Indoor Communication, 802.11g with Multi-Wall Model (COST 231)

The network planning of a local area network in an indoor scenario is investigated. The model is a multi-floor building. The multi-wall model (COST 231) method is used.

Sites and Antennas

There are five antenna sites in different locations in the building. The antennas are installed at a height of 2.5 m. The omnidirectional antennas used in this model are working on different frequencies to minimize interference. The carrier frequencies are around 5.2 GHz.

Air Interface

The wireless local area network (WLAN) air interface is defined by an 802.11a 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. In this example, only downlink carriers are defined since the uplink and downlink are separated in time. The adaptive switching method is used depending on the traffic load.
Tip: Click Project > Edit Project Parameter and click the Air Interface tab to view the carriers and transmission modes.

Computational Method

The computational method used for this model is the multi-wall model (COST 231).
Tip: Click Project > Edit Project Parameter and click the Computation tab to change the model.
This propagation model takes into account various material properties of internal walls, special walls, doors, floors, and ceilings to predict the coverage in the building. This method calculates the path loss as the sum of distance-dependent free-space loss and losses introduced by the walls and floors penetrated by the direct path. Signals are assumed to travel along straight paths, which is good for computational speed, but diffractions and multipath are not considered.
Tip: Click Project > Edit Project Parameter and click the Computation tab to change the model.


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

The network simulation also calculates, among other quantities, the minimum required transmitter power, maximum achievable received signal strength, and the SNIR for all modulation and coding schemes used in this model. One result of interest is the maximum data rate, see Figure 1.

The white pixels are an indication that the received power is too low for communication with this standard or that the interference (SNIR) is too high for communication (but that is not the case here since all antennas employ a different carrier frequency).

Figure 1. Maximum data rate for the network.