The propagation engine uses the open space propagation model to calculate the path loss.
Lbs =K1+K2*10log(F*D)
where:
K1 is the pathloss constant, K2 is the pathloss exponent, F is the frequency of the signal in MHz, D is the distance transmitted in Km. Generally, the scenario is not free space, and you can change the pathloss constant and pathloss exponent to make the model more suitable for the actual scenario.
When the radiowave encounters an obstacle, they have reflection, diffraction and transmission effects. The reflection, diffraction and transmission loss are defined in the material database based on the material type and the frequency range.
You can also define the maximum number of reflections, diffractions and transmission to be calculated before a ray can be abandoned. The ray becomes very weak it can be ignored after it encounters several obstacles.
When you click the Configure button, as shown in Figure 20-2. You can see a pop-up form regarding the selected profile, there are two tabs, Basic Info tab as shown in Figure 20-3 and Link tab as shown in Figure 20-4.
The Basic Info tab includes the basic information of this propagation profile. You can edit the Name, Creation Date and the Description. The Type and Scenario Capability are read only.
The Link tab includes the frequency bands that the current propagation profile can supported, the Properties, Material and Foliage used for those bands.
Figure 20-3: Basic information tab of a propagation profile
Figure 20-4: Link tab of a propagation profile
You can click one of the Properties grids to show the properties sub pane, as shown in Figure 20-5.
Figure 20-5: Properties panel
The Properties panes include the following parameters that used for Indoor antenna and Outdoor antenna under this frequency band:
- Transmission. The maximum number of transmissions to be calculated before a ray is abandoned.
- Diffraction. The maximum number of diffractions to be calculated before a ray is abandoned.
- Reflection. The maximum number of reflections to be calculated before a ray is abandoned.
- K1. The pathloss constant.
- K2. The pathloss exponent.
- Terrain Diffraction. To enable or disable terrain diffraction in outdoor scenario.
- Usefulness ray termination policy. To enable the multiple path ray termination policy, which will have more rays than the traditional ray termination policy. Enable this feature to have more accuracy prediction results. Disable this feature will have a faster prediction speed.
When you click the Material column, you can see the material sub pane at the bottom of the page, as shown in Figure 20-6.
Figure 20-6: Material pane
- Add. You can select the material from the material database and add them to your list.
- Add Material(s) Used in Project. You can add the materials used in the project to your list.
After adding the foliage into this list, you can edit the Transmission Loss(dB/m) and Reflection Loss(dB) of each foliage to a specific value. If there is foliage used in the project, the propagation engine will read the foliage loss from this list, the loss in this list will have higher priority. If the foliage used in the project does not exist in the list, the propagation engine will read the foliage loss from the foliage database. When reading the foliage loss from the foliage database, the system Channel Band is used to find the nearest Link in foliage database and read the foliage loss under that Link.
When you click the Clutters column for Maxwell or RPMLib propagation profile, you can see the clutters sub pane at the bottom of the page, as shown in Figure 20-8.
Figure 20-8: Clutter pane
- Add. You can select Clutter from the clutter database and add them into your list.
- Add Clutters Used in Project. You can add the clutter used in the project to your list.
After adding the clutter into this list, you can edit the Transmission Loss(dB) of each clutter to a specific value. If there are clutters used in the project that exist in this list, the propagation engine will read the clutter loss from this list and the loss in this list will have higher priority. If the clutter used in the project does not exist in the list, the propagation engine will read the clutter loss from the clutter database. When reading the clutter loss from the clutter database, the system Channel Band is used to find the nearest Link in clutter database and read the clutter loss under that Link.
When you click the Body Loss Zone column for Maxwell propagation profile, you can see the body loss zone sub pane at the bottom of the page, as shown in Figure 20-9.
Figure 20-9: Body Loss Zone pane
- Add. You can select the body loss zone from the body loss zone database and add them into your list.
- Add Body Loss Zone Used in Project. You can add the body loss zone used in the project to your list.
After adding the body loss zone into this list, you can edit the Transmission Loss(dB/m) of each body loss zone to a specific value. If there are existing body loss zones listed that are used in the project, the propagation engine will read the body loss zone loss from this list and the loss in this list will have higher priority. If there are body loss zones used in the project, but it is not listed, the propagation engine will read the body loss zone loss from the body loss zone database.
When the body loss zone loss are read from the body loss zone database, the system Channel Band is used to find the nearest Link in body loss zone database and read the body loss zone loss under that Link.