Warehouse - MR66 problems

[FFoods]

Hi, 

Currently taking over an existing building with the current layout, AP's are MR66 and network is using WPA2-PSK and I believe the antennas to be Air-ANT2544V4M-R based on what I can see, looks like a dome pointing mounted on ply screwed to the ceiling.  Currently have antenna type set to MA-Ant-20.  This may not hold true for the cooler or freezer areas as I've haven't been in there.

It's for a food distribution warehouse and using VC5090 and RF guns running over 2.4.  Ceiling is probably 30-60' high, not good with measurements. Each AP seems to be lined up with an aisle in the dry area. 

Have the following weak areas:

I've bumped up transmit power to 21 and it did help, however, warehouse is empty now and once filled, I can only assume they'll have tons of issues.

I'm thinking of re-positioning some of the access points as below:

Before I explore the proposed plan, is there anything else I could try to help the signal strength?  I've heard of external antennas for the VC5090 units.  If no, would the proposed plan work?  Can i use couplers to extend the cables or should i run new lines?

Any help or guidance would greatly be appreciated.  First time using Meraki devices in warehouse.

Thanks

[PhilipDAth]

According to the specs those antennas (in the 2.4Ghz band) throw out a lot of signal "left and right" (blue line) but not much directly down.  So most of your RF energy is probably being lost providing coverage in the roof in itself.  Note the special install instructions for these antenna that say they must be mounted with the cables towards the ground ("Install the antenna vertically and mount it with the cables pointing towards the ground").

https://www.cisco.com/c/en/us/td/docs/wireless/antenna/installation/guide/ant2544v4m-r.html

This is not the correct antenna for you - but contrast this with a sector antenna, and you can see how you can direct most of your RF signal down to the ground.  This example is a 2.4Ghz antenna with 11dBi of gain.

https://meraki.cisco.com/products/wireless/antennas-power#sector-antenna-11

Is there any way you could put them on poles attached to the roof to lower them?  Having antennas 30ft to 60ft above wear the coverage is required burns a lot of the RF signal strength up straight away.

Would it be possible to mount some of the antennas to a wall rather than the roof to lower their height?  Note with those antennas you would need to keep their current orientation so you would need some kind of bracket to mount them at a right angle to a wall.

If the antennas could be kept at the same height you would think the proposed layout would be an improvement.  If the height is increased though (such as an 'A' frame roof) then things could be worse.

I think I would be tempted to splash out and get a predictive site survey done.  If you do, make sure whoever is doing it loads in the heights of everything.  The heights will make a big difference to the results in this case.

[FFoods]

Hi PhillipDAth,

The warehouse ceiling is the same height throughout, so I'd be able to keep the same height if I were to re-positioned the access points.  Hanging them off pipes would probably not work for my scenario as I'm afraid someone might hit them if mounted too low, we've had this happen numerous times at another location.  I could also consider mounting them on the wall, which would allow me to move this lower.  

I'm trying to get a consultant to go out and do a survey, so I'm hoping I'd be able to pinpoint exactly which way I'm going to approach this.  .

Thanks for your suggestions.

Rocky