Recommendation ITU-R P.2001-6
Policy on Intellectual Property Right (IPR)
Annex Wide-range propagation model Description of the
calculation method
1
Introduction
1.1 Applicability
1.2 Reciprocity, and the designation of
terminals
1.3 Iteration
1.4 Organization of the Recommendation
1.5 Style of description
2
Inputs
2.1 Terrain profile
2.2 Other inputs
2.3 Constants
2.4 Integral digital products
3
Preliminary calculations
3.1 Limited percentage times
3.2 Path length, intermediate points, and
fraction over sea
3.3 Antenna altitudes and path inclination
3.4 Climatic parameters
3.4.1 Refractivity in the
lowest 1 km
3.4.2 Refractivity in the
lowest 65 m
3.4.3 Precipitation parameters
3.5 Effective Earth-radius geometry
3.6 Wavelength
3.7 Path classification and terminal horizon
parameters
Case 1. Path is LoS
Case 2. Path is NLoS
Continue for both cases
3.8 Effective heights and path roughness
parameter
3.9 Tropospheric-scatter path segments
3.10 Gaseous absorption on surface paths
3.11 Free-space basic transmission loss
3.12 Knife-edge diffraction loss
4
Obtaining predictions for the principal sub-models
4.1 Sub-model 1. Normal propagation close to the
surface of the Earth
4.2 Sub-model 2. Anomalous propagation
4.3 Sub-model 3. Troposcatter propagation
4.4 Sub-model 4. Sporadic-E
5
Combining sub-model results
5.1 Combining sub-models 1 and 2
5.2 Combining sub-models 1 + 2, 3 and 4
5.3 Combining sub-models within a Monte-Carlo
simulator
Attachment A Diffraction loss
A.1 Introduction
A.2 Spherical-Earth diffraction loss
A.3 First-term spherical-Earth diffraction loss
Start of calculation to be performed twice
A.4 Bullington diffraction loss for actual
profile
Case 1. Path is LoS for effective Earth curvature not
exceeded for p% time
Case 2. Path is NLoS for effective Earth curvature not
exceeded for p% time
A.5 Bullington diffraction loss for a notional
smooth profile
Case 1. Path is LoS for effective Earth radius exceeded
for p% time
Case 2. Path is NLoS for effective Earth radius
exceeded for p% time
Attachment B Clear-air enhancements and fading
B.1 Introduction
B.2 Characterize multi-path activity
For LoS path:
For NLoS path:
B.3 Calculation of the notional zero-fade annual
percentage time
B.4 Percentage time a given clear-air fade level
is exceeded on a surface path
B.5 Percentage time a given clear-air fade level
is exceeded on a troposcatter path
Attachment C Precipitation fading
C.1 Introduction
C.2 Preliminary calculations
C.3 Percentage time a given precipitation fade
level is exceeded
C.4 Melting-layer model
C.5 Path-averaged multiplier
Start of calculation for each slice index:
Attachment D Anomalous/layer-reflection model
D.1 Characterize the radio-climatic zones
dominating the path
Large bodies of inland water
Large inland lake or wet-land areas
D.2 Point incidence of ducting
D.3 Site-shielding losses with respect to the
anomalous propagation mechanism
D.4 Over-sea surface duct coupling corrections
D.5 Total coupling loss to the anomalous
propagation mechanism
D.6 Angular-distance dependent loss
D.7 Distance and time-dependent loss
D.8 Basic transmission loss associated with
ducting
Attachment E Troposcatter
E.1 Introduction
E.2 Climatic classification
E.3 Calculation of troposcatter basic
transmission loss
Attachment F Attenuation due to gaseous absorption
F.1 Introduction
F.2 Gaseous absorption for surface path
F.3 Gaseous absorption for a troposcatter path
F.4 Gaseous absorption for
terminal/common-volume troposcatter path
F.5 Water-vapour density in rain
F.6 Specific sea-level attenuations
Attachment G Sporadic-E propagation
G.1 Derivation of foEs
G.2 1-hop propagation
G.3 2-hop propagation
G.4 Basic transmission loss
Attachment H Great-circle path calculations
H.1 Introduction
H.2 Path length and bearing
H.3 Calculation of intermediate path point
Attachment I Iterative procedure to invert a
cumulative distribution function
I.1 Introduction
I.2 Iteration method
Stage 1: setting the search range
Stage 2: binary search
Attachment J Structure of the wide-range propagation
model
J.1 Introduction
J.2 Combining the sub-models