Monday, July 15, 2019

My Ekahau Sidekick offsets

 

Ekahau users that use the Sidekick have probably discovered that the Sidekick “hears” better than other devices?  How much better, you ask?

 

Since I do a lot of validation surveys, I decided to do a comparison between four devices.  The 5 GHz Vocera “communicator” badge that is deployed quite a bit in Healthcare, the “Netscout” AirCheck G2 (in parenthesis because I heard that Netscout doesn’t own that product anymore though the name is still on the box), my handy dandy Samsung Galaxy S7 Edge (that just so happens to be the platform used by a company that deploys Google Glasses), and my trusty Sidekick.

 

My main concern was “what is my Vocera offset” for doing surveys to determine if the WLAN is voice quality.  So, we took two Vocera badges and put them side by side, and during our testing, averaged the two into one measurement.  I must say this was easy, since the Vocera badges usually agreed with each other within one dB.

 

We tried not to skew the results in any way.  We didn’t look at previous results during the testing.  We didn’t look at other results and compare while testing.  We simply walked through a medical office building and randomly stopped in areas and took readings.  This was intentional, as we didn’t want to add “intelligence” into the equation.  We even took measurements in the basement, where coverage was minimal.  When complete, we added them up and divided by the number of readings.  Very simple.

 

Sometimes we throw out “highs and lows”, and average the rest.

 

When using the data we gathered, not tossing out the highs and lows, our offsets came out like this:

 

Vocera                 -11.66 db

AirCheck G2        -13.44 dB

Galaxy S7 Edge   -13.66 dB

 

When using the data we gathered, tossing out one high and one low, our offsets came out like this:

 

Vocera                 -12.00 db

AirCheck G2        -13.14 dB

Galaxy S7 Edge   -13.28 dB

 

Moving forward, I feel as though a 12 dB offset can be used in my environment when looking at the WLAN surveys with Vocera communicators in mind.

 

Actual readings walking a floor of a medical office building:

 

Ch:         Vocera  G2          S7           Sidekick

 

44           -46         -49         -55         -40

 

44           -77         -75         -76         -64

 

64           -61         -56         -56         -46

 

56           -69         -74         -76         -55

 

52           -68         -69         -74         -59

 

36           -73         -74         -75         -62

 

161        -68         -66         -60         -53

 

36           -70         -79         -76         -59

 

48           -78         -84         -90         -67        

 

 

dB Difference between each device and SK

 

Ch:         Vocera  G2          S7           Sidekick (original dB reading)

 

44           6             9             15           -40

 

44           13           11           12           -64

 

64           15           10           10           -46

 

56           14           19           11           -55

 

52           9             10           15           -59

 

36           11           12           13           -62

 

161        15           13           7             -53

 

36           11           20           17           -59

 

48           11           17           23           -67