GSM-R网络小区覆盖半径的算法研究

随着GSM R网络在中国铁路应用的需要,网络预规划得到广泛的重视。针对中国铁路和环境的实际情况结合GSM R网络技术,研究了预规划GSM R网络小区覆盖半径的算法。本文主要从理论分析、已知条件和算法三方面来系统的介绍预规划小区覆盖半径的算法。该算法充分考虑各种影响小区覆盖半径规划的因素,并在链路预算中进行详细的分析。     

城市轨道交通专用无线通信系统线网频率规划

阐述城市轨道交通专用无线通信系统线网频率规划的必要性;分析大规模无线通信系统存在的各种频率干扰;介绍轨道交通线网频率规划的方法和重点考虑的问题。     

广州地铁CBTC信号系统车-地通信传输方式的分析比较

介绍了广州地铁CBTC信号系统车-地双向连续通信传输方式感应环线、无线天线、裂缝波导管的应用情况,并从原理、功能、特性和运营维护等方面进行了详细描述和分析比较。     

高速铁路障碍物侵限报警方式的研究

为最大可能降低障碍物侵限对运输生产组织造成影响,以提高应急处置效率为目标,根据既有高速铁路电务设备技术条件,从有效性、时效性、可靠性等方面对比分析了4种高速铁路障碍物侵限报警方式,为工程应用提供参考.     

浅谈光纤直放站在山区铁路中的应用

介绍光纤直放站在山区铁路的覆盖方式,使之有效解决无线列车调度信号覆盖问题。     

轨道交通TETRA系统的二次开发应用

根据TETRA数字集群设备在轨道交通的特殊需求及应用经验,阐明如何通过基于TET-RA技术平台进行二次开发以满足地铁无线调度需求。     

多普勒效应与频率容差对无线列调的影响

随着列车速度的不断提高,多普勒效应的影响逐渐增强。在频率容差和多普勒效应的共同作用下,有可能造成在现有场强分布情况下,音频输出信纳比会显著低于TB／T3052—2002的规定。建立更严格的频率容差标准,成为消除这种影响的较好方法。     

磁悬浮列车电磁干扰的测试及研究

针对上海磁悬浮列车在沿线某一定范围内的无线电噪声测试及结果，就磁悬浮列车对周围环境中的重要发信场和收信场以及移动通信等的潜在干扰作初步的评价和研究，为今后磁悬浮铁路的建设提供有意义的预测和建议。     

Quantitative analysis of probe data characteristics: Coverage,speed bias and congestion detection precision

Abstract

In recent years, there has been a growing desire for the use of probe vehicle technology for congestion detection and general infrastructure performance assessment. Unlike costly traditional data collection by loop detectors, wide area detection using probe-based traffic data is significantly different in terms of the nature of data collection, measurement technique, coverage, pricing, and so on. Although many researches have studied probe-based data, there remains critical questions such as data coverage and penetration over time, or the influential factors in the accuracy of probe data. This research studied probe-sourced data from INRIX, to profoundly explore some of these questions. First, to explore coverage and penetration, INRIX real-time data was illustrated temporally over the entire state of Iowa, demonstrating the growth in real-time data over a 4-year timespan. Furthermore, the availability of INRIX real-time and historical data based on type of road and time of day, were explored. Second, a comparison was made with Wavetronix smart sensors, commonly used sensors in traffic management, to explore INRIX’s speed data quality. A statistical analysis on the behavior of INRIX speed bias, identified some of the influential factors in defining the magnitude of speed bias. Finally, the accuracy and reliability of INRIX for congestion detection purposes was investigated based on the road segment characteristics and the congestion type. Overall, this work sheds light onto some of the less explored aspects of INRIX probe-based data to help traffic managers and decision makers in better understanding this source of data and any resultant analyses.     

铁路站内无线控车通信信道的研究与仿真

铁路进行通信前期设计规划过程中,为了缩短设计周期,需要尽快获得网络信道主要性能指标,如误码率(BER)、端到端延时、吞吐量等Qo S,而目前勘测人员现场测量所耗时间较长,而且获得的信号量与以上性能指标不能直接匹配。为了改变这种现状,现采用OPNET计算机仿真工具与铁路现场的参数相结合的方法进行建模,软件仿真大大缩短通信设计时间,并且得到GSM-R网与WLAN同等测试环境下参数的结果,仿真得出的结论还可为前期现场通信设计施工提供部分有效的数据支撑。