WifiInfo.java :  » UnTagged » smartphone-networks » com » mobed » ssn » Android Open Source

/* 
 * Copyright 2009 Chon John, Yonsei University 
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); 
 * you may not use this file except in compliance with the License. 
 * You may obtain a copy of the License at 
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0 
 * 
 * Unless required by applicable law or agreed to in writing, software 
 * distributed under the License is distributed on an "AS IS" BASIS, 
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
 * See the License for the specific language governing permissions and 
 * limitations under the License. 
 */
package com.mobed.ssn;

/**
 * Describes the state of Wifi access point.
 * 
 * @author Chon John (john@mobed.yonsei.ac.kr)
 * @since 1.5
 * @version 1.5
 */
public class WifiInfo implements Cloneable, Comparable {
  private String BSSID;
  private String SSID;
  private long sampleCount;
  private float signal;
  private float signalDeviation;
  private String open;
  private String time;
  
  private long id;
  private boolean dirty;

  /**
   * Constructs a new WifiInfo. By default, signal, sampleCount are 0; BSSID,
   * SSID, open are null.
   */
  public WifiInfo() {
    this.clear();
  }

  /**
   * Clear the contents.
   */
  public void clear() {
    BSSID = null;
    SSID = null;
    signal = 0;
    signalDeviation = 0;
    sampleCount = 0;
    open = null;
    time = null;
    id = 0;
    dirty = false;
  }

  /**
   * Returns sampling count of this access point.
   */
  public long getSampleCount() {
    return sampleCount;
  }

  /**
   * Sets sampling count of this access point.
   */
  public void setSampleCount(long sampleCount) {
    this.sampleCount = sampleCount;
  }

  /**
   * Returns the basic service set identifier (BSSID) of this access point.
   * 
   * @return the BSSID, in the form of a six-byte MAC address:
   *         XX:XX:XX:XX:XX:XX
   */
  public String getBSSID() {
    return BSSID;
  }

  /**
   * Sets the basic service set identifier (BSSID) of this access point.
   * 
   * @param bssid
   *            the BSSID, in the form of a six-byte MAC address:
   *            XX:XX:XX:XX:XX:XX
   */
  public void setBSSID(String bssid) {
    BSSID = bssid;
  }

  /**
   * Returns the service set identifier (SSID) of this access point.
   */
  public String getSSID() {
    return SSID;
  }

  /**
   * Sets the service set identifier (SSID) of this access point.
   */
  public void setSSID(String ssid) {
    ssid.replaceAll(",", ".");
    SSID = ssid;
  }

  /**
   * Returns the received signal strength indicator of this access point.
   */
  public float getSignal() {
    return signal;
  }

  /**
   * Sets the received signal strength indicator of this access point.
   */
  public void setSignal(float signal) {
    this.signal = signal;
  }

  /**
   * Returns the authentication, key management, and encryption schemes
   * supported by the access point.
   */
  public String getOpen() {
    return open;
  }

  /**
   * Sets the authentication, key management, and encryption schemes supported
   * by the access point.
   */
  public void setOpen(String open) {
    this.open = open;
  }

  
  public long getId() {
    return id;
  }

  public void setId(long id) {
    this.id = id;
  }

  public boolean isDirty() {
    return dirty;
  }

  public void setDirty(boolean dirty) {
    this.dirty = dirty;
  }

  public float getSignalDeviation() {
    return signalDeviation;
  }

  public void setSignalDeviation(float signalDeviation) {
    this.signalDeviation = signalDeviation;
  }

  public String getTime() {
    return time;
  }

  public void setTime(String time) {
    this.time = time;
  }
  public String toString() {
    String s = "";
    
    s += id + " " + SSID + "(" + BSSID + ") " + String.format("%.1f", signal) + "/" + String.format("%.1f", signalDeviation) + " of " + sampleCount + "\n";
    
    return s;
  }
  public void merge(WifiInfo w) {
    float wSignal = w.getSignal();
    long wCount = w.getSampleCount();
    float wDeviation = w.getSignalDeviation();
    float mSignal = (wSignal * wCount + signal * sampleCount) / (wCount + sampleCount);
    float mSignalSquare = wCount * (wDeviation * wDeviation + wSignal * wSignal);
    float _mSignalSquare = sampleCount * (signalDeviation * signalDeviation + signal * signal);
    float mSignalDeviation = (float)Math.sqrt((mSignalSquare + _mSignalSquare) / (wCount + sampleCount) - mSignal * mSignal);

    signal = mSignal;
    signalDeviation = mSignalDeviation;
    //Following statement should be used when merge is called in insertAP function
    //sampleCount += wCount;
    
    //Following statement should be used when merge is called every time new BSSID is found ,in this case, sampleCount of "w" is initialized as 1;
    sampleCount+=wCount;
    
    
    if(time == null && w.getTime() != null)
      time = w.getTime();
    else if(time != null && w.getTime() != null && time.compareTo(w.getTime()) > 0)
      time = w.getTime();
  }
  public Object clone() {
    WifiInfo o = null;
    try {
      o = (WifiInfo)super.clone();
      o.BSSID = BSSID;
      o.SSID = SSID;
      o.sampleCount = sampleCount;
      o.signal = signal;
      o.signalDeviation = signalDeviation;
      o.open = open;
      o.time = time;
      o.id = id;
      o.dirty = dirty;
    } catch (CloneNotSupportedException e) {
      e.printStackTrace();
    }

    return o;
  }
  @Override
  public boolean equals(Object obj) {
    return this.BSSID.equals(((WifiInfo)obj).BSSID);
  }
  
  public int compareTo(Object another) {
    return this.BSSID.compareTo(((WifiInfo) another).BSSID);
  }
}