2.2 GHz, the Fresnel zone formed between the transmission and reception antennas is relatively large, and therefore, the Fresnel zone is not blocked by pedestrians completely when they block the line between the Tx and Rx antennas, and significant drops in the received levels do not occur and the distributions of the received levels change smoothly. Conversely, there are cases in which most of the Fresnel zone is blocked by pedestrians in 19.85 GHz, and significant drops occur due to these phenomena. The literature [4] has confirmed that increasing the transmission antenna height is effective in reducing the influence of human body blockage. This can be explained by considering the Fresnel zone as well. 11.2.2 Urban Microcellular Scenario 11.2.2.1 Measurement of Path Loss Path loss measurements were carried out in a dense urban area in Tokyo [2, 5, 6]. Figure 11.13 shows a picture of the measurement site and Tx antenna setting. In the measurement site, the average building height is 18 m, the average road width is 29 m, and buildings occupy 46% of the area. A CW is transmitted from a base station (BS) antenna, and the received power level is recorded at the MS while the MS is moving. The BS antenna height is set to 10 m. The MS antenna is established on a measurement 11.2 Propagation Measurements Above 6 GHz Tx antennas Figure 11.13 Measurement site and setting of Tx antenna. f = 4.7 GHz f = 26.4 GHz f = 37.1 GHz 40 60 80 100 Distance, d (m) Distance, d (m) Figure 11.14 Path loss VS. distance: (a) LOS, (b) NLOS. vehicle, and the height of the antenna is 2.5 m. The antennas used for the BS and MS are sleeve antennas. The measured frequencies are 0.81, 2.2, 4.7, 26.4, and 37.1 GHz. The distance between the BS and the MS was between 30 and 676 m in the LOS case, and between 56 and 959 m in the NLOS case. The path loss is obtained every meter by taking the median value of the received power levels within 10 m (before and after 5 m). Figure 11.14 shows the path loss over the distance from the BS to the MS at 4.7, 26.4