EMC City

Determine whether base stations exceed exposure limits in a rural scenario.

Model Type

This electromagnetic compatibility (EMC) prediction model design represents an urban scenario with base stations. The EMC analysis is used to predict the locations, if any, where the base stations exceed/meet regulatory limits on human exposure.

Sites and Antennas

There are two sites, each with two directional antennas. These antennas are working at different carrier frequencies of 950 MHz and 1850 MHz.
Tip: Click Project > Edit Project Parameter and click the Sites tab to view the horizontal and vertical antenna patterns of the antennas used (Kathrein741794.msi).

Air Interface

The air interface is defined by a GSM wireless standard (.wst) file. Frequency division multiple access (FDMA) was selected for multiple access.
Tip: Click Project > Edit Project Parameter and click the Air Interface tab to view the carriers and transmission modes.

Computational Method

For an urban environment, the dominant path model (DPM) is well-suited. DPM focuses on the most relevant path which leads to shorter computation times compared to ray tracing. In an urban scenario, ray tracing would require a preprocessed geometry database. Since this project is not based on a preprocessed database, intelligent ray tracing model (IRT) is not available.
Tip: Click Project > Edit Project Parameter and click the Computation tab to change the model.

Results

Propagation results show, at every location, the power received from each transmitting antenna individually.

The type of network simulation is a static simulation (homogeneous traffic per cell). The network simulation calculated minimum transmission power, SNIR(max), reception probability (including fast fading) for all transmission modes. The Cell area for separate sites is available under Results: Network.

The main goal is to determine if human exposure to radiation exceeds regulatory limits. This is requested by clicking Project > Edit Project Parameter and clicking the Network tab and select the EMC Analysis check box. Click the Settings button to load a text file with exposure limits. The file contains frequency-dependent exposure limits for Germany and Switzerland. The Swiss limits are stricter than the German limits.

The antennas are located at a height of 4.5 m, while results are calculated at a height of 1.5 m (this corresponds to the height of the general public). The results show that Swiss limits are exceeded.

Figure 1. Swiss exposure limits in an urban scenario.