MassMobility

simple module

This is a random mobility model for a mobile host with mass. It is the one used in "Optimized Smooth Handoffs in Mobile IP" by Perkins & Wang.

"An MH moves within the room according to the following pattern. It moves along a straight line for a certain period of time before it makes a turn. This moving period is a random number, normally distributed with an average of 5 seconds and a standard deviation of 0.1 second. When it makes a turn, the new direction (angle) in which it will move is a normally distributed random number with an average equal to the previous direction and a standard deviation of 30 degrees. Its speed is also a normally distributed random number, with a controlled average, ranging from 0.1 to 0.45 (unit/sec), and a standard deviation of 0.01 (unit/sec). A new such random number is picked as its speed when it makes a turn. This pattern of mobility is intended to model node movement during which the nodes have momentum and thus do not start, stop, or turn abruptly. When it hits a wall, it reflects off the wall at the same angle; in our simulated world, there is little other choice."

This implementation can be parameterized further, using the changeInterval and angleDelta parameters. The parameters described above correspond to the following settings:

changeInterval = normal(5, 0.1)
angleDelta = normal(0, 30)
speed = normal(avgSpeed, 0.01)

3D (spatial movement) is also supported using the rotationAxisAngle parameter.

<b>Author:</b> Emin Ilker Cetinbas

Inheritance diagram

The following diagram shows inheritance relationships for this type. Unresolved types are missing from the diagram.

Extends

Name	Type	Description
MovingMobilityBase	simple module	Abstract base module for mobility models.

Parameters

Name	Type	Default value	Description
displayStringTextFormat	string	"p: %p\nv: %v"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
subjectModule	string	"^"	The module path that determines the subject module, the motion of which this mobility model describes. The default value is the parent module
coordinateSystemModule	string	""	The module path of the geographic coordinate system module
updateDisplayString	bool	true	Enables continuous update of the subject module's position by modifying its display string
constraintAreaMinX	double	-inf m	The minimum x position of the constraint area. It is unconstrained by default (negative infinity)
constraintAreaMinY	double	-inf m	The minimum y position of the constraint area. It is unconstrained by default (negative infinity)
constraintAreaMinZ	double	-inf m	The minimum z position of the constraint area. It is unconstrained by default (negative infinity)
constraintAreaMaxX	double	inf m	The maximum x position of the constraint area. It is unconstrained by default (positive infinity)
constraintAreaMaxY	double	inf m	The maximum y position of the constraint area. It is unconstrained by default (positive infinity)
constraintAreaMaxZ	double	inf m	The maximum z position of the constraint area. It is unconstrained by default (positive infinity)
updateInterval	double	0.1s	The simulation time interval used to regularly signal mobility state changes and update the display
faceForward	bool	true
initialX	double	uniform(constraintAreaMinX, constraintAreaMaxX)
initialY	double	uniform(constraintAreaMinY, constraintAreaMaxY)
initialZ	double	nanToZero(uniform(constraintAreaMinZ, constraintAreaMaxZ))
initialMovementHeading	double	uniform(0deg, 360deg)	Initial heading
initialMovementElevation	double	0deg	Initial elevation
initFromDisplayString	bool	true	Enables one-time initialization from the subject module's display string
changeInterval	double		Frequency of changing speed and angle (can be random)
angleDelta	double		Rotate velocity vector by this much around the rotation axis defined by the rotationAxisAngle parameter (can be random)
rotationAxisAngle	double	0deg	Defines a vector in the plane perpendicular to the velocity, where 0 deg means the Z axis when bank is zero (can be random)
speed	double		Speed (can be random, updated every changeInterval)

Properties

Name	Value	Description
class	MassMobility
display	i=block/cogwheel

Signals

Name	Type	Unit	Description
mobilityStateChanged	inet::MobilityBase		It works in inet, but not in the extended module in another namespace

Source code

//
// This is a random mobility model for a mobile host with mass. It is the
// one used in "Optimized Smooth Handoffs in Mobile IP" by Perkins & Wang.
//
// "An MH moves within the room according to the following pattern. It moves
// along a straight line for a certain period of time before it makes a turn.
// This moving period is a random number, normally distributed with an average of
// 5 seconds and a standard deviation of 0.1 second. When it makes a turn, the
// new direction (angle) in which it will move is a normally distributed
// random number with an average equal to the previous direction and a standard
// deviation of 30 degrees. Its speed is also a normally distributed random
// number, with a controlled average, ranging from 0.1 to 0.45 (unit/sec), and
// a standard deviation of 0.01 (unit/sec). A new such random number is picked
// as its speed when it makes a turn. This pattern of mobility is intended to
// model node movement during which the nodes have momentum and thus do not
// start, stop, or turn abruptly. When it hits a wall, it reflects off the
// wall at the same angle; in our simulated world, there is little other
// choice."
//
// This implementation can be parameterized further, using the `changeInterval`
// and `angleDelta` parameters. The parameters described above
// correspond to the following settings:
// - changeInterval = normal(5, 0.1)
// - angleDelta = normal(0, 30)
// - speed = normal(avgSpeed, 0.01)
//
// 3D (spatial movement) is also supported using the `rotationAxisAngle` parameter.
//
// @author Emin Ilker Cetinbas
//
simple MassMobility extends MovingMobilityBase
{
    parameters:
        double initialX @unit(m) = default(uniform(constraintAreaMinX, constraintAreaMaxX));
        double initialY @unit(m) = default(uniform(constraintAreaMinY, constraintAreaMaxY));
        double initialZ @unit(m) = default(nanToZero(uniform(constraintAreaMinZ, constraintAreaMaxZ)));
        double initialMovementHeading @unit(deg) = default(uniform(0deg, 360deg)); // Initial heading
        double initialMovementElevation @unit(deg) = default(0deg); // Initial elevation
        bool initFromDisplayString = default(true); // Enables one-time initialization from the subject module's display string
        volatile double changeInterval @unit(s); // Frequency of changing speed and angle (can be random)
        volatile double angleDelta @unit(deg); // Rotate velocity vector by this much around the rotation axis defined by the rotationAxisAngle parameter (can be random)
        volatile double rotationAxisAngle @unit(deg) = default(0deg); // Defines a vector in the plane perpendicular to the velocity, where 0 deg means the Z axis when bank is zero (can be random)
        volatile double speed @mutable @unit(mps); // Speed (can be random, updated every changeInterval)
        @class(MassMobility);
}

File: src/inet/mobility/single/MassMobility.ned