respectively. The measurement area is surrounded by some buildings. For the measurement, we rotated the horn antenna and measured the PDPs. The ranges of rotation varied from 11.2 Propagation Measurements Above 6 GHz 6F Building 5F Building B7(1F) 31.0 m 21.0 m 8F Building MS side 2F Building docomo Figure 11.15 Measurement environment. - 180° to + -180° in 1° steps for the azimuth angle, and from -50° to 0° in 10° steps for the elevation angle. In the data analysis, all the PDPs were combined and paths were detected. The delay times, azimuth angles, elevation angles, and path gains of the paths were used to calcu- late the delay spreads (DSs), azimuth spreads (ASDs), and elevation spreads (ESDs). The K-Power-Mean method was used to estimate the number of clusters. Table 11.3 shows the number of paths, DSs, ASDs, ESDs, and the number of clusters depending on the Tx's locations. From this table, it is verified that the differences of these values when the Tx location changes from MS1 to MS6 are not large. The average of the numbers of paths for all locations is about 30, and the average of the DSs, ASDs, and ESDs are 49.6 ns, 19.7°, and 2.0°, respectively. The average of the numbers of clusters is about five. This means that, for the case of using the high frequency band for an outdoor small cell environment like an open square, the numbers of paths and clusters tend to be small. 11.2.3 Indoor Hotspot Scenario 11.2.3.1 Measurement of Path Loss Path loss measurements are carried out in an office of NTT DOCOMO R&D center in Yokosuka, Japan [6]. Figure 11.16 shows the measurement site and measurement route. The measurement was performed in only the LOS environment. In the measurements, a CW is transmitted from a BS antenna, and the received power level is recorded at the MS while the MS is moving. The BS antenna height is set to 2.6 m. The MS antenna is established on a hand truck with a height of 1.5 m. The antennas used for the BS and MS are sleeve antennas. The measurement frequency is 19.85 GHz. The distance betw