Interference on 2.4 GHz

[jmorphew]

We have a newer Meraki wireless deployment. The building is a 2-story office area attached to a large warehouse. Our 2.4 GHz wireless is not working reliably in the warehouse portion of the building, the 5 GHz wireless is working. I am already working with Meraki support and a local vendor, site surveys have been completed. So far neither has provided a solution. Here’s some additional information:

• We are using MR36 and MR44 access points throughout the entire building (warehouse and office)
• Our warehouse access points are mounted at 34 feet, a few feet below ceiling height
• Nearly all access points in our warehouse show 90% or higher utilization on 2.4 GHz
• The minimum power level of our access points in the warehouse was set 29/30 to address some deadspots and low coverage areas. We have been adjusting this setting, they are currently set to 20/30.
  • We adjusted minimum the power level back down to 6 for testing, but it only reduced our average utilization by 4.5%
• The 2.4 GHz connectivity issue is consistent across all SSIDs

There are problems throughout the warehouse, but to make this easier I will focus on one location. The attached image is our floorplan in this location. The red numbers are utilization, the blue numbers are 2.4 GHz channel. Here's some information about one specific location in our warehouse:

• A portion of our warehouse has racks that are 30 feet high and 8 feet across. The racks are filled with pallets containing cardboard, wood, metal, and plastic
  • The access points are 19 feet apart East/West (between racking aisles)
  • The access points are 84 feet apart North/South (down the same aisle)
• When a client is using 2.4 GHz and stands where the Green X is located, they have the following issues:
  • Slow internet (1 mbps or less on a 1 Gbps connection)
  • High latency (500-2,000 ms)
  • Dropped connections, no internet
• This client is closest to access point W-21 (green box)
• Access point W-21 is on channel 6
• The average channel Utilization for access point W-21 is 98% (jammed)
• There are hundreds of entries on the ‘Interfering APs’ list for this access point
  • The top 4 interfering BSSIDs belong to neighboring access points WH20, WH19, WH23, WH28 (red boxes)
  • These access points are also on channel 6

I believe our issues are caused by co-channel interference due to a high density of access points in our warehouse. I also believe the wrong model of access point was chosen for a warehouse deployment, driving higher density and more channel overlap. I would like help confirming this theory or help identifying any other potential causes. I would also love suggestions on how to resolve this issue.

 

 

 

[BlakeRichardson]

I don't mean to sound rude but it seems like your vendor needs to find a new trade. The way I read it you have done all of the troubleshooting (the installer should be doing this).

They shouldn't be selling equipment if they aren't familiar with it.

[jmorphew]

Yes, I wish the vendor was doing more to troubleshoot, and had done better planning upfront. Working with what I have on this one though. We disabled mesh and disabled 2.4 GHz on about 20% of the access points and the interference went down further. Roaming is still not very smooth and a portion of the warehouse is still seeing slower speeds and more connectivity issues. I think we need to disabled 2.4 GHz on more access points.

We're still getting connection complaints from clients and I noticed in the timeline that they are moving between 2.4 and 5 GHz regularly. I'm wondering if I just disable 2.4 GHz entirely what the results would be. We have a high density of access points, wrong model, bad placement, running at high power. But if the 5 GHz coverage is there, do you think it will be reliable? Or is this just a losing battle and we need to replace and relocate access point? Any opinion is appreciated.

[redsector]

We have got in every second line an accesspoint in our warehouses. where not then alternately, on the opposite site. And with patch antennas facing in the shelfe alleys. Running with 12MBit minimum. Autopower. Mixed 2.4GHz and 5GHz. Each line is about 60m (about 200ft) long.