ITU-R P.1411 Model

The ITU-R P.1411 propagation model is intended for outdoor short-range propagation over the frequency range from 300 MHz to 100 GHz.

Short-range propagation over distances less than about 1 km is typically affected more by buildings and trees than by variations in ground elevation. The effect of buildings is expected to dominate, since most short-path radio links are found in urban and suburban areas. The mobile device is most likely to be held by a pedestrian or located in a vehicle.

Propagation Environment

The propagation model distinguishes four categories of propagation environments:

• Urban Very High Rise

  There is a high density of very tall buildings with tens of floors. Propagation is through deep urban canyons. Heavy traffic of cars and pedestrians is present in the streets.

• Urban / Urban High Rise

  The streets are lined with buildings of several floors each. Propagation is through urban canyons and over rooftops. Large numbers of moving vehicles are present in the streets.

• Suburban / Urban Low Rise

  There are buildings and their heights are generally less than three stories. Over-rooftop diffraction is likely. There are some reflections and shadowing from moving vehicles.

• Residential

  There are one and two-story buildings. Streets contain trees with foliage. Parked cars and light traffic are present.

Propagation Models

For propagation models, two options exist:

• Site-Specific

  For this option, the simulation will take the given buildings, as defined in the urban database and visible in the ProMan GUI, accurately into account.

• Site-General

  This option is convenient when an urban database is not available, or when a quick look is desired without specifying all the buildings. When this option is selected, the simulation takes the general properties of the environment (urban high rise or residential) and the antenna height into account and provides representative results. ProMan will always require a database to be part of the project, but with this option the (urban) database can be almost empty, and antenna positions be chosen in an area away from the remaining (unused) buildings.

Propagation Situation

This option is related to the predominant height of the base stations. In al cases, the mobile station is located near street level. The difference lies in the height of the base station.

• Over Roof-Tops

  Base stations are typically located above the roof level. The (short-distance) propagation path must be an over-rooftop path.

• Within Street Canyons

  Base station is located below roof level but above the level of a person’s head.

• Near Street Level

  Both the base station and the mobile station are near street level.

• Auto Detection

  This option is recommended, especially if not all base stations are at similar heights. It allows ProMan to determine automatically the situation that applies.

Calculation mode (LOS)

Even within the line of sight, the path loss is not simply a free-space path loss. Depending on the frequency, ITU recommendations contain expressions for expected path loss, with lower and upper bounds. Based on the properties of your urban area of interest, you may choose to perform calculations based on the Lower Bound or Upper Bound of the line-of-sight path loss, or on the Median Value.

Note: Option only available in combination with Site-Specific propagation models.

Traffic (affects the breakpoint distance)

Traffic can be set to Light or Heavy. Heavy traffic also affect the effective road height and as a result the breakpoint distance. Select the Ignore break-point distance check box if you want to disregard the breakpoint distance.

Site-General Settings

Depending on whether a Site-General or a Site-Specific simulation was chosen, different Site-General Settings are available.

Site-General simulation

In a Site-General simulation, ProMan has the ability to determine, based on the building database, whether paths are line-of-sight or non-line-of-sight paths. If you are performing your site-general simulation in an empty area of the urban database, ProMan might assume pure line-of-sight conditions for all pixels. Select the Use a statistical model to determine LOS/NLOS regions check box to ensure that the two conditions receive the appropriate weight.

Select the Add Gaussian random variable check box to include an additive zero-mean Gaussian random variable in the path-loss computation in the site-general case. It is described in the ITU recommendation¹.

Site-Specific simulation

In a Site-Specific simulation, some pixels may remain without prediction. For such pixels, which otherwise remain white and without value in the result display, you can choose to use the result of a site-general model instead.

When the Use site-general models for unpredicted pixels of site-specific models check box is selected, the Use a statistical model to determine LOS/NLOS regions and Add Gaussian random variable options are available.

Additional loss (Transmitter inside a building)

The ITU-R P.1411 model also allows the transmitter to be inside a building. In such a situation, you have the option to add a value in dB for additional loss: the power loss suffered by the signal to travel through the walls from inside to outside the building.

ProMan will check whether the transmitter is inside a building. If the transmitter is located outside, even with the Site-General propagation models, this setting has no effect. This way, you can have some transmitters inside and some outside buildings.