Wireless in the Warehouse

Editor’s Note: Occasionally, Enterprise Networking Planet is proud to run guest posts from authors in the field. Today, Jay Botelho of WildPackets discusses the benefits and challenges of Wi-Fi in warehouse environments.

The warehouse often forms the heart of an organization’s operations. It’s the place through which all materials, products and merchandise flow en route to their final destinations. And among the many industries that rely on warehousing, retailers are leading the growing trend to embrace wireless technologies to transform their warehouse operations and gain ground on the competition.

Many retailers, including giants such as Amazon, Home Depot, and Wal-Mart, stock inventory and process orders from large warehouses, some occupying more than one million square feet. From receiving to inventory to outbound distribution, these warehouses increasingly rely on wireless technologies to streamline the logistics of their operations and enhance overall productivity by fulfilling orders more accurately and quickly than before.

Reliance on Wi-Fi for these critical warehouse functions makes seamless, uninterrupted connectivity vital. While there are many challenges to providing a high-performing wireless infrastructure, tools exist to help ensure networks are capable of managing these demands and responding with quick troubleshooting when problems arise.

Benefits of Wi-Fi in the warehouse

Wireless and mobile technologies have revolutionized the efficiency and productivity of warehouse operations. Wireless network connections give retailers a clear, real-time view of all activities happening in the warehouse and enable them to efficiently count and track inventory, improve order fulfillment accuracy, and provide workers with real-time communication. Here are some reasons why.

• Asset tracking: Through wireless network connectivity, organizations can automatically track all warehouse assets in real time, enhancing both worker and machine productivity. By outfitting each item with RFID tags in constant communication with a system’s network, organizations have a way to track the whereabouts of each item at all times. This aids not only in loss prevention, but in the rapid fulfillment of orders.
• Inventory counts: No retailer wants to be without the most popular products, but neither do they want to overstock. Excess inventory creates unwanted expenses. Accurate inventory counts provide retailers the data they need to precisely predict product demands and stock inventory accordingly. Accurate inventory counts also allow retailers to provide up-to-the-minute information to customers, particularly important when a specific product is no longer available or is in short supply.
• Voice and data communications: Real-time voice and data communications enhance workers’ task and project management. Mobile communication devices give supervisors a way to see what is happening on the warehouse floor while receiving real-time project updates from the network. Wireless voice communications have proven particularly useful to big-box, warehouse-style stores like Costco and Home Depot. Meanwhile, Wi-Fi-based VoIP systems, as opposed to cellular-based systems, provide sales associates in warehouse stores with strong, clear signals for incoming calls, allowing associates to answer telephone queries from anywhere in the store, even deep within the racks, closing more sales and maintaining a high level of customer satisfaction.

Challenges of Wi-Fi in the warehouse

While the benefits of wireless are many, large-scale deployments, like those required in a retail warehouse environment, can prove difficult to carry out successfully. Warehouses include everything from metal racks stacked high with pallets, to handheld Wi-Fi devices and portable radios, to moving Wi-Fi-equipped vehicles, creating a constantly changing environment that can make connectivity a challenge. Although every large-scale Wi-Fi deployment has its challenges, those in warehouse environments are truly unique. Let’s examine a few.

• Wide-open spaces: At first glance, the wide-open spaces of a warehouse may seem like the perfect environment for a wireless network. Long aisles and high ceilings allow Wi-Fi signals to propagate farther with less attenuation. But the latest Wi-Fi technologies, 802.11n and 802.11ac, actually rely on signals being bounced around for the multiple-input, multiple-output (MIMO) technology to be effective. With no interior walls and APs mounted high up on ceilings, there is less “multi-path,” or signals bouncing around, making MIMO technologies a bit less effective. Additionally, the high-mounted APs require increased transmit power, but a fine line divides too much from too little power. Too little can cause dead spots. Too much can generate interference between APs on the same channel. As with any major Wi-Fi deployment, initial designs must be verified and tweaked in the real environment.
• Dynamic physical environment: A typical enterprise Wi-Fi environment is quite static. The walls, though sources of attenuation, don’t move; the furniture is rarely rearranged; and the most dynamic part is people moving around, which doesn’t happen all that often in a typical office. In contrast, the typical warehouse is a very dynamic environment. Goods with all different types of radio frequency attenuation properties are continually moved around and stacked to various heights, constantly changing the environment for Wi-Fi signal propagation. Now add in forklifts with on-board Wi-Fi for location tracking and a device for navigation and inventory location, and move that device around at 10 to 20 mph, and things start getting really interesting. Not only are the forklifts and all Wi-Fi devices on them constantly changing the environment, but they are also roaming from one AP to another very quickly. Roaming remains one of the primary issues with Wi-Fi connectivity. The warehouse environment pushes this to its limits.
• Harsh physical environment: Warehouses are dirty and dusty. Everyone and everything moves as fast as possible. The mobile devices used in these environments must be designed to stand up to these harsh physical conditions while still meeting industry Wi-Fi standards to ensure interoperability. In many cases, problems that arise stem from device and driver issues rather than the wireless infrastructure.
• Device proliferation : Devices specifically designed for warehousing are not the only concern. BYOD is everywhere, including the warehouse. Unless companies enforce a strict “no personal devices in the warehouse” policy, consumer-grade personal devices, like mobile phones and tablets, will compete for bandwidth on the Wi-Fi network, and may introduce additional and unforeseen problems. Consumer-grade devices may not adapt well to constant movement within the warehouse, for example. Personal devices either need to be factored into the initial design or completely banned from the warehouse.

Real-life example

Many modern warehouses now employ state-of-the-art robots for various functions. These robots communicate over the Wi-Fi network to a central server that controls all operations in the warehouse. A major online retailer was having serious troubles keeping its Wi-Fi network operational. APs were randomly resetting themselves, causing major disruptions to the overall network. The company repeatedly attempted to troubleshoot the problem, but the number of factors involved made the issue quite complex. To remedy the issue, they introduced packet-based Wi-Fi analysis.

Using the appropriate tool, the company quickly determined that the robots were creating a multicast storm, or repeatedly making global network requests to all network participants, each time they roamed. This condition exceeded the processing capabilities of the APs, causing them to reset. Once an AP started to reset, all the robots on that AP had to find a new AP, or roam, and started multicasting, causing all the other surrounding APs to crash. This created a perfect storm that didn’t calm until all the APs had rebooted. Once the cause was determined, the retailer was able to work with the AP vendor to address the root cause of the problem.

Supporting Wi-Fi in the warehouse

While Wi-Fi has enabled organizations to significantly increase warehouse efficiencies, it has also made them critically reliant on a technology that can sometimes be complex to troubleshoot. Any interruption in the network that leads to downtime can completely halt operations at the expense of the organization.

The good news is that there are solutions available to ensure efficient operation of Wi-Fi in the warehouse, regardless of the demands placed on it by this unique and challenging environment. Packet-based network monitoring solutions give network engineers real-time visibility and analytical capability for the complete network, providing a way to quickly identify, analyze, and fix performance bottlenecks anywhere in the Wi-Fi infrastructure.

As automation continues to play a larger role in warehouse operations, the reliance and importance of Wi-Fi will certainly continue to grow. Applying these solutions will allow organizations to deliver the high levels of bandwidth needed to overcome congestion and deliver seamless connectivity in their warehouses.

Header photo courtesy of Shutterstock.

Jay Botelho is director of product management at WildPackets, Inc., which provides network analysis solutions for networks of all sizes and topologies. A networking industry veteran, Jay holds an MSEE and over 25 years of experience in product management, product marketing, and complex analysis. Today, Jay leads the wireless strategy at WildPackets, working with Fortune 1000 customers, network equipment providers and wireless LAN consulting professionals and partners.