Volume 1, Issue 2, March 2010

Flexible Authentication Technique for Ubiquitous Wireless Communication using Passport and Visa Tokens [Full Text]

A.M Almuhaideb, Faculty of Information Technology, Monash University, Melbourne, Australia
M.A. Alhabeeb, Faculty of Information Technology, Monash University, Melbourne, Australia
P.D Le, Faculty of Information Technology, Monash University, Melbourne, Australia
B.Srinivasan, Faculty of Information Technology, Monash University, Melbourne, Australia

Abstract— The development of mobile devices (CPU, memory, and storage) and the introduction of mobile networks (Ad-Hoc, Wi-Fi, WiMAX, and 3.5G) have opened new opportunities for next generation of mobile services. It becomes more convenience and desirable for mobile internet users to be connected everywhere. However, ubiquitous mobile access connectivity faces interoperation issues between wireless network providers and wireless network technologies. Although mobile users would like to get as many services as possible while they travel, there is a lack of technology to identify visited users in current foreign network authentication systems. This challenge lies in the fact that a foreign network provider does not initially have the authentication credentials of a mobile user. Existing approaches use roaming agreement to exchange authentication information between home network and foreign network. This paper proposes a roaming agreement-less approach designed based on our ubiquitous mobile access model. Our approach consist of two tokens, Passport (identification token) and Visa (authorisation token) to provide the mobile user with a flexible authentication method to access foreign network services. The security analysis indicates that our proposal is more suitable for ubiquitous mobile communication especially in roaming agreement-less environment.


Spoken Language Identification Using Hybrid Feature Extraction Methods [Full Text]

Pawan Kumar, Department of ECE, Birla Institute of Technology, Mesra, Ranchi, India
Astik Biswas, Department of ECE, Birla Institute of Technology, Mesra, Ranchi, India
A. N. Mishra, Department of ECE, Birla Institute of Technology, Mesra, Ranchi, India
Dr. Mahesh Chandra, Birla Institute of Techonology, Mesra, Ranchi, India

Abstract—This paper introduces and motivates the use of hybrid robust feature extraction technique for spoken language identification (LID) system. The speech recognizers use a parametric form of a signal to get the most important distinguishable features of speech signal for recognition task. In this paper Mel-frequency cepstral coefficients (MFCC), Perceptual linear prediction coefficients (PLP) along with two hybrid features are used for language Identification. Two hybrid features, Bark Frequency Cepstral Coefficients (BFCC) and Revised Perceptual Linear Prediction Coefficients (RPLP) were obtained from combination of MFCC and PLP. Two different classifiers, Vector Quantization (VQ) with Dynamic Time Warping (DTW) and Gaussian Mixture Model (GMM) were used for classification. The experiment shows better identification rate using hybrid feature extraction techniques compared to conventional feature extraction methods.BFCC has shown better performance than MFCC with both classifiers. RPLP along with GMM has shown best identification performance among all feature extraction techniques.


Wavelet-Based Mel-Frequency Cepstral Coefficients for Speaker Identification using Hidden Markov Models [Full Text]

M.I. Abdalla, Department of electronics and communications, Zagazig University, Egypt

H.S. Ali, Department of electronics and communications, Zagazig University, Egypt

Abstract—To improve the performance of speaker identification systems, an effective and robust method is proposed to extract speech features, capable of operating in noisy environment. Based on the time-frequency multi-resolution property of wavelet transform, the input speech signal is decomposed into various frequency channels. For capturing the characteristic of the signal, the Mel-Frequency Cepstral Coefficients (MFCCs) of the wavelet channels are calculated. Hidden Markov Models (HMMs) were used for the recognition stage as they give better recognition for the speaker’s features than Dynamic Time Warping (DTW). Comparison of the proposed approach with the MFCCs conventional feature extraction method shows that the proposed method not only effectively reduces the influence of noise, but also improves recognition. A recognition rate of 99.3% was obtained using the proposed feature extraction technique compared to 98.7% using the MFCCs. When the test patterns were corrupted by additive white Gaussian noise with 20 dB S/N ratio, the recognition rate was 97.3% using the proposed method compared to 93.3% using the MFCCs.


Bit Error Rate Performance Analysis on Modulation Techniques of Wideband Code Division Multiple Access [Full Text]

M. A. Masud, Dept. of Computer Science & Information Technology, Patuakhali Science and Technology University, Patuakhali, Bangladesh
M. Samsuzzaman, Dept. of Computer and Communication Engineering, Patuakhali Science and Technology University,Patuakhali, Bangladesh
M. A. Rahman, Faculty of Computer Science & Engineering, Patuakhali Science and Technology University, Patuakhali, Bangladesh

Abstract - In the beginning of 21st century there has been a dramatic shift in the market dynamics of telecommunication services. The transmission from base station to mobile or downlink transmission using M-ary Quadrature Amplitude modulation (QAM) and Quadrature phase shift keying (QPSK) modulation schemes are considered in Wideband-Code Division Multiple Access (W-CDMA) system. We have done the performance analysis of these modulation techniques when the system is subjected to Additive White Gaussian Noise (AWGN) and multipath Rayleigh fading are considered in the channel. The research has been performed by using MATLAB 7.6 for simulation and evaluation of Bit Error Rate (BER) and Signal-To-Noise Ratio (SNR) for W-CDMA system models. It is shows that the analysis of Quadrature phases shift key and 16-ary Quadrature Amplitude modulations which are being used in
wideband code division multiple access system, Therefore, the system could go for more suitable modulation technique to suit the channel quality, thus we can deliver the optimum and efficient data rate to mobile terminal.


A Mobile Message Scheduling and Delivery System using m-Learning framework [Full Text]

Moumita Majumder is with the Department of Computer Science and Engineering, Tripura University, India
Sumit Dhar is with the Department of Computer Science and Engineering, Tripura, India

Abstract— Wireless data communications in form of Short Message Service (SMS) and Wireless Access Protocols (WAP) browsers have gained global popularity, yet, not much has been done to extend the usage of these devices in electronic learning (e-learning) and information sharing. This project explores the extension of e learning into wireless/ handheld (W/H) computing devices with the help of a mobile learning (m-learning) framework. This framework provides the requirements to develop mlearning application that can be used to share academic and administrative information among people within the university campus. A prototype application has been developed to demonstrate the important functionality of the proposed system in simulated
environment. This system is supposed to work both in bulk SMS and interactive SMS delivery mode. Here we have combined both Short Message Service (SMS) and Wireless Access Protocols (WAP) browsers’ .SMS is used for Short and in time information delivery and WAP is used for detailed information delivery like course content, training material, interactive evolution tests etc. The push model is used for sending personalized multicasting messages to a group of mobile users with a common profile thereby improving the effectiveness and usefulness of the content delivered. Again pull mechanism can be applied for sending information as SMS when requested by end user in interactive SMS delivery mode. The main strength of the system is that, the actual SMS delivery application can be hosted on a mobile device, which can operate even when the device is on move.


Performance Analysis of Best suited Adaptive Equalization Algorithm for Optical Communication [Full Text]

Tarek Hasan-Al-Mahmud, Computer Science and Telecommunication Engineering Department, Noakhali Science and Technology University, Noakhali, Bangladesh
M.Mahbubur Rahman,  Information and Communication Engineering Department, Islamic University, Kushtia. Bangladesh
Sumon Kumar Debnath is with the Computer Science and Telecommunication Engineering Department, Noakhali Science and Technology University, Noakhali, Bangladesh

Abstract— Fiber optics is one of the highest bandwidth communication channel types in the current communication industry. The paper is to analyze a typical optical channel and perform channel equalization using an adaptive modified DFE with Activity Detection Guidance and Tap Decoupling algorithm. Evaluation can be made on the employment of the DFE algorithm and with enhancements, like Fractionally-Spaced equalization and Activity Detection Guidance, to improve its stability, steady-state error performance and convergence rate. The successful implementation of the Adaptive FS-DFE with ADG and TD technique offers an excellent alternative to linear equalization, which is known to be of little benefit for optical channels because of exorbitant noise enhancement. The FSE technique, when combined with the DFE, would offer improved effectiveness to amplitude distortion. As the impulse response of a typical optical link would have regions that are essentially zero, the employment of the activity detection scheme with Tap Decoupling would further enhance the steady-state error performance and convergence rate.


Web-Based Learning and Training for Virtual Metrology Lab [Full Text]

Fahad Al-Zahrani, Computer Science Department, Faculty of Engineering, Albaha University, 65451 Albaha, KSA

Abstract— The use of World Web Wide for distance education has received increasing attention over the past decades. The real challenge of adapting this technology for engineering education and training is to facilitate the laboratory experiments via Internet. In the sciences, measurement plays an important role. The accuracy of the measurement, as well as the units, help scientists to better understand phenomena occurring in nature. This paper introduces Metrology educators to the use and adoption of Java-applets in order to create virtual, online Metrology laboratories for students. These techniques have been used to successfully form a laboratory course which augments the more conventional lectures in concepts of Metrology course at Faculty of Engineering, Albaha
University, KSA. Improvements of the package are still undergoing to incorporate Web-based technologies (Internet home page, HTML, Java programming etc…). This Web-based education and training has been successfully class-tested within an undergraduate preliminary year engineering course and students reported a positive experience with its use. The use of these labs should be self-explanatory and their reliable operation has been thoroughly tested.