Wireless Access

Hi all,

Does anybody have a heatmaps for AP-ANT-32 antenna? There were some examples for older antenna types, a heatmap measured on different heights and distances.

Other question, please see attached pattern chart (elevation) from AP-ANT-32 datasheet.

The most outer ring is I presume +5 dbi line, because antenna has 4dBi max gain in 5G? Most graphs has linear rings (+5,0,-5,-10 etc.) where this one is +5 and next is already -5dbi?

Others may have heatmaps of the ANT-32 at different heights, but that is not something we regularly produce as most don't have a need for it (each environment will have it's own characteristics that would make any captured heatmaps irrelevant). 

As for reading the antenna patterns, a good place to start is here (https://www.youtube.com/watch?v=YAxJtRTzGOc). The outer ring is normalized at 0dB and each ring in reduces by 5dB (so 0dB, -5dB, -10dB, etc). The antennas are rated by where they are -3dB from the maximum gain, so the outer ring effectively marks the maximum gain of the antenna, and then 3db down from the max peaks will be the beamwidth. These are 360deg in the H-plane, but are effectively 45deg in the E-plane (though in this specific antenna's case, the max gain lobes are effectively at 45deg as it would be wrong to measure the -3dB drop towards the 0deg heading, so in effect the -3dB drops are actually both towards the 'inside' and the 'outside', making it a 45deg on the inside, or an approx 100deg on the outside. However, it being such a low dB gain antenna, it's not really super important that you mark it a 45deg or 100deg e-plane. The important thing to note is that coverage is above the connector. 

Thank you, very thorough explanation.

In your opinion, would it be a good idea to consider this antenna for client coverage with ceiling at 5,5-6m with AP separation apporx 20m in industrial envrironment, ofcourse 2.4G radio at minimal EIRP (6-9dbm) to benefit from 5G band, but would this setup provide acceptable AP-AP dbm separation in 2.4G?

Ofcourse we would do survey but would like to know whether do it with AP228 with AP-ANT-32 or should forget this antenna and go with something else? If yes, which antenna type would you suggest?

That might be fine, it's really hard to say without actually surveying, simply because warehouses and the stuff they house, the shevling arrangements, clearance btween the top of the racks and ceiling, etc all come in to play. The benefit is the 228s have much better EIRP per chain, so coverage won't likely be an issue. What is the ground coverage target?

Do you mean radius/range?

With approx 20m (25m max) between APs, we were thinikg about 15m cell radius on the ground with a bit of overlap. As I said, we don't want APs to transmit at high EIRP, especially in 2.4G. APs will not have LoS with each other (obstacles, steel elements).

In this kind of environment, industrial, a lot of steel elements causing reflections, which one is better approach to reduse channel utilization: decrease EIRP with 1 and 2 mbps transmit rates enabled or slightly higher EIRP without slowest transmit rates? Which gives better link quality?

Link quality is all SNR (IMHO) and alot of what you need to do really depends on the client types. Most warehouses typically have handheld scanners, etc and knowing how they behave helps. Many/most HHTs I have ever worked with expect HOT signal to behave in regards to roaming. As such, more SNR/signal is better (which is why the 228 is a great fit). At 6m AGL, that should give you 12-15m cells under the APs. At 20m spaicing that should give you a good 6-9dB of separation between cells which should be enough to trigger a roam. If there is shelving or vertical assets in the space, that may affect how the cells behave, but I think you're on the right track and at 6m AGL those antennas will be good.

I was thinking of your other post (http://community.arubanetworks.com/t5/Wireless-Access/Warehouse-AP-placement/m-p/261758#M58650) where you mention the warehouse has 20m ceilings. This is not the same deployment then? 20m AGL for the ANT-32 is likely too high for optimal coverage at the ground. That is where I was getting messed up.

When you mean 12-15m cell size, do you mean cell radius or diameter?

Yes, there will be handheld scanners in use, but make and model are unknown yet. I expect/assume them to have poorer receive sensivity than laptops and tablets.

When it comes to my previous post (http://community.arubanetworks.com/t5/Wireless-Access/Warehouse-AP-placement/m-p/261758#M58650) yes, its a separate case. There is ceiling at 15m and I must admit I was thinking of AP-ANT-32 since it is a down-tilt omni antenna, the usage of which is in general recommended for this scenario. Why would you recommend not to go with this antenna and which one would you recommend?

At 6m AGL, that will give you a 6-8m radius of coverage within the main lobe of the antenna, so a cell size of 12-16m-ish. 

If the ANT-32s are mounted REAL high up, a good portion of the RF energy may go out sideways instead of down. The goal when looking at that kind of deployment would be to use more traditional squint or downtilt antennas. It COULD be 6 in one hand, 1/2dozen in the other at that height and in your environment, so that is why you have to test to know for sure whether the ANT-32s are optimal or if you should use some other antenna solution.