public class WirelessLinkExtension extends ObjectExtension implements IAvailableSignalPropagationModelsService, ITransmittedSignalService, IPropagatedSignalService
By default, PropagationModels
(get
) will include an instance of
FreeSpacePathLossModel
and DopplerShiftModel
.
Since free space path loss occurs first in the list, it is computed before any other models.
When adding additional models, make note of the order of the list when determining whether
the model should be applied before or after the doppler shift.
Alternately, the two default models can be removed individually from PropagationModels
(get
),
or PropagationModels
(get
) can be cleared.
This extension requires that the Owner
(get
/ set
) provide ILinkService
and that the Transmitter
(get
) provide ISignalTransmissionService
.
The noise on the signal is assumed to be zero and the noise bandwidth infinite at the start of a wireless communication link.
Modifier | Constructor and Description |
---|---|
|
WirelessLinkExtension()
Initializes a new instance.
|
|
WirelessLinkExtension(Iterable<? extends SignalPropagationModel> propagationModels)
Initialize a new instance based on the given set of propagation models.
|
protected |
WirelessLinkExtension(WirelessLinkExtension existingInstance,
CopyContext context)
Initializes a new instance as a copy of an existing instance.
|
Modifier and Type | Method and Description |
---|---|
protected boolean |
checkForSameDefinition(ObjectExtension other)
Checks to determine if another instance has the same definition as this instance and
returns
true if it does. |
protected boolean |
checkForSameDefinition(WirelessLinkExtension other)
Checks to determine if another instance has the same definition as this instance and
returns
true if it does. |
Object |
clone(CopyContext context)
Clones this object using the specified context.
|
protected int |
computeCurrentDefinitionHashCode()
Computes a hash code based on the current properties of this object.
|
void |
enumerateDependencies(DependencyEnumerator enumerator)
Enumerates the dependencies of this object by calling
DependencyEnumerator#enumerate(T) for each object that this object directly depends upon. |
ISignalSource |
getPropagatedSignal()
Gets the signal source which produces the signals received after being propagated along a communication link.
|
ISignalSource |
getPropagatedSignalAfterModel(SignalPropagationModel model)
Gets the signal source which produces the signals received after the selected propagation model.
|
ISignalSource |
getPropagatedSignalBeforeModel(SignalPropagationModel model)
Gets the signal source which produces the signals received before the given propagation model.
|
List<SignalPropagationModel> |
getPropagationModels()
Gets a list of the propagation models applied when propagating the signal from transmitter to receiver
(free space loss and doppler are added by default).
|
SignalEvaluator |
getSignalEvaluatorFromTransmitter(EvaluatorGroup group,
SignalPropagationGraph graph,
IServiceProvider timeObserver)
Get an evaluator which produces the signal observed directly after transmission in the link direction based
on the given time observer.
|
SignalEvaluator |
getSignalEvaluatorFromTransmitter(EvaluatorGroup group,
SignalPropagationGraph graph,
LinkPath pathFromObserverToTransmitter)
Get an evaluator which produces the signal observed directly after transmission in the link direction.
|
ISignalSource |
getTransmittedSignal()
Gets the signal source which produces the signals transmitted along a communication link.
|
checkForSameDefinition, getOwner, getService
areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, dictionaryItemsAreSameDefinition, freeze, freezeAggregatedObjects, getCollectionHashCode, getCollectionHashCode, getCollectionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDictionaryHashCode, getIsFrozen, isSameDefinition, throwIfFrozen
public WirelessLinkExtension()
public WirelessLinkExtension(@Nonnull Iterable<? extends SignalPropagationModel> propagationModels)
Note: This constructor will NOT add the FreeSpacePathLossModel
and the
DopplerShiftModel
by default.
propagationModels
- The set of propagation models to use on this link.protected WirelessLinkExtension(@Nonnull WirelessLinkExtension existingInstance, @Nonnull CopyContext context)
See ICloneWithContext.clone(CopyContext)
for more information about how to implement this constructor
in a derived class.
existingInstance
- The existing instance to copy.context
- A CopyContext
that controls the depth of the copy.ArgumentNullException
- Thrown when existingInstance
or context
is null
.public Object clone(CopyContext context)
This method should be implemented to call a copy constructor on the class of the
object being cloned. The copy constructor should take the CopyContext
as a parameter
in addition to the existing instance to copy. The copy constructor should first call
CopyContext.addObjectMapping(T, T)
to identify the newly constructed instance
as a copy of the existing instance. It should then copy all fields, using
CopyContext.updateReference(T)
to copy any reference fields.
A typical implementation of ICloneWithContext
:
public static class MyClass implements ICloneWithContext {
public MyClass(MyClass existingInstance, CopyContext context) {
context.addObjectMapping(existingInstance, this);
someReference = context.updateReference(existingInstance.someReference);
}
@Override
public final Object clone(CopyContext context) {
return new MyClass(this, context);
}
private Object someReference;
}
In general, all fields that are reference types should be copied with a call to
CopyContext.updateReference(T)
. There are a couple of exceptions:
If one of these exceptions applies, the CopyContext
should be given an opportunity
to update the reference before the reference is copied explicitly. Use
CopyContext.updateReference(T)
to update the reference. If CopyContext.updateReference(T)
returns
the original object, indicating that the context does not have a replacement registered,
then copy the object manually by invoking a Clone method, a copy constructor, or by manually
constructing a new instance and copying the values.
alwaysCopy = context.updateReference(existingInstance.alwaysCopy);
if (existingInstance.alwaysCopy != null && alwaysCopy == existingInstance.alwaysCopy) {
alwaysCopy = (AlwaysCopy) existingInstance.alwaysCopy.clone(context);
}
If you are implementing an evaluator (a class that implements IEvaluator
), the
IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext)
method shares some responsibilities with the
copy context constructor. Code duplication can be avoided by doing the following:
CopyContext.updateReference(T)
. You should still call CopyContext.updateReference(T)
on any references to
non-evaluators.
IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext)
as the last line in the constructor and pass it the
same CopyContext
passed to the constructor.
IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext)
as normal. See the reference documentation for
IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext)
for more information on implementing that method.
public MyClass(MyClass existingInstance, CopyContext context) {
super(existingInstance, context);
someReference = context.updateReference(existingInstance.someReference);
evaluatorReference = existingInstance.evaluatorReference;
updateEvaluatorReferences(context);
}
@Override
public void updateEvaluatorReferences(CopyContext context) {
evaluatorReference = context.updateReference(evaluatorReference);
}
@Override
public Object clone(CopyContext context) {
return new MyClass(this, context);
}
private Object someReference;
private IEvaluator evaluatorReference;
clone
in interface ICloneWithContext
clone
in class DefinitionalObject
context
- The context to use to perform the copy.protected final boolean checkForSameDefinition(ObjectExtension other)
true
if it does. Derived classes MUST override this method and check
all new fields introduced by the derived class for definitional equivalence. It is NOT necessary
to check base class fields because the base class will already have done that. When overriding this method,
you should NOT call the base implementation because it will return false
for all derived-class instances.
Derived classes should check the type of other
to preserve the symmetric nature of IEquatableDefinition.isSameDefinition(java.lang.Object)
.checkForSameDefinition
in class ObjectExtension
other
- The other instance to compare to this one.true
if the two objects are defined equivalently; otherwise false
.protected boolean checkForSameDefinition(@Nullable WirelessLinkExtension other)
true
if it does. Derived classes MUST override this method and check
all new fields introduced by the derived class for definitional equivalence. It is NOT necessary
to check base class fields because the base class will already have done that. When overriding this method,
you should NOT call the base implementation because it will return false
for all derived-class instances.
Derived classes should check the type of other
to preserve the symmetric nature of IEquatableDefinition.isSameDefinition(java.lang.Object)
.other
- The other instance to compare to this one.true
if the two objects are defined equivalently; otherwise false
.protected int computeCurrentDefinitionHashCode()
WirelessLinkExtension.checkForSameDefinition(agi.foundation.infrastructure.ObjectExtension)
method.computeCurrentDefinitionHashCode
in class ObjectExtension
public void enumerateDependencies(DependencyEnumerator enumerator)
DependencyEnumerator#enumerate(T)
for each object that this object directly depends upon.
Derived classes which contain additional dependencies MUST override this method, call the base
implementation, and enumerate dependencies introduced by the derived class.enumerateDependencies
in interface IEnumerateDependencies
enumerateDependencies
in class ObjectExtension
enumerator
- The enumerator that is informed of the dependencies of this object.@Nonnull public final List<SignalPropagationModel> getPropagationModels()
By default, PropagationModels
(get
) will include an instance of
FreeSpacePathLossModel
and DopplerShiftModel
.
Since free space path loss occurs first in the list, it is computed before any other models.
When adding additional models, make note of the order of the list when determining whether
the model should be applied before or after the doppler shift.
Alternately, the two default models can be removed individually from PropagationModels
(get
),
or PropagationModels
(get
) can be cleared.
getPropagationModels
in interface IAvailableSignalPropagationModelsService
@Nonnull public final ISignalSource getTransmittedSignal()
getTransmittedSignal
in interface ITransmittedSignalService
@Nonnull public final ISignalSource getPropagatedSignal()
IAccessResultService
or the link or either end provides an IAccessConstraintsService
,
and there is no access at the time requested, then the collection of propagated signals produced by this
source will be empty.
If the link has the IAccessResultService
, it will only be evaluated during
the SatisfactionIntervals
(get
) and will throw an
IllegalStateException
during the UnknownIntervals
(get
).
Otherwise, if the link or either of its ends has the IAccessConstraintsService
,
this extension will only propagate signals at times when there is access.
All the constraints provided by the service(s) will be combined in an AccessQueryAnd
except for any CommunicationObjectConstraints
which should never be added to a link.
In this case, an IllegalStateException
is thrown.
Since a CommunicationObjectConstraint
usually involves evaluating the link
when attempting to evaluate an object which occurs after the link.
This would produce an infinite loop and is not allowed.
getPropagatedSignal
in interface IPropagatedSignalService
@Nonnull public final ISignalSource getPropagatedSignalBeforeModel(SignalPropagationModel model)
getPropagatedSignalBeforeModel
in interface IPropagatedSignalService
model
- The model to propagate to.ArgumentNullException
- Thrown if model
is null
.ArgumentException
- Thrown if model
is not found by the service provider.@Nonnull public final ISignalSource getPropagatedSignalAfterModel(SignalPropagationModel model)
getPropagatedSignalAfterModel
in interface IPropagatedSignalService
model
- The model over which to propagate.ArgumentNullException
- Thrown if model
is null
.ArgumentException
- Thrown if model
is not found by the service provider.@Nonnull public final SignalEvaluator getSignalEvaluatorFromTransmitter(@Nonnull EvaluatorGroup group, @Nonnull SignalPropagationGraph graph, @Nonnull IServiceProvider timeObserver)
To determine total time delay, this method uses the communication graph
to determine the shortest path from the given timeObserver
to this particular transmitter.
group
- The evaluator group in which to create the evaluator.graph
- The graph of the links used in the analysis.timeObserver
- A service provider representing the receiver at which to observe times.timeObserver
.@Nonnull public final SignalEvaluator getSignalEvaluatorFromTransmitter(@Nonnull EvaluatorGroup group, @Nonnull SignalPropagationGraph graph, LinkPath pathFromObserverToTransmitter)
group
- The evaluator group in which to create the evaluator.graph
- The graph of the links used in the analysis.pathFromObserverToTransmitter
- A path indicating the chain of links from the final observer
on which to observe times, ending at this particular transmitter.pathFromObserverToTransmitter
.