Wednesday, February 25, 2009

Mechanism to measure WiFi signals

For my Final Year Project progress, I need to measure the signals produced from the Wi-Fi access points in Kulliyyah of ICT.

In Wi-Fi access points, there is three (3) signals that can be measure and take into account for my FYP research, which are (a) Signal Strength, (b) Signal Quality, and (c) Signal Noise. The things that matter right now is the mechanism to measure those signals and save it as the experiment data.

After several moment of research, I found out that Linux has an application that can scan the signal strength, quality and noise from the access points, which called iwlist.

This application (iwlist) scans and retrieve the information of the access points like the MAC Address, Signal Strength, Signal Quality, Signal Noise and etc. What actually matters to my project are the Signal Strength, Signal Quality, Signal Noise of the access points.

From here, I then manipulated the source code of built-in iwlist in Linux and make it smaller and standalone. Next, I develop another script that integrate with iwlist to manipulate the output and save the information in a database-like form for later retrieval and calculation.

Might need several days to finish developing those measurement mechanism. hmmm.

Friday, February 20, 2009

Final Year Project progress

Tracking Indoor Symbolic Location Using IEEE 802.11 Signals in Location-Aware Computing, it is a topic that me and my partner have choosen to work on for our final year project.

Our supervisor, who is specialized in this area (pervasive and ubiquitous computing) has guided us to select this topic and giving a tremendous inspiration to us about its future development.

So, back to the project topic, what does this project is all about? Basically, we will going to conduct a study and develop a system which will determine user location based on Wi-Fi signals.


Several access points on a corridor with different points will generate a unique signals. Thus, from this uniqueness, the user location can be determine. Based on the diagram above, we can see that there are 3 access points on a corridor, and 4 points of location where the user might be standing. So, for every point 1, 2, 3, and 4, the signal strength of 3 access points will be different. Below can represent a mock data;

Point 1
  • Signal strength AP1: -20
  • Signal strength AP2: -65
  • Signal strength AP3: -83

Point 2
  • Signal strength AP1: -45
  • Signal strength AP2: -32
  • Signal strength AP3: -69

Point 3
  • Signal strength AP1: -89
  • Signal strength AP2: -57
  • Signal strength AP3: -36

Point 4
  • Signal strength AP1: -93
  • Signal strength AP2: -67
  • Signal strength AP3: -21

Basically, we need to develop an application to scan the signal strength of all existing access points on the corridor and make it as training data-set and also an application to validate the data-set collected.

But, before that, we might need to do something with our first project report since the due date has reached its end :\ . Be back soon with other progress

Monday, February 16, 2009

Configure Ubuntu 8.10 with IIUM Wireless (ARUBA)

As for my experience when the IIUM Wireless Environment has implemented, Ubuntu 8.10 (Intrepid Ibex) has a problem to connect to to the wireless network. One of the millions way to fix this problem is by downgrade the version of Network Manager to the previous version. This is the method that I use to enable me to connect to the wireless network. If you have much easier solution to fix this problem, you are welcome to share with us.
Lets get our hand dirty:

1. Open terminal

2. Kill related process
$sudo killall NetworkManager
$sudo killall nm-applet

3. remove network-manager application
$ sudo apt-get remove network-manager

Reading package lists… Done
Building dependency tree
Reading state information… Done
The following packages were automatically installed and are no longer required:
linux-headers-2.6.27-7 linux-headers-2.6.27-7-generic
Use ‘apt-get autoremove’ to remove them.
The following packages will be REMOVED:
network-manager network-manager-gnome
0 upgraded, 0 newly installed, 2 to remove and 0 not upgraded.
After this operation, 4764kB disk space will be freed.
Do you want to continue [Y/n]? y
(Reading database … 129296 files and directories currently installed.)
Removing network-manager-gnome …
Removing network-manager …
* Stopping NetworkManager… [ OK ]
Removing any system startup links for /etc/init.d/NetworkManager …
/etc/rc2.d/S28NetworkManager
/etc/rc3.d/S28NetworkManager
/etc/rc4.d/S28NetworkManager
/etc/rc5.d/S28NetworkManager
Processing triggers for man-db …
Processing triggers for libc6 …
ldconfig deferred processing now taking place

——done—–

4. Download this 6 packages.
  • dhcdbd_3.0-1ubuntu1_i386.deb
http://packages.ubuntu.com/hardy/i386/dhcdbd/download

  • gnome-system-tools_2.22.0-0ubuntu9_i386.deb
http://ubuntu.interlegis.gov.br/ubuntu/pool/main/g/gnome-system-tools/

  • libnm-glib0_0.6.6-0ubuntu5_i386.deb
http://packages.ubuntu.com/hardy/i386/libnm-glib0/download

  • libnm-util0_0.6.6-0ubuntu5_i386.deb
http://packages.ubuntu.com/hardy/i386/libnm-util0/download

  • network-manager_0.6.6-0ubuntu5_i386.deb
http://packages.ubuntu.com/hardy/i386/network-manager/download

  • network-manager-gnome_0.6.6-0ubuntu3_i386.deb
http://packages.ubuntu.com/hardy/i386/network-manager-gnome/download

5. Install the packages that we have download (there are serveral way to install all the packages and in this tutorial we are going to use “dpkg”
$ cd /to/folder/you/save/the/packages
$ sudo dpkg -i *.deb

6. Lastly lock all the 6 packages version that we have downgrade to avoide this 6 packages been upgrade to the newer version when we do system update in future.