Wednesday, June 20, 2012

Site Surveying with the Motion Computing F5v Tablet

Lately I've been doing some research into different tablets/netbooks/handheld PCs for performing wireless site surveys. Ingram Technologies loaned me a demo unit of the Motion Computing F5v tablet PC and put it to use as a survey kit running AirMagnet Survey Pro along with Spectrum XT in a multi adapter setup. My goal was to see how long the internal battery would last, and to see if I'd experience any application crashes, slowness or anything out of the ordinary with a slightly tweaked demo unit. The only power adjustments I made to the F5v system power settings were to not turn off the display, hard drive or the USB nic while the tablet was running on battery power.

I secured the usb hub to the handle of the unit with narrow velcro strips (cut down from larger double-sided velcro) and used masking tape on the usb hub cable to keep it flat to the back of the unit. The stylus pen is stored in the underside of the unit handle, so Velcroing everything to the handle made it so I had nowhere to store the tablet stylus when I wasn't using it. 
I did some googling and came up with a halfway decent floor plan of a local mall where I was betting I'd wouldn't get stopped by security while I was testing out the F5v tablet.

I loaded up the maps into AirMagnet, set the scale and I was ready to start testing. The overall square footage of the public walkways totaled about 100,000 square feet for the 1st & 2nd floor of the mall, and the batteries on the F5v lasted about an hour and a half with AirMagnet Survey Pro and Spectrum XT running the entire time. Luckily the F5v's batteries are hot swappable and the battery has an external charger docking station available. I wish the screen was a bit larger since I could not see the Spectrum XT inset in the Survey Pro application while I was doing the survey. The Spectrum XT data was collected during the survey even though no major sources of interference were detected. Overall I was pleased by the performance of the F5v and I'm betting it will be a rugged site survey tablet to replace the IBM x201 I'd used for years.

Below are the survey images for the 2.4GHz and 5GHz frequencies of the SIMON WiFi wireless network in the mall in case you were curious about what kind of coverage you might get from "free" mall Wi-Fi. I tried to spot the access points as I was collecting the RF data, but I didn't see them at all on the first pass. Maybe now that I have the data showing where the hot spots are I might be able to find the installation locations.

1st Floor 2.4GHz RSSI
1st Floor 5GHz RSSI
1st Floor 2.4GHz SNR
1st Floor 5GHz SNR
2nd Floor 2.4GHz RSSI
2nd Floor 5GHz RSSI
2nd Floor 2.4GHz SNR
2nd Floor 5GHz SNR
I ran a few AirMagnet reports (overall by SSID, overall by AP, spectrum analysis report) on the data I collected to see what that would look like for a mall where every shop has its own wireless network. Naturally, many of the shops' wireless networks were configured to operate on channels 2, 3, 5, 9. This is fairly typical for multi tenant buildings of any kind. You can download an archive of the reports here.

Updated with Spectrum Analysis & Laptop Analyzer captures (here).
The duty cycle utilization was quite high due to all of the SSIDs contending for the same RF airspace. I spotted a microwave and an X-box, but no strange fixed frequency devices.
I did find it amusing that their signage for the open SSID isn't capitalized the same as the SSID being broadcast, and I spotted a couple of the APs providing the mall Wi-Fi (Proxim AP-700s) as I was leaving.

For future reference, this tablet had 4GB of RAM installed and I didn't have any issues with AirMagnet application slowness or hangs.


  1. Love the DIY stuff. I can see you huddled on the floor with a roll of duct tape and scissors.

  2. Totally. That and a couple of coat hangers and I can fix just about anything! :-)