interfaces

Class ConnectivityGrid

java.lang.Object

interfaces.ConnectivityOptimizer

interfaces.ConnectivityGrid

public class ConnectivityGrid
extends ConnectivityOptimizer

Overlay grid of the world where each interface is put on a cell depending of its location. This is used in cell-based optimization of connecting the interfaces.

The idea in short:
Instead of checking for every interface if some of the other interfaces are close enough (this approach obviously doesn't scale) we check only interfaces that are "close enough" to be possibly connected. Being close enough is determined by keeping track of the approximate location of the interfaces by storing them in overlay grid's cells and updating the cell information every time the interfaces move. If two interfaces are in the same cell or in neighboring cells, they have a chance of being close enough for connection. Then only that subset of interfaces is checked for possible connectivity.

Note: this class does NOT support negative coordinates. Also, it makes sense to normalize the coordinates to start from zero to conserve memory.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	ConnectivityGrid.GridCell A single cell in the cell grid.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	CELL_SIZE_MULT_S Cell based optimization cell size multiplier -setting id ("cellSizeMult").
static int	DEF_CON_CELL_SIZE_MULT default value for cell size multiplier (5)

Method Summary

Methods

Modifier and Type	Method and Description
void	addInterface(NetworkInterface ni) Adds a network interface to the overlay grid
void	addInterfaces(java.util.Collection<NetworkInterface> interfaces) Adds interfaces to overlay grid
static ConnectivityGrid	ConnectivityGridFactory(int key, double maxRange) Returns a connectivity grid object based on a hash value
java.util.Collection<NetworkInterface>	getAllInterfaces() Returns all interfaces that use the same technology and channel
java.util.Collection<NetworkInterface>	getNearInterfaces(NetworkInterface ni) Returns all interfaces that are "near" (i.e., in neighboring grid cells) and use the same technology and channel as the given interface
void	removeInterface(NetworkInterface ni) Removes a network interface from the overlay grid
static void	reset()
java.lang.String	toString() Returns a string representation of the ConnectivityCells object
void	updateLocation(NetworkInterface ni) Checks and updates (if necessary) interface's position in the grid

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

CELL_SIZE_MULT_S

public static final java.lang.String CELL_SIZE_MULT_S

Cell based optimization cell size multiplier -setting id ("cellSizeMult"). Used in World.OPTIMIZATION_SETTINGS_NS name space. Single ConnectivityCell's size is the biggest radio range times this. Larger values save memory and decrease startup time but may result in slower simulation. Default value is DEF_CON_CELL_SIZE_MULT. Smallest accepted value is 1.

See Also:

Constant Field Values

DEF_CON_CELL_SIZE_MULT

public static final int DEF_CON_CELL_SIZE_MULT

default value for cell size multiplier (5)

See Also:

Constant Field Values

Method Detail

reset

public static void reset()

ConnectivityGridFactory

public static ConnectivityGrid ConnectivityGridFactory(int key,
                                       double maxRange)

Returns a connectivity grid object based on a hash value

Parameters:

key - A hash value that separates different interfaces from each other

maxRange - Maximum range used by the radio technology using this connectivity grid.

Returns:

The connectivity grid object for a specific interface

addInterface

public void addInterface(NetworkInterface ni)

Adds a network interface to the overlay grid

Specified by:

addInterface in class ConnectivityOptimizer

Parameters:

ni - The new network interface

removeInterface

public void removeInterface(NetworkInterface ni)

Removes a network interface from the overlay grid

Parameters:

ni - The interface to be removed

addInterfaces

public void addInterfaces(java.util.Collection<NetworkInterface> interfaces)

Adds interfaces to overlay grid

Specified by:

addInterfaces in class ConnectivityOptimizer

Parameters:

interfaces - Collection of interfaces to add

updateLocation

public void updateLocation(NetworkInterface ni)

Checks and updates (if necessary) interface's position in the grid

Specified by:

updateLocation in class ConnectivityOptimizer

Parameters:

ni - The interface to update

getAllInterfaces

public java.util.Collection<NetworkInterface> getAllInterfaces()

Returns all interfaces that use the same technology and channel

Specified by:

getAllInterfaces in class ConnectivityOptimizer

getNearInterfaces

public java.util.Collection<NetworkInterface> getNearInterfaces(NetworkInterface ni)

Returns all interfaces that are "near" (i.e., in neighboring grid cells) and use the same technology and channel as the given interface

Specified by:

getNearInterfaces in class ConnectivityOptimizer

Parameters:

ni - The interface whose neighboring interfaces are returned

Returns:

List of near interfaces

toString

public java.lang.String toString()

Returns a string representation of the ConnectivityCells object

Overrides:

toString in class java.lang.Object

Returns:

a string representation of the ConnectivityCells object