a Friis propagation loss model More...

#include <propagation-loss-model.h>

Inheritance diagram for ns3::FriisPropagationLossModel:

Collaboration diagram for ns3::FriisPropagationLossModel:

Public Member Functions
	FriisPropagationLossModel ()

double	GetFrequency (void) const

double	GetMinDistance (void) const

double	GetSystemLoss (void) const

void	SetFrequency (double frequency)

void	SetMinDistance (double minDistance)

void	SetSystemLoss (double systemLoss)

Public Member Functions inherited from ns3::PropagationLossModel
	PropagationLossModel ()

virtual	~PropagationLossModel ()

int64_t	AssignStreams (int64_t stream)
	If this loss model uses objects of type RandomVariableStream, set the stream numbers to the integers starting with the offset 'stream'. More...

double	CalcRxPower (double txPowerDbm, Ptr< MobilityModel > a, Ptr< MobilityModel > b) const

Ptr< PropagationLossModel >	GetNext ()
	Gets the next PropagationLossModel in the chain of loss models that act on the signal. More...

void	SetNext (Ptr< PropagationLossModel > next)
	Enables a chain of loss models to act on the signal. More...

Public Member Functions inherited from ns3::Object
	Object ()

virtual	~Object ()

void	AggregateObject (Ptr< Object > other)

void	Dispose (void)
	Run the DoDispose methods of this object and all the objects aggregated to it. More...

AggregateIterator	GetAggregateIterator (void) const

virtual TypeId	GetInstanceTypeId (void) const

template<typename T >
Ptr< T >	GetObject (void) const

template<typename T >
Ptr< T >	GetObject (TypeId tid) const

void	Initialize (void)
	This method calls the virtual DoInitialize method on all the objects aggregated to this object. More...

Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
	SimpleRefCount ()
	Constructor. More...

	SimpleRefCount (const SimpleRefCount &o)
	Copy constructor. More...

uint32_t	GetReferenceCount (void) const
	Get the reference count of the object. More...

SimpleRefCount &	operator= (const SimpleRefCount &o)
	Assignment. More...

void	Ref (void) const
	Increment the reference count. More...

void	Unref (void) const
	Decrement the reference count. More...

Public Member Functions inherited from ns3::ObjectBase
virtual	~ObjectBase ()
	Virtual destructor. More...

void	GetAttribute (std::string name, AttributeValue &value) const

bool	GetAttributeFailSafe (std::string name, AttributeValue &attribute) const

void	SetAttribute (std::string name, const AttributeValue &value)

bool	SetAttributeFailSafe (std::string name, const AttributeValue &value)

bool	TraceConnect (std::string name, std::string context, const CallbackBase &cb)

bool	TraceConnectWithoutContext (std::string name, const CallbackBase &cb)

bool	TraceDisconnect (std::string name, std::string context, const CallbackBase &cb)

bool	TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb)

Static Public Member Functions
static TypeId	GetTypeId (void)

Static Public Member Functions inherited from ns3::PropagationLossModel
static TypeId	GetTypeId (void)

Static Public Member Functions inherited from ns3::Object
static TypeId	GetTypeId (void)
	Register this type. More...

Static Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
static void	Cleanup (void)
	Noop. More...

Static Public Member Functions inherited from ns3::ObjectBase
static TypeId	GetTypeId (void)
	Get the type ID. More...

Private Member Functions
	FriisPropagationLossModel (const FriisPropagationLossModel &o)

double	DbmFromW (double w) const

double	DbmToW (double dbm) const

virtual int64_t	DoAssignStreams (int64_t stream)
	Subclasses must implement this; those not using random variables can return zero. More...

virtual double	DoCalcRxPower (double txPowerDbm, Ptr< MobilityModel > a, Ptr< MobilityModel > b) const

FriisPropagationLossModel &	operator= (const FriisPropagationLossModel &o)

Private Attributes
double	m_frequency

double	m_lambda

double	m_minDistance

double	m_systemLoss

Static Private Attributes
static const double	PI = 3.14159265358979323846

Additional Inherited Members
Protected Member Functions inherited from ns3::Object
	Object (const Object &o)

virtual void	DoDispose (void)
	This method is called by Object::Dispose or by the object's destructor, whichever comes first. More...

virtual void	DoInitialize (void)
	This method is called only once by Object::Initialize. More...

virtual void	NotifyNewAggregate (void)
	This method is invoked whenever two sets of objects are aggregated together. More...

Protected Member Functions inherited from ns3::ObjectBase
void	ConstructSelf (const AttributeConstructionList &attributes)

virtual void	NotifyConstructionCompleted (void)
	This method is invoked once all member attributes have been initialized. More...

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.

In the implementation, $\lambda$ is calculated as $\frac{C}{f}$ , where $ C = 299792458$ m/s is the speed of light in vacuum, and $ f $ is the frequency in Hz which can be configured by the user via the Frequency attribute.

Config Paths

ns3::FriisPropagationLossModel is accessible through the following paths with Config::Set and Config::Connect:

/ChannelList/[i]/$ns3::WifiChannel/$ns3::YansWifiChannel/PropagationLossModel/$ns3::FriisPropagationLossModel
/ChannelList/[i]/$ns3::YansWifiChannel/PropagationLossModel/$ns3::FriisPropagationLossModel
/NodeList/[i]/DeviceList/[i]/$ns3::WifiNetDevice/Channel/$ns3::YansWifiChannel/PropagationLossModel/$ns3::FriisPropagationLossModel

Attributes

Frequency: The carrier frequency (in Hz) at which propagation occurs (default is 5.15 GHz).
- Set with class: ns3::DoubleValue
- Underlying type: double -1.79769e+308:1.79769e+308
- Initial value: 5.15e+09
- 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 are defined for this type.

Definition at line 180 of file propagation-loss-model.h.

Constructor & Destructor Documentation

ns3::FriisPropagationLossModel::FriisPropagationLossModel ( )

Definition at line 174 of file propagation-loss-model.cc.

ns3::FriisPropagationLossModel::FriisPropagationLossModel ( const FriisPropagationLossModel & o )

private

Member Function Documentation

double ns3::FriisPropagationLossModel::DbmFromW ( double w ) const

private

Definition at line 220 of file propagation-loss-model.cc.

double ns3::FriisPropagationLossModel::DbmToW ( double dbm ) const

private

Definition at line 213 of file propagation-loss-model.cc.

int64_t ns3::FriisPropagationLossModel::DoAssignStreams ( int64_t stream )

privatevirtual

Subclasses must implement this; those not using random variables can return zero.

Implements ns3::PropagationLossModel.

Definition at line 273 of file propagation-loss-model.cc.

double ns3::FriisPropagationLossModel::DoCalcRxPower	(	double	txPowerDbm,
		Ptr< MobilityModel >	a,
		Ptr< MobilityModel >	b
	)		const

privatevirtual

Implements ns3::PropagationLossModel.

Definition at line 227 of file propagation-loss-model.cc.

References ns3::MobilityModel::GetDistanceFrom(), m_lambda, m_minDistance, m_systemLoss, NS_LOG_DEBUG, and PI.

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

Returns: the current frequency (Hz)

Definition at line 207 of file propagation-loss-model.cc.

References m_frequency.

Referenced by GetTypeId().

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

Returns: the minimum distance.

Definition at line 193 of file propagation-loss-model.cc.

References m_minDistance.

Referenced by GetTypeId().

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

Returns: the current system loss (dimension-less)

Definition at line 183 of file propagation-loss-model.cc.

References m_systemLoss.

TypeId ns3::FriisPropagationLossModel::GetTypeId ( void )

static

Definition at line 149 of file propagation-loss-model.cc.

References GetFrequency(), GetMinDistance(), m_systemLoss, SetFrequency(), SetMinDistance(), and ns3::TypeId::SetParent().

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FriisPropagationLossModel& ns3::FriisPropagationLossModel::operator= ( const FriisPropagationLossModel & o )

private

void ns3::FriisPropagationLossModel::SetFrequency ( double frequency )

Parameters

frequency (Hz)

Set the carrier frequency used in the Friis model calculation.

Definition at line 199 of file propagation-loss-model.cc.

References m_frequency, and m_lambda.

Referenced by GetTypeId().

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

Parameters

minDistance the minimum distance

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

Definition at line 188 of file propagation-loss-model.cc.

References m_minDistance.

Referenced by GetTypeId().

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

Parameters

systemLoss (dimension-less)

Set the system loss used by the Friis propagation model.

Definition at line 178 of file propagation-loss-model.cc.

References m_systemLoss.

Member Data Documentation

double ns3::FriisPropagationLossModel::m_frequency

private

Definition at line 233 of file propagation-loss-model.h.

Referenced by GetFrequency(), and SetFrequency().

double ns3::FriisPropagationLossModel::m_lambda

private

Definition at line 232 of file propagation-loss-model.h.

Referenced by DoCalcRxPower(), and SetFrequency().

double ns3::FriisPropagationLossModel::m_minDistance

private

Definition at line 235 of file propagation-loss-model.h.

Referenced by DoCalcRxPower(), GetMinDistance(), and SetMinDistance().

double ns3::FriisPropagationLossModel::m_systemLoss

private

Definition at line 234 of file propagation-loss-model.h.

Referenced by DoCalcRxPower(), GetSystemLoss(), GetTypeId(), and SetSystemLoss().

const double ns3::FriisPropagationLossModel::PI = 3.14159265358979323846

staticprivate

Definition at line 231 of file propagation-loss-model.h.

Referenced by DoCalcRxPower().

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

src/propagation/model/propagation-loss-model.h
src/propagation/model/propagation-loss-model.cc

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Static Private Attributes

Additional Inherited Members

Detailed Description

Config Paths

Attributes

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation