Overcoming Wi-Fi Challenges in Warehouses, Factories and other industrial settings: How to get the Reliable, Secure Coverage your Business needs

Inadequate Wi-Fi coverage can significantly affect business efficiency and productivity. Dead spots can hinder critical business operations, disrupting communication, inventory updates, and automated machinery operation. Frequent disconnects and session interruptions can delay tasks reliant on real-time data access, like order processing or manufacturing process monitoring, leading to operational cost increases, missed deadlines, and potential business losses. Hence, consistent and reliable Wi-Fi coverage is essential to maintain smooth business operations.

Recently we were asked to look at a warehouse with wi-fi reliability issues. There were close on 500 access points. We reckoned it could have been done with somewhere between 250 and 300 access points, and recommended turning some of them off, which sounds rather counter-intuitive. The client was sceptical, but it did dramatically improve things. To understand why more isn’t necessarily better, though, lets consider some of the challenges of providing reliable Wi-Fi coverage in a warehouse or factory setting:

The Challenges

Let's first discuss the most common problems that can arise when attempting to provide reliable Wi-Fi in industrial settings such as warehouses and factories.

Physical Obstacles

Warehouses and factories are typically large sheds clad in metal and filled with metal structures and/or heavy machinery. Examples would include racking and shelving systems and safety cages around moving equipment. These elements can create physical and/or electromagnetic barriers that obstruct Wi-Fi signals, resulting in dead zones where connectivity is weak or non-existent. Clients roaming into these dead zones may disconnect from the network.

Warehouse racking systems, in particular, present a challenge for Wi-Fi connectivity, because they typically consist of long, narrow aisles, creating a maze-like environment that can be difficult for Wi-Fi signals to navigate. Variable stocking densities can also pose a problem. When shelves are fully stocked, they can absorb Wi-Fi signals, reducing their strength and range. Conversely, when shelves are empty, too many access points may visible to the client device, which can cause a problem known as the "sticky client" issue. This occurs when a device, such as a smartphone or tablet, maintains a connection with an access point even when it has moved closer to another access point with a stronger signal. This can lead to poor network performance for that device, as it is connected to a distant access point with a weaker signal, rather than switching to the closer one with a stronger signal.

Moreover, the stock itself can absorb or reflect signals, depending on its nature. For example, items made of metal or filled with liquid can cause signal reflection or absorption, respectively.

In short, the Radio Frequency (RF) characteristics of the space are in constant flux, which makes it challenging to maintain consistent Wi-Fi coverage. Careful planning and strategic placement of access points is essential.

Often companies try to compensate for these factors by having more access points, but that can cause a problem because it can lead to signal interference. In the UK, there are 13 channels available for 2.4GHz Wi-Fi and 19 channels available for 5GHz Wi-Fi. Cells on the same channel should not overlap otherwise their signals can interfere with each other, causing connectivity issues and reduced network performance.

RF Interference

Wi-Fi signals can be disrupted by interference from electronic devices such as machinery or equipment that emits electromagnetic radiation. This interference can degrade the Wi-Fi signal quality, resulting in slower speeds and unreliable connections. Electric motors, such as the ones on roller-shutter doors, can - especially if they’re are old and/or poorly maintained - interfere with Wi-Fi signals due to the electromagnetic radiation they emit, which can disrupt the Wi-Fi's radio waves and lead to signal degradation or loss.

Signal-to-noise ratio (SNR) is used to quantify how much a signal has been corrupted by noise. It is the ratio of the power of a signal (meaningful information) to the power of background noise (unwanted signal). The higher the ratio, the less obtrusive the background noise is.

Spectrum analysers are an essential tool for mapping and understanding RF interference. They work by capturing and visually displaying the signal amplitude in the frequency domain, giving you a comprehensive view of all the RF activity in a given environment.

Spectrum analysers can identify and measure non-Wi-Fi interference from various sources such as machinery, electronic devices, or other wireless networks. They help to locate sources of RF interference that could be degrading the Wi-Fi network's performance, allowing you to identify problematic areas and make any necessary adjustments to the design.

Distance Limitations of Copper Data Cables

Standard copper Ethernet cables, which are needed to provide network connectivity to access points, have a maximum distance of around 100 metres. Beyond this length, signal degradation occurs, leading to reduced network performance or even complete loss of connectivity.

In the expansive environments of warehouses and factories, these distance limitations pose a challenge. To cover the entire facility with Wi-Fi access points, each access point needs a wired connection not exceeding 100 metres to a network switch. That, in turn, often requires several outlying wiring closets to house these network switches safety, and each wiring closet has to be linked back to some central communications room, usually by fibre-optic cable.

Running cables can be difficult due to obstacles like racking, machinery, etc., so it isn’t always possible to find a direct route. And in any case you would ideally utilise any existing tray-work where possible to save costs, which makes it even more likely that you will run up against the 100 metre limit.

In sum. there is usually some compromise involved between where you might ideally like to put the access points and where it is practical or cost-effective to put them, so the design often needs to go through several iterations to find the best solution.

Overcoming the Challenges

Despite the many challenges, there are strategies that can be employed to deliver reliable Wi-Fi connectivity in warehouses and factories.

Access Point Placement and Antenna Selection

Strategic placement of access points is one of the most effective ways to improve Wi-Fi coverage. By positioning these access points in areas where they can bypass physical barriers and high-interference zones, the quality of the Wi-Fi signal can be significantly enhanced.

Additionally, the use of directional antennas can enhance Wi-Fi connectivity in challenging environments like warehouses and factories. Unlike omnidirectional antennas that distribute the signal in all directions, directional antennas concentrate the signal in a specific direction. This results in a more robust signal strength and a longer range, aiding in overcoming physical barriers and extending the network's reach. Moreover, directional antennas can alleviate interference by directing the signal away from sources of electromagnetic radiation. However, careful planning is necessary when deploying directional antennas to ensure all necessary areas receive coverage.

The Role of a Wireless LAN Controller

A Wireless LAN Controller (WLC) - which can be a physical appliance or cloud-based system - plays a key role in managing wireless networks in challenging environments like warehouses and factories. The WLC is a central device that simplifies the deployment and management of wireless access points, helping improve the reliability, security, and efficiency of the Wi-Fi network.

The WLC manages the distribution of data traffic, optimises the network by dynamically adjusting RF parameters for best performance, and automatically tunes the system for environmental changes. In large-scale industrial settings where numerous access points are involved, the WLC can manage them as a single system, reducing complexity and administrative overhead.

Moreover, the WLC is crucial for network scalability. As businesses grow and their wireless network needs to expand, the WLC makes it easier to add and manage new access points. This feature is particularly useful in dynamic warehouse or factory environments where the network layout might need regular adjustments due to changes in the facility's physical layout or operational needs.

The WLC also enhances network security. It provides centralised control over the entire WLAN, allowing for consistent security policies, rapid detection, and mitigation of potential threats. In an industrial environment where numerous devices are connected to the network, this centralised security management is crucial.

In conclusion, a Wireless LAN Controller is an essential tool in the deployment and management of Wi-Fi in warehouses and factories. It offers centralised control, eases scalability, improves network efficiency, and enhances security, and for all those reasons we would not entertain using standalone access points in this type of environment.

Use of Industrial-Grade Equipment and Enclosures

Some warehouse and factory environments present extra challenges, for example they may be especially dusty, operate at extreme temperatures (e.g. freezers) or handle volatile (potentially explosive) materials. Here industrial-grade Wi-Fi hardware can be used. Using IP-rated equipment ensures that the Wi-Fi devices are shielded from the environmental hazards, significantly enhancing their durability and reliability.

When planning your Wi-Fi network it’s important to consider whether you need your Access Points (APs) to support industrial protocols. Many industrial devices, such as sensors, actuators, and PLCs, communicate using protocols that are different from the TCP/IP protocol commonly used in office environments. These might include protocols like Modbus, PROFIBUS, Ethernet/IP, and others. Access Points that support these industrial protocols can translate between the industrial protocol and the TCP/IP protocol, ensuring that data can be exchanged smoothly between the industrial devices and the rest of the network. But these access points are typically more expensive than standard access points, due to the expanded feature set.

Leveraging Wi-Fi 6

Wi-Fi 6, the latest Wi-Fi generation, is designed for high-density environments like warehouses and factories. It manages multiple connections better, thanks to Orthogonal Frequency Division Multiple Access (OFDMA), which allows one transmission to send data to many devices at once. This increases network efficiency and capacity. Wi-Fi 6 also offers faster speeds, about 30% more than its predecessor. While individual devices may not reach the maximum speed, the network's overall efficiency improvements should boost device performance. The new Wi-Fi 6 feature, Target Wake Time (TWT), helps devices manage their communication with the router, enhancing battery life. Wi-Fi 6 also improves network performance in congested areas by using BSS Coloring technology for better packet management. In summary, with its ability to handle multiple connections, faster speeds, and efficient packet management, Wi-Fi 6 is a good choice for high-density settings.

Retire Legacy 2.4Ghz Devices

Retiring legacy 2.4Ghz devices and migrating to 5Ghz frequencies is a strategic move to optimize your Wi-Fi network. The 2.4Ghz frequency band is crowded. It is used not only by Wi-Fi but also by many other devices such as microwaves and cordless phones, leading to a high possibility of interference, which can impact the performance of your Wi-Fi network.

The 5Ghz frequency band, on the other hand, is less congested and offers more channels. This means there are more lanes for data traffic, reducing the chances of data collision and improving the overall speed and efficiency of your Wi-Fi network.

If you have dual-radio access points, turning off the 2.4GHz frequencies allows both radios to operate in the 5GHz frequency band, effectively doubling the capacity of your network in that band. This could be particularly beneficial in high-density environments where there's a need to support a large number of connected devices simultaneously.

Wireless Survey & Planning Tools

Wireless survey tools are essential in helping to overcome the Wi-Fi challenges in warehouses and factories. These tools provide a comprehensive analysis of the wireless environment, including the detection of interference sources, signal strength mapping, and identification of optimal placement locations for access points and antennas.

Any competent wireless installer should have access to these tools, as it takes a lot of the guesswork out of designing a Wi-Fi solution.

By performing a site survey using these tools, we can gain a clear understanding of the wireless landscape in the facility. This helps with access point placement and antenna selection, ensuring the Wi-Fi network is optimized for the specific layout and requirements of the warehouse or factory.

These tools can also predict the performance of the Wi-Fi network before it's installed, allowing for adjustments to be made in the planning stage to avoid potential issues later. By using these tools in the planning and implementation stages of Wi-Fi deployment, businesses can dramatically improve their network's performance, reliability, and coverage.

One important feature of these tools is the ability to simulate and environment that has yet to be built. We often get asked to design a Wi-Fi solution before the racking systems, conveyors, and robotics/automation technology has been installed.

Conclusion

Achieving reliable, secure Wi-Fi coverage in challenging environments such as warehouses and factories is no small feat. It requires careful consideration of the physical environment, strategic placement of access points, the use of directional antennas, the implementation of a Wireless LAN Controller to manage the access points, and possibly industrial-grade equipment.

Despite the complexities, with the right knowledge and strategic approach, these challenges can be overcome. Remember, a reliable Wi-Fi network can significantly enhance operational efficiency and productivity, making all the effort worthwhile.

Choosing a partner with experience and the necessary survey and planning tools is crucial as they will have a better understanding of the many factors that can impact Wi-Fi performance in these settings.

Next Steps

Over the years, we have amassed extensive experience in dealing with the unique Wi-Fi challenges in warehouses and factories. Our understanding of the myriad of factors that can impact Wi-Fi performance in these environments, combined with our proven strategies for optimizing Wi-Fi deployment, make us the ideal partner for your next warehouse or factory Wi-Fi project.

Don't let Wi-Fi challenges slow down your operations. Reach out to your team for more information on how we can help you improve the efficiency, reliability, and coverage of your Wi-Fi network.