Railway Wireless Communications Channel Characterization (original) (raw)
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Because of the measurement restriction and measurement efficiency issues of applying conventional channel sounders in high-speed railway (HSR) scenarios, railway network based channel measurement methods have recently attracted much attention. A method that employs long-term evolution (LTE) railway networks to achieve channel measurements for HSR communications is presented. The principle of the method is described and the channel sounding performance is analyzed. The method is implemented by a novel measurement system which can enable the collection of time-frequency-space channel data. Based on the system, field measurements that consider both direct and relay coverage schemes are conducted on Beijing to Tianjin HSR in China. Measurement data are partitioned into single-link case in which the common channel parameters can be extracted and multi-link case in which the correlation between different links can be characterized. Finally, statistical results, involving path loss (PL), Ricean K-factor, root mean square (RMS) delay spread (DS), single-link spatial correlation (SC) and multi-link SC, are presented, which not only confirm the viability of the proposed method but also provide realistic channel characteristics available for the study of both existing HSR LTE systems and future HSR dedicated systems.
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Channel characterization is the prerequisite condition for the research and development of the next-generation high-speed railway (HSR) communication system. Train station is one of typical HSR scenarios, where channel characteristics have not yet been investigated sufficiently. In this paper, wideband multiantenna channel measurements are performed at 1.89 GHz in an open-type train station environment based on long-term evolution networks along Beijing to Tianjin HSR in China. Large-scale characteristics of the HSR station channel, focusing on path loss, shadow fading (SF), and the autocorrelation property of SF, are studied. Moreover, small-scale characteristics, such as Ricean K-factor, delay spread, and spatial correlation, are analyzed and modeled. In addition, the stationary region is characterized using the RUN test method. The obtained results provide useful information for deployment and assessment of the future HSR communication system in the HSR station scenario.
Wireless Technologies in the Railway: Train-to-Earth Wireless Communications}
Among the technologies of communication "train-to-earth", one of the most important advances of the last decade has been the GSM-R (Global System for Mobile Communications -Railway) (International Union of Railways, 2011). This system is based on the GSM telephony, but has been adapted to the field of railways. GSM-R is designed to exchange information between trains and control centres, and has as key advantages its low cost, and worldwide support.
2018
Global System for Mobile Communications – Railway (GSM-R) is one of the most used radio technologies in railway network for transmitting control information. However, nowadays IP-based technology is quite up-to-date and mature. Since there are many approaches for providing support to IP mobility and adaptable communications, it is important first to measure and understand the performance of IP networks in current railway routes. This paper provides the details of a framework entitled Channel Characterization Tool (CCT), a distributed network performance evaluation framework for the feasibility study of public IP networks in railway network. This paper describes the architecture of CCT, and some results obtained in field testing, as the first step in the validation of the framework. Finally, future research lines and conclusions are drawn.