How to Determine Offset Values Against the Ekahau Sidekick

 

Many times I have been on site performing a passive survey at a facility using the Ekahau sidekick and whatever audio device that I am testing with for a particular client, and realize that the readings on the device and the readings on the sidekick do not match. Receive sensitivity values can differ from vendor to vendor; Ekahau realizes this and has created off sets to have the sidekick closely match the device being tested. There is a standard -10dB mobile offset that can be applied very easily. If you have a handheld device that isn't a cell phone, you can create custom offsets easily.

Create a Profile by going to Project > Device Profiles

Step 1. Create a name that matches the name used in the report template (in this case B3000n)

Step 2. Choose what Wireless Technology the devices use.

Step 3. Choose the MAX Bandwidth

Step 4. Choose the how many spatial streams is has

Step 5. Set the proper offset for the device

Step 6. Hit the Add button to save the profile

If you CTRL -Left mouse button on the Legend, you can choose to view as B3000n

from here you will see this and click 'View as' to see the offset you created

Make sure this line of code is in your report template: 

"adapter" : "B3000n",

The easiest way to do that is to go to Template Reporting and Copy current visualization to clipboard. If you set everything up correctly, that will generate the proper JSON code you will use to place in your custom report template.

But what if you do not know what the offset for your device is? Here is how to test and measure.

Test Methodology: 

• Record how far the test site is away from the access point you are testing against.
• 15 captures per device waiting 10 seconds between captures to write down the reading.
• Max value and Min value removed to get an average of the remaining 13 readings.
• Line 19 has this formula in it for each column =(SUM(x3:x17)-MAX(x3:x17)-MIN(x3:x17))/(COUNT(x3:x17)-2)   where x is the column.

This example was my testing the SA-1 adapters against the Sidekick, which turned out to be negligible which means the SA-1 adapters will produce the same results as the Sidekick. The testing is the same for any other device, obviously, the results will be different. The difference between the device and Sidekick results will be the offset.