Assessing the Wi-Fi Network of a Warehouse

In this article, we will talk about the important of assessing the Wi-Fi in a warehouse and talk about specificities brought by these type of environments.

The main challenge of a warehouse is the fact that the environment can be moving a lot. Here is a list of changes I have seen happening in warehouses:
Change is the type of goods stocked in the racks (one day it is cloth, the next day it’s car break pads)

• Change is the type of goods stocked in the racks (one day it is cloth, the next day it’s car break pads)
• Change in the rack layout (new racks might be introduced to store more goods)
• Dynamic creation of zone of attenuation (especially in the loading docks areas, piles of goods might be temporary stored somewhere before being moved
• Addition of a mezzanine or mezzanine levels

The building structure is also a challenge in itself. Warehouses typically have high ceilings. This means that a proper Wi-Fi design is required in order to make sure that the proper antennas are being used. Part of the building structure is metal. You will find a lot of metal in a warehouse. This metal will tend to reflect Wi-Fi signals. This is not necessary a bad thing but it can drastically change how the signal will propagate throughout the environment. So you cannot expect the signal propagation within an aisle to be the same as the signal propagation in an open space. To be sure, the signal needs to be measured in order to assess the real signal propagation.

All of these might impact the Wi-Fi service and negatively impact the user experience and productivity of the warehouse.

More recently, I have also seen a lot of device changes in warehouses. We start to see the introduction of IoT devices such as AGV (Automated Guided Vehicles), robots, asset tracking tags or machine monitoring tools that connect to the enterprise warehouse Wi-Fi network. Moreover, the more traditional devices might get replaced (RF barcode scanners, lift truck embedded computers…). All these changes might introduce new requirements and this might require to adjust the initial Wi-Fi design.

I recently worked for a customer that introduced VoIP Wi-Fi phones into their environment. Since the initial design wasn’t done to meet VoIP requirements, the user experience was poor. We had to assess the current Wi-Fi network and re-adjust it in order to make sure that VoIP would work over the Warehouse Wi-Fi.

When assessing the Wi-Fi network of a warehouse, perform the following:

1. Review the initial design requirements
2. Understand what has changed since the installation of the current Wi-Fi network
3. Study the most critical devices and understand how they operate within the warehouse
4. Perform a site survey in order to validate the RF environment
5. Perform additional spectrum analysis if need be
6. Review the APs (or controller) configurations
7. Work on a plan to improve the current situation
8. Produce a report detailing all the work performed and detailing the recommendations

he first step is to work with the customer to understand what was the Wi-Fi network designed for. What were the initial Wi-Fi requirements? The focus here should be placed on the critical devices used by the users. These critical devices usually drive the design requirements.

At the end of this process, the following questions should be answered:

• Which devices are critical for the business? Which applications do they use?
• Which frequency band(s) are they connecting on?
• Are these critical devices still operating properly over the current Wi-Fi?

Most of the time, customers are requesting an assessment because the Wi-Fi network is not meeting expectations and they are experiencing Wi-Fi issues.
So in order to understand why, we need to understand what has changed since the initial installation. Going back to the previous section. A lot can change in a warehouse environment and negatively impact the Wi-Fi service.
​Once you have understood what has changed, you can define, alongside your customer, a new set of Wi-Fi requirements. These new Wi-Fi requirements can take into account any changes made on the client devices and applications used in the warehouse.

Here are example of a couple of questions you could ask to understand what has changed:

• Are you experiencing Wi-Fi issues everywhere in the warehouse?
• Were new racks installed? Was a new mezzanine floor added?
• Were new devices introduced? (Very common)
• Are you experiencing Wi-Fi issues from specific devices?
• Were new application introduced?

This task is critical. Here we need to select which device (or devices) are critical for the business of our customer and used over the Wi-Fi. Then we will spend time analyzing how they operate.

The following need to be addressed:

• Study how the device “hear” the signal in different sections of the warehouse and on both frequency band (if supported). Compare how the device hears the signal to how well your Sidekick hears the signal. You will then be able to offset the difference in your site survey results and look at the coverage from the critical device standpoint.
• Understand the full Wi-Fi capabilities of the device. This will help you to adjust the requirements and the configurations.
• Understand how the device is configured. Some obvious mis-configurations can be caught there sometimes.
• Validate the drivers installed and the latest drivers available from the manufacturer. It is amazing how a simple Wi-Fi driver update can fix problems. Watch out for multiple versions of drivers being used by different devices.

This task is the most obvious one. You wan to perform a site survey in order to validate the RF environment. In a warehouse environment, you want to focus on making sure that the coverage is good and meeting the requirements.
Make sure that you apply the device offsets calculated previously (cf. section 3) to the results of the site survey in order to analyze the signal from the critical device standpoint.
The site survey will also help you to notice any big problems (maybe an access point is down!).

Based on your client device analysis and refinement of the Wi-Fi requirements, you can now analyze the controller configuration to see how it could be improved.

Here is a list of items to look at:

• Configuration of the SSID profiles (Frequency band, 802.11k/r, security, Qos…)
• Configuration of the Access Point radios (Tx Powers, Channels)
• Configurations of AP Groups and RF Profiles

With the results of the site survey, spectrum analysis and the analysis of the controller configurations, you should be able to work on a plan to improve the current Wi-Fi network.
Here we are talking about configuration changes you might be able to implement in order to improve the performance of the critical devices. More important changes might be recommended in the report if, for instance, access points need to be moved, removed or added.

Once this plan is implemented, it is a good idea to re-do a site survey in order to confirm that the changes improved the situation. I also like to perform application testing with my customer in order to evaluate the user experience and make sure that it has been improved and meeting the expectations.

This task is very important for us. It is also very important for your customer so they can have all the relevant information.

The report should include the following information:

• Results of the critical device analysis
• Results of the site survey (RF)
• Results of the spectrum analysis
• Results of the controller (or APs) configuration analysis
• List of changes made on the infrastructure
• Results of any application testing performed
• List of recommendations

It is also a good opportunity to transfer other documents to your customers. We like to provide the additional following documents, alongside the report:

• An spreadsheet detailing all configuration changes
• Device manufacturer documentations
• Videos of any spectrum activity of non-Wi-Fi interferences
• Pictures and videos of the device and application testing
• Ekahau site survey source files
• Pictures of each Access Points located in the warehouse

It is important to assess the Wi-Fi network when new devices or applications are introduced. This is especially true in a warehouse environment. Identify which devices are critical for your environment and make sure that the Wi-Fi is tailored to them. They should, then, operate properly.

Thank you for reading!