Thursday, 14 June 2012

One User, Many Devices

I've been read lots recently about BYOD and how many users in an organisation may well have 2, 3, 4 or more devices that they wish to use on a WiFi network. The will often have a laptop, possibly a tablet and almost certainly some type of smartphone.

The characteristics of these different types of device vary enormously, depending on the device capabilities and their RF characteristics.

I thought it might be interesting to just fire up 4 random devices I have in my home and compare the signal levels I could see from the same SSID on my home ADSL router. Each device had some type of software installed that could (allegedly) report the signal level that the AP is observed at from the client device point of view.

I know this isn't a particularly definitive approach, as the software used probably has varying levels of accuracy, so I wouldn't treat these results as being too accurate. But, they may give an indication of different device performance.

The devices I tested were:


  • Samsung GT-S5570 (Android Version 2.2.1) - smartphone
  • iPad2 (IOS 5.0.1) - tablet
  • iPod Touch 3rd Generation (IOS 5.1) - tablet...well, sort of
  • Dell Latitude E6420 (Intel(R) Centrino(R) Ultimate-N 6300 AGN) - laptop
The graphical results are shown in the screen shots below. The SSID used in each case was 'CiscoNet' (it's an ironic SSID, as the ADSL router used isn't a Cisco device...):

Samsung GT-S5570

iPad 2


iPod

Dell Laptop

The results, if accurate were pretty much what I expected. The laptop RSSI was the highest, averaging around the -60 to -63dBm level, with the iPad coming in second (varying quite a bit, but lets call it an average of -70dBm). The iPod was third around the -75dBm level, with the Samsung smartphone coming in a miserable fourth at around -82dBm.

This certainly shows the value of surveying with a device similar in characteristics to the actual device that will be used on the network. Just relying on a laptop survey on this network may have left things sadly lacking for smartphone users who were hoping for a a good WiFi connection. :)