MassMobility

simple module

This is a random mobility model for a mobile host with a 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 average of 5 seconds and 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 average equal to the previous direction and 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 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 a bit more, via the changeInterval, changeAngleBy and changeSpeedBy parameters. The parameters described above correspond to the following settings:

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

Author: Emin Ilker Cetinbas, Andras Varga

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
coordinateSystemModule	string	""	module path of the geographic coordinate system module
visualizeMobility	bool	true	false means this mobility module does no visualization
visualRepresentation	string	"^"	determines the module that is moved by this mobility
constraintAreaMinX	double	-1m/0	min x position of the constraint area, unconstrained by default (negative infinity)
constraintAreaMinY	double	-1m/0	min y position of the constraint area, unconstrained by default (negative infinity)
constraintAreaMinZ	double	-1m/0	min z position of the constraint area, unconstrained by default (negative infinity)
constraintAreaMaxX	double	1m/0	max x position of the constraint area, unconstrained by default (positive infinity)
constraintAreaMaxY	double	1m/0	max y position of the constraint area, unconstrained by default (positive infinity)
constraintAreaMaxZ	double	1m/0	max z position of the constraint area, unconstrained by default (positive infinity)
updateInterval	double	0.1s	the simulation time interval used to regularly signal mobility state changes and update the display
initialX	double	uniform(constraintAreaMinX, constraintAreaMaxX)
initialY	double	uniform(constraintAreaMinY, constraintAreaMaxY)
initialZ	double	nanToZero(uniform(constraintAreaMinZ, constraintAreaMaxZ))
startAngle	double	uniform(0deg, 360deg)	initial angle in degrees
initFromDisplayString	bool	true
changeInterval	double		frequency of changing speed and angle (can be random)
changeAngleBy	double		change angle by this much (can be random)
speed	double		speed (can be random, updated every changeInterval)

Properties

Name	Value	Description
display	i=block/cogwheel
class	MassMobility

Signals

Name	Type	Unit
mobilityStateChanged	inet::MobilityBase

Source code

//
// This is a random mobility model for a mobile host with a 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 average of
// 5 seconds and 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 average equal to the previous direction and 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
// 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 a bit more, via the changeInterval,
// changeAngleBy and changeSpeedBy parameters. The parameters described above
// correspond to the following settings:
//    - changeInterval = normal(5, 0.1)
//    - changeAngleBy = normal(0, 30)
//    - speed = normal(avgSpeed, 0.01)
//
// @author Emin Ilker Cetinbas, Andras Varga
//
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 startAngle @unit(deg) = default(uniform(0deg, 360deg)); // initial angle in degrees
        bool initFromDisplayString = default(true);
        volatile double changeInterval @mutable @unit(s); // frequency of changing speed and angle (can be random)
        volatile double changeAngleBy @mutable @unit(deg); // change angle by this much (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