wiki:WiMAX/30/02
close Warning: Can't synchronize with repository "(default)" (/common/SVN/wimax does not appear to be a Subversion repository.). Look in the Trac log for more information.

Version 12 (modified by Nilanjan Paul, 10 years ago) ( diff )

Wimax Measurement Application: wimax_gps_oml2

Description

Collects Wimax radio link parameters with corresponding GPS coordinates on the client and sends to OML server. The following parameters are recorded and sent to the OML server: Center frequency, RSSI, CINR, Transmit power, Time from GPS, Latidute, Longitude, Altitude.

Everything described below must be running on a mobile client.

Software Requirements

  1. wimaxcu : Wimax radio utility. Must be installed on machine to operate wimax radio.
  1. oml2-server: OML measurement collection server. Note: this server may be locally installed on the mobile.
  1. gpsd: GPS service daemon running locally. Information on gpsd can be found on http://gpsd.berlios.de/
  1. wimax_gps_oml2: Wimax measurement application. The application's source code is available at wimax_client/trunk. To compile from the source, use the makefile or enter the following:
    gcc -loml2 -lgps wimax_gps_oml2_main.c libiWmxSdk.so lwimaxcu.a -o wimax_gps_oml2
    

Hardware Requirements

  1. GPS receiver: for example a Garmin USB Receiver - model#: GPS18x-5Hz. Other compatible GPS models can be found on http://gpsd.berlios.de/hardware.html

Installation / setup procedures

  1. Edit the /etc/apt/sources.list and add the following line:
    deb http://packages.orbit-lab.org/ubuntu jaunty main
    deb http://pkg.mytestbed.net/ubuntu maverick/
    
  1. Update information based on the changed sources.list.
    sudo apt-get update
    
  1. Install the wimaxcu utility if not already installed, then reboot the machine
    sudo apt-get install wimaxcu-1.0
    reboot
    
  1. Run the following commands to start wimax daemon service, and operate wimax radio
    wimaxd -i wmx0 -b
    
    wimaxcu ron
    wimaxcu scan
    wimaxcu connect network 51
    
  1. Install the Wimax measurement application (wimax_gps_oml2) and the GPS Daemon (gpsd)
    sudo apt-get install wimax-gps-oml2
    
  1. If measurements are to be collected locally install the oml2-server otherwise this step may be skipped.
    sudo apt-get install oml2-server
    

Note: The default settings for the OML server are stored in /etc/default/oml2-server. By default the database files are saved in /tmp directory which is purged after every reboot. To change this default directory, edit the —data-dir flag to point to some other directory and then restart the oml server.

  1. Attach GPS receiver to mobile. At this point please refer to http://gpsd.berlios.de/troubleshooting.html and verify that GPS is able to send data and also able to talk to gpsd.

Usage

  1. Refer to http://gpsd.berlios.de/troubleshooting.html and verify the GPS receiver is able to send data and also able to talk to gpsd.
  1. Verify oml2-server is running
    ps -elf | grep oml2-server
    

If needed restart oml2-server:

/etc/init.d/oml2-server restart
  1. Verify gpsd is running
    ps -elf | grep gpsd
    

If needed start gpsd as a daemon with the following command. Note: /dev/tty* name may be different. Refer to gpsd troubleshooting to find correct /dev/tty* name.

gpsd /var/run.gpsd.sock /dev/ttyUSB0
  1. Run wimax_gps_oml2 collection application.
    ./wimax_gps_oml2 --oml-id 4 --oml-exp-id exp4 --oml-server localhost:3003
    

This will create an sqlite database file (exp4.sq3) on the oml server.

Troubleshooting GPS Service Daemon

Please refer to troubleshooting gpsd please refer to http://gpsd.berlios.de/troubleshooting.html.

Sample data

Here's are the snapshots of drive data collected around the Wimax BS at Rugters Winlab.

Resulting RSSI trace in !GoogleEarth
RSSI
Resulting CINR trace in !GoogleEarth
CINR

Post processing data

After the application is run, it'll create an sql file on the oml server. Processing this file to extract the measured data can be done in several ways. The steps outlined here can be used to generate the image shown above.

  1. Process the sql file into delimited ascii text.
    sqlite3 exp4.sq3 "select * from wimax_measurements;" > exp4.dat
    
  1. Extract the rssi field from delimited ascii text file. This was done via awk script: rssi.awk
    awk -f rssi.awk exp4.dat > exp4_rssi.dat
    
  1. Use gpsvisualizer to plot exp4_rssi.dat.
  • Under Upload your GPS data files for File #1 select exp4_rssi.dat.
  • Under Track options for Colorize by select custom field from the pull down. Once the Custom colorization field appears enter rssi.
  • Finally click Draw the map

Alternatively, OCTAVE or MATLAB can be used to process the data. The Octave script plot3d.m was used to plot the RSSI in 3D from the datafile: exp5_rssi_oct.dat. The following is a rudimentary 3D plot of the RSSI in front of Rutgers Winlab.

3D RSSI Plot
3D RSSI plot.

Attachments (9)

Note: See TracWiki for help on using the wiki.