Propagation Models

For the installation of mobile radio systems, wave propagation models are necessary to determine propagation characteristics for any arbitrary configuration. The predictions are required for a proper coverage planning, the determination of multipath effects as well as for interference and cell calculations, which are the basis for the high-level network planning process.

The environments where these systems are intended to be installed, are ranging from indoor up to large rural areas. Hence wave propagation prediction methods are required covering the whole range of macro-, micro- and pico-cells including indoor scenarios and situations in special environments like tunnels or along highways.

Figure 1. Definition of different cell types.

For the wave propagation prediction of leaky feeder cables special models are used, which can be specified and parameterized on the Computation tab.

The phenomena which influence radio wave propagation can generally be described by four basic mechanisms: Reflection, diffraction, penetration and scattering. For the practical usage of propagation models in real scenarios these mechanisms must be described by approximations.

The basis for any propagation model is a data base which describes the propagation environment. Considering indoor propagation suggests, for the purpose of propagation modeling, that each building element should be categorized into classes (wall, floor, door, window) and specified by its coordinates and finally its material properties (thickness, permittivity, conductivity).

To get a more accurate description of wave propagation, the building data are stored in a 3D-vector format including all walls, doors, and windows. All elements inside the building are described in terms of plane elements. Every wall is for example represented by a plane and its extent and location is defined by its corners. Additionally, for each element individual material properties can be taken into account. With respect to an efficient use it is also possible to import .dxf files, a common data format in architecture.

Figure 2. Example of a 3D building database used in ProMan for indoor propagation.