A few days ago I was working on a predictive RF design for a client and needed to create a custom antenna pattern in Ekahau Site Survey.
In essence, what I needed to do seemed pretty simple, take an existing antenna pattern in ESS (Cisco AIR-ANT2566P4W-R) and invert the H-Plane and E-Plane patterns, in other words turn the antenna 90 degrees on its side.
By default the 2566 provides a coverage of 105/70 in the 2.4GHz band and 125/60 in 5GHz and when I am finished that will be flipped to provide me a 70/105 and 60/125 antenna pattern.
The process to achieve this in ESS is actually remarkably straight forward and involved editing just a few files – I’m sure if you had time it would be even easier to get in touch with Ekahau, but hey, I like to tinker…
The first thing to do is create the new antenna pattern, I did this by locating the existing 2566 antenna files in:
C:\Program Files\Ekahau\Ekahau Site Survey\conf\antennas\Cisco AIR-ANT2566P4W-R 2.4GHz 6dBi.xml
C:\Program Files\Ekahau\Ekahau Site Survey\conf\antennas\Cisco AIR-ANT2566P4W-R 5GHz 6dBi.xml
I copied the files and appended “INVERTED” to the end of the file names.
Opening one of the files up in your favourite text editor reveals some XML formatted information, and you will see there are containers for <hplane> and <eplane> for my purposes all I needed to do was swap the antenna data between the two containers.
There is also a set of files that creates a Cisco AP with the antenna already chosen, so I found those files and applied the same process, I also changed the “apModel” tag in those files:
Once that was done with I needed to get the AP and pattern into the list to select from in ESS, I found the file to edit now was:
C:\Program Files\Ekahau\Ekahau Site Survey\conf\accessPointTypes.xml
I located the existing 3702e + 2566 data and copied it adding “INVERTED” to the name.
<accessPointType model="AP3700e + AIR-ANT2566P4W-R INVERTED" vendor="Cisco"><radioType spatialStreams="3" mimo="4x4" frequencyBand="2.4" technology="n"/><radioType spatialStreams="3" mimo="4x4" frequencyBand="5" technology="ac" maxSupportedBandwidth="80MHz"/>
Once that was done with I saved the files, and fired up ESS.
I now had an extra option in my simulated AP selection list, and if I go to edit the simulated AP I can also see the new “INVERTED” antenna patterns I created, and judging from the preview images it would appear my tinkering has worked!
This was certainly easy as the antenna data was already there from Ekahau, however if you needed to do this from scratch working with just the plots from a vendor it may be worth getting in touch with either @ or @ on Twitter.