Computer Science & Communications

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3 - 10 GHz Ultra-Wideband Low-Noise Amplifier Using Inductive-Series Peaking Technique with Cascode Common-Source Circuit
(Scientific Research Publishing, 2011-10) Wu, Chia-Song; Lin, Tah-Yeong; Chang, Chien-Huang; Wu, Hsien-Ming
The objective of this paper is to investigate a ultra-wideband (UWB) low noise amplifier (LNA) by utilizing a two-stage cascade circuit schematic associated with inductive-series peaking technique, which can improve the bandwidth in the 3-10 GHz microwave monolithic integrated circuit (MMIC). The proposed UWB LNA amplifier was implemented with both co-planer waveguide (CPW) layout and 0.15-μm GaAs D-mode pHEMT technology. Based on those technologies, this proposed UWB LNA with a chip size of 1.5 mm x 1.4 mm, obtained a flatness gain 3-dB bandwidth of 4 - 8 GHz, the constant gain of 4 dB, noise figure lower than 5 dB, and the return loss better than –8.5 dB. Based on our experimental results, the low noise amplifier using the inductive-series peaking technique can obtain a wider bandwidth, low power consumption and high flatness of gain in the 3 - 10 GHz. Finally, the overall LNA characterization exhibits ultra-wide bandwidth and low noise characterization, which illustrates that the proposed UWB LNA has a compact size and favorable RF characteristics. This UWB LNA circuit demonstrated the high RF characterization and could provide for the low noise micro-wave circuit applications.
Ad Hoc Network Hybrid Management Protocol Based on Genetic Classifiers
(Scientific Research Publishing, 2010-10) Garzia, Fabio; Perna, Cristina; Cusani, Roberto
The purpose of this paper is to solve the problem of Ad Hoc network routing protocol using a Genetic Algorithm based approach. In particular, the greater reliability and efficiency, in term of duration of communication paths, due to the introduction of Genetic Classifier is demonstrated.
Address Resolution Protocol (ARP): Spoofing Attack and Proposed Defense
(Scientific Research Publishing, 2016-07) Al Sukkar, Ghazi; Saifan, Ramzi; Khwaldeh, Sufian; Maqableh, Mahmoud; Jafar, Iyad
Networks have become an integral part of today’s world. The ease of deployment, low-cost and high data rates have contributed significantly to their popularity. There are many protocols that are tailored to ease the process of establishing these networks. Nevertheless, security-wise precautions were not taken in some of them. In this paper, we expose some of the vulnerability that exists in a commonly and widely used network protocol, the Address Resolution Protocol (ARP) protocol. Effectively, we will implement a user friendly and an easy-to-use tool that exploits the weaknesses of this protocol to deceive a victim’s machine and a router through creating a sort of Man-in-the-Middle (MITM) attack. In MITM, all of the data going out or to the victim machine will pass first through the attacker’s machine. This enables the attacker to inspect victim’s data packets, extract valuable data (like passwords) that belong to the victim and manipulate these data packets. We suggest and implement a defense mechanism and tool that counters this attack, warns the user, and exposes some information about the attacker to isolate him. GNU/Linux is chosen as an operating system to implement both the attack and the defense tools. The results show the success of the defense mechanism in detecting the ARP related attacks in a very simple and efficient way.
Advances in Intrusion Detection System for WLAN
(Scientific Research Publishing, 2011-08) Kaur, Ravneet
A wireless network is not as secure as compare the wired network because the data is transferred on air so any intruder can use hacking techniques to access that data. Indeed it is difficult to protect the data and provide the user a secure information system for lifetime. An intrusions detection system aim to detect the different attacks against network and system. An intrusion detection system should be capable for detecting the misuse of the network whether it will be by the authenticated user or by an attacker. Cross layer based technique help to make decision based on two layer physical layer where we compute RSS value and on MAC layer where one compute RTS-CTS time taken. This will reduce the positive false rate.They detect attempts and active misuse either by legitimate users of the information systems or by external. The paper has higlighted the advances in intrusion detection in wireless local area network.
Analysis of Geo Positioning System Using RF & DA
(Scientific Research Publishing, 2016-04) Kohli, Jaspreet K.; Potgantwar, Amol
Indoor positioning systems (IPSs) have been intended to provide position information of persons and devices. Higher user percentage of handheld devices such as tablets or mobile phones had led to the development of a number of indoor positioning systems. In this research a work on a real time portable RFID indoor positioning device such as on smartphone will be performed. The personal networks will be designed to meet the users’ needs and interconnect users’ devices equipped with different communications technologies in various places to form one network for better result. Radio frequency identification (RFID) with directional antenna has proved its potential for locating objects in indoor environment. Hence, the proposed device idea will be used to exploit various unknown locations in an indoor environment such as college campus; this interpretation will rely on Wireless LAN, Received Signal Strength values from Access Points (AP) in specific mentioned arenas; these APs will be monitored constantly by RFID with directional antenna (DA) and handheld devices. For obtaining the better results from existing devices, algorithms of Range Estimation are proposed, which can be used on various handheld devices for locating indoor objects.
Aperture Coupled Microstrip Antenna for Dual-Band
(Scientific Research Publishing, 2011-04) Vishwakarma, Rajesh K.; Tiwari, Sanjay
This paper presents air gap aperture coupled microstrip antenna for dual-band operation over the frequency range of (2.9 to 6.0 GHz). This antenna differs from any other microstrip antenna with their feeding structure of the radiating patch element. Input signal couples to the radiating patch trough the aperture that exists on the ground plane of microstrip feed line. The dual-band achieved by variation of air gap [2 mm to 6 mm] between single patch antenna and aper-ture coupled microstrip antenna. The main advantage of this type antenna is increased the bandwidth of the antenna as compared to a single layered patch antenna. The two resonant frequencies can vary over a wide frequency range and the input impedance is easily matched for both frequencies. The obtain ratios of resonance frequencies are variable from 2.1 GHz to 1.1 GHz with increasing the air gap between single patch and aperture coupled microstrip antenna. The measured return loss [–14 dB] exhibits an impedance bandwidth of 35%. The input impedance and VSWR return loss have been measured with the help of Network analyzer.
Bandwidth Enhancement and Size Reduction of Microstrip Patch Antenna by Magnetoinductive Waveguide Loading
(Scientific Research Publishing, 2011-01) Joshi, Jayant G.; Pattnaik, Shyam S.; Devi, Swapna; Lohokare, Mohan R.
A planar magnetoinductive (MI) waveguide loaded rectangular microstrip patch antenna is presented and discussed. The MI waveguide consists of two planar metamaterial split squared ring resonators (SSRRs) placed in between two microstrip lines. The backward wave propagation takes place through this structure. The rectangular microstrip patch antenna is magnetically coupled to the MI waveguide. The unloaded rectangular microstrip patch antenna resonates at 37.10 GHz. When loaded with planar MI waveguide, its resonant frequency is reduced to 9.38 GHz with the bandwidth and gain of 44% and 4.16 dBi respectively. In loaded condition, the dimension of antenna is 12.50 mm × 3.70 mm (0.390 λ × 0.115 λ). The appreciable bandwidth is achieved in such a small size antenna. The pass band frequency of MI waveguide is predicted by using the theoretical model of dispersion equation. The effective medium theory is used to verify the metamaterial characteristics of SSRR. The simulated results and theoretical calculations are also presented. The results show that the proposed method can be used to design compact and high bandwidth microstrip patch antennas.
Based on Adaptive Backstepping Error Control for Permanent Magnet Synchronous Motor
(Scientific Research Publishing, 2016-05) Jiang, Hua; Lin, Da; Liu, Yongchun; Song, Hong
Permanent Magnet Synchronous Motor (PMSM) displays chaotic phenomenon when PMSM in power on or power off. At present, there are many methods to control chaos in PMSM. However, there appears oscillation in course of control chaos in PMSM, which has an effect on practical application. This paper proposes error control based on adaptive backstepping to control chaos in PMSM; an error control item is added in each step virtual control design which has control effect of unknown dynamical error on system. This scheme can eliminate oscillation in course of control chaos. Finally, the simulation results show the effectiveness of theoretical analysis.
Capacitive Model and S-Parameters of Double-Pole Four-Throw Double-Gate RF CMOS Switch
(Scientific Research Publishing, 2011-01) Srivastava, Viranjay M.; Yadav, Kalyan S.; Singh, Ghanashyam
In this paper, we have analyzed the Double-Pole Four-Throw Double-Gate Radio-Frequency Complementary Metal-Oxide-Semiconductor (DP4T DG RF CMOS) switch using S-parameters for 1 GHz to 60 GHz of frequency range. DP4T DG RF CMOS switch for operation at high frequency is also analyzed with its capacitive model. The re-sults for the development of this proposed switch include the basics of the circuit elements in terms of capacitance, re-sistance, impedance, admittance, series equivalent and parallel equivalent of this network at different frequencies which are present in this switch whatever they are ON or OFF.
Cloud Computing of E-Government
(Scientific Research Publishing, 2016-02) Almarabeh, Tamara; Majdalawi, Yousef Kh.; Mohammad, Hiba
Over the past years, many businesses, government and individuals have been started to adopt the internet and web-based technologies in their works to take benefits of costs reduction and better utilization of existing resources. The cloud computing is a new way of computing which aims to provide better communication style and storage resources in a safe environment via the internet platform. The E-governments around the world are facing the continued budget challenges and increasing in the size of their computational data so that they need to find ways to deliver their services to citizens as economically as possible without compromising the achievement of desired outcomes. Considering E-government is one of the sectors that is trying to provide services via the internet so the cloud computing can be a suitable model for implementing E-government architecture to improve E-government efficiency and user satisfaction. In this paper, the adoption of cloud computing strategy in implementing E-government services has been studied by focusing on the relationship between E-government and cloud computing by listing the benefits of creation E-government based on cloud computing. Finally in this paper, the challenges faced the implementation of cloud computing for E-government are discussed in details. As a result from understanding the importance of cloud computing as new, green and cheap technology is contributed to fixing and minimizing the existing problems and challenges in E-government so that the developed and developing countries need to achieve E-government based on cloud computing.
Cloud Computing Solution and Services for RFID Based Supply Chain Management
(Scientific Research Publishing, 2013-09) Jamal, S. M. Khalid; Omer, A.; Qureshi, Asiya A. S.
Deploying and Implementing RFID Systems for tracking and controlling products in supply chain management is not affordable for small and midsized companies due to its complexity, cost, and difficulties pertaining data management and maintenance. Cloud computing can be used to mitigate the risks associated with the implementation and deployment of RFID based on system in supply chain management because the complex system for data filtering, management and maintenance can be implemented on the cloud that otherwise requires the purchase of new hardware, staff and professional services.
Cognitive Radio Sensing Using Hilbert Huang Transform
(Scientific Research Publishing, 2010-07) Narayanankutty, K. A.; A. Nair, Abhijith; Soori, Dilip; Pradeep, Deepak; Teja, V. Ravi; K.B., Vishnu
Vast segments of the frequency spectrum are reserved for primary (licensed) users. These legacy users often un-der-utilize their reserved spectrum thus causing bandwidth waste. The unlicensed (secondary) users can take advantage of this fact and exploit the spectral holes (vacant spectrum segments). Since spectrum occupancy is transient in nature it is imperative that the spectral holes are identified as fast as possible. To accomplish this, we propose a novel adaptive spectrum sensing procedure. This procedure scans a wideband spectrum using Hilbert Huang Transform and detects the spectral holes present in the spectrum.
Colluding Jamming Attack on a Grand Coalition by Aggrieved Nodes
(Scientific Research Publishing, 2016-03) Sharah, Ashraf A.; Oyedare, Taiwo; Shetty, Sachin
Mobile Ad-Hoc Networks (MANETs) are highly vulnerable to insider jamming attacks. Several approaches to detect insider jammers in MANET have been proposed. However, once the insider jammer is detected and removed from the network, it is possible for the insider jammer to leverage the knowledge of insider information to launch a future attack. In this paper, we focus on collaborative smart jamming attacks, where the attackers who have been detected as insider jammers in a MANET, return to attack the MANET based on the knowledge learned. The MANET uses a reputation-based coalition game to detect insider jammers. In the collaborative smart jamming attack, two or more smart jammers will form a coalition to attack the coalitions in the MANET. The smart jammers were detected and then excluded from their initial coalition, they then regrouped to start their own coalition and share previously gained knowledge about legitimate nodes in their erstwhile coalition with the aim of achieving a highly coordinated successful jamming attack on the legitimate coalition. The success of the attack largely depends on the insider jammer’s collective knowledge about the MANET. We present a technique to appropriately represent knowledge gathered by insider jammers which would lead to a successful attack. Simulation results in NS2 depict that coalition of jammers can leverage past knowledge to successfully attack MANET.
Comparison of Indoor Localization Systems Based on Wireless Communications
(Scientific Research Publishing, 2011-10) Dalce, Rejane; Val, Thierry; Bossche, Adrien V.
Localization using a Wireless Sensor Network (WSN) has become a field of interest for researchers in the past years. This information is expected to aid in routing, systems maintenance and health monitoring. For example, many projects aiming to monitor the elderly at home include a personal area network (PAN) which can provide current location of the patient to the medical staff. This article presents an overview of the current trends in this domain. We introduce the mathematical tools used to determine position then we introduce a selection of range-free and range-based proposals. Finally, we provide a comparison of these techniques and suggest possible areas of improvement.
A Comprehensive Parametric Study of Planar Inverted-F Antenna
(Scientific Research Publishing, 2012-01) Chattha, Hassan T.; Huang, Yi; Ishfaq, Muhammad K.; Boyes, Stephen J.
This paper presents a comprehensive numerical and experimental study of Planar Inverted-F Antennas (PIFA) involving all the parameters which may affect the characteristics of PIFA. It is found that PIFA characteristics are affected by a number of parameters including the dimensions of the ground plane, length, width, height and position of the top plate, positions and widths of shorting pin/plate and feed pin/plate. It is also found that the width of feed plate plays an important role in broadening the antenna bandwidth. It is shown that a fractional impedance bandwidth up to 65% can be obtained using an optimized design. Furthermore, a new empirical formula is introduced for the estimation of the central operational frequency of PIFA. These results are very useful for aiding PIFA design in practical applications.
Design of a Low Loss RF Mixer in Ku-Band (12 - 18 GHz)
(Scientific Research Publishing, 2012-01) Shah, Sanjeev K.; Chauhan, Rudra P.; Singh, Sanjay; Pandey, Lalit; Singh, Sandeep
The goal of this paper is to design and develop low conversion loss mixers at Ku Band (12 - 18 GHz) in microstrip line configuration. The Ku-band (Kurtz-under band) is primarily used for satellite Communications, particularly for editing and broadcasting satellite television. CAD tools (Agilent’s Advance Design System software) have been used for simulation and optimization of the circuits. 180 degree balanced mixer configuration has been adopted due to better RF to LO isolation requirement. The circuit is designed on microstrip line using RT Duroid (Dielectric Constant = 2.22). Initially a rat race coupler (180 degree hybrid) was designed and simulated and optimized for required performance successfully.
Design of an Acoustic Communication System Based on FHMA for Multiple Underwater Vehicles
(Scientific Research Publishing, 2010-07) Zhao, Zixin; Guo, Shuxiang
This paper designs an underwater acoustic communication system based on tamed spread spectrum and Frequency Hopping Multiple Access (FHMA) for multiple underwater vehicles. In this system, multiple underwater vehicles can communicate with the console on the water surface simultaneously successfully. The communication system is com-posed of tamed spread spectrum modulation and demodulation, frequency hopping modulation and demodulation with synchronization function, 4FSK modulation and demodulation and Rake Receiver. In order to make the system more feasible, underwater channel and the effect of user number on Bit Error Ratio (BER) are also taken into account. The simulation results indicate that it is feasible to use this system to accomplish underwater communication reliably for multiple users due to the low BER.
Design of Aperture Coupled Microstrip Antenna Using Radial Basis Function Networks
(Scientific Research Publishing, 2010-10) Bose, Tanushree; Gupta, Nisha
This paper, two Artificial Neural Network (ANN) models using radial basis function (RBF) nets are developed for the design of Aperture Coupled Microstrip Antennas (ACMSA) for different number of design parameters. The effect of increasing the number of design parameters on the ANN model is also discussed in this work. The performances of the models when compared are found that on decreasing the number of design parameters, accuracy of the model is in-creased. The results given by the prepared models are comparable with the results of the IE3D software. So, these models are accurate enough to measure the design parameters of ACMSAs. Thus the neural network approach elimi-nates the long time consuming process of finding various designing parameters using costly software packages.
Design of Low Power and High Speed CMOS Comparator for A/D Converter Application
(Scientific Research Publishing, 2012-04) Yewale, Shubhara; Gamad, Radheshyam
This paper presents an improved method for design of CMOS comparator based on a preamplifier-latch circuit driven by a clock. Design is intended to be implemented in Sigma-delta Analog-to-Digital Converter (ADC). The main advantage of this design is capable to reduce power dissipation and increase speed of an ADC. The design is simulated in 0.18 μm CMOS Technology with Cadence environment. Proposed design exhibits good accuracy and a low power consumption about 102 μW with operating sampling frequency 125 MHz and 1.8 V supply. Simulation results are reported and compared with earlier work done and improvements are observed in this work.
Effect of Changes in Sea-Surface State on Statistical Characteristics of Sea Clutter with X-Band Radar
(Scientific Research Publishing, 2011-07) Ishii, Seishiro; Sayama, Syuji; Mizutani, Koichi
We have made observations of X-band radar sea clutter from the sea surface and sea-surface state in the Uraga Suido Traffic Route, which is used by ships entering and leaving Tokyo Bay, and the nearby Daini Kaiho Sea Fortress. We estimated the distributions of reflected amplitudes due to sea clutter using models that assume Weibull, Log-Weibull, Log-normal, and K-distributions. We then compared the results of estimating these distributions with sea-surface state data to investigate the effects of changes in the sea-surface state on the statistical characteristics of sea clutter. As a result, we showed that observed sub-ranges not containing a target conformed better to the Weibull distribution regardless of Significant Wave Height (SWH). Further, sub-ranges conforming to the Log-Weibull or Log-normal distribution in areas contained a target when the SWH was large, and as SWH decreases, sub-ranges conforming to a Log-normal. We also showed that for observed sub-ranges not containing a target, the shape parameter, c, of both Weibull and Log-Weibull distribution correlated with SWH. The correlation between wave period and shape parameters of Weibull and Log-Weibull distribution showed a weak correlation.

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