5153 research outputs found
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Interference of 802.11B WLAN and Bluetooth: Analysis and Performance Evaluation
No full textIEEE 802.11 and Bluetooth, these two operating in the unlicensed 2.4 GHz frequency band are becoming more and more popular in the mobile computing world. The number of devices equipped with IEEE 802.11 and Bluetooth is growing drastically. Result is the number of co-located devices, say within 10 meters, grown to a limit, so that it may causes interference issues in the 2.4 GHz radio frequency spectrum. Bluetooth supports both voice synchronous connection oriented (SCO) data and asynchronous connection less (ACL) packets. In this paper, we investigate the interference issues of 2.4 GHz frequency band. In addition, this paper presents a new Bluetooth voice packet Synchronous Connection Oriented with Repeated Transmission (SCORT) scheme to optimize the performance of 2.4 GHz frequency band by minimizing the interference between Bluetooth and 802.11 wireless networks. For the sake of experimental verifications, we provide a comprehensive simulation results using Matlab Simulink
Strategies for Developing Your Successful Career in Information Technology and Technology Management (or any other field)
No full textProfessor Gad Selig's presentation on "Strategies for Developing Your Successful Career in Information Technology and Technology Management (or any other field)"
School of Engineering Newsletter Spring 2010
No full textThis news letter contains SOE Accomplishments, Faculty Notes, Student Awards, Scholarships, Faculty Publications, Alumni News, Laboratory Lineup and Colloquium Series
Security in Wireless Sensor Networks: Key Management Module in SOOAWSN
No full textDue to high restrictions in wireless sensor networks, where the resources are limited, clustering protocols for routing organization have been proposed in much research for increasing system throughput, decreasing system delay and saving energy. Even these algorithms have proposed some levels of security, but because of their dynamic nature of communication, most of their security solutions are not suitable. In this paper we focus on how to achieve the highest possible level of security by applying new key management technique that can be used during wireless sensor networks communications. For our proposal to be more effective and applicable to a large number of wireless sensor networks applications, we work on a special kind of architecture that have been proposed to cluster hierarchy of wireless sensor networks and we pick one of the most interesting protocols that have been proposed for this kind of architecture, which is LEACH. This proposal is a module of a complete solution that we are developing to cover all the aspects of wireless sensor networks communication which is labeled Secure Object Oriented Architecture for Wireless Sensor Networks (SOOAWSN)
A Novel Optimization of the Distance Source Routing (DSR) Protocol for the Mobile Ad Hoc Networks (MANET)
Get PDFThe final publication is available at www.springerlink.comThis paper presents a new scheme for the Distance Source Routing (DSR) protocol which shows the improvement over the two major metrics of the DSR protocol: Route Discovery and Route Maintenance. In addition, we present a mathematical model that includes probability density function for these two observed metrics. Our simulation results demonstrate a significant improvement in the route discovery, transmission time, and the overall network utilization. As an interesting side result, our analysis also shows that the proposed model can be used to effectively reduce the packet losses.http://link.springer.com/chapter/10.1007%2F978-90-481-3662-9_4
Investigating the Effects of Trees and Butterfly Barriers on the Performance of Optimistic GVT Algorithm
No full textThe final publication is available at www.springerlink.comThere is two approaches for handling timing constraints in a heterogeneous network; conservatives and optimistic algorithms. In optimistic algorithms, time constraints are allowed to be violated with the help of a time wrap algorithm. Global Virtue Time (GVT) is a necessary mechanism for implementing time wrap algorithm. Mattern [2] has introduced an algorithm for GVT based computation using a ring structure. which showed high latency. The performance of this optimistic algorithm is optimal since it gives accurate GVT approximation. However, this accurate GVT approximation comes at the expense of high GVT latency. Since this resultant GVT latency is not only high but may vary, the multiple processors involve in communication remain idle during that period of time. Consequently, the overall throughput of a parallel and distributed simulation system degrades significantly In this paper, we discuss the potential use of trees and (or) butterflies structures instead of the ring structure. We present our analysis to show the effect of these new mechanisms on the latency of the system.http://link.springer.com/chapter/10.1007%2F978-90-481-3660-5_7
Performance Evaluation of Routing Protocols in Wireless Sensor Networks
No full textThe efficiency of sensor networks strongly depends on the routing protocol used. In this paper, we analyze three different types of routing protocols: LEACH, PEGASIS, and VGA. Sensor networks are simulated using Sensoria simulator. Several simulations are conducted to analyze the performance of these protocols including the power consumption and overall network performance. The simulation results, using same limited sensing range value, show that PEGASIS outperforms all other protocols while LEACH has better performance than VGA. Furthermore, the paper investigates the power consumption for all protocols. On the average, VGA has the worst power consumption when the sensing range is limited, while VGA is the best when the sensing range is increased
