5.4.2 Below-rooftops propagation environments 22 shows the results of the number of signal components for below-rooftops environments from measurements in different scenarios such as type of environments, frequency bands and antenna heights. TABLE 22 Maximum number of signal components for below-rooftops environments Antenna height Maximum number of components (m) Type of Time Frequency Range environment resolution (GHz) (m) 3 dB 5 dB 10 dB h1 h2 20 ns 3.35 4 1.6 0-200 2 3 2 4 5 6 0-1 000 2 3 2 4 5 9 20 ns 8.45 4 1.6 0-200 1 3 2 3 4 6 Urban 0-1 000 1 2 2 4 4 8 20 ns 15.75 4 1.6 0-200 1 3 2 3 4 5 0-1 000 2 3 2 4 6 10 Residential 20 ns 3.35 4 2.7 0-480 2 2 2 2 2 3 5.5 Fading characteristics The fading depth, which is defined as the difference between the 50% value and the 1% value in the cumulative probability of received signal levels, is expressed as a function of the product (2fLmax MHz·m) of the received bandwidth 2f MHz and the maximum difference in propagation path lengths m as shown in Fig. 13. is the maximum difference in propagation path Lmax Lmax lengths between components whose level is larger than the threshold, which is 20 dB lower than the highest level of the indirect waves as shown in Fig. 14. In this Figure, in decibels is the power a ratio of the direct to the sum of indirect waves, and = dB represents a NLoS situation. When a − 2fLmax is less than 10 MHz·m, the received signal levels in LoS and NLoS situations follow Rayleigh and Nakagami-Rice distributions, corresponding to a narrow-band fading region. When it is larger than 10 MHz·m, it corresponds to a wideband fading region, where the fading depth becomes smaller and the received signal levels follow neither Rayleigh nor Nakagami-Rice distributions. FIGURE 13 Relationship between fading and 2fLmax FIGURE 14 Model for calculating Lmax
5.4.2 Below-rooftops propagation environments 22 shows the results of the number of signal components for below-rooftops environments from measurements in different scenarios such as type of environments, frequency bands and antenna heights. TABLE 22 Maximum number of signal components for below-rooftops environments Type of environment Time resolution Frequency (GHz) Antenna height (m) Range (m) Maximum number of components h1 h2 3 dB 5 dB 10 dB Urban 20 ns 3.35 4 1.6 0-200 0-1 000 2 2 3 3 2 2 4 4 5 5 6 9 20 ns 8.45 4 1.6 0-200 0-1 000 1 1 3 2 2 2 3 4 4 4 6 8 20 ns 15.75 4 1.6 0-200 0-1 000 1 2 3 3 2 2 3 4 4 6 5 10 Residential 20 ns 3.35 4 2.7 0-480 2 2 2 2 2 3 5.5 Fading characteristics The fading depth, which is defined as the difference between the 50% value and the 1% value in the cumulative probability of received signal levels, is expressed as a function of the product (2fLmax MHz·m) of the received bandwidth 2f MHz and the maximum difference in propagation path lengths Lmax m as shown in Fig. 13. Lmax is the maximum difference in propagation path lengths between components whose level is larger than the threshold, which is 20 dB lower than the highest level of the indirect waves as shown in Fig. 14. In this Figure, a in decibels is the power ratio of the direct to the sum of indirect waves, and a = − dB represents a NLoS situation. When 2fLmax is less than 10 MHz·m, the received signal levels in LoS and NLoS situations follow Rayleigh and Nakagami-Rice distributions, corresponding to a narrow-band fading region. When it is larger than 10 MHz·m, it corresponds to a wideband fading region, where the fading depth becomes smaller and the received signal levels follow neither Rayleigh nor Nakagami-Rice distributions. FIGURE 13 Relationship between fading and 2fLmax FIGURE 14 Model for calculating Lmax
R-REC-P.1411-9-201706-I!!MSW-E.docx