This is the point-to-area propagation loss model. There are two implementation of this recommendation in SEAMCAT (ITU-R Rec.P.1546-1 and ITU-R Rec.P.1546-4 (see next section)).
This recommendation replaced the original broadcasting propagation prediction curves given in recommendation ITU-R P.370. The adjusted P.1546 model is suitable for modelling propagation path loss in the broadcasting, land mobile and certain fixed services (e.g. those employing point-to-multipoint systems) in the frequency range 30 to 3 000 MHz and for the distance range 1 km to 1 000 km.
A few simplifications have been introduced for SEAMCAT implementation of the model:
- Restriction to propagation over land paths only;
- Flat terrain;
- No negative antenna heights.
Figure 471: SEAMCAT Interface to the P1546-1 propagation model
Table 84: ITU-R Recommendation P.1546-1 propagation model
Description | Symbol | Type | Unit | Comments |
Variation |
|
|
| Variation in path loss takes into account the uncertainty of building design, furniture, room size, etc. |
General environment |
|
|
| Environment of the propagation: urban, rural, suburban |
System |
|
|
| Digital (BW<1MHz), Digital (BW>1MHz), Analogue |
Time Percentage (min) |
|
|
| Minimum time variability from which the field strengths value are exceeded |
Time percentage (max) |
|
|
| Maximum time variability from which the field strengths value are exceeded |
use user specified local clutter height |
|
|
| User selectable clutter height value which overwrite any predefined value when selected |
This propagation model is described in Recommendation ITU-R P.1546-1 Annex 8, which was developed based on the prior model in Recommendation ITU-R P.370. This is a propagation model for point-to-area prediction of field strength for the broadcasting, land mobile, maritime mobile and certain fixed services (e.g. those employing point-to-multipoint systems) in the frequency range 30 to 3000 MHz and for the distance range 1 km to 1000 km. The model provided in Recommendation ITU-R P.1546-1 should be used in the frequency range (30 to 3 000 MHz) and the same distance range (1 km to 1 000 km). The Land curves are implemented only. The sea curves or the mixed sea-land path are not implemented.