Warehouse Dilemna

[JimL]

I am not sure if this a question or just me venting. Have a customer who in part of their warehouse has a four level pick module. Each level is 9 feet tall with the usual 4" to 6" floor/ceiling between them. The whole thing is a tower of multi-path and dirty RF. It is hard enough to design proper Wi-Fi for these types of areas. Not impossible, but hard. So here comes the monkey wrenches: 1. All their RF Scanner are 2.4GHz only. 2: The four levels are shared with a different tenant. Levels 1 & 2 are theirs, but 3 & 4 are their tenants. 3. Tenant's services (SSID, MXs, etc.) will be different and thus different APs - thankfully of my design and choosing.

With only 3 Channels, how am I supposed to design a four level structure in 3 dimensions that is essential a giant 100'x200' cage full of metal - without causing myself so much self-inflicted interference between them and the Tenant  that the whole doesn't slows to crawl, or worse! 

I don't think it is possible. Channel Overlap is already going to be a huge concern, without the issue of a second WLAN sitting over their heads. Ugh.

[PhilipDAth]

Consider the cost of upgrading the RF scanners as part of the WiFi upgrade, and not something that is seperate.

[JimL]

Oh I agree completely with that, but since they are a customer I am not sure how that will look in my report! Ha-ha.

[Asavoy]

Have you looked into the Meraki Narrow Patch Antennas?  That may be a solution, albeit and expensive one.

[JimL]

The F-Series are nice to some degree and I do like them. The issue is any AP I place on level 4 facing down, will penetrate to the bottom. If I place it on the wall, it will still hit level 2, even the Narrow Patch Antenna. Worse is the each level is only 9 feet. If I place it vertically on the wall, the pickers themselves become RF obstacles. To make matters worse, if I lower the TxPower to contain as much as I can, it won't cover enough rack space. If it was one WLAN for the area, I would just throw in some 42/53 internals in a staggered pattern going up and down. 

I think my solution is design to 5GHz, so they see what it SHOULD look like and then one for 2.4GHz that shows them my "best effort". They can either upgrade their RF Scanners to 5GHz, segregate their Tenant via SSID/VLANs and such, or accept 2.4GHz will be sub-standard in that area.

My head hurts. 🙂

[NolanHerring]

Is it just scanners being used?

Telnet traffic is minimal, so as long as the noise floor isn't crazy, or channel utilization through the roof, it 'should' work in theory. Not sure how many clients or access points you'll be using though.

Work with the other party to ensure they don't have any 802.11b rates enabled still is one big improvement you can do.

Meraki won't let you 'choose' which data rates you want to use for management frames, so you have to use the slider, so set it to 12Mbps to cut off 802.11b rates, and probably not a good idea to go any higher. If the clients are 2.4GHz only, are they 802.11g only also or do they hopefully at least have 802.11n?

[NolanHerring]

Any chance you can show a photo or example of what this looks like? I can't seem to visualize it in my head lol

[JimL]

It looks something like this, except the stairs are inside. It might as well be four levels of chicken wire running every which way. Ha-ha.

[PhilipDAth]

If you really really have to use 2.4Ghz, this might be a good use case for RX-SOP.

https://documentation.meraki.com/MR/Radio_Settings/Receive_Start_of_Packet_(RX-SOP)

https://documentation.meraki.com/MR/Radio_Settings/RF_Profiles#RX-SOP

[JimL]

Just wanted to update this for those who responded and were interested. Despite the complexity I ended doing three surveys and gave them three options:

The first focused solely on supporting their legacy 2.4GHz scanners and containing the RF in pick modules via severely reduced TxPower in the pick modules. I have MR53Es with the A-series dipoles salt and peppered overhead on each level. Even at 1 mW there will be areas of Channel Overlap. It simply cannot be avoided.

The second option was similar to the first, but was also designed to provide near VoIP grade 5GHz throughout, including the pick modules. For the pick modules I am used Meraki's F-Series Narrow-Beam Patch Antennas at the ends of the rows at the top (9') with a ~5 degree down-tilt. I was able to stagger them zigzag style on each level. It is about 1 every other row. Surprisingly the model shows them providing great coverage with very little bleed between levels, even for 2.4GHz - so long as I keep 2.4GHz to around 4mW. The rub is these antennas MSRP at $1,400 and they will need about 70 to cover all four levels. I am not holding the purse, but I had sticker shock!

The third focused only on 5GHz, which meant I had plenty of non-overlapping channels for the the pick-module and could use the E-Series Wide Patches to cover the pick modules. They still needed a fair amount, about 60 for the area, but at almost 1/4 the cost, I wanted to show them the savings of upgrading or replacing their legacy scanners.

In the end, they didn't even hesitate to jump for Option 2. I guess I should be happy with it, but who really knows if this will shake out as expected once the warehouse is built and these things are deployed. Something tells me I will not only have to make more post install tweaks and optimizations than normal, I am going to have to be present to assist the cable vendor figure out how they are getting the almost 2'x2' F-Series antennas where they are needed.

Anyways, thank everyone for chiming in on this, I used everyone's advice for this project!

[NolanHerring]

Glad to hear you had several options. Feel free to update again with some photos of the final product as I'm sure others (including myself) are still interested 😃

[JimL]

Sure thing. I will either update this post or update my resume following this project. 🙂

I have done a lot of warehouse work, including pick modules, but almost always with either Cisco and/or third-party antennas. This is my first 100% Meraki warehouse/pick-module and their antenna selection is somewhat lacking for this environment. For example, their downtilt omnis and patches only work on indoor rated APs. The only Meraki four port antenna for their Industrial rated APs is the Cisco Stadium antenna, which is only for the MR84. This is fine for the N.E. and air conditioned warehouses, but I would seriously hesitate to use MR53s at 30' in any steel building in Arizona or NM. I was on a call with Meraki and Cisco pretty much begging them to certify or copy the Cisco 2566p4w antenna and add N-type connectors to it. That was would be a big win for Meraki and the Warehouse market. Right now the only true option for the MR74/84 is a third-party one, which is out of bounds for Meraki Support.

Anyways, I am kind of holding my breath to see how those massive F-Series actually perform in the pick modules.

[NolanHerring]

I'm using MR74 with Acceltex antennas. Works great.

[JimL]

+1 for Acceltex. They have some real nice solutions, including their AP skins. Maybe one day Meraki Support won't balk at third-party antennas.