@nilesf wrote:
1. If am correct 5Ghz has a shorter range.
Actually, that's a very common misconception. Signals in both frequency bands (2.4 and 5 GHz) propagate exactly the same, governed by the inverse square law. What makes a difference are the sources of attenuation that happen to be in their path. Some materials cause more attenuation to 5 GHz and others to 2.4 GHz since it is a function of wavelehgth.
@nilesf wrote:
2. Based on the antenna design these should produce a "cone", instead of a "donut", thus penetrating downward.
That's not correct. If you take a close look at the AC-M-PRO's antenna radiation pattern you'll notice that it doesn't resemble a cone at all. It is pretty much a typical omni(ish) radiation pattern found in outdoor APs with captive antennas. In your case less than 1/3 of the radiated energy is directed to your client devices.
@nilesf wrote:
3. I believe they are 40-50 feet above the floor.
That's way too high for any AP with non-directional antennas.
If you wanted to go with UniFi you should have chosen the AC-M APs and pair them with addecuate directional antennas (e.g. UMA-D). That's about the only feasible option for your scenario. Mounting "hundreds" of AC-M-PROs 40+ feet above the floor all transmitting at max power is a recipe for disaster. The problem is further compounded by using 2.4 GHz, which means you only have 3 channels available. If for example you had 210 APs in that facility it would mean that there will be 70 APs in each channel. So potentially those 70 APs and all their associated client devices will be contending for a chance to access the medium. It you look at channel utilization over time you should notice sustained values at or above 60%.
I'd recommend you go with a 5 GHz only configuration using 20 MHz-wide channels and transmit power set to medium. While it could improve things, I don't think any amount of configuration tweaking will be able to provide for a problem-free deployment with good roaming behavior. I'm afraid that would require a complete rip and replace, based on a design made by a qualified WLAN consultant.
Omar
