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Location Agent: A Study Using Different Wireless Protocols for Indoor Localization
Ana Régia de M. Neves,
Humphrey C. Fonseca,
Célia G. Ralha
Issue:
Volume 1, Issue 1, May 2013
Pages:
1-6
Received:
15 March 2013
Published:
2 May 2013
Abstract: Context-aware systems have received greater interest in the computing community. In order to provide relevant services at context-aware applications, the first task is to locate the user, what can be done preferably dynamically and intelligently. However, indoor mobile users localization is not a trivial problem, since it involves checking various devices, transmitting signals simultaneously on the same radio frequency, with possibly the three existing wireless network protocols: Wi-Fi, Bluetooth and ZigBee. In this direction, this paper presents an agent-based architecture with the Location Agent module defined for context-aware applications that uses three artificial neural network algorithms trained for the different protocols: backpropagation, backpropagation with momentum and levenberg–marquardt. Considering the research experimental aspects, a study is presented to compare the neural network algorithms including performance, regression analysis, precision and accuracy. The results indicate that the backpropagation algorithm trained with Bluetooth provides better accuracy (the average error of 0.42 meters) and the backpropagation trained with Wi-Fi provides better precision (73%). We consider our approach promising since the Location Agent has a quality of service component associated with the neural network algorithms that can choose the best received signal strength to locate indoor users.
Abstract: Context-aware systems have received greater interest in the computing community. In order to provide relevant services at context-aware applications, the first task is to locate the user, what can be done preferably dynamically and intelligently. However, indoor mobile users localization is not a trivial problem, since it involves checking various ...
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The Details of Virtual Contention Window Concept for 802.11 IBSS Wireless Local Area Network Mathematic Modeling
Anton V. Lazebnyy,
Volodymyr S. Lazebnyy
Issue:
Volume 1, Issue 1, May 2013
Pages:
7-13
Received:
24 March 2013
Published:
2 May 2013
Abstract: The concept of a virtual contention window for assessment of temporal and probabilistic characteristics of the processes occurring in the wireless LAN 802.11 is considered. The relations for determining the transmission time delay of the data package, the uneven of transmission time, throughput of wireless channel, the probability of packet loss for networks with saturated load are proposed in this paper.
Abstract: The concept of a virtual contention window for assessment of temporal and probabilistic characteristics of the processes occurring in the wireless LAN 802.11 is considered. The relations for determining the transmission time delay of the data package, the uneven of transmission time, throughput of wireless channel, the probability of packet loss fo...
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An Adaptive Energy-Aware Transmission Scheme for Wireless Sensor Networks
Abdullahi Ibrahim Abdu,
Muhammed Salamah
Issue:
Volume 1, Issue 1, May 2013
Pages:
14-20
Received:
17 April 2013
Published:
2 May 2013
Abstract: In this paper, we proposed a scheme to extend the lifetime of a wireless sensor network, in which each sensor node decides whether to transmit a message or not and with what range to transmit the message, based on its own energy reserve level and the information contained in each message. The information content in each message is determined through a system of rules describing prospective events in the sensed environment, and how important such events are. The messages deemed to be important are propagated by all sensor nodes and with different transmission ranges depending on nodes energy resource level, while messages deemed to be less important are handled by only the nodes with high energy reserves level and transmitted with different transmission ranges based on nodes energy resource level. The results show that by adapting the transmission range based on nodes energy reserve and message importance, a considerable increase in network lifetime and connectivity can be achieved.
Abstract: In this paper, we proposed a scheme to extend the lifetime of a wireless sensor network, in which each sensor node decides whether to transmit a message or not and with what range to transmit the message, based on its own energy reserve level and the information contained in each message. The information content in each message is determined throug...
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Performance Evaluation of Cooperative Multi-Layer IDMA Communications with Amplify-and-Forward Protocol
Basma A. Mahmoud,
Esam A. A. Hagras,
Mohamed A. Abo El-Dhab
Issue:
Volume 1, Issue 1, May 2013
Pages:
21-25
Received:
23 April 2013
Published:
30 May 2013
Abstract: In this paper, we consider the Bit Error Rate (BER) performance analysis of a cooperative relay communication system for Multi-Layer IDMA (ML-IDMA) using Maximal-Ratio-Combining (MRC) technique. We examine the effect of layers number on the performance and derive the average bit error probability of the Amplify-and-Forward (AF) relay scheme by using the closed-form relay link Signal-to-Noise Ratio (SNR). The proposed system has been simulated to evaluate the performance of ML-IDMA with different numbers of layers and different number of relays in the ML-IDMA cooperative environment. The simulation results show that the BER performance has been improved by about 4dB in the case of double layer (K=2) IDMA system with 4-relays, also, the saving in the band width is 50%. Finally, the BER performance has been degraded with increasing in the number of layers and the proposed system has improved the band width by about 1/K.
Abstract: In this paper, we consider the Bit Error Rate (BER) performance analysis of a cooperative relay communication system for Multi-Layer IDMA (ML-IDMA) using Maximal-Ratio-Combining (MRC) technique. We examine the effect of layers number on the performance and derive the average bit error probability of the Amplify-and-Forward (AF) relay scheme by usin...
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Two Aspect Authentication System Using Secure Mobile Devices
S. Uvaraj,
S. Suresh,
N. KannaiyaRaja
Issue:
Volume 1, Issue 1, May 2013
Pages:
26-34
Received:
16 May 2013
Published:
10 June 2013
Abstract: Mobile devices are becoming more pervasive and more advanced with respect to their processing power and memory size. Relying on the personalized and trusted nature of such devices, security features can be deployed on them in order to uniquely identify a user to a service provider. In this paper, we present a strong authentication mechanism that exploits the use of mobile devices to provide a two-aspect authentication system. Our approach uses a combination of one-time passwords, as the first authentication aspect, and credentials stored on a mobile device, as the second aspect, to offer a strong and secure authentication approach. By Adding an SMS-based mechanism is implemented as both a backup mechanism for retrieving the password and as a possible mean of synchronization. We also present an analysis of the security and usability of this mechanism. The security protocol is analyzed against an adversary model; this evaluation proves that our method is safe against various attacks, most importantly key logging, shoulder surfing, and phishing attacks. Our simulation result evaluation shows that, although our technique does add a layer of indirectness that lessens usability; participants were willing to trade-off that usability for enhanced security once they became aware of the potential threats when using an untrusted computer.
Abstract: Mobile devices are becoming more pervasive and more advanced with respect to their processing power and memory size. Relying on the personalized and trusted nature of such devices, security features can be deployed on them in order to uniquely identify a user to a service provider. In this paper, we present a strong authentication mechanism that ex...
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Effect of Temperature Variation on Microstrip Patch Antenna and Temperature Compensation Technique
Sarita Maurya,
R. L. Yadava,
R. K. Yadav
Issue:
Volume 1, Issue 1, May 2013
Pages:
35-40
Received:
30 May 2013
Published:
20 June 2013
Abstract: This paper describes the effect of temperature variation on microstrip patch antenna for different substrate materials. Eight materials are chosen as substrate and the effect of temperature variation is studied on each substrate material. A technique of temperature compensation has also been developed with substrate height variation. It is also seen that the change in resonance frequency due to variation of temperature can be compensated by varying the height of the substrate. The proposed antenna is designed and simulated by using HFSS software.
Abstract: This paper describes the effect of temperature variation on microstrip patch antenna for different substrate materials. Eight materials are chosen as substrate and the effect of temperature variation is studied on each substrate material. A technique of temperature compensation has also been developed with substrate height variation. It is also see...
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Performance Analysis of MSE-OFDM System
Poonam Singh,
Saswat Chakrabarti
Issue:
Volume 1, Issue 1, May 2013
Pages:
41-50
Received:
14 May 2013
Published:
20 June 2013
Abstract: In this paper we analyze the effects of interchannel interference (ICI) and intersymbol interference (ISI) on the performance of a Multi-Symbol Encapsulated Orthogonal Frequency Division Multiplexing (MSE-OFDM) system. MSE-OFDM is a bandwidth efficient OFDM scheme, where a number of OFDM symbols are grouped together as a frame and protected by one single cyclic prefix. This reduces the extent of redundancy caused by the CP and increases the bandwidth efficiency of the system. We have derived expressions for probability of error for MSE-OFDM in presence of ICI and ISI, which result from the time variation and delay spread of mobile channels. Both analysis and simulation results are presented for the MSE-OFDM system and are found to be almost identical.
Abstract: In this paper we analyze the effects of interchannel interference (ICI) and intersymbol interference (ISI) on the performance of a Multi-Symbol Encapsulated Orthogonal Frequency Division Multiplexing (MSE-OFDM) system. MSE-OFDM is a bandwidth efficient OFDM scheme, where a number of OFDM symbols are grouped together as a frame and protected by one ...
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Internet Authentication and Billing (Hotspot) System Using MikroTik Router Operating System
Adam Mohammed Saliu,
Mohammed Idris Kolo,
Mohammed Kudu Muhammad,
Lukman Abiodun Nafiu
Issue:
Volume 1, Issue 1, May 2013
Pages:
51-57
Received:
5 June 2013
Published:
30 June 2013
Abstract: This paper is based on using MikroTik Router Operating System (OS) to build an authentication and billing System. This kind of system is always used to create security, billing and administration of users on a network connected to the Internet. It is used to restrict usage and bandwidth allocations to users. A case study of Federal University of Technology, Minna website was considered and it was found that additional stages and radius server services should be incorporated with the antenna design in its hotspot server.
Abstract: This paper is based on using MikroTik Router Operating System (OS) to build an authentication and billing System. This kind of system is always used to create security, billing and administration of users on a network connected to the Internet. It is used to restrict usage and bandwidth allocations to users. A case study of Federal University of Te...
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