Recommendation ITU-R P.1411-10 provides guidance on outdoor short-range propagation over the path lengths below about 1 km and over the frequency range 300 MHz to 100 GHz. For typical scenarios in urban and suburban areas, three closed-form algorithms for site-general models are defined in this Recommendation and implemented in SEAMCAT:
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This site-general model is applicable to situations where both the transmitting and receiving stations are located below-rooftop, regardless of their antenna heights. The median basic transmission loss is given by: site-general model is provided by the following equation:
PLd
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with an additive zero mean Gaussian random variable N(0,σ) with
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The recommended values for LoS and NLoS situations to be used for below-rooftop propagation in urban and suburban environments are provided in Table 1.
TABLE 4
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Table 1: Basic transmission loss coefficients for ITU-R P.1411-10 §4.1.1
Frequency (GHz) | Distance (m) | Environment | LoS/ NloS | α | β | γ | σ |
0.8-73 | 5-660 | Urban high-rise, Urban low-rise/Suburban | LoS | 2.12 | 29.2 | 2.11 | 5.06 |
0.8-38 | 30-715 | Urban high-rise | NloS | 4.00 | 10.2 | 2.36 | 7.6 |
10-73 | 30-250 | Urban low-rise/Suburban | NloS | 5.06 | -4.68 | 2.02 | 9.33 |
0.8-73 | 30-170 | Residential | NloS | 3.01 | 18.8 | 2.07 | 3.07 |
Description of the model ITU-R P.1411-10 §4.2.
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See description of the model ITU-R P.1411-9 §4.2.1
Description of the model ITU-R P.1411-9 §4.3.
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See description of the model ITU-R P.1411-9 §4.3.1
SEAMCAT Specific Implementation
The site-general propagation models from §4.1.1 and §4.2.1 are valid only for a given range of Tx-Rx 3D distances , If the Tx-Rx 3D distances in the simulation scenario are outside this range, SEAMCAT will inform the user about that in a consistency check before the simulation starts. The simulations can still be run and the values of the basic transmission loss will be computed using the formulas from Recommendation ITU-R P.1411 even for distances that are outside the range of validity.
A special care needs to be taken for distances as they can result in non-physical values of the basic transmission loss that can be smaller than free-space loss, or even be negative. In that particular case, the median values of the basic transmission loss are capped from below by the free space loss as follows:
Compute PL=PL_1411
if d<d_min:
Compute PL_FreeSpace
PL=max〖(PL,〗 PL_FreeSpace)
Input parameters
The input parameters for the three site-general propagation models from ITU-R P.1411-10 are shown in SEAMCAT GUI in Figure 2 and defined in Table 4.
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Description | Symbol | Type | Unit | Comments | ||||||
Variations | - | B | - | Variation in basic transmission loss (applicable to models §4.1.1 and §4.2.1) | ||||||
Local environment | - | - | - | Environment of the propagation: Suburban, Urban, Dense Urban, Urban/High-rise, Urban/Low-rise, Residential, LoS, NLoS | ||||||
Location percentage | - | S | % | Percentage of locations: between 0% and 100 % (applicable to model §4.3.1) | ||||||
LoS/NLoS transition width | - | S | m | Average street width: typical value is 20 m (applicable to model §4.3.1) |
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