WiMAX, Urban, Fixed

Perform network planning for fixed WiMAX coverage in an urban scenario.

Model Type

The geometry is described by urban buildings, see Figure 1. There is no additional topography meaning the terrain is flat.



Figure 1. An urban database showing the geometry.

Sites and Antennas

There are six sites in this scenario at different locations. Site 1 has six directional antennas at a height of 40 m. Sites 2 to 5 have three directional antennas, each at a height of 32 m. Site 6 has four directional radiators at a height of 32 m. The antennas use twelve different carrier frequencies between 3.5 and 3.6 GHz. Since the number of carriers is smaller than the number of antennas, there will be some interference.

Tip: Click Project > Edit Project Parameter and click the Sites tab to view the sites and antennas.

Air Interface

The air interface is defined by a wireless standard WiMAX_Sample_Urban.wst file. All available carriers and transmission modes are listed in the file. Orthogonal frequency division multiple access (OFDM/SOFDMA) is selected for a multiple access scheme.
Tip: Click Project > Edit Project Parameter and click the Air Interface tab.

A list of different modulation and coding schemes are added to this interface on the Air Interface tab, under Transmission Modes.

Computational Method

The dominant path model (DPM) is selected as this method focuses on the most relevant path, which leads to shorter computation times compared to ray tracing.

Results

Propagation results show at every location the power received from each transmitting antenna. Power received at a given location from Site 4 Antenna 1 is shown in Figure 2. The image shows the results at a prediction plane of 27 m in height and the buildings above that plane only. In general, for fixed WiMAX, the receiver site antennas would likely be located on rooftops.


Figure 2. Maximum downlink throughput for Site 4 Antenna 1.
The network simulation calculates the following:
  • cell area
  • site area
  • best server
  • maximum data rate for both uplink and downlink
  • minimum required transmitter power
  • reception probability
  • SNIR (max) for all modulation and coding schemes for uplink and downlink
Figure 3 shows the maximum data rate in the downlink. Various network results for the defined modulation schemes can be viewed by selecting in the result tree.


Figure 3. Maximum data rate in the downlink.