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Concurrent Programming with Java
Lab Manual, Version 1.0, F. Astha Ekadiyanto, 2002.

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Lab 1: Introduction to Lab. Environment and Object Orientation

Object First
- Cell Class
- RBS Class (Radio Base Station)
- MSC Class (Mobile Switching Center)

Cell Class

A cell is an area assumed will be served by an RBS. The cell is the area description of how to cover a certain shape of area. Among them, three types of area shapes will be defined. In order to treat any types of cell in the same way, there should be a general classification for cell that can be defined in Cell Class.

The general classification of a Cell Class is as follows:

What a cell should have?
- A central point (x and y location/coordinate)
- Radius of Cell
What a cell should behave?
- Supply Information about its location
- Calculate its area
- Measure the coverage to an access point (may assume radial coverage)

These definitions can be implemented in Java Language as follows :

File name: Cell.java

Class Fields :

x : x coordinate of the Cell's Center
y : y coordinate of the Cell's Center
r : outer radius of the Cell

Class Constructors:

Cell( ) : Non Argument Constructor (initializes all Class Fields)
Cell(x,y,r) : Initializes all Class Fields using passing arguments

Class Methods:

getX( ) : returns the x coordinate of the Cell's Center
getY( ) : returns the y coordinate of the Cell's Center
getR( ) : returns the radius of the Cell
coverage(x,y) : returns true if the x,y is located in the cell
distance(x,y) : returns the distance of x,y from the Cell's center.
area( ) : returns the area of the Cell (defined as abstract - to be defined by subclasses).
toString( ) : returns the String representation of the Cell (useful for implicit String operations)

import java.lang.Math; 
// Required by Math.sqrt() static method call in the class definition
/**
 * Abstract class Cell - Defines signatures of a cell
 * 
 * @author: CPwJ
 * @version: 1.0 (2002)
 */
public abstract class Cell
{
	// instance variables 
	//Information about a cell (x,y coordinate and r cell radius)
	private double x,y,r;

	/**
	 * Cell constructor
	 */
	public Cell()
	{
   	x=0;
		y=0;
		r=0;
	}
	/**
	 * Cell constructor
	 * @param x Cell X Location 
	 * @param y Cell Y Location
	 * @param r Cell radius 
	 */
	public Cell(double x, double y, double r)
	{
		this.x=x;
		this.y=y;
		this.r=r;
	}
	/**
 	 * Get x coordinate of the cell
	 * @return Cell X Location
	 */
	public double getX() 
	{
		return this.x;
	}
	/**
	 * Get y coordinate of the cell
	 * @return Cell Y Location
	 */
	public double getY()
	{
		return this.y;
	}
	/**
	 * Get radius of the cell
	 * @return Cell Radius
	 */
	public double getR()
	{
		return this.r;
	}
	/**
	 * Check whether a point is covered by the cell
	 * @param x The x point of access coordinate
	 * @param y The y point of access coordinate
	 * @return True/False
	 */
	public boolean coverage(double x, double y) 
	{
		if ( distance(x,y) > this.r) 
		{
			return false;
		} else {
			return true;
		}
	}
	/**
	 * Calculate the distance of a point to the cell centre
	 * @param x The x point of access coordinate
	 * @param y The y point of access coordinate
	 * @return Distance to the cell centre
	 */
	public double distance(double x, double y) 
	{
		return Math.sqrt((x-this.x)*(x-this.x) + (y-this.y)*(y-this.y));
	} 
	/**
	 * Calculate the area of the cell
	 * @return Cell Area
	 */
	public abstract double area(); //Leave this to be constructed by sub classes
	/**
	 * Represent the Cell content information
	 * @return String cell information
	 */
	public String toString() 
	{
		return ("Cell location at x="+ x +",y=" + y +" serving    area= "+area());
	}
}

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