ptolemy.domains.wireless.lib
Class ErasureChannel
java.lang.Object
ptolemy.kernel.util.NamedObj
ptolemy.kernel.InstantiableNamedObj
ptolemy.kernel.Entity
ptolemy.kernel.ComponentEntity
ptolemy.actor.AtomicActor
ptolemy.actor.TypedAtomicActor
ptolemy.domains.wireless.kernel.AtomicWirelessChannel
ptolemy.domains.wireless.lib.ErasureChannel
- All Implemented Interfaces:
- java.io.Serializable, java.lang.Cloneable, Actor, Executable, FiringsRecordable, Initializable, TypedActor, ChannelListener, PropertyTransformer, WirelessChannel, Changeable, Debuggable, DebugListener, Derivable, Instantiable, ModelErrorHandler, MoMLExportable, Moveable, Nameable, ValueListener
- Direct Known Subclasses:
- DelayChannel
public class ErasureChannel
- extends AtomicWirelessChannel
Model of a wireless channel with a specified loss probability. If the
loss probability is greater than zero then on each
call to the transmit() method, for each receiver in range,
with the specified probability, the transmission to that
receiver will not occur. Whether a transmission occurs to a particular
receiver is independent of whether it occurs to any other receiver.
For convenience, a variable named "distance" is available and
equal to the distance between the transmitter and the receiver
when the lossProbability is evaluated. Thus, the
loss probability can be given as an expression that depends
on this distance.
The distance between the transmitter and receiver is determined
by the protected method _distanceBetween(), which is also used
to set the value of the distance variable that can be
used in the expression for loss probability.
In this base class, that method uses
the _location attribute of the transmit and receive actors,
which corresponds to the position of the icon in the Vergil
visual editor. Subclasses may override this protected method
to provide some other notion of distance.
- Since:
- Ptolemy II 4.0
- Version:
- $Id: ErasureChannel.java 57040 2010-01-27 20:52:32Z cxh $
- Author:
- Edward A. Lee
- See Also:
- Serialized Form
- Accepted Rating:
- Proposed Rating:
|
Field Summary |
protected java.util.Random |
_random
A random number generator. |
Variable |
distance
A variable that is set to the distance between the transmitter
and the receiver before the
powerLossFactor expression is evaluated. |
Parameter |
lossProbability
The probability that a call to transmit() will fail to deliver
the token to a receiver that is in range. |
Parameter |
seed
The seed that controls the random number generation. |
| Fields inherited from class ptolemy.kernel.util.NamedObj |
_changeListeners, _changeLock, _changeRequests, _debugging, _debugListeners, _elementName, _isPersistent, _verbose, _workspace, ATTRIBUTES, CLASSNAME, COMPLETE, CONTENTS, DEEP, FULLNAME, LINKS |
| Methods inherited from class ptolemy.domains.wireless.kernel.AtomicWirelessChannel |
_distanceBetween, _isInRange, _locationOf, _receiversInRange, addChannelListener, channelNotify, getChannelPort, listeningInputPorts, listeningOutputPorts, preinitialize, registerPropertyTransformer, removeChannelListener, sendingInputPorts, sendingOutputPorts, transformProperties, transmit, unregisterPropertyTransformer, valueChanged |
| Methods inherited from class ptolemy.actor.AtomicActor |
_actorFiring, _actorFiring, addActorFiringListener, addInitializable, connectionsChanged, createReceivers, declareDelayDependency, fire, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, isFireFunctional, isStrict, iterate, newReceiver, outputPortList, postfire, prefire, pruneDependencies, recordFiring, removeActorFiringListener, removeDependency, removeInitializable, setContainer, stop, stopFire, terminate, wrapup |
| Methods inherited from class ptolemy.kernel.ComponentEntity |
_adjustDeferrals, _checkContainer, _getContainedObject, _propagateExistence, getContainer, instantiate, isAtomic, isOpaque, moveDown, moveToFirst, moveToIndex, moveToLast, moveUp, propagateExistence, setName |
| Methods inherited from class ptolemy.kernel.Entity |
_description, _exportMoMLContents, _removePort, _validateSettables, connectedPortList, connectedPorts, containedObjectsIterator, getAttribute, getPort, getPorts, linkedRelationList, linkedRelations, portList, removeAllPorts, setClassDefinition, uniqueName |
| Methods inherited from class ptolemy.kernel.util.NamedObj |
_addAttribute, _adjustOverride, _attachText, _cloneFixAttributeFields, _debug, _debug, _debug, _debug, _debug, _getIndentPrefix, _isMoMLSuppressed, _markContentsDerived, _propagateValue, _recordDecoratedAttributes, _removeAttribute, _splitName, _stripNumericSuffix, addChangeListener, addDebugListener, attributeChanged, attributeList, attributeList, deepContains, depthInHierarchy, description, description, event, executeChangeRequests, exportMoML, exportMoML, exportMoML, exportMoML, exportMoMLPlain, getAttribute, getAttributes, getChangeListeners, getClassName, getDecoratorAttribute, getDecoratorAttributes, getDerivedLevel, getDerivedList, getDisplayName, getFullName, getModelErrorHandler, getName, getName, getSource, handleModelError, isDeferringChangeRequests, isOverridden, isPersistent, lazyContainedObjectsIterator, message, propagateValue, propagateValues, removeChangeListener, removeDebugListener, requestChange, setClassName, setDeferringChangeRequests, setDerivedLevel, setDisplayName, setModelErrorHandler, setPersistent, setSource, sortContainedObjects, toplevel, toString, validateSettables, workspace |
| Methods inherited from class java.lang.Object |
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
lossProbability
public Parameter lossProbability
- The probability that a call to transmit() will fail to deliver
the token to a receiver that is in range.
This is a double that defaults to 0.0, which means that
no loss occurs.
seed
public Parameter seed
- The seed that controls the random number generation.
A seed of zero is interpreted to mean that no seed is specified,
which means that each execution of the model could result in
distinct data. For the value 0, the seed is set to
System.currentTimeMillis() + hashCode(), which means that
with extremely high probability, two distinct actors will have
distinct seeds. However, current time may not have enough
resolution to ensure that two subsequent executions of the
same model have distinct seeds.
This parameter contains a LongToken, initially with value 0.
distance
public Variable distance
- A variable that is set to the distance between the transmitter
and the receiver before the
powerLossFactor expression is evaluated.
_random
protected java.util.Random _random
- A random number generator.
ErasureChannel
public ErasureChannel(CompositeEntity container,
java.lang.String name)
throws IllegalActionException,
NameDuplicationException
- Construct a channel with the given name and container.
The container argument must not be null, or a
NullPointerException will be thrown. If the name argument
is null, then the name is set to the empty string.
- Parameters:
container - The container.name - The name of the channel.
- Throws:
IllegalActionException - If the container is incompatible.
NameDuplicationException - If the name coincides with
a relation already in the container.
clone
public java.lang.Object clone(Workspace workspace)
throws java.lang.CloneNotSupportedException
- Clone the object into the specified workspace. The new object is
not added to the directory of that workspace (you must do this
yourself if you want it there).
- Overrides:
clone in class AtomicWirelessChannel
- Parameters:
workspace - The workspace for the cloned object.
- Returns:
- The new Attribute.
- Throws:
java.lang.CloneNotSupportedException - Not thrown in this base class- See Also:
NamedObj.exportMoML(Writer, int, String),
NamedObj.setDeferringChangeRequests(boolean)
initialize
public void initialize()
throws IllegalActionException
- Initialize the random number generator with the seed, if it
has been given.
- Specified by:
initialize in interface Initializable- Overrides:
initialize in class AtomicActor
- Throws:
IllegalActionException - If the parent class throws it.
_transmitTo
protected void _transmitTo(Token token,
WirelessIOPort sender,
WirelessReceiver receiver,
RecordToken properties)
throws IllegalActionException
- Transmit the specified token to the specified receiver.
If the lossProbability is zero, (the default) then
the specified receiver will receive the token if it has room.
If lossProbability is greater than zero, the token will
be lost with the specified probability, independently
for each channel in range.
Note that in this base class, a port is in range if it refers to
this channel by name and is at the right place in the hierarchy.
This base class makes no use of the properties argument.
But derived classes may limit the range or otherwise change
transmission properties using this argument.
- Overrides:
_transmitTo in class AtomicWirelessChannel
- Parameters:
token - The token to transmit, or null to clear
the specified receiver.sender - The sending port.receiver - The receiver to which to transmit.properties - The transmit properties (ignored in this base class).
- Throws:
IllegalActionException - If the token cannot be converted
or if the token argument is null and the destination receiver
does not support clear.