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