Volume 13, Issue 1, March 2012

A Novel Design of Triple Frequency Dipole Antenna for Wireless Applications [Full Text]

Krishnendu Chattopadhyay, Soumava Mukherjee, Santanu Das and Sekhar Ranjan Bhadra Chaudhuri

Abstract—
A novel method for designing multi-frequency dipole antenna using proximity coupled feeding technique has been presented in this paper. A comparative study with two distinguished design methods (proximity coupling through longitudinal orientation of feed line & proximity coupling through transverse orientation of feed line) has been presented. The proposed antenna is designed to operate in Digital Video Broadcasting (DVB-SH: 2.170 GHz – 2.20 GHz), GPS (1.575 GHZ) & Multimedia Mobile Broadcasting (2.635 GHz – 2.660 GHZ) respectively. The design is fabricated and a comparative study between measured & simulated results is also discussed in this paper.


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Design of Modified Sierpinski Gasket Fractal Antenna
[Full Text]

Sanjeev Budhauliya, Suneel Yadav and Dr. P.K. Singhal

Abstract—
In this paper, the design and fabrication of modified sierpinski gasket fractal antenna is studied. The analysis took place between ranges of 0.5GHz to 4GHz. In particular, multiband frequencies of the modified sierpinski gasket fractal antenna are described. There are nine resonant frequencies appear at 1GHz, 1.79GHz, 1.88GHz, 3.40GHZ, 3.45GHz, 3.5GHz, 3.63GHZ, 3.68GHz, and 3.89GHz. In addition, on the basis of return losses, number of iterations, and radition patterns, multiband behavior of the modified sierpinski gasket fractal antenna is studied. IE3D software is used to simulate the results for return losses and radition patterns.

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Improving Handover Performance in HMIPv6 Using Area Border Routers in Wireless Mobile Networks [Full Text]

Md. Khaliluzzaman, Deepak Kumar Chy, and Madina Akter

Abstract—
Hierarchical Mobile IPv6 (HMIPv6) introduces a mobility anchor point (MAP) that localizes the signaling traffic and hence reduces the handoff latency. To support inter-area handovers, several methods have been proposed in the literature to address the challenging problems of minimizing the handoff signaling delay and call blocking probability for Hierarchical Mobile IP version 6 (HMIPV6). In this paper, we propose a new concept for inter-area handovers to solve signaling delay and call blocking probability. In this concept, the border zone is made between two different neighboring cells. Each neighboring cells is assigned as MAP region. Since the border zone is an overlapping MAP region, MHs can maintain the same MAP as long as they remain inside the border zone.

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Role of Haar and Daubechies Wavelet in Bangla Vowel Processing
[Full Text]

S. Haque and A. U. Khan

Abstract—
Wavelet Transform (WT) is applied to the seven Bangla vowel /i/, /e/, /æ/, /a/, / /, /o/, /u/ samples for analysis and synthesis. The performance of WT for synthesizing the selected Bangla vowels is measured by calculating Normalized Root Mean Square Error (NRMSE) between the original and synthesized signal and by calculating Retained Energy (RE) in the reconstructed waveform. It is observed from our study that WT with Haar, Daubechies wavelet at decomposition level 5 reproduces the Bangla vowel signal with a very small NRMSE and large RE. Among the tested wavelets, use of Haar wavelet produced NRMSE in the order of 10-15 and 92% RE, Daubechies wavelet produced NRMSE in the order of 10-11 and 98% RE. Although Daubechies wavelet produced NRMSE larger than Haar but RE in the first few coefficient obtained by Daubechies wavelet is much larger than Haar. Therefore, the performance of Daubechies wavelet is better than Haar wavelet for Bangla vowel reconstruction.

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Mobile Network Planning With WIMAX Technology for Territory of Gjakova City [Full Text]

Shkelzen S.Nuza, Artan Mazrekaj and Blerim Rexha

Abstract-
Wireless communication has now entered the second century of its use and has valuable merits of improving the quality of life of all mankind. Technologies for wireless and mobile communications replace each other every 2-3 years. WiMAX technology is abbreviation for “Worldwide Interoperability for Microwave Access”, a completely new protocol for communication that provides Internet access to fix and mobile users. The main purpose of WiMAX technology is to be estabilished as the "last mile" Internet access provider and thus replace the current technologies that today dominate the market. The current version of the Protocol provides Internet access up to 40 Mbps and this version is expected to increase the bandwidth. The telecommunications sector is covered by three operators (Kujtesa, Ipko and PTK) and leaves much to be desired in improving service quality and increasing technological penetration. This paper presents the possibilities of implementation of WiMAX technology in the territory of Gjakova. This paper analyzes the technical challenges and geographical constraints. Also in this paper are discussed some aspects of mobile network design, architecture of the network and at the end a comparison is also made with other existing communication technologies. Numerous simulations are done with software package and GIS spectra.

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Design and Analysis of Sierpinski Gasket Fractal Antenna [Full Text]

Praveen Tiwari, Rajneesh Chawhan, Dr. R. P. Agarwal and Sanjay Sharma


Abstract-
The progress in wireless communication systems and increasing of a variety wireless applications have remarkably increase the demand of multiband/wideband antennas with smaller dimensions than conventionally possible. This wider bandwidth and low profile antennas are in great demand for both commercial and military applications. This has initiated antenna research in various directions; one of which is by using fractal shaped antenna elements. Traditionally, each antenna operates at a single or dual frequency bands, where different antenna is needed for different applications. This cause a limited space and place problem.There are an important relation between antenna dimension and wavelength. This relation states if antenna size less than half of wave length, than antenna is not an efficient radiator because the radiation resistance, gain and bandwidth are deteriorated. The entire fractal antenna family shows multiband in resonant frequencies.

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Android Security Model that provide a Base Operating System [Full Text]

Ahmad Talha Siddiqui, Abu Sarwar Zamani and Jawed Ahmed

Abstract- Android is a software stack for mobile devices that includes an operating system, middleware and key applications The android provides the tools and APIs necessary to begin developing applications on the Android platform using programming language. Android is a widely anticipated open source operating system for mobile devices that provides a base operating system, an application middleware layer, a Java software development kit (SDK), and a collection of system applications.  Android has a unique security model, which focuses on putting the user in control of the device. Android devices however, don't come from one place, the open nature of the platform allows for proprietary extensions and changes. This paper we should already be familiar with Android's basic architecture and major abstractions including: Intents, Activities, Broadcast Receivers, Services, Content providers and Binder.  As android is open source we should also have this code available to us.  Both the java and C code is critical for understanding how Android works, and far more detailed than any of the platform documentation.


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Application of Positional Statistics and Simulation Means to Alamouti MIMO Systems Analysis [Full Text]

Jozef Pawelec and Krzysztof Kosmowski

Abstract- The two models of Alamouti MIMO2x2 system have been formed: the analytical and digital one. The first model is simple and reflects the quasi-static Rayleigh fading, the second one is advanced and processes the fast fading effects.  The results of analysis and simulations show that Alamouti MIMO architecture over performs the SISO systems mainly in the quasi-static environment.