Indoor Communication, 802.11g with DPM

The network planning of a local area network planning project in an indoor scenario is investigated. The model is a multi-floor building. The dominant path model (DPM) method is used.

Sites and Antennas

There are eight antenna sites at different locations and elevations in the building for best signal coverage. Each antenna site has one isotropic antenna. They are placed at four levels of height, that are 2.5 m, 6.2 m, 9.9 m, and 13.6 m. Four different carrier frequencies around 2.4 GHz are used to minimize interference.

Four prediction heights are specified.
Tip: Open the Edit Project Parameter dialog and click the Simulation tab.
The heights are typed in the Height field with a space between the values as follows:
1.500 5.200 8.900 12.600


Figure 1. Selectable heights to view the prediction.

Air Interface

The wireless local area network (WLAN) air interface is defined by an 802.11g wireless standard (.wst) file. OFDM/SOFDMA (orthogonal frequency-division multiplexing) is selected for multiple access. It uses time division duplex (TDD) for switching between uplink and downlink. With this definition, only downlink carriers are defined since uplink and downlink are separated in time. In this model, the adaptive switching method is used depending on traffic load.
Tip: Click Project > Edit Project Parameter and click the Air Interface tab to view the carriers and transmission modes.

Computational Method

As the model is a large multi-floor building, the preferred computation method is the DPM. The DPM focuses on the most relevant path, which leads to shorter computation times than standard ray tracing model (SRT).
Tip: Click Project > Edit Project Parameter and click the Computation tab to change the model.

Results

Propagation results show the power received from each transmitting antenna at every location. Results were computed for several prediction levels. When viewing results, these levels can be selected from the drop-down list.


Figure 2. Selectable height levels for the prediction.

The type of network simulation used is a static simulation (homogeneous traffic per cell). The network simulation calculates results like cell area, site area, best server, and maximum data rate. The network simulation calculates the maximum receiver power and the maximum signal-to-noise-and-interference ratio (SNIR) for all modulation and coding schemes used in this model, for both downlink and uplink.

As an example, the image below shows the uplink SNIR, at the prediction height 8.9 m, for one of the modulation schemes.



Figure 3. Uplink SNIR for the BPSK low modulation scheme at a height of 8.9 m.