a Friis propagation loss model More...

#include <propagation-loss-model.h>

Inheritance diagram for ns3::FriisPropagationLossModel:

Collaboration diagram for ns3::FriisPropagationLossModel:

Public Member Functions
void	SetLambda (double frequency, double speed)
void	SetLambda (double lambda)
void	SetSystemLoss (double systemLoss)
void	SetMinDistance (double minDistance)
double	GetMinDistance (void) const
double	GetLambda (void) const
double	GetSystemLoss (void) const
virtual double	GetLoss (Ptr< MobilityModel > a, Ptr< MobilityModel > b) const
Static Public Member Functions
static TypeId	GetTypeId (void)
	This method returns the TypeId associated to ns3::FriisPropagationLossModel.

Detailed Description

a Friis propagation loss model

The Friis propagation loss model was first described in "A Note on a Simple Transmission Formula", by "Harald T. Friis".

The original equation was described as: $\frac{P_r}{P_t} = \frac{A_r A_t}{d^2\lambda^2}$ with the following equation for the case of an isotropic antenna with no heat loss: $A_{isotr.} = \frac{\lambda^2}{4\pi}$

The final equation becomes: $\frac{P_r}{P_t} = \frac{\lambda^2}{(4 \pi d)^2}$

Modern extensions to this original equation are: $P_r = \frac{P_t G_t G_r \lambda^2}{(4 \pi d)^2 L}$

With:

: reception power (W)
: transmission power (W)
: transmission gain (unit-less)
: reception gain (unit-less)
$\lambda$ : wavelength (m)
: distance (m)
: system loss (unit-less)

This model is invalid for small distance values. The current implementation returns the txpower as the rxpower for any distance smaller than MinDistance.

Member Function Documentation

double ns3::FriisPropagationLossModel::GetLambda ( void ) const

Returns:: the current wavelength (m)

virtual double ns3::FriisPropagationLossModel::GetLoss	(	Ptr< MobilityModel >	a,
		Ptr< MobilityModel >	b
	)			const `[virtual]`

Parameters:

	a	the mobility model of the source
	b	the mobility model of the destination

Returns:: the attenuation coefficient (dB)

Implements ns3::PropagationLossModel.

double ns3::FriisPropagationLossModel::GetMinDistance ( void ) const

Returns:: the minimum distance.

double ns3::FriisPropagationLossModel::GetSystemLoss ( void ) const

Returns:: the current system loss (dimention-less)

static TypeId ns3::FriisPropagationLossModel::GetTypeId ( void ) [static]

This method returns the TypeId associated to ns3::FriisPropagationLossModel.

This object is accessible through the following paths with Config::Set and Config::Connect:

/NodeList/[i]/DeviceList/[i]/$ns3WifiNetDevice/Channel/PropagationLossModel/$ns3FriisPropagationLossModel

Attributes defined for this type:

Lambda: The wavelength (default is 5.15 GHz at 300 000 km/s).
- Set with class: ns3::DoubleValue
- Underlying type: double -1.79769e+308:1.79769e+308
- Initial value: 0.0582524
- Flags: construct write read
SystemLoss: The system loss
- Set with class: ns3::DoubleValue
- Underlying type: double -1.79769e+308:1.79769e+308
- Initial value: 1
- Flags: construct write read
MinDistance: The distance under which the propagation model refuses to give results (m)
- Set with class: ns3::DoubleValue
- Underlying type: double -1.79769e+308:1.79769e+308
- Initial value: 0.5
- Flags: construct write read

No TraceSources defined for this type.

Reimplemented from ns3::PropagationLossModel.

void ns3::FriisPropagationLossModel::SetLambda	(	double	frequency,
		double	speed
	)

Parameters:

	frequency	(Hz)
	speed	(m/s)

Set the main wavelength used in the Friis model calculation.

void ns3::FriisPropagationLossModel::SetLambda ( double lambda )

Parameters:

lambda

(m) the wavelength

Set the main wavelength used in the Friis model calculation.

void ns3::FriisPropagationLossModel::SetMinDistance ( double minDistance )

Parameters:

minDistance

the minimum distance

Below this distance, the txpower is returned unmodified as the rxpower.

void ns3::FriisPropagationLossModel::SetSystemLoss ( double systemLoss )

Parameters:

systemLoss

(dimension-less)

Set the system loss used by the Friis propagation model.

The documentation for this class was generated from the following files:

src/devices/wifi/propagation-loss-model.h
doc/introspected-doxygen.h

ns3::FriisPropagationLossModel Class Reference

Public Member Functions

Static Public Member Functions

Detailed Description

Member Function Documentation