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It is widely believed that IEEE 802.11 standard is aimed mainly for fixed indoor wireless local area networks and is not suited for mobile applications, even though the IEEE 802.11b systems may work in either infrastructure mode or ad hoc mode. The impact of node mobility on ad hoc network performance has already been studied intensively, but these studies mostly do not consider temporal fluctuations of the mobile wireless channel due to the Doppler shift. An investigation of the mobility impact on the performance of IEEE 802.11b ad hoc systems with Rician/Rayleigh fading under different node velocities is presented. A comprehensive and in-depth analysis of the impacts of a multitude of different signal distortions on an IEEE 802.11b system performance is also presented. Specifically, the authors study the bit-error rate performances with respect to node velocities for different modulation schemes. The simulation results show that, owing to its extremely low implementation and deployment cost, the current IEEE 802.11b standard has its potential to be deployed in a mobile ad hoc environment if the line-of-sight path between transmitter and receiver exists. 相似文献
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Ting Zhou Hamid Sharif Michael Hempel Puttipong Mahasukhon Wei Wang Hsiao-Hwa Chen 《Mobile Networks and Applications》2009,14(6):782-797
In this paper, we study the performance of IEEE 802.11a/b in a large-scale mobile railway networks and introduce our developed
passive measurement approach. To provide a comprehensive evaluation, we built an outdoor multi-hop multi-interface railroad
testbed (UNL-FRA Testbed), which consists of eight access points deployed along 3.5 mile of railroad track. We propose a novel
large-scale passive measurement approach that synchronizes the system clocks of our monitoring systems, merges packet traces
collected from multiple wireless channels across a multi-hop network, and enables a global performance view for the entire
monitored network and across multiple layers. Based on the testing data collected from 15 field experiments carried out using
BNSF locomotives and HyRail vehicles over a period of 18 months we conclude that in typical outdoor 802.11 railway environments
the wireless link quality, the channel assignment scheme, and the handoff latency have much more significant impacts on the
performance than the velocity. Furthermore, we discuss the implications of our conclusions on guaranteeing the quality of
mobile services. We believe this is the first analysis on such a scale for 802.11-family railway networks. 相似文献
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