideband DOA estimation which does not require any preliminary DOA estimation or calibration of the array during the whole estimating process with the performance similar to the autofocusing approach. Our method is based on the autofocusing approach and uses the ESPRIT algorithm during the narrowband processing stage. Meanwhile, we suggest the method of selecting the best focusing frequency which minimizes the mean square error.
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A Scalable Simulation Method for Network Attack
Scientific article
In order to found a scalable platform for attack resistance test, this paper proposed a simulation method for network attack. We designed a modular framework and using XML to describe the test cases. We also realized both stateful and stateless attacks by Socket programming and Jpcap packet forging method. Experiment results showed that the system has good scalability and provides a template-based testing circuit.
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A Scheme on PN Code Tracking of DS/FH Signals for Telemetry, Tracking, and Commanding (TT&C)
Scientific article
The impact of Doppler frequency hopping on code tracking performance is simulated. A design on pseudo-noise (PN) Code Tracking Loop aided by the carrier tracking loop according to the carrier frequency hoping pattern is proposed in this paper. This scheme can be applied in the Telemetry, Tracking, and Commanding system which uses Direct Sequence/Frequency Hopping Spread Spectrum (DS/FH) hybrid spread spectrum technology. Simulations of the code tracking loop under different carrier to noise ratios are compared based on this scheme. The results show this method on PN code tracking of DS/FH signals is valid.
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Scientific article
The blockchain technology has been widely adopted for various applications due to its decentralization, transparency, and security features. Consensus algorithms, such as Proof of Work (PoW) and Proof of Stake (PoS), are fundamental components of blockchain technology, ensuring the integrity and validity of the blockchain network. However, the current consensus algorithms face challenges such as scalability, energy consumption, and security threats. To address these challenges, a new secure network for streamlined and high-performance consensus algorithm based on blockchain technology has been proposed. This new network incorporates the advantages of PoW and PoS, resulting in a hybrid consensus algorithm that is more efficient and secure than the existing algorithms. Additionally, the new network utilizes a dynamic sharding mechanism to improve scalability, reducing the overall processing time of transactions. The simulation results help identify potential vulnerabilities and inefficiencies in the consensus algorithm. Optimal combinations of block interval and propagation delay are determined based on specific use cases, balancing high throughput with security and consensus stability. The study also validates the security of Proof-of-Work (PoW) by comparing the fraction of generated blocks with the expected blocks based on miners' hashing power. This study establishes a foundation for future improvements in consensus algorithms, contributing to their evolution and facilitating the implementation of blockchain applications in various domains such as finance, healthcare, supply chain management, and more. The proposed solution aims to provide a more robust and efficient blockchain platform that can handle a higher volume of transactions while maintaining its security features.
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A Secure and Efficient Client-Side Encryption Scheme in Cloud Computing
Scientific article
Computation process has changed itself from desktop computing to cluster computing and to grid computing and now a days it goes towards cloud computing. In today's trend, Cloud computing is being preferred by majority of the organization because of its major advantages in terms of scalability and multi tenancy. Among all these advantageous features of cloud computing, the only hitch is the security of the data that is stored in the cloud. The security clause rests with the cloud service provider but security can be applied on client side also and it is possible if the user knows how his data is secured. This paper proposes a mechanism which can help the user to ensure the security of his data at the client-side.
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A Security Routing Protocol Protecting Mobile Agent Against Cluster Attack
Scientific article
The security issue of MA(mobile agent) is concerned for a long time, Especially for attack from malicious hosts. The paper proposes a new security routing protocol whose highlight is integrating group signature into MA system. It will decrease the probability that malicious hosts cluster to skip one host deliberately, and avoid too much invalid connection to host who is offline or rejective to service. Besides, in new protocol, each host will hold less public keys of other hosts and save time on verifying MA. The last superiority of new protocol is improving the efficiency of DoS(denial of service) attacker tracing.
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A Simple Algorithm to Strengthen the Brightness of Color Images
Scientific article
This paper puts forward a simple algorithm to make color images lighter based on Wavelet transformation and histogram smoothing. This algorithm uses HIS space which is based on human visual features. Without changing hue, it can conduct histogram smoothing in low brightness frequency domain through wavelet decomposition and make the images lighter, which at the same time avoids vagueness of details and increase of noises. According to experiment results, this algorithm can make low brightness color images lighter effectively with low time complexity.
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A Source-Based Multicast Scheme in IEEE 802.16 Mesh Mode
Scientific article
WiMAX based on IEEE 802.16 is known as one of effective technologies for transmission of multimedia to groups of receivers. There are two operational modes in WiMAX: point to multi point (PMP) for single hop transmission and a mesh node for multi-hop transmission. The current standard only defines unicast transmission under mesh mode thus the performance is deteriorated for multimedia applications with multicast nature. In this paper, we first propose a mechanism for source-based tree topology construction aiming at facilitating multicast transmission in WiMAX mesh network. In the proposed approach, the multicast tree is constructed considering available link's bandwidth and multicast group members. After constructing the multicast tree we propose a novel scheduling algorithm to improve the transmission throughout. In the proposed scheduling algorithm a parent node uses broadcasting when the number of its children belonging to a multicast group excesses a threshold. Extensive simulation results show that the proposed multicast mechanism improves multicast transmission efficiency and reduces scheduling time slots noticeably in comparison to the approach mandated by the IEEE 802.16 standard.
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A Speech Enhancement Method Based on Kalman Filtering
Scientific article
The enhancement of speech degraded by non-stationary interferers is a highly relevant and difficult task for many signal processing applications. In this study, we present a monaural speech enhancement method based on spectral subtraction and Kalman filtering (KF) by extracting the Liljencrants–Fant (LF) excitation during voiced speech, in which the nature of glottal flow can be maintained. Therefore, the approach could preserve the glottal pulse's nature characteristic in Kalman filtering and thus achieve significant improvements on objective quality. The quality of the enhanced speech has been evaluated by perceptual evaluation of speech quality (PESQ) score. The results indicate that the proposed algorithm could improve the output speech quality compared with the conventional KF algorithm and sub-band spectral subtraction.
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A Structured Multi-signature Scheme Against Forgery Attack
Scientific article
There are some classic structured multi-signature programs, such as Burmester’s, Harn’s and Lin’s schemes that can not resist inside attack and outside attack. In this paper, we briefly review Burmester’s program and relate safety analysis, Burmester’s scheme vulnerable to forgery attack. Then we propose a structured multi-signature scheme against forgery attack. In the new scheme, we increase the signature parameter verification to improve security.
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A Study and Analysis of Congestion Control Wireless Sensor Networks
Scientific article
WSNs are becoming popular in real world uses. Due to resource-constrained and battery-aware features of the sensor; WSNs energy use in a major research topic was found to be interesting. WSNs contain battery powered nodes that for certain action or tasks are connected with the base station. The lifetime of battery-powered sensor nodes, after the consumption of the battery will be dead in WSNs. To prolong the lifetime of WSNs the energy has to be well organized. The cluster head selection and assignment, and construction of clusters require additional overhead. Cluster nodes distributed algorithms designed incorrectly can lead to isolation from cluster heads. Such isolated nodes waste large amount of energy to communicate with the sink. In this paper, energy conservation techniques related to WSNs are discussed. Also, the existing energy conservation algorithms are reviewed and the comparative analysis is also performed.
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A Survey on Detection and Prevention Techniques for SQL Injection Attacks
Scientific article
In this current scenario web application are widely using for various purpose like online shopping, online money transfer, e-bill payment, online mobile recharges etc. As per increasing the dependency on these web applications also raises the attacks on these applications. SQL injection Attacks (SQLIA) and Cross Site Scripting (XSS) are being a major problem for web applications. SQL injection Attack (SQLIA) is the most common type of vulnerability in which a malicious mind person is inserts its own crafted query as input for retrieving personal information about others sensitive users. In this paper, for detection and prevention of SQL injection attacks various techniques are described and perform a comparison between them.
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A Survey on Secure Routing Protocols in Wireless Sensor Networks
Scientific article
Wireless Sensor Networks (WSNs) are typically formed by collaboration of the large amount of partial sensor nodes, which are connected through wireless medium. In wireless sensor network, security is an essential aspect because of its usage in applications like monitoring, tracking, controlling, surveillance etc. Secure communication is extremely crucial in delivering vital information accurately and on the time through resource constraint sensor nodes. In this paper, our contribution is threefold. Firstly, we have summarized the network layer routing attacks on WSNs. Secondly, we have provided taxonomy of secure routing protocols of WSNs. Thirdly, we have provided a qualitative comparison of existing secure routing protocols. Results show that most of the existing secure routing schemes are not very efficient due to various reasons like high-energy consumption, and large communication overhead.
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A Survey on Topology Maintenance in Wireless Sensor Networks
Scientific article
The content presented in this article provides an insight into the current topology maintenance techniques in general and algorithms in particular. It makes the fine line between topology control, topology construction and topology maintenance all the more prominent. Additionally, it tries to find out how the meaning of topology control has evolved over a period of time since the inception of Wireless Sensor Networks (WSN). An attempt has been made to standardize the definition of topology control and topology maintenance.
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Scientific article
Wireless multicast networks, especially in the domains of IoT, 5G, and e-health, are experiencing a growing adoption of random linear network coding (RLNC). Nevertheless, the exponential growth of data can lead to congestion problems. This paper presents a review on novel technique called singular value decomposition (SVD) for the identification of network congestion. When SVD combines with statistical concepts like linear regression can to effectively handle large datasets and conduct comprehensive data analytics. The svd improves network performance and reliability by proactively identifying and mitigating congestion. Additionally, it improves the efficiency of data transmission and delivery in different application scenarios.
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A Systematic Review of Privacy Preservation Models in Wireless Networks
Scientific article
Privacy preservation in wireless networks is a multidomain task, including encryption, hashing, secure routing, obfuscation, and third-party data sharing. To design a privacy preservation model for wireless networks, it is recommended that data privacy, location privacy, temporal privacy, node privacy, and route privacy be incorporated. However, incorporating these models into any wireless network is computationally complex. Moreover, it affects the quality of services (QoS) parameters like end-to-end delay, throughput, energy consumption, and packet delivery ratio. Therefore, network designers are expected to use the most optimum privacy models that should minimally affect these QoS metrics. To do this, designers opt for standard privacy models for securing wireless networks without considering their interconnectivity and interface-ability constraints. Due to this, network security increases, but overall, network QoS is reduced. To reduce the probability of such scenarios, this text analyses and reviews various state-of-the-art models for incorporating privacy preservation in wireless networks without compromising their QoS performance. These models are compared on privacy strength, end-to-end delay, energy consumption, and network throughput. The comparison will assist network designers and researchers to select the best models for their given deployments, thereby assisting in privacy improvement while maintaining high QoS performance.Moreover, this text also recommends various methods to work together to improve their performance. This text also recommends various proven machine learning architectures that can be contemplated & explored by networks to enhance their privacy performance. The paper intends to provide a brief survey of different types of Privacy models and their comparison, which can benefit the readers in choosing a privacy model for their use.
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