How to plan a wireless network in a warehouse? 

When the operator provides us with the Internet, we get a product that we have to take care of allocating within the company. The server becomes our storage center, wireless network access points are local distribution points, and at the end there is the client – the user. Many factors contribute to success in both logistics and IT. The key to success is also similar – planning, optimization and full control. The situation is no different when we have to plan a network in a warehouse (whether high-bay or autonomous).

Start with a firm plan 

Designing and implementing a wireless network in an environment such as warehouses or maneuvering yards is a much more demanding challenge than in an office space. High shelves full of goods, narrow aisles and obstacles blocking the signal, or on the contrary – huge spaces, often exposed to environmental factors or easily accessible to unauthorized persons. In addition, there are high requirements for devices, software and people in terms of signal coverage, connection speed and stability. 

We start by conducting a Site Survey, i.e. a site visit. We create a map of the space we need to design and identify potential obstacles. 

Site Survey is not an activity whose effect will be lasting. Any change in the environment, different arrangement of goods or expansion of space or the number of end devices will affect the quality of the connection. By repeating the process regularly, we will keep the network in optimal condition at all times. 

It is worth understanding that repeating tests does not necessarily mean modernizing the entire system or purchasing additional devices. From the very beginning, we take into account the client’s strategic plans and select equipment for future needs to limit the need for further investments. Sometimes it is enough to change the location of the access point or configure it differently. 

Problems in an autonomous warehouse  

If any of these elements do not work well enough, downtime may occur, which will sooner or later lead to costly problems for the company. 

• IT systems – double stock levels, duplicate names, missing receipts and issues in documents are just some of the problems that occur with a slow or unstable Internet connection. 
• Robotization and automation – modern devices, although they can work wonders, can be very sensitive to even a few milliseconds of signal loss, e.g. when switching between access points. 
• Employees – it’s not the year 2000 anymore when we could make coffee while the interface was loading. In the dynamic environment of logistics facilities, everyone is expected to operate like a well-oiled machine. However, long loading times for SAP, ERP or AST applications and websites may result in downtime, which will cause frustration and real problems in the functioning of teams. 

We can recognize poor coverage tangibly on the device we use to move around the warehouse. What could be the cause? 

• Too many available SSIDs to which we can connect, which may mean that we do not control wireless networks broadcast by other systems or production devices, for example robots in autonomous warehouses 
• Incorrect selection of antennas, which means that the signal does not cover the warehouse evenly and white spots occur 
• Too few or too many access points causing problems with switching devices and ultimately drops of the connection  

Although poor internet or signal coverage sounds trivial, these are the challenges our clients most often face in their warehouses. In addition, they report slow loading of business application interfaces, slow loading of images or switching pages in the application or browser. Large financial outlays and the resulting top-class equipment are not always the solution. Staying one step ahead of the competition and preventing network problems in your warehouse is all about proper planning, not the most expensive equipment. 

How to plan a network in a warehouse? 

A multi-faceted approach to design will help us avoid not only possible problems related to signal coverage in warehouses, but also many unnecessary costs in the future, such as the purchase of more expensive infrastructure or the need for constant modernization. 

Every plan should start with checking the actual situation, the availability of resources and defining or including a strategic goal that will allow us to look into the future. 

The materials from which the building is made and those stored in warehouses are of great importance for the wave propagation. Are we dealing with high storage and shelves, or rather with an open storage area? Are there metal mezzanines in the warehouse? Do we store large metal parts or small and loose materials? All the above-mentioned factors are important for the correct design of a wireless network in a warehouse. 

Another issue is the devices used, their number and nature. Apart from stationary and mobile devices, cameras, sensors and IoT devices are increasingly used in warehouses. For autonomous warehouses, redundancy, smooth switching between subsequent access points and perfect signal coverage are of great importance. Every square centimeter is important. We must ensure smooth roaming, i.e. ensure that breaks for robots moving around the hall are as short as possible, and protect ourselves in the event of a robot failure. So that everything is available 24/7. 

Devices and people can move on the ground and at heights of up to 6 or 9 meters, so we also have to take the nature of the work into account. The applications and management systems used in the organization will also be important. 

A real-life example 

Let’s look at an example of an autonomous warehouse. We are dealing here with high storage, warehouse racks, and autonomous robots. All this means that there are relatively many endpoints in the warehouse, each of which must have a reliable connection to the network 24/7. Additionally, the warehouse was operated unmanned, so no human could move between the racks to, for example, react in the event of a failure or disconnection of a single device. The network had to be designed from the outset so that it would function flawlessly even in the event of a device loss. 

We used access point redundancy here and also ensured smooth roaming for moving endpoints. The key was also the use of enterprise-class solutions, i.e. professional switches, access points and controllers. In home or small business solutions, it is often not possible to use external antennas, which is the only effective solution for high-bay warehouses. 

How to choose WiFi antennas in a warehouse? 

Let’s look at two types of antennas: directional and omnidirectional. We see that in the case of a directional antenna, the signal propagates in a given direction, e.g. up-down, while an omnidirectional antenna propagates the signal in all directions around the access point, and specifically around the antenna itself built into the access point. Why is this distinction so important? 

Let’s imagine a high-bay warehouse, approximately 18 meters high, and access points mounted under the ceiling. We assume they are installed correctly. 

In the drawing on the left, these are access points with built-in omnidirectional antennas, very often the ones we have somewhere in our home or office. In the case of a warehouse, this signal will propagate around the antenna, i.e. mainly below and above the access point, up to 5-8 m down, and in the horizontal plane it will overlap, subject to interference. In such a case, there is no possibility of effective roaming or ensuring signal coverage or obtaining other parameters that are also important and which we will not focus on today. 

On the right we see an example of using the same access point, but with a directional antenna. We see that the signal is directed between the shelves. The coverage is correct, the employee with the data collector, printer or reader is within the signal range. At the same time, even if an access point is installed in each aisle, interference is avoided and the power of the radiated signal is regulated by the wireless network controller. 

Equipment operating in a given space should also be adapted to the conditions prevailing there. In the case of heavily dusty spaces, it should be dustproof. If installed outdoors, it is waterproof and insensitive to temperature changes. 

It’s not enough to install. Must be installed correctly 

A plan is one thing, correct implementation is another. You can have the best plan, but if we implement it incorrectly and execute the project poorly, the network may also not function properly. That is why post-implementation measurements are so important. Contrary to appearances, warehouses are living organisms. Things change often. 

Below is an example of the installation of access points in another high-bay warehouse. It’s an AP with directional antennas aimed at the aisles between the shelves. In the middle photo you can see that the access point is slightly tilted. This is correct assembly, based on calculations taking into account the length of the aisle. 

And now the assembly errors. We have installation behind sewage pipes, “upside down”, behind a grid, with incorrectly positioned antennas or contrary to the manufacturer’s recommendations. 

Plan and measure the network in your autonomous warehouse 

In such unusual projects as those for the logistics industry, there are no two identical environments, the same challenges and the same golden mean. However, there are common points, and the experience gained over the years helps to combine them into a coherent whole. 

For the correct operation and communication of devices in an autonomous warehouse, it is necessary to professionally design the wireless network, followed by implementation and post-implementation measurement of parameters. Measurements should be performed before production launch, after installation, and after any change in the environment. 

For this purpose, professional solutions should be used. We use the Ekahau device and software. This is a special device with nine antennas that analyzes the spectrum, i.e. interference with other networks, e.g. microwave, Bluetooth. 

Trouble with connectivity in your warehouse? Approach the problem professionally. Order Site Survey measurements and improve the performance of your wireless network. Contact our engineers.