2D random walk mobility model which avoids buildings. More...

#include "random-walk-2d-outdoor-mobility-model.h"

Inheritance diagram for ns3::RandomWalk2dOutdoorMobilityModel:

Collaboration diagram for ns3::RandomWalk2dOutdoorMobilityModel:

Public Types
enum	Mode { MODE_DISTANCE , MODE_TIME }
	An enum representing the different working modes of this module. More...

Public Types inherited from ns3::MobilityModel
typedef void(*	TracedCallback) (Ptr< const MobilityModel > model)
	TracedCallback signature.

Static Public Member Functions
static TypeId	GetTypeId ()
	Register this type with the TypeId system.

Static Public Member Functions inherited from ns3::MobilityModel
static TypeId	GetTypeId ()
	Register this type with the TypeId system.

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

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

Private Member Functions
void	AvoidBuilding (Time delayLeft, Vector intersectPosition)
	Avoid a building.

Vector	CalculateIntersectionFromOutside (const Vector &current, const Vector &next, const Box boundaries) const
	Compute the intersecting point of the box represented by boundaries and the line between current and next.

int64_t	DoAssignStreams (int64_t) override
	The default implementation does nothing but return the passed-in parameter.

void	DoDispose () override
	Destructor implementation.

Vector	DoGetPosition () const override

Vector	DoGetVelocity () const override

void	DoInitialize () override
	Initialize() implementation.

void	DoInitializePrivate ()
	Perform initialization of the object before MobilityModel::DoInitialize ()

void	DoSetPosition (const Vector &position) override

void	DoWalk (Time delayLeft)
	Walk according to position and velocity, until distance is reached, time is reached, or intersection with the bounding box, or building.

std::pair< bool, Ptr< Building > >	IsLineClearOfBuildings (Vector currentPosition, Vector nextPosition) const
	Check if there is a building between two positions (or if the nextPosition is inside a building).

void	Rebound (Time timeLeft)
	Performs the rebound of the node if it reaches a boundary.

Private Attributes
Rectangle	m_bounds
	Bounds of the area to cruise.

Ptr< RandomVariableStream >	m_direction
	rv for picking direction

double	m_epsilon
	Tolerance for the intersection point with buildings.

EventId	m_event
	stored event ID

ConstantVelocityHelper	m_helper
	helper for this object

uint32_t	m_maxIter
	Maximum number of tries to find the next position.

Mode	m_mode
	whether in time or distance mode

double	m_modeDistance
	Change direction and speed after this distance.

Time	m_modeTime
	Change current direction and speed after this delay.

Vector	m_prevPosition
	Store the previous position in case a step back is needed.

Ptr< RandomVariableStream >	m_speed
	rv for picking speed

Additional Inherited Members
Public Member Functions inherited from ns3::MobilityModel
	MobilityModel ()

	~MobilityModel () override=0

int64_t	AssignStreams (int64_t stream)
	Assign a fixed random variable stream number to the random variables used by this model.

double	GetDistanceFrom (Ptr< const MobilityModel > position) const

Vector	GetPosition () const

Vector	GetPositionWithReference (const Vector &referencePosition) const
	This method may be used if the position returned may depend on some reference position provided.

double	GetRelativeSpeed (Ptr< const MobilityModel > other) const

Vector	GetVelocity () const

void	SetPosition (const Vector &position)

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

	~Object () override
	Destructor.

void	AggregateObject (Ptr< Object > other)
	Aggregate two Objects together.

void	Dispose ()
	Dispose of this Object.

AggregateIterator	GetAggregateIterator () const
	Get an iterator to the Objects aggregated to this one.

TypeId	GetInstanceTypeId () const override
	Get the most derived TypeId for this Object.

template<typename T >
Ptr< T >	GetObject () const
	Get a pointer to the requested aggregated Object.

template<>
Ptr< Object >	GetObject () const
	Specialization of () for objects of type ns3::Object.

template<typename T >
Ptr< T >	GetObject (TypeId tid) const
	Get a pointer to the requested aggregated Object by TypeId.

template<>
Ptr< Object >	GetObject (TypeId tid) const
	Specialization of (TypeId tid) for objects of type ns3::Object.

void	Initialize ()
	Invoke DoInitialize on all Objects aggregated to this one.

bool	IsInitialized () const
	Check if the object has been initialized.

void	UnidirectionalAggregateObject (Ptr< Object > other)
	Aggregate an Object to another Object.

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

	SimpleRefCount (const SimpleRefCount &o)
	Copy constructor.

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

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

void	Ref () const
	Increment the reference count.

void	Unref () const
	Decrement the reference count.

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

void	GetAttribute (std::string name, AttributeValue &value, bool permissive=false) const
	Get the value of an attribute, raising fatal errors if unsuccessful.

bool	GetAttributeFailSafe (std::string name, AttributeValue &value) const
	Get the value of an attribute without raising errors.

void	SetAttribute (std::string name, const AttributeValue &value)
	Set a single attribute, raising fatal errors if unsuccessful.

bool	SetAttributeFailSafe (std::string name, const AttributeValue &value)
	Set a single attribute without raising errors.

bool	TraceConnect (std::string name, std::string context, const CallbackBase &cb)
	Connect a TraceSource to a Callback with a context.

bool	TraceConnectWithoutContext (std::string name, const CallbackBase &cb)
	Connect a TraceSource to a Callback without a context.

bool	TraceDisconnect (std::string name, std::string context, const CallbackBase &cb)
	Disconnect from a TraceSource a Callback previously connected with a context.

bool	TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb)
	Disconnect from a TraceSource a Callback previously connected without a context.

Protected Member Functions inherited from ns3::MobilityModel
void	NotifyCourseChange () const
	Must be invoked by subclasses when the course of the position changes to notify course change listeners.

Protected Member Functions inherited from ns3::Object
	Object (const Object &o)
	Copy an Object.

virtual void	NotifyNewAggregate ()
	Notify all Objects aggregated to this one of a new Object being aggregated.

Protected Member Functions inherited from ns3::ObjectBase
void	ConstructSelf (const AttributeConstructionList &attributes)
	Complete construction of ObjectBase; invoked by derived classes.

virtual void	NotifyConstructionCompleted ()
	Notifier called once the ObjectBase is fully constructed.

Related Symbols inherited from ns3::ObjectBase
static TypeId	GetObjectIid ()
	Ensure the TypeId for ObjectBase gets fully configured to anchor the inheritance tree properly.

Detailed Description

2D random walk mobility model which avoids buildings.

This class reuses most of the code of RandomWalk2dMobilityModel, but adds the awareness of buildings objects which are avoided by moving users. Each instance moves with a speed and direction chosen at random with the user-provided random variables until either a fixed distance has been walked or until a fixed amount of time. If we hit one of the boundaries (specified by a rectangle) of the model, we rebound on the boundary with a reflexive angle and speed. If we hit one of the buildings, we rebound with a random direction which makes sure that the next step does not enter the building.

The default values for the random variable that describes the speed is taken from Figure 1 in the paper: Henderson, L.F., 1971. The statistics of crowd fluids. nature, 229(5284), p.381.

Definition at line 48 of file random-walk-2d-outdoor-mobility-model.h.

Member Enumeration Documentation

◆ Mode

enum ns3::RandomWalk2dOutdoorMobilityModel::Mode

An enum representing the different working modes of this module.

Enumerator
MODE_DISTANCE
MODE_TIME

Definition at line 58 of file random-walk-2d-outdoor-mobility-model.h.

Member Function Documentation

◆ AvoidBuilding()

void ns3::RandomWalk2dOutdoorMobilityModel::AvoidBuilding	(	Time	delayLeft,
		Vector	intersectPosition )

private

Avoid a building.

Parameters

delayLeft	The remaining time of the walk
intersectPosition	The position at which the building is intersected

Definition at line 401 of file random-walk-2d-outdoor-mobility-model.cc.

References ns3::CalculateDistance(), DoWalk(), ns3::Time::GetSeconds(), ns3::RandomVariableStream::GetValue(), ns3::Rectangle::IsInside(), IsLineClearOfBuildings(), m_bounds, m_direction, m_helper, m_maxIter, m_prevPosition, m_speed, NS_FATAL_ERROR, NS_LOG_FUNCTION, NS_LOG_INFO, NS_LOG_LOGIC, ns3::ConstantVelocityHelper::SetVelocity(), ns3::ConstantVelocityHelper::Unpause(), and ns3::ConstantVelocityHelper::Update().

Referenced by DoWalk().

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◆ CalculateIntersectionFromOutside()

Vector ns3::RandomWalk2dOutdoorMobilityModel::CalculateIntersectionFromOutside	(	const Vector &	current,
		const Vector &	next,
		const Box	boundaries ) const

private

Compute the intersecting point of the box represented by boundaries and the line between current and next.

Notice that we only consider a 2d plane.

Parameters

current	The current position
next	The next position
boundaries	The boundaries of the building we will intersect

Returns: a vector with the position of the intersection

Definition at line 288 of file random-walk-2d-outdoor-mobility-model.cc.

References ns3::Rectangle::BOTTOMLEFTCORNER, ns3::Rectangle::BOTTOMRIGHTCORNER, ns3::Rectangle::BOTTOMSIDE, ns3::Rectangle::GetClosestSideOrCorner(), ns3::Box::IsInside(), ns3::Rectangle::LEFTSIDE, m_epsilon, NS_ABORT_MSG_IF, NS_ASSERT, NS_LOG_DEBUG, NS_LOG_FUNCTION, ns3::Rectangle::RIGHTSIDE, ns3::Rectangle::TOPLEFTCORNER, ns3::Rectangle::TOPRIGHTCORNER, ns3::Rectangle::TOPSIDE, ns3::Box::xMax, ns3::Box::xMin, ns3::Box::yMax, and ns3::Box::yMin.

Referenced by DoWalk(), and IsLineClearOfBuildings().

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◆ DoAssignStreams()

int64_t ns3::RandomWalk2dOutdoorMobilityModel::DoAssignStreams ( int64_t start )

overrideprivatevirtual

The default implementation does nothing but return the passed-in parameter.

Subclasses using random variables are expected to override this.

Parameters

start starting stream index

Returns: the number of streams used

Reimplemented from ns3::MobilityModel.

Definition at line 524 of file random-walk-2d-outdoor-mobility-model.cc.

References m_direction, m_speed, and ns3::RandomVariableStream::SetStream().

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◆ DoDispose()

void ns3::RandomWalk2dOutdoorMobilityModel::DoDispose ( )

overrideprivatevirtual

Destructor implementation.

This method is called by Dispose() or by the Object's destructor, whichever comes first.

Subclasses are expected to implement their real destruction code in an overridden version of this method and chain up to their parent's implementation once they are done. i.e, for simplicity, the destructor of every subclass should be empty and its content should be moved to the associated DoDispose() method.

It is safe to call GetObject() from within this method.

Reimplemented from ns3::Object.

Definition at line 495 of file random-walk-2d-outdoor-mobility-model.cc.

References ns3::Object::DoDispose().

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◆ DoGetPosition()

Vector ns3::RandomWalk2dOutdoorMobilityModel::DoGetPosition ( ) const

overrideprivatevirtual

Returns: the current position.

Concrete subclasses of this base class must implement this method.

Implements ns3::MobilityModel.

Definition at line 502 of file random-walk-2d-outdoor-mobility-model.cc.

References ns3::ConstantVelocityHelper::GetCurrentPosition(), m_bounds, m_helper, and ns3::ConstantVelocityHelper::UpdateWithBounds().

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◆ DoGetVelocity()

Vector ns3::RandomWalk2dOutdoorMobilityModel::DoGetVelocity ( ) const

overrideprivatevirtual

Returns: the current velocity.

Concrete subclasses of this base class must implement this method.

Implements ns3::MobilityModel.

Definition at line 518 of file random-walk-2d-outdoor-mobility-model.cc.

References ns3::ConstantVelocityHelper::GetVelocity(), and m_helper.

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◆ DoInitialize()

void ns3::RandomWalk2dOutdoorMobilityModel::DoInitialize ( )

overrideprivatevirtual

Initialize() implementation.

This method is called only once by Initialize(). If the user calls Initialize() multiple times, DoInitialize() is called only the first time.

Subclasses are expected to override this method and chain up to their parent's implementation once they are done. It is safe to call GetObject() and AggregateObject() from within this method.

Reimplemented from ns3::Object.

Definition at line 95 of file random-walk-2d-outdoor-mobility-model.cc.

References ns3::Object::DoInitialize(), and DoInitializePrivate().

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◆ DoInitializePrivate()

void ns3::RandomWalk2dOutdoorMobilityModel::DoInitializePrivate ( )

private

Perform initialization of the object before MobilityModel::DoInitialize ()

Definition at line 102 of file random-walk-2d-outdoor-mobility-model.cc.

References DoWalk(), ns3::RandomVariableStream::GetValue(), m_direction, m_helper, m_mode, m_modeDistance, m_modeTime, m_speed, MODE_TIME, ns3::Seconds(), ns3::ConstantVelocityHelper::SetVelocity(), ns3::ConstantVelocityHelper::Unpause(), and ns3::ConstantVelocityHelper::Update().

Referenced by DoInitialize(), DoSetPosition(), and DoWalk().

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◆ DoSetPosition()

void ns3::RandomWalk2dOutdoorMobilityModel::DoSetPosition ( const Vector & position )

overrideprivatevirtual

Parameters

position the position to set.

Concrete subclasses of this base class must implement this method.

Implements ns3::MobilityModel.

Definition at line 509 of file random-walk-2d-outdoor-mobility-model.cc.

References DoInitializePrivate(), ns3::Rectangle::IsInside(), m_bounds, m_event, m_helper, NS_ASSERT, ns3::Simulator::Remove(), ns3::Simulator::ScheduleNow(), and ns3::ConstantVelocityHelper::SetPosition().

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◆ DoWalk()

void ns3::RandomWalk2dOutdoorMobilityModel::DoWalk ( Time delayLeft )

private

Walk according to position and velocity, until distance is reached, time is reached, or intersection with the bounding box, or building.

Parameters

delayLeft The remaining time of the walk

Definition at line 124 of file random-walk-2d-outdoor-mobility-model.cc.

References AvoidBuilding(), ns3::Rectangle::CalculateIntersection(), CalculateIntersectionFromOutside(), ns3::EventId::Cancel(), DoInitializePrivate(), ns3::ConstantVelocityHelper::GetCurrentPosition(), ns3::Time::GetSeconds(), ns3::ConstantVelocityHelper::GetVelocity(), ns3::Rectangle::IsInside(), IsLineClearOfBuildings(), ns3::Time::IsNegative(), m_bounds, m_event, m_helper, m_prevPosition, ns3::MobilityModel::NotifyCourseChange(), NS_ABORT_MSG, NS_LOG_FUNCTION, NS_LOG_INFO, NS_LOG_LOGIC, Rebound(), ns3::Simulator::Schedule(), and ns3::Seconds().

Referenced by AvoidBuilding(), DoInitializePrivate(), and Rebound().

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◆ GetTypeId()

TypeId ns3::RandomWalk2dOutdoorMobilityModel::GetTypeId ( )

static

Register this type with the TypeId system.

Returns: the object TypeId

Definition at line 34 of file random-walk-2d-outdoor-mobility-model.cc.

References m_bounds, m_direction, m_epsilon, m_maxIter, m_mode, m_modeDistance, m_modeTime, m_speed, ns3::MakeDoubleAccessor(), ns3::MakeDoubleChecker(), ns3::MakeEnumAccessor(), ns3::MakeEnumChecker(), ns3::MakePointerAccessor(), ns3::MakePointerChecker(), ns3::MakeRectangleAccessor(), ns3::MakeRectangleChecker(), ns3::MakeTimeAccessor(), ns3::MakeTimeChecker(), ns3::MakeUintegerAccessor(), ns3::MakeUintegerChecker(), MODE_DISTANCE, MODE_TIME, ns3::Seconds(), and ns3::TypeId::SetParent().

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◆ IsLineClearOfBuildings()

std::pair< bool, Ptr< Building > > ns3::RandomWalk2dOutdoorMobilityModel::IsLineClearOfBuildings	(	Vector	currentPosition,
		Vector	nextPosition ) const

private

Check if there is a building between two positions (or if the nextPosition is inside a building).

The code is taken from MmWave3gppBuildingsPropagationLossModel from the NYU/UNIPD ns-3 mmWave module

Parameters

currentPosition	The current position of the node
nextPosition	The position to check

Returns: a pair with a boolean (true if the line between the two position does not intersect building), and a pointer which is 0 if the boolean is true, or it points to the building which is intersected

Definition at line 254 of file random-walk-2d-outdoor-mobility-model.cc.

References ns3::BuildingList::Begin(), ns3::CalculateDistance(), CalculateIntersectionFromOutside(), ns3::BuildingList::End(), NS_LOG_FUNCTION, and NS_LOG_LOGIC.

Referenced by AvoidBuilding(), and DoWalk().

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