LTE Indoor

Perform indoor network planning for long term evolution (LTE).

Model Type

This is an example of an indoor network-planning project based on a description file for an air interface (a .wst file). The model is a single-story office building.

Sites and Antennas

There are three antennas at different locations for the best coverage. All antennas have an omnidirectional radiation pattern and transmit at carrier frequencies near 2.1 GHz. Two different carrier frequencies are used by the three antennas, which means that two antennas use the same carrier.

Air Interface

The LTE air interface is defined in this model with a .wst file, LTE_Band1_BW_05MHz_FDD.wst. Orthogonal frequency-division multiplexing (OFDM/SOFDMA) is selected for multiple access. The duplex separation between uplink and downlink is 190 MHz and is achieved using frequency division duplex (FDD).
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 complex building with many interactions, the preferred method is the dominant path model (DPM). DPM focuses on the most relevant path, which leads to shorter computation times compared to the standard ray tracing model (SRT).
Tip: Click Project > Edit Project Parameter and click the Computation tab to specify the method.

Empirical losses are used for the computation of the signal level along the propagation path. Empirical material properties are often easier to obtain than electrical properties.


Propagation results show, at every location, the power received from each transmitting antenna individually. Figure 1 shows a prediction at 1.5 m.

Figure 1. Propagation results: Power of site 1.

The type of network simulation is a Static Simulation (homogenous traffic per cell).
Tip: Click Project > Edit Project Parameter and click the Simulation tab.
For all modulation and coding schemes used in this model, the network simulation calculates the following results for both downlink and uplink:
  • cell area
  • site area
  • best server
  • maximum data rate
  • minimum required transmitter power
  • maximum received power
  • SNIR
  • deception probability
  • maximum number of parallel streams at pixel
  • throughput at pixel in transmission mode
In this model, the following line-of-sight conditions are also determined:
  • Line-of-sight (LOS) condition: a direct line of sight between transmitter and receiver.
  • Obstructed-line-of-sight (OLOS) condition: transmitter and receiver can be connected without a wall intersection - the transmitter and the receiver are in the same corridor but without having a direct line of sight (only in indoor scenarios).
  • Non-line-of-sight (NLOS) condition: No direct line of sight between transmitter and receiver - the transmitter cannot see the receiver and vice versa, due to shadowing by obstacle(s).
  • Line-of-sight for buildings but shadowing caused by vegetation objects (LOS-V).
  • Non-line-of-sight for buildings and shadowing caused by vegetation objects (NLOS-V).
Figure 2. Line-of-sight (LOS) results for site 1.

Note: Antennas at sites 1 and 2 transmit individual signals on the same carrier.
Tip: Click Project > Edit Project Parameter and click the Sites tab to view each antenna.
As a consequence, the sites do not form a distributed antenna system, and between the antennas their signals interfere with each other. The signal-to-noise-and-interference ratio (SNIR) is locally low.
Figure 3. SNIR results for the downlink - the SNIR is low outside the building between sites 1 and 2, leading to low data rates.