关键词: 铁路长大隧道, 数字直放站, 拉远距离, 切换区设备间距

Abstract: The wireless coverage of long railway tunnels is mainly by the way of extending the distance of repeater from the base station, however, the distance cannot be extended without limitation. At the same time, for the long railway tunnel scenario, when a single set of remote terminal is set up, the spacing of 1.5 km does not necessarily meet the requirements of the design specifications for overlapping area. In this paper, based on the two networking modes of repeater, aiming at the characteristics of GSM and the repeater as well as the propagation characteristics of leaky cables and optical cables, the ideal extended distance of the remote terminal is given through formula derivation. Based on the link budget analysis of the single-point fault solution of the repeater in the long railway tunnel, the general spacing between devices in the switching zone is proposed.

Key words: long railway tunnel, digital repeater, extended distance, spacing between devices in switching zone