Guide to the application of the propagation methods of Radiocommunication Study Group 3




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Rec. ITU-R P.1144-3 1

RECOMMENDATION ITU-R P.1144-3

Guide to the application of the propagation methods of Radiocommunication Study Group 3


(1995-1999-2001-2001)

The ITU Radiocommunication Assembly,

considering

a) that there is a need to assist users of the ITU-R Recommendations P Series (developed by Radiocommunication Study Group 3),



recommends

1 that the information contained in Table 1 be used for guidance on the application of the various propagation methods contained in the ITU-R Recommendations P Series (developed by Radiocommunication Study Group 3);

2 that the information contained in Table 2 and Annex 1 be used for guidance on the use of the various digital maps of geophysical parameters necessary for the application of the propagation methods in recommends 1 above.

NOTE 1 – For each of the ITU-R Recommendations in Table 1, there are associated information columns to indicate:



Application: the service(s) or application for which the Recommendation is intended.

Type: the situation to which the Recommendation applies, such as point-to-point, point-to-area, line-of-sight, etc.

Output: the output parameter value produced by the method of the Recommendation, such as path loss.

Frequency: the applicable frequency range of the Recommendation.

Distance: the applicable distance range of the Recommendation.

% time: the applicable time percentage values or range of values of the Recommendation; % time is the percentage of time that the predicted signal is exceeded during an average year.

% location: the applicable per cent location range of the Recommendation; % location is the percentage of locations within, say, a square with 100 to 200 m sides that the predicted signal is exceeded.

Terminal height: the applicable terminal antenna height range of the Recommendation.

Input data: a list of parameters used by the method of the Recommendation; the list is ordered by the importance of the parameter and, in some instances, default values may be used.

The information, as shown in Table 1, is already provided in the Recommendations themselves; however, the Table allows users to quickly scan the capabilities (and limitations) of the Recommendations without the requirement to search through the text.



TABLE 1

ITU-R radiowave propagation prediction methods


Method

Application

Type

Output

Frequency

Distance

% time

% location

Terminal height

Input data

Rec. ITU-R P.368

All services

Point-to-point

Field strength

10 kHz to 30 MHz

1 to 10 000 km

Not applicable

Not applicable

Ground-based

Frequency
Ground conductivity

Rec. ITU-R P.1546

Terrestrial services

Point-to-area

Field strength

30 to 3 000 MHz

1 to 1 000 km

1 to 50

1 to 99

Tx/base: effective height from less than 0 m to 3 000 m
Rx/mobile:  

Terrain height and ground cover (optional)
Path classification
Distance
Tx antenna height
Frequency
Percentage time
Rx antenna height
Terrain clearance angle
Percentage locations

Rec. ITU-R P.1147

Broadcasting

Point-to-area

Sky-wave field strength

0.15 to 1.7 MHz

50 to 12 000 km

10, 50

Not applicable

Not applicable

Latitude and longitude of Tx
Latitude and longitude of Rx
Distance
Sunspot number
Tx power
Frequency

Rec. ITU-R P.452

Services employing stations on the surface of the Earth; interference

Point-to-point

Path loss

700 MHz to 30 GHz

Not specified but up to and beyond the radio horizon

0.001 to 50
Average year and worst month

Not applicable

No limits specified

Path profile data
Frequency
Percentage time
Tx antenna height
Rx antenna height
Latitude and longitude of Tx
Latitude and longitude of Rx Meteorological data

TABLE 1 (continued)




Method

Application

Type

Output

Frequency

Distance

% time

% location

Terminal height

Input data

Rec. ITU-R P.528

Aeronautical
mobile

Point-to-area

Path loss

125 MHz to 15 GHz

0 to 1 800 km
(for aeronautical applications 0 km horizontal distance does not mean 0 km path length)

5, 50, 95

Not applicable

H1: 15 m to 20 km
H2: 1 to 20 km

Distance
Tx height
Frequency
Rx height
Percentage time

Rec. ITU-R P.530

Line-of-sight fixed links

Point-to-point line-of-sight

Path loss
Diversity improvement (clear air conditions)
XPD
Outage
Error performance

Approximately
150 MHz to 40 GHz

Up to 200 km if line-of-sight

All percentages of time in clear air conditions;
1 to 0.001 in
precipitation conditions(1)

Not applicable

High enough to ensure specified path clearance

Distance
Tx height
Frequency
Rx height
Percentage time
Path obstruction data
Climate data
Terrain information

Rec. ITU-R P.533

Broadcasting Fixed
Mobile

Point-to-point

Basic MUF Sky wave field strength
Available receiver power
Signal-to-noise ratio
LUF
Circuit reliability

2 to 30 MHz

0 to 40 000 km

All percentages

Not applicable

Not applicable

Latitude and longitude of Tx
Latitude and longitude of Rx
Sunspot number
Month
Time(s) of day
Frequencies
Tx power
Tx antenna type
Rx antenna type

Rec. ITU-R P.534

Fixed
Mobile Broadcasting

Point-to-point
via sporadic E

Field strength

30 to 100 MHz

0 to 4 000 km

0 to 50

Not applicable

Not applicable

Distance
Frequency

Rec. ITU-R P.617

Trans horizon fixed links

Point-to-point

Path loss

30 MHz

100 to 1 000 km

20, 50, 90, 99,
and 99.9

Not applicable

No limits specified

Frequency
Tx antenna gain
Rx antenna gain
Path geometry

TABLE 1 (continued)




Method

Application

Type

Output

Frequency

Distance

% time

% location

Terminal height

Input data

Rec. ITU-R P.618

Satellite

Point-to-point

Path loss
Diversity gain and (for precipitation condition) XPD

1 to 55 GHz

Any practical orbit height

0.001-5 for attenuation; 0.001-1 for XPD

Not applicable

No limit

Meteorological data
Frequency
Elevation angle
Height of earth station
Separation and angle between earth station sites (for diversity gain)
Antenna diameter and efficiency (for scintillation)
Polarization angle (for XPD)

Rec. ITU-R P.679

Broadcast satellite

Point-to-area

Path loss
Effect of local environment

0.5 to 5.1 GHz

Any practical orbit height

Not applicable

No limits specified

No limits specified

Frequency
Elevation angle
Features of local environment

Rec. ITU-R P.620

Earth station frequency coordination

Coordination distance

Distance of which the required propagation loss is achieved

100 MHz to 105 GHz

Up to 1 200 km

0.001 to 50

Not applicable

No limits specified

Minimum basic transmission loss
Frequency
Percentage of time
Earth-station elevation angle

Rec. ITU-R P.680

Maritime mobile satellite

Point-to-point

Sea-surface fading
Fade duration Interference (adjacent satellite)

0.8-8 GHz

Any practical orbit height

To 0.001% via Rice-Nakagami distribution
Limit of 0.01% for interference(1)

Not applicable

No limit

Frequency
Elevation angle
Maximum antenna boresight gain

Rec. ITU-R P.681

Land mobile satellite

Point-to-point

Path fading
Fade duration
Non-fade duration

0.8 to 20 GHz

Any practical orbit height

Not applicable
Percentage of distance travelled 1 to 80%(1)

Not applicable

No limit

Frequency
Elevation angle
Percentage of distance travelled
Approximate level of optical shadowing

TABLE 1 (end)




Method

Application

Type

Output

Frequency

Distance

% time

% location

Terminal height

Input data

Rec. ITU-R P.682

Aeronautical mobile satellite

Point-to-point

Sea surface fading

1 to 2 GHz

Any practical orbit height

To 0.001% via Rice-Nakagami distribution(1)

Not applicable

No limit

Frequency
Elevation angle
Polarization
Maximum antenna boresight gain
Antenna height

Rec. ITU-R P.684

Fixed
Mobile

Point-to-point
Point-to-area

Sky wave field strength

30 to 150 kHz

0 to 40 000 km

50

Not applicable

Not applicable

Latitude and longitude of Tx
Latitude and longitude of Rx
Distance
Tx power
Frequency
Ground constants
Season
Sunspot number
Hour of day

Rec. ITU-R P.843

Fixed
Mobile Broadcasting

Point-to-point via meteor burst

Received power
Burst rate

30 to 100 MHz

100 to 1 000 km

0 to 5

Not applicable

Not applicable

Frequency
Distance
Tx power
Antenna gains

Rec. ITU-R P.1238

Mobile
RLAN

In building propagation methods

Path loss
Delay spread

900 MHz to 100 GHz

Within buildings

Not applicable

Not applicable

Base: about 2-3 m
Mobile: about 0.5 3 m

Frequency
Distance
Floor and wall factors

Rec. ITU-R P.1411

Mobile

Short-path propagation methods

Path loss
Delay spread

300 MHz to 100 GHz

< 1 km

Not applicable

Not applicable

Base: about 4-50 m
Mobile: about 0.5 3 m

Frequency
Distance
Street dimensions
Structure heights

Rec. ITU-R P.1410

Broadband radio access

Point-to-area

Coverage
Temporal coverage reduction due to rain

20 to 50 GHz

0-5 km

0.001 to 1 (for calculating reduction in coverage due to rain)

Up to 100

No limit; 0-300 m (typical)

Frequency
Cell size
Terminal heights
Building height statistical parameters
Area-averaged rainfall rate

(1) Time percentage of outage; for service availability, subtract value from 100.




TABLE 2


ITU-R digital maps of geophysical parameters


Recommendation ITU-R

Description

Grid resolution

Spatial interpolation required (see Annex 1)

Interpolation in probability

Interpolation of the variable

File names

P.839

Mean annual 0C isotherm height (km) (zerodeg)

1.5 × 1.5

Bi-linear

Not applicable

Not applicable

ESA0HEIGHT.TXT

P.837

Rain rate exceedence probability (%) (rain rate)

1.5 × 1.5

Bi-linear

Not applicable

Not applicable

ESARAINxxx.TXT; xxx = PR6, MC, MS

P.1511

Topographic altitude (a.m.s.l.) (km)
(altitude)

0.5 × 0.5

Bi-cubic

Not applicable

Not applicable

TOPO0DOT5.TXT

P.836

Columnar water vapour exceedence probability (%) (IWVC)

1.5 × 1.5

Bi-linear

Logarithmic

Linear

ESAWVCxx.TXT; xx = 1, 2, 3, 5, 10, 20, 30, 50

P.836

Surface water vapour exceedence probability (%) (Rho)

1.5 × 1.5

Bi-linear

Logarithmic

Linear

SURF_WVxx.TXT; xx = 1, 2, 3, 5, 10, 20, 30, 50

P.1510

Mean annual surface temperature (temperature)

1.5 × 1.5

Bi-linear

Not applicable

Not applicable

ESATEMP.TXT

P.453

Median value of the wet term of the refractivity (Nwet)

1.5 × 1.5

Bi-linear

Not applicable

Not applicable

ESANWET.TXT

P.840

Columnar cloud liquid water exceedence probability (%) (CLW)

1.5 × 1.5

Bi-linear

Logarithmic

Linear

WREDPxx.TXT; xx = 1, 2, 3, 5, 10, 20, 30, 50

IWVC: integrated water vapour content

For easy reference, Fig. 1 shows the relationship between the geophysical maps (black boxes) and propagation effects (white boxes).




ANNEX 1

1 Bi-linear interpolation




Given: Values at four surrounding grid points: I(R,C), I(R, 1), I( 1,C), and I( 1, 1).

Problem: Determine I(r,c), where r is a fractional row number and c is a fractional column number, using bi-linear interpolation.

Solution: Calculate

I(r,c)  I(R,C) [( 1  r)( 1  c)]

 I( 1,C) [(r – R)( 1  c)]

 I(R, 1) [( 1  r)( C)]

 I( 1, 1) [( R)( C)]

2 Bi-cubic interpolation




Given: Values at 16 surrounding grid points:

I(R,C), I(R, 1), I(R, 2), I(R, 3),

I( 1,C), I( 1, 1), I( 1, 2), I( 1, 3),

I( 2,C), I( 2, 1), I( 2, 2), I( 2, 3),

I(R  3,C), I(  1), I( 3, 2), I( 3, 3).

Problem: Calculate I(r,c), where r is a fractional row number and c is a fractional column number, using bi-cubic interpolation.

Solution:

Step 1: For each row, x, where x  {r, r  1, r  2, r  3}, compute the interpolated value at the desired fractional column c as:

where:

and


a  –0.5

Step 2: Calculate I(r,c) by interpolating the one-dimensional interpolations, RI(R,c), RI( 1,c), RI( 2,c), and RI( 3,c) in the same manner as the row interpolations.


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