For many years, warehouses utilized “un-planned” WiFi connectivity, meaning they installed access points in areas where people needed wireless network coverage and hoped for the best. As wireless technology cemented into the network architecture, some businesses saw the need for reliable coverage. Due to the lack of qualified WiFi experts, they extended the coverage by adding more access points to fill in the coverage hole. This approach continued until they had an over-saturated WiFi environment with a strong signal to send a rocket to the moon. At the same time, they provided poor service to the wireless clients due to high levels of interference and noise. In the spectrum.
Warehouses and Distributions Centers have unique characteristics that make the WiFi network deployment challenging. Proper planning and design require considering the many variables that can affect the wireless network performance. Some of those variables are RF-related; others are network configuration settings, physical environment, and even business policies. Implementing reliable WiFi designs for this environment goes beyond the broadcast of radio signals.
An experienced WiFi design company also looks into all possible factors that can affect the performance, including:
- What type of devices of are\will be used.
- How high will APs be mounted?
- Walls and ceiling materials.
- How often – if at all does the rack layout change.
- Are the shelf at capacity, or do they change during the year?
- Is WiFi signal coverage expected at the floor level or different shelf heights?
- IDFs location.
- Are devices be mounted on carts, or will they be mostly stationary?
- Besides looking at the physical planning aspect, you also need to look at the network administration side.
- Do you need on-premise on cloud administration?
- Do the edge and core switches support the traffic.
- What kind of monitoring and reporting is expected.
- Are you integrating the WiFi architecture with the same network vendor, or will you use a different one?
Those are some of the common that need to be answered for most Warehouses WiFi deployments, each company is unique, and you need to tailor the configuration accordingly. With the answers to those questions in mind, the wireless engineer starts planning the design for the warehouse.
Another interesting point, and it’s something that’s not unique to this type of environment, is the need to understand the difference between planning for coverage and capacity. We wrote an article about it, but just as a reminder, planning for coverage ensures that there’s a proper WiFi signal in the desired areas, and planning for capacity ensures that WiFi architecture can support a large number of concurrent connections and heavy traffic volume. Most warehouses don’t need capacity deployments because the devices used for connectivity don’t carry large amounts of data.
With that being said, let’s go over a couple of points required for proper WiFi planning.
Access points installation height is an essential aspect of WiFi planning that’s usually overlooked. Most WiFi deployments for warehouses install APs on the metal beams under the ceiling to provide general coverage. Sometimes APs with special antennas are mounted on walls for coverage in specific areas. Still, a combination of ceiling and wall mount is usually necessary for proper signal coverage. It is essential to point out that ceiling heights over 25 feet may require special considerations for the installation. However, there are no written rules about it. An installation of 20-25 feet is considered best practice for proper signal propagation. You also need to consider the logistics to ensure the APs are installed above anything that can hit them and damage them as forklifts and any other type of vehicle.
Building materials are another essential factor for WiFi planning as the RF signal will be affected as it encounters different types of objects as it propagates. Radio signal behaviors such as reflection, refraction, diffraction, gain, loss, absorption, attenuation, etc. are directly affected by building materials. Each type of material will affect the signal as it travels through it. A significant challenge to consider, and something unavoidable in warehouses, is that cardboard has a high level of RF signal absorption; for that matter, the wireless engineer needs to plan for proper signal propagation between aisles at the ground level.
Material Absorption rates:
Material Absorption Rate
- Plaster\Drywall 3-5 dB
- Glass wall and Metal Frame 6 dB
- Metal Door 6-10 dB
- Window 3 dB
- Concrete wall 6-15 dB
- Block wall 4-6 dB
RF Signal Strength.
Radio signal strength is one of the essential aspects of WiFi deployments, but it’s not the only one. You can have a strong WiFi signal and still have significant connection issues. A signal level of -65 to -70 dBm is considered reliable for most applications. Anything above -70 dBm may cause low bandwidth and connection issues. Also, maxing out the AP powers to broadcast stronger signals will create a myriad of wireless connection issues because of the high noise level and interference created by the APs, thus making the network less reliable. Don’t look at the WiFi signal strength as a sign of proper implementation, but rather as one of the many elements that need to consider for a successful Wireless network implementation. – New Jersey Warehouses WiFi Deployment -.
The chart below demonstrates best practice signal strength values.
- -67 dBm — Minimum signal strength for applications that require timely delivery of data packets.
- -70 dBm — Minimum signal strength for general applications such as web browsing.
- -80 dBm — Unreliable network connectivity.
- -90 dBm — Useless connection.
Do you need on-premise on cloud administration?
Infrastructure grade WiFi deployments require advanced centralized configuration and administration. Wireless Controllers provide the platform for Wireless administrators to manage the WLAN environment seamlessly and efficiently. In the early WiFi days, WLAN controllers were only available as an on-premise device solution integrated as part of the network architecture. Still, the wide acceptance of cloud computing over the past years gave way to Cloud-based WLAN controllers.
The features and functionality of cloud and on-prem WLAN controllers are the same; what may dictate which option you use may be internal policies related to data privacy. It is also important to clarify that cloud-based WLAN solutions do not send user data to the cloud; it only transmits the device configuration to the cloud hosting services. Although on-prem WLAN controllers are an option, most companies opt for a cloud-based approach as it offers more flexibility and redundancy than hosting a physical device in the company. That’s not to say that on-premise solutions are a thing of the past, especially in a large enterprise environment.
Benefits of Cloud-based administration.
- Unlimited throughput, no bottlenecks.
- Add devices or sites in minutes.
- Highly available cloud multiple datacenters.
- Network functions even if the connection to the cloud is interrupted.
- 99.99% uptimes SLA.
- No user traffic passes through the cloud.
- HIPAA/PCI compliance.
- Automatic firmware and Security updates.
Co-channel interference (CCI) occurs when two WiFi coverage cells next to each other operate on the channel.
Adjacent channel interference (ACI) occurs when adjacent channels overlap with each other. Both types of interference negatively affect WiFi performance, although ACI has a more negative impact than CCI.
You can avoid CCI by proper network planning, including AP placement, SSID planning, channel allocation, and adjusting power settings (if necessary). ACI may be harder to prevent because RF signals outside your control may cause it. What you can do as a wireless administrator in that situation is to find non-overlapping channels not affected by ACI; that’s much easier when you’re working on the 5 GHz band compared to the 2.4 GHz band. Let me reiterate that point, one of the most effective ways to avoid CCI and ACI is by implementing the 5 GHz band as it provides more non-overlapping channels to work with and allocate to the different networks.
As you can see, planning a reliable WiFi network for a warehouse or distribution center takes planning, we touched on a few points of WiFi planning, but the list goes beyond the five points explained here. As wireless communication keeps expanding in the IT infrastructure and becoming a core component of network connectivity, companies need highly skilled WiFi experts to help them design, implement, and manage the wireless network.
We are a leader in the wireless world, planning and implementing solutions from the leaders in the field. With a technical team of network, wireless, and security engineers, we help you deploy resilient WiFi network solutions for your environment. Contact us at 888-580-4450 | www.jdtechsolutions.net | [email protected] to learn more about our services and solutions.