Package: inet.physicallayer.wireless.common.pathloss

FreeSpacePathLoss

compound module

Implements the free space path loss model, which models signal attenuation over distance according to the Friis transmission equation. Calculates signal power loss as a function of distance, wavelength, and configurable parameters. The alpha parameter controls the path loss exponent (default 2), while the systemLoss parameter accounts for hardware inefficiencies. Provides an ideal baseline model for wireless propagation in environments with line-of-sight and no obstacles.

Inheritance diagram

The following diagram shows inheritance relationships for this type. Unresolved types are missing from the diagram.

Known subclasses

Name	Type	Description
LogNormalShadowing	compound module	Path loss model that combines free space path loss with log-normal shadowing. Extends the deterministic free space model by adding a random component that follows a normal distribution with zero mean and configurable standard deviation (sigma). This accounts for signal variations due to obstacles and environmental factors, providing more realistic wireless signal propagation modeling than pure deterministic models.
NakagamiFading	compound module	Implements the Nakagami fading model for wireless signal propagation. This statistical model extends the free space path loss model by adding multipath fading effects. The shapeFactor parameter determines the severity of fading, with lower values representing more severe fading conditions. When shapeFactor equals 1, the Nakagami distribution reduces to the Rayleigh distribution, modeling severe multipath with no line-of-sight component.
RayleighFading	compound module	Models Rayleigh fading in wireless channels, which occurs when signals propagate through multipath environments with no dominant line-of-sight path. This model extends free space path loss with stochastic variations based on the Rayleigh distribution, making it suitable for dense urban and indoor environments. Represents a special case of Rician fading with no dominant signal component, providing realistic signal strength fluctuations for non-line-of-sight wireless communication scenarios.
RicianFading	compound module	Models Rician fading in wireless channels, which occurs when a signal reaches the receiver through both direct line-of-sight and multipath propagation. The k parameter (in dB) controls the ratio between the direct and scattered signal components, with higher values indicating stronger line-of-sight conditions. This model extends free space path loss with stochastic variations based on the Rician distribution, making it suitable for indoor and urban environments where a dominant signal path exists alongside weaker multipath components.
TwoRayGroundReflection	compound module	Implements the two-ray ground reflection path loss model for wireless communications. This model accounts for both the direct line-of-sight path and a ground-reflected path between transmitter and receiver. For distances less than the crossover distance, it uses the free space model; beyond that, it applies the two-ray formula which considers transmitter and receiver heights above ground. (The crossover distance is computed from the heights and the frequency.) This model provides more accurate predictions than free space models for medium to long distances in environments with significant ground reflections.

Extends

Name	Type	Description
Module	compound module	Base module for all INET compound modules.

Parameters

Name	Type	Default value	Description
displayStringTextFormat	string	""	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
alpha	double	2
systemLoss	double	0dB

Properties

Name	Value	Description
class	FreeSpacePathLoss
display	i=block/control

Source code

//
// Implements the free space path loss model, which models signal attenuation
// over distance according to the Friis transmission equation. Calculates signal
// power loss as a function of distance, wavelength, and configurable parameters.
// The alpha parameter controls the path loss exponent (default 2), while the
// systemLoss parameter accounts for hardware inefficiencies. Provides an ideal
// baseline model for wireless propagation in environments with line-of-sight
// and no obstacles.
//
module FreeSpacePathLoss extends Module like IPathLoss
{
    parameters:
        double alpha = default(2);
        double systemLoss @unit(dB) = default(0dB);
        @class(FreeSpacePathLoss);
        @display("i=block/control");
}

File: src/inet/physicallayer/wireless/common/pathloss/FreeSpacePathLoss.ned