I work in a distribution plant that has a wifi network that consists of 12 Cisco Aironet 1200 series access points that are controlled centrally by a Cisco WLSE which has run pretty much flawlessly for the past two years when I took over.
Here is our current layout with the access points power settings and coverage:
For the past couple of weeks we have been having problems around aisles 9 & 10 (which is between access points 02 and 04 - which on the map, aisle 10 is 3 rows right from AP 04, and aisle 9 is 4 rows right from AP 04) where the connection will just drop out on our RF guns and they will have to reboot the whole gun to reconnect. Access point 02 was originally set at 20mW, but I lowered it to 5mW just in case I was having co channel interference. However, the problem still exists.
The wireless signal seems to fluctuate widely in this general area, and none of the access points are reporting any errors. I've attempted to reboot the access points, the WLSE, and even turn off access points to see if the issue was any better, but alas nothing seems to make the problem any better. Even if I look at signal strength and walk around, sometimes the entire connection will die before the signal strength goes to a low number. I also notice a drop out sometimes between AP01 and AP02.
I've been working on this for a couple weeks and I am entirely out of ideas. I've had maintenance turn off lights, electronics, and everything else they could think of in this location and not a change in the signal fluctuating. The only thing that has changed is that there are less items in the racks close to AP02 and less racks in general near AP01.
Edit: After I started writing this post, I learned that aisle 9 and 10 house close to 30,000 pieces of items that have RF ID tags located on them. We do not have systems here to read RF ID and as far as I know these are passive tags, but I get conflicting statements on whether these tags can cause interference with our wifi. If so, is there any way to mitigate this?