A17.7.1.1 Description of the model

Owned by Former user (Deleted)
Last updated: Jan 16, 2020 by Zeljko Tabakovic
2 min read

This is a point-to-area propagation loss model. There are three implementations of this recommendation in SEAMCAT (Recommendation ITU-R P.1546-1, ITU-R P.1546-4, and ITU-R P.1546-5 (see the next two sections)). 

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 ITU-R P.1546-1 propagation model

 

Table 84: ITU-R P.1546-1 propagation model

 

Description

Symbol

Type

Unit

Comments

Variation

 

 

 

Variation in path loss 

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.