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ns3::TwoRayGroundPropagationLossModel Class Reference
Propagation Models

a Two-Ray Ground propagation loss model ported from NS2 More...

#include <propagation-loss-model.h>

+ Inheritance diagram for ns3::TwoRayGroundPropagationLossModel:

Public Member Functions

double GetFrequency (void) const
 
double GetMinDistance (void) const
 
double GetSystemLoss (void) const
 
void SetFrequency (double frequency)
 
void SetHeightAboveZ (double heightAboveZ)
 
void SetMinDistance (double minDistance)
 
void SetSystemLoss (double systemLoss)
 
- Public Member Functions inherited from ns3::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. 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
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 Initialize (void)
 
- Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
 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
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)
 
- Static Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
static void Cleanup (void)
 
- Static Public Member Functions inherited from ns3::ObjectBase
static TypeId GetTypeId (void)
 

Private Member Functions

 TwoRayGroundPropagationLossModel (const TwoRayGroundPropagationLossModel &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
 
TwoRayGroundPropagationLossModel & operator= (const TwoRayGroundPropagationLossModel &o)
 

Private Attributes

double m_frequency
 
double m_heightAboveZ
 
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 DoInitialize (void)
 
virtual void NotifyNewAggregate (void)
 
- Protected Member Functions inherited from ns3::ObjectBase
void ConstructSelf (const AttributeConstructionList &attributes)
 
virtual void NotifyConstructionCompleted (void)
 

Detailed Description

a Two-Ray Ground propagation loss model ported from NS2

Two-ray ground reflection model.

$ Pr = \frac{Pt * Gt * Gr * (ht^2 * hr^2)}{d^4 * L} $

The original equation in Rappaport's book assumes L = 1. To be consistent with the free space equation, L is added here.

Ht and Hr are set at the respective nodes z coordinate plus a model parameter set via SetHeightAboveZ.

The two-ray model does not give a good result for short distances, due to the oscillation caused by constructive and destructive combination of the two rays. Instead the Friis free-space model is used for small distances.

The crossover distance, below which Friis is used, is calculated as follows:

$ dCross = \frac{(4 * pi * Ht * Hr)}{lambda} $

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

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

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
  • HeightAboveZ: The height of the antenna (m) above the node's Z coordinate
    • Set with class: ns3::DoubleValue
    • Underlying type: double -1.79769e+308:1.79769e+308
    • Initial value: 0
    • Flags: construct write read

No TraceSources are defined for this type.

Definition at line 266 of file propagation-loss-model.h.

Member Function Documentation

int64_t ns3::TwoRayGroundPropagationLossModel::DoAssignStreams ( int64_t  stream)
privatevirtual

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

Implements ns3::PropagationLossModel.

Definition at line 445 of file propagation-loss-model.cc.

double ns3::TwoRayGroundPropagationLossModel::GetFrequency ( void  ) const
Returns
the current frequency (Hz)

Definition at line 351 of file propagation-loss-model.cc.

double ns3::TwoRayGroundPropagationLossModel::GetMinDistance ( void  ) const
Returns
the minimum distance.

Definition at line 332 of file propagation-loss-model.cc.

double ns3::TwoRayGroundPropagationLossModel::GetSystemLoss ( void  ) const
Returns
the current system loss (dimension-less)

Definition at line 322 of file propagation-loss-model.cc.

void ns3::TwoRayGroundPropagationLossModel::SetFrequency ( double  frequency)
Parameters
frequency(Hz)

Set the carrier frequency used in the TwoRayGround model calculation.

Definition at line 343 of file propagation-loss-model.cc.

void ns3::TwoRayGroundPropagationLossModel::SetHeightAboveZ ( double  heightAboveZ)
Parameters
heightAboveZthe model antenna height above the node's Z coordinate

Set the model antenna height above the node's Z coordinate

Definition at line 337 of file propagation-loss-model.cc.

void ns3::TwoRayGroundPropagationLossModel::SetMinDistance ( double  minDistance)
Parameters
minDistancethe minimum distance

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

Definition at line 327 of file propagation-loss-model.cc.

void ns3::TwoRayGroundPropagationLossModel::SetSystemLoss ( double  systemLoss)
Parameters
systemLoss(dimension-less)

Set the system loss used by the TwoRayGround propagation model.

Definition at line 317 of file propagation-loss-model.cc.

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