ptolemy.domains.wireless.kernel
Interface PropertyTransformer

All Known Subinterfaces:

WirelessChannel

All Known Implementing Classes:

AtomicWirelessChannel, DelayChannel, ErasureChannel, LimitedRangeChannel, PowerLossChannel, TerrainProperty, TransmitPropertyTransformer

public interface PropertyTransformer

Interface for transmit property transformers. Property transformers are components that register with the channel a callback that they can use to modify the transmission properties of a transmission. They can register to modify the transmission properties of transmissions from a specific port, or they can register to modify all transmissions through the channel. Note that if multiple property transformers are registered that can operate on a given transmission, then the order in which they are applied is arbitrary. Thus, property transformers should implement commutative operations on the properties (such as multiplying a field by a value).

It is possible to return the modified transmission properties with different record types from the previous transmit property, i.e. some record fields may be removed or added. The channel should merge the returned transmission properties with its defaultProperties to make sure that the transmission properties contains at least all the fields of the defaultProperties.

Anything that needs to know the locations of the sender and receiver to alter the transmit properties should implement this interface. For example, for a sender with a specific antenna pattern to send data to receivers, it needs to know each receiver's position and its own position to calculator the antenna gain. To do so, the sender can implement this interface and register itself with the wireless channel it uses. The channel will call the transformProperties method later and provide the required information for the sender to calculate, for example, the antenna gain to a specific receiver.

Since:

Ptolemy II 4.0

Version:

$Id: PropertyTransformer.java 57040 2010-01-27 20:52:32Z cxh $

Author:

Yang Zhao and Edward Lee

See Also:

WirelessChannel

Accepted Rating:

Yellow (cxh)

Proposed Rating:

Green (cxh)

Method Summary

RecordToken

transformProperties(RecordToken properties, WirelessIOPort source, WirelessIOPort destination) Modify the transmission properties and return a new token with the modifications.

Method Detail

transformProperties

RecordToken transformProperties(RecordToken properties,
                                WirelessIOPort source,
                                WirelessIOPort destination)
                                throws IllegalActionException

Modify the transmission properties and return a new token with the modifications. Implementers may also return the specified token unchanged.

Parameters:

properties - The transmission properties to modify.

source - The sending port.

destination - The receiving port.

Returns:

The (possibly) modified transmission properties.

Throws:

IllegalActionException - If the properties cannot be transformed for some reason.