/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2005,2006,2007 INRIA
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation;
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
* Contributions: Timo Bingmann <timo.bingmann@student.kit.edu>
* Contributions: Gary Pei <guangyu.pei@boeing.com> for fixed RSS
* Contributions: Tom Hewer <tomhewer@mac.com> for two ray ground model
* Pavel Boyko <boyko@iitp.ru> for matrix
*/
#ifndef PROPAGATION_LOSS_MODEL_H
#define PROPAGATION_LOSS_MODEL_H
#include "ns3/object.h"
#include "ns3/random-variable.h"
#include "ns3/node.h"
#include <map>
namespace ns3 {
class MobilityModel;
/**
* \brief Modelize the propagation loss through a transmission medium
*
* Calculate the receive power (dbm) from a transmit power (dbm)
* and a mobility model for the source and destination positions.
*/
class PropagationLossModel : public Object
{
public:
static TypeId GetTypeId (void);
PropagationLossModel ();
virtual ~PropagationLossModel ();
void SetNext (Ptr<PropagationLossModel> next);
/**
* \param txPowerDbm current transmission power (in dBm)
* \param a the mobility model of the source
* \param b the mobility model of the destination
* \returns the reception power after adding/multiplying propagation loss (in dBm)
*/
double CalcRxPower (double txPowerDbm,
Ptr<MobilityModel> a,
Ptr<MobilityModel> b) const;
private:
PropagationLossModel (const PropagationLossModel &o);
PropagationLossModel &operator = (const PropagationLossModel &o);
virtual double DoCalcRxPower (double txPowerDbm,
Ptr<MobilityModel> a,
Ptr<MobilityModel> b) const = 0;
Ptr<PropagationLossModel> m_next;
};
/**
* \brief The propagation loss follows a random distribution.
*/
class RandomPropagationLossModel : public PropagationLossModel
{
public:
static TypeId GetTypeId (void);
RandomPropagationLossModel ();
virtual ~RandomPropagationLossModel ();
private:
RandomPropagationLossModel (const RandomPropagationLossModel &o);
RandomPropagationLossModel & operator = (const RandomPropagationLossModel &o);
virtual double DoCalcRxPower (double txPowerDbm,
Ptr<MobilityModel> a,
Ptr<MobilityModel> b) const;
RandomVariable m_variable;
};
/**
* \brief 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:
* \f$ \frac{P_r}{P_t} = \frac{A_r A_t}{d^2\lambda^2} \f$
* with the following equation for the case of an
* isotropic antenna with no heat loss:
* \f$ A_{isotr.} = \frac{\lambda^2}{4\pi} \f$
*
* The final equation becomes:
* \f$ \frac{P_r}{P_t} = \frac{\lambda^2}{(4 \pi d)^2} \f$
*
* Modern extensions to this original equation are:
* \f$ P_r = \frac{P_t G_t G_r \lambda^2}{(4 \pi d)^2 L}\f$
*
* With:
* - \f$ P_r \f$ : reception power (W)
* - \f$ P_t \f$ : transmission power (W)
* - \f$ G_t \f$ : transmission gain (unit-less)
* - \f$ G_r \f$ : reception gain (unit-less)
* - \f$ \lambda \f$ : wavelength (m)
* - \f$ d \f$ : distance (m)
* - \f$ L \f$ : 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.
*/
class FriisPropagationLossModel : public PropagationLossModel
{
public:
static TypeId GetTypeId (void);
FriisPropagationLossModel ();
/**
* \param frequency (Hz)
* \param speed (m/s)
*
* Set the main wavelength used in the Friis model
* calculation.
*/
void SetLambda (double frequency, double speed);
/**
* \param lambda (m) the wavelength
*
* Set the main wavelength used in the Friis model
* calculation.
*/
void SetLambda (double lambda);
/**
* \param systemLoss (dimension-less)
*
* Set the system loss used by the Friis propagation model.
*/
void SetSystemLoss (double systemLoss);
/**
* \param minDistance the minimum distance
*
* Below this distance, the txpower is returned
* unmodified as the rxpower.
*/
void SetMinDistance (double minDistance);
/**
* \returns the minimum distance.
*/
double GetMinDistance (void) const;
/**
* \returns the current wavelength (m)
*/
double GetLambda (void) const;
/**
* \returns the current system loss (dimention-less)
*/
double GetSystemLoss (void) const;
private:
FriisPropagationLossModel (const FriisPropagationLossModel &o);
FriisPropagationLossModel & operator = (const FriisPropagationLossModel &o);
virtual double DoCalcRxPower (double txPowerDbm,
Ptr<MobilityModel> a,
Ptr<MobilityModel> b) const;
double DbmToW (double dbm) const;
double DbmFromW (double w) const;
static const double PI;
double m_lambda;
double m_systemLoss;
double m_minDistance;
};
/*
*
* \brief a Two-Ray Ground propagation loss model ported from NS2
*
* Two-ray ground reflection model.
*
* \f$ Pr = \frac{Pt * Gt * Gr * (ht^2 * hr^2)}{d^4 * L} \f$
*
* 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:
*
* \f$ dCross = \frac{(4 * pi * Ht * Hr)}{lambda} \f$
*/
class TwoRayGroundPropagationLossModel : public PropagationLossModel
{
public:
static TypeId GetTypeId (void);
TwoRayGroundPropagationLossModel ();
/**
* \param frequency (Hz)
* \param speed (m/s)
*
* Set the main wavelength used in the TwoRayGround model
* calculation.
*/
void SetLambda (double frequency, double speed);
/**
* \param lambda (m) the wavelength
*
* Set the main wavelength used in the TwoRayGround model
* calculation.
*/
void SetLambda (double lambda);
/**
* \param systemLoss (dimension-less)
*
* Set the system loss used by the TwoRayGround propagation model.
*/
void SetSystemLoss (double systemLoss);
/**
* \param minDistance the minimum distance
*
* Below this distance, the txpower is returned
* unmodified as the rxpower.
*/
void SetMinDistance (double minDistance);
/**
* \returns the minimum distance.
*/
double GetMinDistance (void) const;
/**
* \returns the current wavelength (m)
*/
double GetLambda (void) const;
/**
* \returns the current system loss (dimention-less)
*/
double GetSystemLoss (void) const;
/**
* \param heightAboveZ the model antenna height above the node's Z coordinate
*
* Set the model antenna height above the node's Z coordinate
*/
void SetHeightAboveZ (double heightAboveZ);
private:
TwoRayGroundPropagationLossModel (const TwoRayGroundPropagationLossModel &o);
TwoRayGroundPropagationLossModel & operator = (const TwoRayGroundPropagationLossModel &o);
virtual double DoCalcRxPower (double txPowerDbm,
Ptr<MobilityModel> a,
Ptr<MobilityModel> b) const;
double DbmToW (double dbm) const;
double DbmFromW (double w) const;
static const double PI;
double m_lambda;
double m_systemLoss;
double m_minDistance;
double m_heightAboveZ;
};
/**
* \brief a log distance propagation model.
*
* This model calculates the reception power with a so-called
* log-distance propagation model:
* \f$ L = L_0 + 10 n log_{10}(\frac{d}{d_0})\f$
*
* where:
* - \f$ n \f$ : the path loss distance exponent
* - \f$ d_0 \f$ : reference distance (m)
* - \f$ L_0 \f$ : path loss at reference distance (dB)
* - \f$ d \f$ : distance (m)
* - \f$ L \f$ : path loss (dB)
*
* When the path loss is requested at a distance smaller than
* the reference distance, the tx power is returned.
*
*/
class LogDistancePropagationLossModel : public PropagationLossModel
{
public:
static TypeId GetTypeId (void);
LogDistancePropagationLossModel ();
/**
* \param n the path loss exponent.
* Set the path loss exponent.
*/
void SetPathLossExponent (double n);
/**
* \returns the current path loss exponent.
*/
double GetPathLossExponent (void) const;
void SetReference (double referenceDistance, double referenceLoss);
private:
LogDistancePropagationLossModel (const LogDistancePropagationLossModel &o);
LogDistancePropagationLossModel & operator = (const LogDistancePropagationLossModel &o);
virtual double DoCalcRxPower (double txPowerDbm,
Ptr<MobilityModel> a,
Ptr<MobilityModel> b) const;
static Ptr<PropagationLossModel> CreateDefaultReference (void);
double m_exponent;
double m_referenceDistance;
double m_referenceLoss;
};
/**
* \brief A log distance path loss propagation model with three distance
* fields. This model is the same as ns3::LogDistancePropagationLossModel
* except that it has three distance fields: near, middle and far with
* different exponents.
*
* Within each field the reception power is calculated using the log-distance
* propagation equation:
* \f[ L = L_0 + 10 \cdot n_0 log_{10}(\frac{d}{d_0})\f]
* Each field begins where the previous ends and all together form a continuous function.
*
* There are three valid distance fields: near, middle, far. Actually four: the
* first from 0 to the reference distance is invalid and returns txPowerDbm.
*
* \f[ \underbrace{0 \cdots\cdots}_{=0} \underbrace{d_0 \cdots\cdots}_{n_0} \underbrace{d_1 \cdots\cdots}_{n_1} \underbrace{d_2 \cdots\cdots}_{n_2} \infty \f]
*
* Complete formula for the path loss in dB:
*
* \f[\displaystyle L =
\begin{cases}
0 & d < d_0 \\
L_0 + 10 \cdot n_0 \log_{10}(\frac{d}{d_0}) & d_0 \leq d < d_1 \\
L_0 + 10 \cdot n_0 \log_{10}(\frac{d_1}{d_0}) + 10 \cdot n_1 \log_{10}(\frac{d}{d_1}) & d_1 \leq d < d_2 \\
L_0 + 10 \cdot n_0 \log_{10}(\frac{d_1}{d_0}) + 10 \cdot n_1 \log_{10}(\frac{d_2}{d_1}) + 10 \cdot n_2 \log_{10}(\frac{d}{d_2})& d_2 \leq d
\end{cases}\f]
*
* where:
* - \f$ L \f$ : resulting path loss (dB)
* - \f$ d \f$ : distance (m)
* - \f$ d_0, d_1, d_2 \f$ : three distance fields (m)
* - \f$ n_0, n_1, n_2 \f$ : path loss distance exponent for each field (unitless)
* - \f$ L_0 \f$ : path loss at reference distance (dB)
*
* When the path loss is requested at a distance smaller than the reference
* distance \f$ d_0 \f$, the tx power (with no path loss) is returned. The
* reference distance defaults to 1m and reference loss defaults to
* ns3::FriisPropagationLossModel with 5.15 GHz and is thus \f$ L_0 \f$ = 46.67 dB.
*/
class ThreeLogDistancePropagationLossModel : public PropagationLossModel
{
public:
static TypeId GetTypeId (void);
ThreeLogDistancePropagationLossModel ();
// Parameters are all accessible via attributes.
private:
ThreeLogDistancePropagationLossModel (const ThreeLogDistancePropagationLossModel& o);
ThreeLogDistancePropagationLossModel& operator= (const ThreeLogDistancePropagationLossModel& o);
virtual double DoCalcRxPower (double txPowerDbm,
Ptr<MobilityModel> a,
Ptr<MobilityModel> b) const;
double m_distance0;
double m_distance1;
double m_distance2;
double m_exponent0;
double m_exponent1;
double m_exponent2;
double m_referenceLoss;
};
/**
* \brief Nakagami-m fast fading propagation loss model.
*
* The Nakagami-m distribution is applied to the power level. The probability
* density function is defined as
* \f[ p(x; m, \omega) = \frac{2 m^m}{\Gamma(m) \omega^m} x^{2m - 1} e^{-\frac{m}{\omega} x^2} = 2 x \cdot p_{\text{Gamma}}(x^2, m, \frac{m}{\omega}) \f]
* with \f$ m \f$ the fading depth parameter and \f$ \omega \f$ the average received power.
*
* It is implemented by either a ns3::GammaVariable or a ns3::ErlangVariable
* random variable.
*
* Like in ns3::ThreeLogDistancePropagationLossModel, the m parameter is varied
* over three distance fields:
* \f[ \underbrace{0 \cdots\cdots}_{m_0} \underbrace{d_1 \cdots\cdots}_{m_1} \underbrace{d_2 \cdots\cdots}_{m_2} \infty \f]
*
* For m = 1 the Nakagami-m distribution equals the Rayleigh distribution. Thus
* this model also implements Rayleigh distribution based fast fading.
*/
class NakagamiPropagationLossModel : public PropagationLossModel
{
public:
static TypeId GetTypeId (void);
NakagamiPropagationLossModel ();
// Parameters are all accessible via attributes.
private:
NakagamiPropagationLossModel (const NakagamiPropagationLossModel& o);
NakagamiPropagationLossModel& operator= (const NakagamiPropagationLossModel& o);
virtual double DoCalcRxPower (double txPowerDbm,
Ptr<MobilityModel> a,
Ptr<MobilityModel> b) const;
double m_distance1;
double m_distance2;
double m_m0;
double m_m1;
double m_m2;
ErlangVariable m_erlangRandomVariable;
GammaVariable m_gammaRandomVariable;
};
/**
* \brief The propagation loss is fixed. The user can set received power level.
*/
class FixedRssLossModel : public PropagationLossModel
{
public:
static TypeId GetTypeId (void);
FixedRssLossModel ();
virtual ~FixedRssLossModel ();
/**
* \param rss (dBm) the received signal strength
*
* Set the RSS.
*/
void SetRss (double rss);
private:
FixedRssLossModel (const FixedRssLossModel &o);
FixedRssLossModel & operator = (const FixedRssLossModel &o);
virtual double DoCalcRxPower (double txPowerDbm,
Ptr<MobilityModel> a,
Ptr<MobilityModel> b) const;
double m_rss;
};
/**
* \brief The propagation loss is fixed for each pair of nodes and doesn't depend on their actual positions.
*
* This is supposed to be used by synthetic tests. Note that by default propagation loss is assumed to be symmetric.
*/
class MatrixPropagationLossModel : public PropagationLossModel
{
public:
static TypeId GetTypeId (void);
MatrixPropagationLossModel ();
virtual ~MatrixPropagationLossModel ();
/**
* \brief Set loss (in dB, positive) between pair of nodes.
*
* \param a Source node
* \param b Destination node
* \param loss a -> b path loss, positive in dB
* \param symmetric If true (default), both a->b and b->a paths will be affected
*/
void SetLoss (Ptr<Node> a, Ptr<Node> b, double loss, bool symmetric = true);
/// Set default loss (in dB, positive) to be used, \infty if not set
void SetDefaultLoss (double);
private:
virtual double DoCalcRxPower (double txPowerDbm,
Ptr<MobilityModel> a,
Ptr<MobilityModel> b) const;
private:
/// default loss
double m_default;
typedef std::pair< Ptr<MobilityModel>, Ptr<MobilityModel> > MobilityPair;
/// Fixed loss between pair of nodes
std::map<MobilityPair, double> m_loss;
};
} // namespace ns3
#endif /* PROPAGATION_LOSS_MODEL_H */