Class MobileClient

java.lang.Object
  MobileClient

All Implemented Interfaces:

Constants, DatagramUpdateListener, UltrasoundUpdateListener

public class MobileClient

extends java.lang.Object

implements UltrasoundUpdateListener, DatagramUpdateListener, Constants

This class provides location awareness to the granularity of a room inside a building based on the reception of 802.11 broadcasts and the corresponding detection of ultrasound. This class is intended to be used by an application running on a mobile device. If the mobile device moves close to a desktop running the ServerBeacon class/application, it will know that it is in the same room as the desktop based on the information provided by this MobileClient class.

An application using this class needs to provide a reference to a LocationTracker object in the MobileClient class's constructor so that the MobileClient class can signal the LocationTracker object when a room change has occurred.

The MobileClient class implements both an UltrasoundUpdateListener and a DatagramUpdateListener so that it can be informed of ultrasound detections and datagram receptions.

Field Summary

protected boolean	debug
protected java.lang.String[]	detections
protected int	latestUpdate
protected Room[]	messageHistory
protected int	msgHistInd
protected LocationTracker	notifyApp

Fields inherited from interface Constants

AVG_DETECT_TIME, BIGEND, DEBOUNCE_VAL, GROUPADDR, HISTORY_SIZE, MAX_DETECT_TIME, MAXMSGSIZE, N, NUMTHREADS, PORTNUM, ROOM_MSG_BUF, SAMPLE_SIZE, SAMPLING_RATE, SEQUENCE, SIGN, TARGET_FREQUENCY, WEIGHT

Constructor Summary

MobileClient(LocationTracker extApp, boolean inDebug)
This is the only constructor for this class.

Method Summary

void	datagramDetected(java.lang.String message, long timeDetected) Callback method for the DatagramListener thread that receives notifications of newly received datagram messages.
void	ultrasoundDetected(long timeDetected) Callback method for the UltrasoundListener thread that receives notifications of newly received ultrasound detections.

Methods inherited from class java.lang.Object

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

Field Detail

notifyApp

protected LocationTracker notifyApp

messageHistory

protected Room[] messageHistory

msgHistInd

protected int msgHistInd

detections

protected java.lang.String[] detections

latestUpdate

protected int latestUpdate

debug

protected boolean debug

Constructor Detail

MobileClient

public MobileClient(LocationTracker extApp,
                    boolean inDebug)

This is the only constructor for this class. It takes a reference to a LocationTracker object so that the MobileClient class can notify the object when a room change has occurred. No other constructor is provided because the MobileClient class must have access to a roomChanged() method.

Parameters:

extApp - Reference to the LocationTracker object that will receive room change notifications.

inDebug - Whether or not to turn debugging information on.

Method Detail

ultrasoundDetected

public void ultrasoundDetected(long timeDetected)

Callback method for the UltrasoundListener thread that receives notifications of newly received ultrasound detections. This method attempts to correlate the time of the received ultrasound detection with the time of one of the previously received datagram transmissions in order to make a determination of room location.

Specified by:

ultrasoundDetected in interface UltrasoundUpdateListener

Parameters:

timeDetected - The time (in milliseconds since January 1, 1970) at which the ultrasound was received.

datagramDetected

public void datagramDetected(java.lang.String message,
                             long timeDetected)

Callback method for the DatagramListener thread that receives notifications of newly received datagram messages. This method stores the received datagram message and the time at which it was received for later correlation with ultrasound detections. If an ultrasound detection is later correlated with the datagram message received by this callback method, then the received datagram message describes the current room location.

Specified by:

datagramDetected in interface DatagramUpdateListener

Parameters:

timeDetected - The time (in milliseconds since January 1, 1970) at which the datagram message was received.

message - The string that was transmitted in the datagram.