Статьи журнала - International Journal of Wireless and Microwave Technologies

Все статьи: 454

A Novel IoT Based Approach to Notify Motion Detection in User’s Absence through Handheld Devices

A Novel IoT Based Approach to Notify Motion Detection in User’s Absence through Handheld Devices

K. Murali Krishna, H. Jayashree

Статья научная

Security Camera Notifier helps detect any motion (i.e., suspicious activity) happening in the personal room in the user’s absence. Nowadays, privacy & security are major concerns. User can install a security camera in the room which helps them to keep their belongings & any other important things safe under surveillance. Unlike other CCTV activities, this process doesn’t require 24hrs surveillance. It doesn’t require a long list of equipment like big cameras or a big screen (say TV) to watch activities or even a heavy budget. It is simple and easy to install. A stranger wouldn’t be able to guess that there’s a secret security camera installed in the room. This protocol works when a hidden camera placed in the room detects any motion in the user’s time off. A notification is sent to users mobile; the moment the camera detects any kind of motion (say someone entering the room). Here, the user would be provided with ‘@snap’ function, if he/she sends ‘@snap’ then the camera will capture a live picture of that moment and send it to the Smartphone. So, by this process security of the room is assured in user absence.

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A Novel Method of Web Services Selection Based on Weighted Grey Relational Model in Ubiquitous Computing Environments

A Novel Method of Web Services Selection Based on Weighted Grey Relational Model in Ubiquitous Computing Environments

Yiming He, Xianyi Qian

Статья научная

Selecting high quality web services based upon QoS(Quality of Service) is a significant task in service-oriented computing environments. In this paper, according a real Quality of Web Service data sets:QWS Dataset (1.0), we developed a Weighted Grey Relational Analysis Model(WGRAM) for web service selection based on QoS, and combined with Analytic Hierarchy Process(AHP) and Grey Relational Analysis (GRA) to prioritize the relative importance of the QoS of web services. The comprehensive evaluation model (WGRAM) fully considered the influence of many factors given by experts, incorporating the qualitative analysis of the index of various factors and the quantization for scientific decision-making, it can provide weighted grey relational degree for each Web Services with the same functions(operations), and the grey relational sequence which can guide the optimal service selection from multiple functions similar service. The model possessed the characteristic of simple calculating process, and the result was reliable, It’s a reliable and effective method of web service quality factor assessment and a significant attempt for web services selection.

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A Novel Orthogonal Minimum Correlation Spreading Code in CDMA System

A Novel Orthogonal Minimum Correlation Spreading Code in CDMA System

Shibashis Pradhan, Sudipta Chattopadhyay, Sujatarani Raut

Статья научная

Code Division Multiple Access (CDMA) is a technique in which transmission of information takes place simultaneously over the same available channel bandwidth. CDMA systems make use of spread spectrum (SS) technique for transmission of information by employing spreading codes. Each user is assigned with a unique spreading code which acts as a signature code for that individual user. The CDMA system experiences Multiple Access Interference (MAI) and Inter Symbol Interference (ISI) because of the non-orthogonality of the spreading codes. Both the MAI and ISI are the functions of auto-correlation and cross-correlation values of the spreading code respectively. In this paper, a novel orthogonal spreading code called “Orthogonal Minimum Correlation Spreading Code” (OMCSC) has been proposed which can serve a large number of users and is simultaneously expected to reduce the effect of MAI and ISI. Moreover, the Bit Error Rate (BER) performance of the proposed code has been compared with the existing codes using Additive White Gaussian Noise (AWGN) channel under multi-user scenario.

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A Novel RTS/CTS based Relative Time Synchronization Technique for RFID based Wireless Sensor Network

A Novel RTS/CTS based Relative Time Synchronization Technique for RFID based Wireless Sensor Network

Gursimran Kaura, Geetanjali Babbar

Статья научная

Wireless Sensor Network (WSN) is a self-configuring and highly flexible distributed network used for real time monitoring and is comprised of a number of wireless, minute, battery-operated independent sensor nodes connected to a common sink. Due to energy considerations, the network is generally divided into clusters and the entire communication is carried out through the cluster heads. The clock mismatch between various nodes and clusters often leads to collisions, delay and data loss. In order to overcome this problem, a novel RTS/CTS based Relative Time Synchronization Protocol is being proposed for Radio-Frequency Identification based WSN. It achieves better performance due to its energy efficiency and lower service messages. Simulation results show a substantial improvement in the net throughput and reliability of the network when compared with the GPS-based Synchronization technique.

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A Performance Perspective of Live Migration of Virtual Machine in Cloud Data Center with Future Directions

A Performance Perspective of Live Migration of Virtual Machine in Cloud Data Center with Future Directions

Divya Kapil, Saurabh Kumar Mishra, Vishan Kumar Gupta

Статья научная

Live virtual machine migration is a valuable feature for the virtualized data center or cloud environment. This is the process to migrate running virtual machines from one physical host to another host. Live virtual machine migration can be used to provide various benefits such as server consolidation, energy-saving, and maintenance. It is a valuable feature for the virtualized data center or cloud environment. Cloud computing provides IT capabilities as a service and its key technology is virtualization. The key benefit of virtualization is to offer better resource employment by executing various VMs on the same physical system. In this research, we analyze the performance of the various hypervisors based on their migration features and compares the migration feature. Hypervisors are Xen, VMWare, KVM, and their migration feature are XenMotion, vMotion, and KVM migration, respectively. According to our study, we find that there are many factors that affect the performance of the live virtual machine migration such as a long downtime, the large amount of data that is sent in an iteration manner so with a higher dirtying rate the total migration time extends. In our comparison, we show VMWare has the least downtime. We also identify and discuss the various research challenges in detail to stimulate the researchers to work in this direction.

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A Proposal for Detection of Underground Water Contamination via Multilayer Reflection Approach

A Proposal for Detection of Underground Water Contamination via Multilayer Reflection Approach

Murat Koray Akkaya, Asım Egemen Yilmaz

Статья научная

Contamination and degradation in the quality of the fresh water under the ground is one of the major problems of our world. Water quality on the other hand, determined by the physical, chemical and biological compounds in the water. TDS (Total Dissolved Solid), salinity, dissolved oxygen, temperature, metabolic wastes, toxic compounds and conductivity are some of the major indicators of the water quality. These items are sometimes correlated and any increase in one factor may decrease/increase other factors as well. The aim of this work is to develop an idea about the contamination due to chemicals dissolved or biological anomalies in the water. Mainly the indicator of this change has been examined by the change in the conductivity parameter, which is a major electrical property that affects the Electromagnetic reflectivity of the surface ground.

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A QoS Multicast Routing in TDMA-Based MANET Using Directional Antennas

A QoS Multicast Routing in TDMA-Based MANET Using Directional Antennas

Yuan Li, Xing Luo

Статья научная

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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A Real-Time Directed Routing Protocol Based on Projection of Convex Holes on Underwater Acoustic Networks

A Real-Time Directed Routing Protocol Based on Projection of Convex Holes on Underwater Acoustic Networks

Hu HongNing, Liu Zhong,Li Lu

Статья научная

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

A Rectangular Microstrip Patch Antenna for Wireless Communications Operates in Dual Band

Sheikh Dobir Hossain, K. M. Abdus Sobahan, Md. Khalid Hossain, Md. Masud Ahamed Akash, Rebeka Sultana, Md. Masum Billah

Статья научная

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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A Robust Approach for Best Probability Distribution Model Selection for Optimal Analysis of Radio Signals

A Robust Approach for Best Probability Distribution Model Selection for Optimal Analysis of Radio Signals

Joseph Isabona, Osaghae Edgar, Agbotiname Lucky Imoize, Ikechi Irisi

Статья научная

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

A Robust Autofocusing Approach for Estimating Directions-of-Arrival of Wideband Signals

GONG Bing, XU Yi-tao, LI Jia, LIU Zhong-jun

Статья научная

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

A Scalable Simulation Method for Network Attack

Jinsong Wang, Wenchao Dou, Kai Shi

Статья научная

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)

A Scheme on PN Code Tracking of DS/FH Signals for Telemetry, Tracking, and Commanding (TT&C)

Shaohua Chen, Jiaqi Li, Ju Wang

Статья научная

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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A Secure and Efficient Client-Side Encryption Scheme in Cloud Computing

A Secure and Efficient Client-Side Encryption Scheme in Cloud Computing

Tania Gaur, Divya sharma

Статья научная

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

A Security Routing Protocol Protecting Mobile Agent Against Cluster Attack

Wenbing Wang, Zhifeng Zhang

Статья научная

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

A Simple Algorithm to Strengthen the Brightness of Color Images

Hua ZHANG

Статья научная

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

A Source-Based Multicast Scheme in IEEE 802.16 Mesh Mode

Mortaza Maleki, Saleh Yousefi, Ali Azarpeyvand

Статья научная

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

A Speech Enhancement Method Based on Kalman Filtering

Chaogang Wu, Bo Li, Jin Zheng

Статья научная

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

A Structured Multi-signature Scheme Against Forgery Attack

Wenjun Luo, Changying Li

Статья научная

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

A Study and Analysis of Congestion Control Wireless Sensor Networks

Maninder Pal Singh, Kiranbir Kaur

Статья научная

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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