(10) The basic propagation loss is defined as: Ls (11) in equations (9) to (11) has been experimentally determined to be 20 m. Rs on measurements, a median value is given by: (12) Millimetre-wave propagation At frequencies above about 10 GHz, the breakpoint distance in equation (3) is far beyond the Rbp expected maximum cell radius (500 m). This means that no fourth-power law is expected in this frequency band. Hence the power distance decayrate will nearly follow the free-space law with a path-loss exponent of about 1.9-2.2. With directional antennas, the path loss when the boresights of the antennas are aligned is by dB (13) where is the path loss exponent, is the distance between Station 1 and Station 2 and is the n d L0 path loss at the reference distance For a reference distance at 1 m, and assuming free-space d0. d0 propagation log10 where is in MHz. and are attenuation by atmospheric L0=20 f f Lgas Lrain, −28 gases and by rain which can be calculated from Recommendation ITU-R P.676 and Recommendation ITUR P.530, respectively. Values of path loss exponent are listed in Table 7. n 7 Directional path loss coefficients for millimetre-wave propagation Half power beam width Path loss exponent Frequency (degree) Type of environment (GHz) Tx Ant Rx Ant n very high-rise 30 10 2.21 28 Urban low-rise 30 10 2.06 60 Urban low 15.4 15.4 1.9 4.1.3 Site-specific for NLoS situations This situation is depicted as the paths between D and E in Fig. 1. 4.1.3.1 Frequency range from 800 to 2 000 MHz For NLoS2 situations where both antennas are below roof-top level, diffracted and reflected waves at the corners of the street crossings have to be considered (see Fig. 3). dB (14) where:
(10) The basic propagation loss Ls is defined as: (11) Rs in equations (9) to (11) has been experimentally determined to be 20 m. on measurements, a median value is given by: (12) Millimetre-wave propagation At frequencies above about 10 GHz, the breakpoint distance Rbp in equation (3) is far beyond the expected maximum cell radius (500 m). This means that no fourth-power law is expected in this frequency band. Hence the power distance decayrate will nearly follow the free-space law with a path-loss exponent of about 1.9-2.2. With directional antennas, the path loss when the boresights of the antennas are aligned is by dB (13) where n is the path loss exponent, d is the distance between Station 1 and Station 2 and L0 is the path loss at the reference distance d0. For a reference distance d0 at 1 m, and assuming free-space propagation L0=20 log10 f −28 where f is in MHz. Lgas and Lrain, are attenuation by atmospheric gases and by rain which can be calculated from Recommendation ITU-R P.676 and Recommendation ITUR P.530, respectively. Values of path loss exponent n are listed in Table 7. 7 Directional path loss coefficients for millimetre-wave propagation Frequency (GHz) Type of environment Half power beam width (degree) Path loss exponent Tx Ant Rx Ant n 28 very high-rise 30 10 2.21 Urban low-rise 30 10 2.06 60 Urban low 15.4 15.4 1.9 4.1.3 Site-specific for NLoS situations This situation is depicted as the paths between D and E in Fig. 1. 4.1.3.1 Frequency range from 800 to 2 000 MHz For NLoS2 situations where both antennas are below roof-top level, diffracted and reflected waves at the corners of the street crossings have to be considered (see Fig. 3). dB (14) where:
R-REC-P.1411-9-201706-I!!MSW-E.docx