Mount with Antenna Down? Concern for Signal Pattern

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Mount with Antenna Down? Concern for Signal Pattern

This thread has been locked for further replies. You can start a new thread to share your ideas or ask questions.
Mount with Antenna Down? Concern for Signal Pattern
Mount with Antenna Down? Concern for Signal Pattern
2020-09-04 14:09:23
Model: Adapter  
Hardware Version: V3
Firmware Version:

TP-Link EAP110-OUTDOOR V3 300 Mb/s Wireless-N Outdoor Access Point

Mounting in a large warehouse. If I mount it upside down, the antenna will ahve straight line view to coverage area.

Is there a problem mounting upside down with the signal pattern ? 
I will seal the exposed connections, etc.

 

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Re:Mount with Antenna Down? Concern for Signal Pattern
2020-09-04 22:32:53 - last edited 2020-09-04 22:35:43

 

DrBobTech wrote

Is there a problem mounting upside down with the signal pattern ?

 

No, but it doesn't matter whether it's mounted upside down or upside top. The antenna pattern will in both cases remain the same for omnidirectional antennas: in an ideal world it's a sphere, but with more energy radiated on the H plane at right angles to the antennas with less energy radiated downward or upward (V plane). Thus, the pattern is actually more like a donut rather than a sphere.

 

As a result: you should avoid to mount the EAP too high over ground to provide WLAN to clients on the ground.

 

How many clients do you plan to serve? What are the dimensions of the floors (length x width)? How many EAP110-Outdoors?

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Re:Mount with Antenna Down? Concern for Signal Pattern
2020-09-05 00:45:59

Hi @R1D2  Thanks for the reply.

 

The number of clients will probably be less than 25 max (the whole warehouse area) and 12 to 15 daily, constant use. These will be on iPad carried for inventory control, mounted on forklift and maybe a couple of laptops doing inventory control. We are using Cisco unlimited license for max throughput on Firewall, Router and Switch.

The all metal constructed warehouse, ceiling center is about 25 (probably 22 feet) feet to the concrete flooring. There is a metall constructed wall down the center as shown in the drawing. Two very large doors between the two 'halves' of the warehouose. See the drawing for a better idea. The drawing is not to scale but generally close.


How tall is the "doughnut" shape of the signal?

I thought about dropping the EAP110-Outdoor units a few feet on 1.5" PCV pipe hung from the Girders in warehouse ceiling. I just don't want opportunity for the forklifts to bump into them. Dropping them a few feet may also reduce lightning damaged introduced via the girders. The wire cablers will be using Cat5e Grounded shielded cable. Dropping them a few feet would put them more even with the eves of the warehouse wall.  Forklift drivers will just need to be aware they are hanging there.

Here is a rough drawing of the warehouse. Wht do you think? :)

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Re:Mount with Antenna Down? Concern for Signal Pattern
2020-09-05 09:01:52 - last edited 2020-09-05 09:02:41

@DrBobTech, you should hire a professional which plans, deploys and troubleshoots the WLAN installation. He will do measurements using a WiFi heat mapper during the whole deployment process and can determine the places to mount the APs.

 

The main challenge will be to mount the APs in a way which compensates for signal reflections caused by the metal structures.

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Re:Mount with Antenna Down? Concern for Signal Pattern
2020-09-05 12:10:30 - last edited 2020-09-05 12:11:46

Okay, thanks... Yes these will be adjusted after the initial installation. It is understood some tweaking will need to be done.

Does anyone know how tall the said "doughnut signal" pattern is over open ground?

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Re:Mount with Antenna Down? Concern for Signal Pattern
2020-09-05 14:59:33

Welcome @DrBobTech!

 

You mentioned that this is a warehouse.  On each half of the building do you have tall metal racking with aisles for the forklifts -- like in Sam's Club or Costco?  Or is it more of a wide-open "shop floor" style like a machine shop or stamping operation?

 

The reason I ask is that the radiation pattern from the Outdoor units (like the 110 and 225-OD) is much more horizontal as R1D2 said.  Though the flatness of the donut depends on the gain of the dipole antennas used.  Generally speaking, this type of antenna / AP is much better suited for wall mounting.  Which you could do if you have a large open shop floor, but not if you have tall metal racks.

 

Your other option would be to use a ceiling-mounted AP like the EAP225V3 instead.  Your ceilings are perhaps a little high for these which have a downward-facing conical radiation pattern, and you would most likely need more of them (than the 6 110's you were considering).  But if you have tall metal shelving, this may be a better option for you if you can situate an AP over each aisle in between the shelves.

 

As R1D2 suggested, having this done professionally would be your best bet -- performance-wise -- but I understand this would be significantly more expensive than doing it yourself.  Given that you have so few clients with limited connectivity demand, I think the trial and error might be your best bet.  This way you can learn as you go and see what works best for your environment.

 

Both AP's the EAP225V3 and EAP225-OD are very inexpensive $60-70 on Amazon.  So you could buy a few of each and test them out.  Don't forget to plan for PoE and check the voltage requirements of the AP's versus your PoE switch.  Some of the TP-Link products use different PoE voltages.  Total cable runs need to be less than 100M in general.   But for PoE, the injector or PoE switch generally needs to be less than 50M away.

 

Personally, I'd use at least Cat-6 or 6A cabling these days instead of 5e.  Not sure STP is really necessary.  Unless you have a lot of fluorescent lights and electrical wiring near the data lines.

 

Also plan to use Omada or SDN server software or get an OC-200 for easier management and configuration.

 

-Jonathan

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Re:Mount with Antenna Down? Concern for Signal Pattern
2020-09-05 19:44:34 - last edited 2020-09-05 20:10:30

 

DrBobTech wrote

Okay, thanks... Yes these will be adjusted after the initial installation. It is understood some tweaking will need to be done.

 

The point is that inside a metal structure you have to deal with reflections which can create massive interferences and even completely eliminate a signal if signal waves are shifted by 180º due to reflections. So you need to adjust the EAPs to mitigate against this before finally installing/mounting them. You need to do exact measurements, not just some tweaking (I deployed WLANs in metall containers, that's part of my business).

 

Does anyone know how tall the said "doughnut signal" pattern is over open ground?

 

This are the antenna patterns of an EAP225-Outdoor:

 

 

 

This are the antenna patterns of an EAP225 (indoor):

 

 

 

EAP225 coverage:

 

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