 m 7th floor (Near) (Far) 2.5 m Figure 11.5 Measurement site and conditions. floors. Note that the line-of-sight (LOS) distance in the figure means the distance from the window facing the Tx. The measured frequencies are 5.2 and 26.4 GHz. In this case, the difference in the building penetration loss between the frequencies is expected to be 14.1 dB (=20log(26.4/5.2)) if the direct wave is dominant, or 21.2 dB (=30log(26.4/5.2)) if the diffracted wave is dominant. Note that the frequency dependence of glass is not considered. Figure 11.6 shows the measurement results. Here, the vertical axis represents the median value in the near or far region. The average value of the difference between frequencies is 16-22 dB. 11.2.1.4 Scattering Effect on Rough Surface Measurements were carried out for the building facing the parking space [1]. Figure 11.7 shows the measurement site and conditions. In the surroundings, there is an aluminum wall with a regular unevenness on the order of millimeters. In front of the aluminum wall, antennas of the transmitters (Txs) and receivers (Rxs) of the channel sounders for 11.2 Propagation Measurements Above 6 GHz Figure 11.6 Building penetration loss Near region Far region on each floor. 5.2 GHz 26.4 GHz Floor Surface of wall (Period: 3 cm, height: 7 mm) Entrance shutter (Glass) 5.81 m Measurement route Figure 11.7 Measurement site and conditions. the 2 GHz and 20 GHz bands were located. The distance between the Txs and the Rxs was fixed as 3 m. The distances between the Txs, the Rxs, and the wall were also fixed. In the measurements, the Txs and the Rxs were moved parallel to the wall within 50 cm in 30 S and recorded data 30 times at 1 S intervals. For each time of recoding, 10 delay profiles with 1 ms interval were recorded. From the delay profiles, the received powers due to scattering of the aluminum wall were obtained and normalized by the power which was calculated for the case of no roughness and no reflection loss of the wall. Figure 11.8 shows the measurement results of the rela