Guys, I need your advice. I'm looking for some solution for WiFi infrastructure in our packing hall.
Bellow, I enclose images of how it looks. Packing hall dimensions are 25m x 100m
We need mainly it for hand-data-collectors.
I have tried building network with 3 CAPac devices. If the packing hall is empty it works. Maybe not ideal but works - some scanners have problems while migrating between APs.
But we need to scan datamatrix codes (similar to QR codes) from carton boxes on CC trolleys. These trolleys are a standard in horticulture - like EUR-pallets (so they can't be changed). The main problem is that trolleys and shelves on it have metal construction which disturb WiFi waves.
Now we have those 3 CAPac mounted on hall construction above trolleys. Scanning from the highest shelves is OK, but going down starts the problem. If the AP is above the alley where you are scanning it works much better. So in my opinion signal is blocked by the metal construction of trolleys.
We also have tried GSM scanners with the same effect - at the top working, when going down losing GSM signal.

What can we do/try?
- Moving those APs around eg. mounting them on walls probably nothing changes - only the first alley from AP will be OK, next will be blocked by trolleys. Even if waves go horizontally, parallel to shelves, they will be blocked by the content of those shelves (plants in pots with soil).
- Making a static layout of trolleys and alleys, then for each alley some narrow sector AP, mounting them on a wall. What about interference between each AP? There will be around 12 alleys so it will be 12 AP. Which AP or antenna can you recommend?
- If everything else failed we need some backpacks with an external antenna connected to the scanner so when scanning lower shelves the external antenna will be still above trolleys :)

We don't need super speed, but a stable connection so 2,4GHz is OK as 2,4GHz waves go better thru obstacles. On the other hand, 5GHz has more channels so there will be less interference between APs. Or should I build some mesh with all AP on same frequency?

So probably I should start with the second solution. But I don't know which device to choose.
- 5GHz or 2,4GHz (as written above - more channels vs better permeability
- AP with integrated anntena or external anntena? External antennas have horizontal or vertical polarity - don't know what that matters
- Each AP on non-overalping channel or each on the same channel? I never use WDS but it is probably if you want to build some mesh with only one main node connected to a wired network. In my case, all AP can be connected to the wired network. I also never use HWMP+ - maybe it will be better for this?

So I really enjoy any hints. Thanks a lot.

Hi,
I really need help. If you need more details please feel free to ask me. I thought I've written all, but maybe I've missed some. So please ask.

This is probably an area where Mikrotik Wifi isn't superior - I think some of the real enterprise WIFI solutions can actually share channels would be better.
But I would try with cheap Mikrotiks this way:
5Ghz - and different channels. (2,4Ghz will interefer more with other AP's, and you only have 3 non-overlapping channels). Remember to disable extension channels, you need stability - not speed.
Many AP's set at a really low TX strength. If you can shield the AP's from each other somehow that would be best - preferably the shelves should have gone all the way to the roof, so you could place AP's between all the shelves.

I would use a beam AP down each isle on it's own channels. The channels could be set to 12mb 2.5GHz and 40mb on 5GHz bandwidth since you are using it for POS equipment only.

You can use something like this https://mikrotik.com/product/RBMetalG-52SHPacn But you will have to turn the power way down so you do not over load the POS equipment or microwave your staff.

Guys thank you very much for your advice.
If I may, I'll have more detailed questions.
I can start with some 5GHz routerBOARDs which I have. But I'm not sure with which antennas should I try.
So firstly should I start with standard omni antennas with some DIY shield to make the wifi wave very narrow? Some 'U' shaped metal plate will be okay?
Or better should I start immediately with typical direct antennas? But I think that they are with high antenna gain for long PtP or PtMP connections. Or everything will be good if I set low TX power on routerboard?

I would test a triple chain NetMetal or RouterBoard with a triple chain wireless card. Treat each chain as a seperate AP as far as mounting is concerned. This way you should only need 4 APs. You will need to get as much physical separation as possible and reduce the power some. You should be able to achieve single chain connectivity at the least.

- Do your hand-data-collectors support 5 GHz at all? Do you have a link to its datasheet?
- Do you have a PoE switch available for powering the access points?
- If they do 12 access points with omnidirectional antennas would fit. You might not need all 12 access points. You have to check.
- Don´t use wifi extenders.
- No meshing, use cables as long it is possible. Take a look here (http://www.grandstream.com/sites/defaul ... etwork.pdf) for meshing design and its limitations.
- 20 MHz channels for 2.4 and 5.0 GHz. Different channel on each access point.
- I wouldn´t use MikroTik in such a situation as roaming ("migrating between access points) won´t work as you want it.
- What about cabling? Would you be able to cable the whole room?

I would go for this device. https://mikrotik.com/product/mantbox_52_15s
If there is a lot of Iron then 2.4ghz is recommended.