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	GetLambda (void) const
double	GetMinDistance (void) const
double	GetSystemLoss (void) const
void	SetLambda (double frequency, double speed)
void	SetLambda (double lambda)
void	SetMinDistance (double minDistance)
void	SetSystemLoss (double systemLoss)
Public Member Functions inherited from ns3::PropagationLossModel
	PropagationLossModel ()
virtual	~PropagationLossModel ()
int64_t	AssignStreams (int64_t stream)
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.
void	SetNext (Ptr< PropagationLossModel > next)
	Enables a chain of loss models to act on the signal.
Public Member Functions inherited from ns3::Object
	Object ()
virtual	~Object ()
void	AggregateObject (Ptr< Object > other)
void	Dispose (void)
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	Start (void)
Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
	SimpleRefCount ()
	SimpleRefCount (const SimpleRefCount &o)
uint32_t	GetReferenceCount (void) const
SimpleRefCount &	operator= (const SimpleRefCount &o)
void	Ref (void) const
void	Unref (void) const
Public Member Functions inherited from ns3::ObjectBase
virtual	~ObjectBase ()
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)

Private Member Functions
	FriisPropagationLossModel (const FriisPropagationLossModel &o)
double	DbmFromW (double w) const
double	DbmToW (double dbm) const
virtual int64_t	DoAssignStreams (int64_t stream)
virtual double	DoCalcRxPower (double txPowerDbm, Ptr< MobilityModel > a, Ptr< MobilityModel > b) const
FriisPropagationLossModel &	operator= (const FriisPropagationLossModel &o)

Private Attributes
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)
virtual void	DoStart (void)
virtual void	NotifyNewAggregate (void)

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.

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

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