Propagation aspects can be divided in three different topics:

• LOS propagation (Line Of Sight):

The transmitter and the receiver are in visibility one with each other. The propagation in LOS is based upon clearly defined propagation methods, such as the ITU-R P 525 model.

Note that in ICS Telecom nG, taking full advantage of the quality of the cartography loaded, deterministic propagation models, have proved to give the best correlation when correlated with on-field measurements. Of course, additional effects, such as attenuations due to the rain or gas are also considered.

• NLOS propagation (NON Line Of Sight):

The transmitter and the receiver are not in visibility one with each other. A typical example is a WiMax BTS located in Outdoor enviroment.

The building file describes the building height above ground level. In ICS telecom nG, the Digital Terrain Model is now separated from the above-the-ground features (buildings, trees…). Specific attenuation coefficients can be applied to the buildings in order to simulate the diffusion effect when the Outdoor signal penetrates an Indoor environment. For a thorough description of this model, please refer to ATDI’s White-paper called "Mixed absorption-diffraction propagation models for wireless proximity networks".

• nLOS propagation(near Line Of Sight):

This case is a mix between the LOS and the NLOS case. The transmitter and the receiver can be for instance in visibility one with each other, but part of the Fresnel ellipsoid is obstructed. A transmitter and a receiver almost in visibility one with each other is all a possibility: the signal can then propagate using diffraction or multi-reflection on building sides.

Diffraction effect:

The diffraction models in ICS telecom nG do quantify the losses due to obstacles between the BTS and the CPE, avoiding the two entities to be in Line of Sight one with each other.

Subpath attenuation effect:

The subpath model in ICS telecom nG quantifies the losses due partial obstructions of the Fresnel zone. Such an attenuation term can be defined for partial obstruction in the Z axis only, or in full 3D.

Multi-reflection effect:

This model calculates the field strength at all point of the simulation area according to reflected signals contribution, taking into account a reflection coefficient defined by the user. Note that the multipath calculation engine of ICS telecom nG also allows dedicated analysis of power delay spread effect. This refers to the maximum difference in arrival times at the receiver when there is more than one signal received via different transmission paths. Studies show that for delays limited to a fraction of the symbol time, the amount of signal degradation depends not in the actual delay profile, but on the rms value of the delay, weighted by their respective power levels.

To read white paper