To cover the high demand for wireless data services for different applications in the wireless networks, different frequency bands below 6 GHz and in millimeter-wave (mm-Wave) above 24 GHz are proposed for the fifth generation (5G) of communication. The communication network is supposed to handle, among others, indoor traffic in normal situations as well as during emergencies. The stairway is one of those areas which has less network traffic during normal conditions but increases significantly during emergencies. This paper presents the radio propagation in an indoor stairway environment based on wideband measurements in the line of sight (LOS) at two candidate frequencies for 5G wireless networks, namely, 3.5 GHz and 28 GHz. The path loss, root mean square (RMS) delay spread, K-factor results, and analysis are provided. The close-in free-space reference distance (CI), floating intercept (FI), and the close-in free-space reference distance with frequency weighting (CIF) path loss models are provided. The channel parameters such as the number of clusters, the ray and cluster arrival rates, and the ray and cluster decay factors are also obtained for both frequencies. The findings of the path loss show that the CI, FI, and CIF models fit the measured data well in both frequencies with the path loss exponent identical to the free-space path loss. Based on clustering results, it is found that the cluster decay rates are identical at both bands. The results from this and previous measurements indicate that at least one access point is required for every two sections of the stairway to support good coverage along the stairwell area in 5G wireless networks. Moreover, for 5G systems utilizing mm-Wave frequency bands, one access point for each stair section might be necessary for increased reliability of the 5G network in stairwell environments.

中文翻译：

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5G无线网络在3.5 GHz和28 GHz室内楼梯间环境中的无线电传播测量

为了满足无线网络中不同应用对无线数据服务的高要求，对于第五代（5G）通信，提出了6 GHz以下和24 GHz以上毫米波（mm-Wave）的不同频段。在正常情况下以及紧急情况下，通信网络都应处理室内流量。楼梯是那些在正常情况下网络流量较少但在紧急情况下会显着增加的区域之一。本文基于在5G无线网络的两个候选频率（即3.5 GHz和28 GHz）的视线（LOS）上的宽带测量结果，介绍了室内楼梯环境中的无线电传播。路径损耗，均方根（RMS）延迟扩展K因素结果，并提供分析。提供了近距离自由空间参考距离（CI），浮动截距（FI）和带频率加权的近距离自由空间参考距离（CIF）路径损耗模型。对于这两个频率，还可以获得信道参数，例如集群数，射线和集群到达率以及射线和集群衰减因子。路径损耗的发现表明，CI，FI和CIF模型在两个频率上均很好地拟合了测量数据，并且路径损耗指数与自由空间路径损耗相同。根据聚类结果，发现在两个频带上的聚类衰减率相同。此和之前的测量结果表明，楼梯的每两个部分至少需要一个接入点，以支持5G无线网络中沿楼梯间区域的良好覆盖。此外，对于利用毫米波频段的5G系统，可能需要为每个楼梯部分提供一个接入点，以提高楼梯间环境中5G网络的可靠性。