Wednesday, July 22, 2020

Why doesn't 802.11a data show up when surveying with Ekahau Pro and an iPad?


Why doesn't my 802.11a data show up when surveying with Ekahau Pro and an iPad?

For over a year now, I have been plagued by an issue when troubleshooting/upgrading WLANs.  The issue is simple - when I step into a site with little to no documentation, I start off with a Validation Survey to see what the environment looks like - and it helps to find APs that might be lurking behind filing cabinets, on desks, on book shelves or sitting on top of ceiling tiles - or my favorite, which is hanging on the wall like a clock.  When I find them, I always ask my colleague what time it is.  The reply is always, "it's time to get that AP mounted properly!".  Please don't put ceiling mount APs where they don't belong!

Back to the issue regarding the validation survey and the "Mystery of the Missing 802.11a 5GHz data".  The first time it happened, I thought I had done something wrong.  Surely I had misconfigured something on the iPad somewhere.  I walked a site that had both 1131s and 3502s on the ceilings and I noticed a pretty green map on the 3502i series side of the house.  I kept walking, not looking at the data as I thought it was collecting fine.  When I returned to the office, I noticed when reviewing the file on my desktop that the 5GHz 802.11a appeared to be missing where the 1131s were.  I asked around and nobody had a great answer as to why this is happening.  After all, Ekahau Pro is a WLAN survey platform and there are a bazillion customers using it and nobody has seen my issue.  I was convinced it was something I was doing.

This is what the floor looks like from the documentation/monitoring side of the deployment:





It is difficult to see, but that is the floor with the APs on it, showing the APs with the channel and power levels on them.  They are Cisco 1131s (they have internal antennas) and are dual band access points with 802.11a and 802.11g.  They are not 802.11n or greater.  The graphic show both radios online, and their power and channel selection.

A few weeks ago, I went to a site I needed to schedule and did a quick test run with a laptop and Sidekick as I knew the site had 1131s on the ceiling.  I walked the site with my laptop and Sidekick for five minutes and verified I had both bands in a very small area, and then made an appointment to walk the facility with the building supervisor.

I changed one thing the following week when I walked it.  I saved the project to Ekahau Cloud, and walked it with my iPad and Sidekick.  When I saw the results below, I started to wonder if the problem was with the Ekahau Cloud/iPad/Sidekick combination.  Here's what the first floor validation looks like with that combination of survey and only that floor's APs selected: (three APs in the middle were upgraded to 802.11n and they show up)



As you can see above, there is no 802.11a data at all from the 802.11a radios.

Next, I walked the floor with Ekahau/Laptop/Sidekick (project saved on SK) combination.  See graphic below.  Here's what the first floor validation looks like with that combination of survey and only that floor's APs selected.  Since we all know battery life is important (and we had already walked the entire second floor with this combination, we decided to only do this half.  As you can see, the 5 GHz 802.11a data shows up when we use the Ekahau/Laptop/Sidekick combination.


Next, I walked the floor with Ekahau/iPad/Sidekick (project saved on SK) combination.  See graphic below.  Here's what the first floor validation looks like with that combination of survey and only that floor's APs selected.  As you can see, the 5 GHz 802.11a data does not show up when we use the Ekahau/iPad/Sidekick combination.



Finally, I turned to a trusted old friend, AirMagnet Survey Pro.  I used the Edimax AC1750 adpater and walked the site yet again.  As you can see from the graphic below, the 5GHz spectrum is correctly mapped out for me.



My conclusion is that the iPad will not gather 5GHz (802.11a) data from an 802.11a radio.  I do not mean 802.11a/n or 802.11a/n/ac/ax radio.  I think I have ruled out the issue as an Ekahau Cloud issue, as I saved the projects to the Sidekick for this test.  It looks as if the iPad is the culprit.

I looked at some older surveys (pre-iPad) and verified that 802.11a data displays properly.

I feel that being able to see 802.11a data is important.  Even if you don't have older protocol APs in your network, your neighbor might have them and when you survey, you won't pick them up if you use the iPad.  I'm just going to have to use a laptop and Sidekick.  I'm also wondering if I can get a refund for the iPad/cloud, as it is not useful to me anymore.