Server Beacon
-------------

ServerBeacon class
	-- Has the main() method
	-- Handles all the necessary setup to get the desktop
	computer on which it's running to broadcast the appropriate
	information.
	-- Reads in a file named by the first command-line argument.
	-- Converts the information in the file to a byte array, then
	instantiates and starts a Broadcaster with this byte array as a
	parameter.

Broadcaster class
	-- Extends Thread class.
	-- Constructed with the byte array that will be broadcasted over
	802.11.
	-- Has constants BCAST_ADDR, MIN_WAIT, MAX_WAIT, and PORTNUM.
	-- run() method has main loop that goes forever until an IO
	exception occurs.
	-- Each loop iteration, send datagram broadcast with the byte
	array information and play special wave file.
	-- At end of loop, sleep beteween MIN_WAIT and MAX_WAIT amount
	of time.

Mobile Client
-------------

MobileClient class
	-- Has an UltrasoundListener class, which has an
	UltrasoundDetector class.
	-- Will decide when to listen for ultrasound based on the
	reception of 802.11 broadcasts.
	-- Associates 802.11 broadcasts with ultrasound detections,
	deciding the location of the device.
	-- Have reference to external application that instantiated
	MobileClient object because external application needs to
	register as a listener of room updates.
	-- MobileClient class constructor takes a reference to the
	external application that instantiated it, initializes the
	802.11 communication system and the UltrasoundListener object
	that it will use to detect ultrasound.  At the end of this
	constructor, a Listener object, which extends the Thread class,
	will be instantiated with the proper parameters and started.
	-- Listener thread uses both the MobileClient object's datagram
	socket for receiving 802.11 messages and the MobileClient
	object's UltrasoundListener object for detecting ultrasound.
	-- Listener thread runs once and terminates, performing the
	following sequence:
	---- 1) Call socket.receive() using MobileClient object's
	socket.  This method blocks until an 802.11 message is received.
	---- 2) Instantiate and run a new Listener thread with the same
	parameters so that new 802.11 messages are not missed while the
	current thread runs to completion.
	---- 3) Call the UltrasoundListener object's listen() method,
	followed by this object's analyze() method in order to
	obtain a boolean decision regarding the presence of ultrasound.
	---- 4) Invoke a callback method on the object that instantiated
	this thread in order to inform it of the new information that
	was obtained from the combined 802.11/ultrasound reception.
	-- MobileClient class must have an update() method that takes an
	802.11 message and an ultrasound boolean decision as parameters.
	This method will be called by the Listener threads and decides
	whether or not a room change has occurred.  If the update()
	method decides that a room update has occurred, it invokes the
	external application's roomChanged() method so that the external
	application receives an appropriate update event to inform it of
	the recent room change.