A Discrete-Event Network Simulator
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ns3::RandomWalk2dOutdoorMobilityModel Class Reference

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. More...
 

Static Public Member Functions

static TypeId GetTypeId (void)
 Register this type with the TypeId system. More...
 
- Static Public Member Functions inherited from ns3::MobilityModel
static TypeId GetTypeId (void)
 Register this type with the TypeId system. More...
 
- Static Public Member Functions inherited from ns3::Object
static TypeId GetTypeId (void)
 Register this type. More...
 
- Static Public Member Functions inherited from ns3::ObjectBase
static TypeId GetTypeId (void)
 Get the type ID. More...
 

Private Member Functions

void AvoidBuilding (Time delayLeft, Vector intersectPosition)
 Avoid a building. More...
 
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 Notice that we only consider a 2d plane. More...
 
virtual int64_t DoAssignStreams (int64_t)
 The default implementation does nothing but return the passed-in parameter. More...
 
virtual void DoDispose (void)
 Destructor implementation. More...
 
virtual Vector DoGetPosition (void) const
 
virtual Vector DoGetVelocity (void) const
 
virtual void DoInitialize (void)
 Initialize() implementation. More...
 
void DoInitializePrivate (void)
 Perform initialization of the object before MobilityModel::DoInitialize () More...
 
virtual void DoSetPosition (const Vector &position)
 
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. More...
 
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). More...
 
void Rebound (Time timeLeft)
 Performs the rebound of the node if it reaches a boundary. More...
 

Private Attributes

Rectangle m_bounds
 Bounds of the area to cruise. More...
 
Ptr< RandomVariableStreamm_direction
 rv for picking direction More...
 
double m_epsilon
 Tolerance for the intersection point with buildings. More...
 
EventId m_event
 stored event ID More...
 
ConstantVelocityHelper m_helper
 helper for this object More...
 
uint32_t m_maxIter
 Maximum number of tries to find the next position. More...
 
enum Mode m_mode
 whether in time or distance mode More...
 
double m_modeDistance
 Change direction and speed after this distance. More...
 
Time m_modeTime
 Change current direction and speed after this delay. More...
 
Vector m_prevPosition
 Store the previous position in case a step back is needed. More...
 
Ptr< RandomVariableStreamm_speed
 rv for picking speed More...
 

Additional Inherited Members

- Public Member Functions inherited from ns3::MobilityModel
 MobilityModel ()
 
virtual ~MobilityModel ()=0
 
int64_t AssignStreams (int64_t stream)
 Assign a fixed random variable stream number to the random variables used by this model. More...
 
double GetDistanceFrom (Ptr< const MobilityModel > position) const
 
Vector GetPosition (void) const
 
Vector GetPositionWithReference (const Vector &referencePosition) const
 This method may be used if the position returned may depend on some reference position provided. More...
 
double GetRelativeSpeed (Ptr< const MobilityModel > other) const
 
Vector GetVelocity (void) const
 
void SetPosition (const Vector &position)
 
- Public Member Functions inherited from ns3::Object
 Object ()
 Constructor. More...
 
virtual ~Object ()
 Destructor. More...
 
void AggregateObject (Ptr< Object > other)
 Aggregate two Objects together. More...
 
void Dispose (void)
 Dispose of this Object. More...
 
AggregateIterator GetAggregateIterator (void) const
 Get an iterator to the Objects aggregated to this one. More...
 
virtual TypeId GetInstanceTypeId (void) const
 Get the most derived TypeId for this Object. More...
 
template<>
Ptr< ObjectGetObject () const
 Specialization of () for objects of type ns3::Object. More...
 
template<typename T >
Ptr< T > GetObject (TypeId tid) const
 Get a pointer to the requested aggregated Object by TypeId. More...
 
template<>
Ptr< ObjectGetObject (TypeId tid) const
 Specialization of (TypeId tid) for objects of type ns3::Object. More...
 
template<typename T >
Ptr< T > GetObject (void) const
 Get a pointer to the requested aggregated Object. More...
 
void Initialize (void)
 Invoke DoInitialize on all Objects aggregated to this one. More...
 
bool IsInitialized (void) const
 Check if the object has been initialized. More...
 
- Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
 SimpleRefCount ()
 Default constructor. More...
 
 SimpleRefCount (const SimpleRefCount &o)
 Copy constructor. More...
 
uint32_t GetReferenceCount (void) const
 Get the reference count of the object. More...
 
SimpleRefCountoperator= (const SimpleRefCount &o)
 Assignment operator. 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
 Get the value of an attribute, raising fatal errors if unsuccessful. More...
 
bool GetAttributeFailSafe (std::string name, AttributeValue &value) const
 Get the value of an attribute without raising erros. More...
 
virtual TypeId GetInstanceTypeId (void) const =0
 Get the most derived TypeId for this Object. More...
 
void SetAttribute (std::string name, const AttributeValue &value)
 Set a single attribute, raising fatal errors if unsuccessful. More...
 
bool SetAttributeFailSafe (std::string name, const AttributeValue &value)
 Set a single attribute without raising errors. More...
 
bool TraceConnect (std::string name, std::string context, const CallbackBase &cb)
 Connect a TraceSource to a Callback with a context. More...
 
bool TraceConnectWithoutContext (std::string name, const CallbackBase &cb)
 Connect a TraceSource to a Callback without a context. More...
 
bool TraceDisconnect (std::string name, std::string context, const CallbackBase &cb)
 Disconnect from a TraceSource a Callback previously connected with a context. More...
 
bool TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb)
 Disconnect from a TraceSource a Callback previously connected without a context. More...
 
- Protected Member Functions inherited from ns3::MobilityModel
void NotifyCourseChange (void) const
 Must be invoked by subclasses when the course of the position changes to notify course change listeners. More...
 
- Protected Member Functions inherited from ns3::Object
 Object (const Object &o)
 Copy an Object. More...
 
virtual void DoDispose (void)
 Destructor implementation. More...
 
virtual void DoInitialize (void)
 Initialize() implementation. More...
 
virtual void NotifyNewAggregate (void)
 Notify all Objects aggregated to this one of a new Object being aggregated. More...
 
- Protected Member Functions inherited from ns3::ObjectBase
void ConstructSelf (const AttributeConstructionList &attributes)
 Complete construction of ObjectBase; invoked by derived classes. More...
 
virtual void NotifyConstructionCompleted (void)
 Notifier called once the ObjectBase is fully constructed. More...
 

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.

Config Paths

ns3::RandomWalk2dOutdoorMobilityModel is accessible through the following paths with Config::Set and Config::Connect:

  • "/NodeList/[i]/$ns3::MobilityModel/$ns3::RandomWalk2dOutdoorMobilityModel"

Attributes

  • Bounds: Bounds of the area to cruise.
  • Time: Change current direction and speed after moving for this delay.
    • Set with class: ns3::TimeValue
    • Underlying type: Time +9.22337e+18ns:+9.22337e+18ns
    • Initial value: +2e+10ns
    • Flags: construct write read
  • Distance: Change current direction and speed after moving for this distance.
    • Set with class: ns3::DoubleValue
    • Underlying type: double -1.79769e+308:1.79769e+308
    • Initial value: 30
    • Flags: construct write read
  • Mode: The mode indicates the condition used to change the current speed and direction
    • Set with class: ns3::EnumValue
    • Underlying type:
    • Initial value: Distance
    • Flags: construct write read
  • Direction: A random variable used to pick the direction (radians).
  • Speed: A random variable used to pick the speed (m/s).The default value is taken from Figure 1 of the paperHenderson, L.F., 1971. The statistics of crowd fluids. nature, 229(5284), p.381.
  • Tolerance: Tolerance for the intersection point with buildings (m).It represents a small distance from where the building limitis actually placed, for example to represent a sidewalk.
    • Set with class: ns3::DoubleValue
    • Underlying type: double -1.79769e+308:1.79769e+308
    • Initial value: 1e-06
    • Flags: construct write read
  • MaxIterations: Maximum number of attempts to find an alternative next positionif the original one is inside a building.
    • Set with class: ns3::UintegerValue
    • Underlying type: uint32_t 0:4294967295
    • Initial value: 100
    • Flags: construct write read

Attributes defined in parent class ns3::MobilityModel

  • Position: The current position of the mobility model.
  • Velocity: The current velocity of the mobility model.

No TraceSources are defined for this type.

TraceSources defined in parent class ns3::MobilityModel

Size of this type is 248 bytes (on a 64-bit architecture).

Definition at line 57 of file random-walk-2d-outdoor-mobility-model.h.

Member Enumeration Documentation

◆ Mode

An enum representing the different working modes of this module.

Enumerator
MODE_DISTANCE 
MODE_TIME 

Definition at line 66 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
delayLeftThe remaining time of the walk
intersectPositionThe position at which the building is intersected

Definition at line 308 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
currentThe current position
nextThe next position
boundariesThe boundaries of the building we will intersect
Returns
a vector with the position of the intersection

Definition at line 231 of file random-walk-2d-outdoor-mobility-model.cc.

References ns3::Rectangle::BOTTOM, ns3::Rectangle::GetClosestSide(), ns3::Box::IsInside(), ns3::Rectangle::LEFT, m_epsilon, NS_ABORT_MSG_IF, NS_ASSERT, NS_LOG_FUNCTION, NS_LOG_INFO, ns3::Rectangle::RIGHT, ns3::Rectangle::TOP, 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)
privatevirtual

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

Subclasses using random variables are expected to override this.

Parameters
startstarting stream index
Returns
the number of streams used

Reimplemented from ns3::MobilityModel.

Definition at line 430 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 ( void  )
privatevirtual

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 405 of file random-walk-2d-outdoor-mobility-model.cc.

References ns3::Object::DoDispose().

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◆ DoGetPosition()

Vector ns3::RandomWalk2dOutdoorMobilityModel::DoGetPosition ( void  ) const
privatevirtual
Returns
the current position.

Concrete subclasses of this base class must implement this method.

Implements ns3::MobilityModel.

Definition at line 411 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 ( void  ) const
privatevirtual
Returns
the current velocity.

Concrete subclasses of this base class must implement this method.

Implements ns3::MobilityModel.

Definition at line 425 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 ( void  )
privatevirtual

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 99 of file random-walk-2d-outdoor-mobility-model.cc.

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

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◆ DoInitializePrivate()

void ns3::RandomWalk2dOutdoorMobilityModel::DoInitializePrivate ( void  )
private

◆ DoSetPosition()

void ns3::RandomWalk2dOutdoorMobilityModel::DoSetPosition ( const Vector &  position)
privatevirtual
Parameters
positionthe position to set.

Concrete subclasses of this base class must implement this method.

Implements ns3::MobilityModel.

Definition at line 417 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
delayLeftThe remaining time of the walk

Definition at line 130 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(), m_bounds, m_event, m_helper, m_prevPosition, ns3::MobilityModel::NotifyCourseChange(), NS_LOG_FUNCTION, 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 ( void  )
static

◆ 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
currentPositionThe current position of the node
nextPositionThe 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 198 of file random-walk-2d-outdoor-mobility-model.cc.

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

Referenced by AvoidBuilding(), and DoWalk().

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◆ Rebound()

void ns3::RandomWalk2dOutdoorMobilityModel::Rebound ( Time  timeLeft)
private

Member Data Documentation

◆ m_bounds

Rectangle ns3::RandomWalk2dOutdoorMobilityModel::m_bounds
private

Bounds of the area to cruise.

Definition at line 127 of file random-walk-2d-outdoor-mobility-model.h.

Referenced by AvoidBuilding(), DoGetPosition(), DoSetPosition(), DoWalk(), GetTypeId(), and Rebound().

◆ m_direction

Ptr<RandomVariableStream> ns3::RandomWalk2dOutdoorMobilityModel::m_direction
private

rv for picking direction

Definition at line 126 of file random-walk-2d-outdoor-mobility-model.h.

Referenced by AvoidBuilding(), DoAssignStreams(), DoInitializePrivate(), and GetTypeId().

◆ m_epsilon

double ns3::RandomWalk2dOutdoorMobilityModel::m_epsilon
private

Tolerance for the intersection point with buildings.

Definition at line 128 of file random-walk-2d-outdoor-mobility-model.h.

Referenced by CalculateIntersectionFromOutside(), and GetTypeId().

◆ m_event

EventId ns3::RandomWalk2dOutdoorMobilityModel::m_event
private

stored event ID

Definition at line 121 of file random-walk-2d-outdoor-mobility-model.h.

Referenced by DoSetPosition(), and DoWalk().

◆ m_helper

ConstantVelocityHelper ns3::RandomWalk2dOutdoorMobilityModel::m_helper
private

◆ m_maxIter

uint32_t ns3::RandomWalk2dOutdoorMobilityModel::m_maxIter
private

Maximum number of tries to find the next position.

Definition at line 129 of file random-walk-2d-outdoor-mobility-model.h.

Referenced by AvoidBuilding(), and GetTypeId().

◆ m_mode

enum Mode ns3::RandomWalk2dOutdoorMobilityModel::m_mode
private

whether in time or distance mode

Definition at line 122 of file random-walk-2d-outdoor-mobility-model.h.

Referenced by DoInitializePrivate(), and GetTypeId().

◆ m_modeDistance

double ns3::RandomWalk2dOutdoorMobilityModel::m_modeDistance
private

Change direction and speed after this distance.

Definition at line 123 of file random-walk-2d-outdoor-mobility-model.h.

Referenced by DoInitializePrivate(), and GetTypeId().

◆ m_modeTime

Time ns3::RandomWalk2dOutdoorMobilityModel::m_modeTime
private

Change current direction and speed after this delay.

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

Referenced by DoInitializePrivate(), and GetTypeId().

◆ m_prevPosition

Vector ns3::RandomWalk2dOutdoorMobilityModel::m_prevPosition
private

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

Definition at line 130 of file random-walk-2d-outdoor-mobility-model.h.

Referenced by AvoidBuilding(), and DoWalk().

◆ m_speed

Ptr<RandomVariableStream> ns3::RandomWalk2dOutdoorMobilityModel::m_speed
private

rv for picking speed

Definition at line 125 of file random-walk-2d-outdoor-mobility-model.h.

Referenced by AvoidBuilding(), DoAssignStreams(), DoInitializePrivate(), and GetTypeId().


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