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02/2012; , ISBN: 978-953-307-956-1
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ABSTRACT: In recent years, very interesting researches are concentrated to develop several protocols for Wireless sensor networks (WSN) and to explore WSN in various scenarios. The standardization of the IEEE 802.15.4 protocol as a flexible communication solution for low-rate wireless sensor networks leads to the widespread deployment of this technology in many potential applications with different requirements especially in industrial automation. The IEEE 802.15.4 specifies physical and media access control layers that could be optimized to ensure low-power consumption and to guarantee real-time constraints by using its guaranteed time slot (GTS) mechanism and enabling Beacon mode. Our focus in this paper is on real-time capabilities and reliability. We analyzed and compared the performance of the IEEE 802.15.4 standard using OMNET++ Simulator. Among the objectives of our study is to outline which degree the standard accomplish real time requirements. Different application scenarios were been evaluated. The analysis gives a full understanding of the behavior of the IEEE 802.15.4 access mechanism concerning data delivery delay, goodput, throughput and packet errors rate metrics. We have focused on single sink scenarios and we have analyzed some network performance according to nodes number. Our simulation results pave the way for an efficient dimensioning and deploying of an IEEE 802.15.4 cluster.
International Journal of Computer Networks & Communications. 10/2011; 315.
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IJEHMC. 01/2011; 2:50-66.
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IJEHMC. 01/2011; 2:1-30.
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ABSTRACT: Wireless sensor networks (WSN) were been explored in various scenarios and several protocols have been developed. With the
standardization of the IEEE 802.15.4 protocol, sensor networks became interesting for application in industrial automation.
The IEEE 802.15.4 specifies physical and media access control layers that could be optimized to ensure low-power consumption.
The focus in this paper is on real-time capabilities and reliability. We analyzed and compared the performance of the IEEE
802.15.4 standard using OMNET++ Simulator. Among the objectives of our study is to outline which degree the standard accomplish
real time requirements. Different application scenarios were been evaluated. Performance parameters such as data delivery
delay and goodput are the main factors, which been considered in our study. We have focused on single sink scenarios and we
have analyzed some network performance according to nodes number. Our simulation results can be explored for planning and
deploying IEEE 802.15.4 based sensor networks with specific performance demands. Besides, specific protocol limitations in
real time environment can be identified and solutions can be suggested.
KeywordsIEEE 802.15.4–Zigbee–OMNET++–Real time
12/2010: pages 54-68;
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ABSTRACT: This paper proposes, a hardware implementation of Wireless Mesh Networks (WMN) medium Access Controller (MAC) layer transmitter. In the literature a lot of works are focused on WMN routing protocol as well as performance analysis and software integration of WMN units, however few works deals with WMN hardware implementation. In this field our contribution is to conceive and to implements on FPGA a WMN MAC transmitter module. Our implementation, written in hardware description language (HDL) is based on the IEEE 802.11 s standard. The hardware implementation retains a good performance in speed. Comment: Lamia Chaari, Rim Ayadi and Lotfi Kamoun, "Conception and FPGA implementation of IEEE 802.11s mesh network MAC layer transmitter"
04/2010;
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ABSTRACT: Wireless sensors networks performance are strictly related to the medium access mechanism. An effective one, require non-conventional paradigms for protocol design due to several constraints. An adequate equilibrium between communication improvement and data processing capabilities must be accomplished. To achieve low power operation, several MAC protocols already proposed for WSN. The aim of this paper is to survey and to analyze the most energy efficient MAC protocol in order to categorize them and to compare their performances. Furthermore we have implemented some of WSN MAC protocol under OMNET++ with the purpose to evaluate their performances. Comment: Lamia Chaari and Lotfi Kamoun, "Wireless sensors networks MAC protocols analysis", Journal of Telecommunications, Volume 2, Issue 1, p42-48, April 2010
04/2010;
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ABSTRACT: Software Defined Radio (SDR) is a technology that facilitates the implementation of adaptable and flexible transmission schemes and protocols of different radio and wireless communications standards. Although the potential of SDR technology, there are several design challenges and implementation issues. In this paper, we are focused on the properties of universal radio terminal, the techniques that are used to obtain multimode operation and functionalities of baseband processing module. This paper discusses and compares different approaches for implementing baseband-processing unit using reconfigurable architectures.
Wireless Conference 2006 - Enabling Technologies for Wireless Multimedia Communications (European Wireless), 12th European; 05/2006
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ABSTRACT: BCH (Bose, Chaudhuri, Hocquenghem) codes are becoming more frequently used due to the availability of VLSI components. BCH codes have a powerful random and burst correcting ability. BCH codes also leave the data in its original form which allows video decoders to be specified with "optional" error correction. The BCH code can be adapted towards the burst error correcting capabilities and this will be shown in the contribution. This paper investigates the effects of noise-induced transmission errors on the performance of BCH coding methods for different errors correction capability. First, the relations among the bit error rate, signal-to-noise ratio (SNR), and code lengths are analyzed. Further, the transmission performance of BCH codes association with different modem schemes are analyzed. Also QCIF image transmission quality over BCH codes for different errors capability are simulated, discussed and compared. The results listed in this article denote the effects of the using BCH codes in a selected method. Based on this analysis an adaptive BCH scheme is proposed to pick the correcting capabilities that offers the best reconstructed image quality for each average SNR.
