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随着高性能无线数据网络技术(如电气与电子工程师学会(IEEE)的802.11a/b/g,802.16e等)的广泛使用,铁路行业可利用标准的无线技术提高运输效率、加强监控和保证运输安全。在使用这些无线系统之前,必须解决一些关键问题,才能确保满足铁路部门关于移动性、运量、覆盖范围、多普勒作用及反应时间的要求。内布拉斯加州大学在联邦铁路局的资助下,开展了对在铁路移动环境下利用基于802.11a/b/g的无线网络可行性的研究。在位于林肯市附近的伯灵顿北圣菲铁路(BNSF)的黑斯廷斯分公司管辖范围内设计了3.5英里长的试验段,为满足研究的需要,设置了一系列的入口点。试验段利用详细的计算机模型和模拟试验,对不同速度列车环境下802.11a/b/g网络通过量进行了检测和分析,完成了理论研究。利用试验段的检测数据,对模拟结果进行了对比和论证,对基于802.11的网络适应移动列车的特性进行了分析。试验结果和分析证明,尽管在高速环境下,802.11标准的系统通过量有所下降,但只要提供覆盖范围,该系统仍可满足铁路运输的需要。因此,基于802.11的无线网络可满足列车乘务员、旅客和铁路工作人员对实时上网的要求,从而提高铁路运输的安全性及效率。
With the widespread use of high-performance wireless data networking technologies such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11a / b / g, 802.16e, etc., the railroad industry can utilize standard wireless technologies to increase transport efficiency, enhance monitoring and assurance Transport safety. Before using these wireless systems, a number of key issues had to be resolved in order to ensure that the rail sector’s requirements for mobility, volume, coverage, Doppler effect and response time were met. The University of Nebraska, funded by the Federal Railroad, conducted a study of the feasibility of using 802.11a / b / g based wireless networks in a railway mobile environment. A 3.5-mile pilot section was designed under the jurisdiction of the Hastings Branch of the Northern Santa Fe Railway (BNSF) in Burlington, near Lincoln, to provide a series of entry points to meet research needs. The experimental section uses the detailed computer model and simulation test to test and analyze the throughput of 802.11a / b / g network under different speed train environments, and completes the theoretical research. Using the test data of the test section, the simulation results are compared and demonstrated, and the characteristics of the network-adapted mobile trains based on 802.11 are analyzed. The test results and analysis show that although the system throughput of the 802.11 standard has declined in high-speed environments, the system can still meet the needs of railway transportation provided the coverage is provided. Therefore, 802.11-based wireless networks can meet the requirements of real-time Internet access by flight attendants, passengers and railway staff to improve the safety and efficiency of railway transportation.