Why Warehouse WiFi Is Different From Office WiFi
At first glance, WiFi is WiFi.
Install enough access points, provide sufficient Internet bandwidth and users should have a reliable connection.
Unfortunately, that approach can fail badly inside a warehouse.
A warehouse is one of the most challenging environments in which to design a wireless network. High ceilings, metal racking, changing inventory, long aisles, forklifts, barcode scanners and automated equipment all influence how the network performs.
A wireless design that works perfectly in an office may perform poorly when applied to a warehouse.
Understanding these differences is the first step toward building a reliable warehouse WiFi network.
1. The RF Environment Is Completely Different
A typical office contains drywall partitions, desks, furniture, glass and relatively predictable room layouts.
Warehouses are different.
They commonly contain:
Tall metal pallet racking
Large quantities of inventory
Steel structures
Machinery
Concrete walls and floors
Refrigerated areas
Loading docks
Large open spaces
Long, narrow aisles
Radio frequency signals interact with all of these materials.
Metal structures can reflect wireless signals, while dense products stored on racks can absorb or attenuate them. The result can be an RF environment containing reflections, shadowing, interference and significant variations in signal levels.
This means warehouse WiFi cannot be designed effectively by simply looking at the building dimensions.
The contents of the building matter too.
2. Warehouse Inventory Changes the Wireless Environment
One unusual characteristic of warehouse WiFi is that the RF environment can change from day to day.
Consider an aisle containing pallet racks.
When the racks are relatively empty, wireless signals may travel considerable distances through the warehouse.
Fill those same racks with pallets of liquids, food products, machinery or other dense materials and RF propagation can change significantly.
A wireless network therefore needs to be designed for the real operational environment, not simply an empty building.
This is one reason WiFiMax USA places significant importance on professional site surveys and real-world RF measurements when designing industrial wireless networks.
3. High Ceilings Create Unique Problems
Warehouse ceilings can be 30, 40 or even 50 feet high.
Installing access points at the highest available point may be convenient for the installer, but it isn't necessarily good RF design.
The devices using the network are normally much closer to the floor.
Barcode scanners may be held approximately five feet above floor level. Forklift terminals may operate slightly higher. Autonomous robots may have antennas positioned only a few feet above the floor.
The wireless network needs to provide reliable connectivity where the devices operate, not where the access points are installed.
Access point mounting height, antenna pattern and transmit power therefore become critical design considerations.
4. Metal Racking Creates RF Corridors
Long rows of metal shelving can behave almost like RF corridors.
A signal may travel very effectively along an aisle while being significantly attenuated when trying to cross several rows of loaded pallet racking.
This can make conventional office-style access point placement unsuitable.
In some warehouses, strategically positioned directional antennas can be used to direct RF energy along specific aisles.
The objective is not simply to generate the strongest possible signal.
It is to put the right amount of RF energy in the right place.
5. Warehouse Devices Are Different
Office WiFi primarily supports devices such as:
Laptops
Smartphones
Tablets
Printers
Video conferencing systems
Warehouse networks may support an entirely different device ecosystem:
Barcode scanners
Handheld mobile computers
Forklift terminals
Voice picking systems
Industrial tablets
Label printers
IoT equipment
Automated Guided Vehicles (AGVs)
Autonomous Mobile Robots (AMRs)
Some industrial devices have very different wireless capabilities from modern smartphones and laptops.
A warehouse WiFi design therefore needs to consider the actual client devices that will use the network.
Designing only around the capabilities of the access points can lead to poor results.
6. Roaming Is Much More Important
An office worker may sit at the same desk for several hours.
A warehouse worker may travel across the entire facility repeatedly during a single shift.
A barcode scanner can move from one wireless coverage cell to another dozens or hundreds of times per day.
Forklifts, AGVs and AMRs may also be continuously moving.
This makes roaming extremely important.
As a device moves through the warehouse, it must transition between access points while maintaining its network session.
Poor RF cell design can result in:
Sticky clients
Delayed roaming
Dropped connections
Application interruptions
Scanner delays
Lost productivity
Good warehouse WiFi therefore requires carefully designed cell boundaries, appropriate signal overlap, sensible transmit power and proper channel planning.
And importantly, the client device ultimately makes the roaming decision. The wireless network can assist and optimize the environment, but it cannot simply force every client to roam perfectly.
7. More Access Points Doesn't Necessarily Mean Better WiFi
When warehouse WiFi performs poorly, one common reaction is:
“Let's install more access points.”
Sometimes additional APs are required.
But sometimes adding more access points makes the problem worse.
Too many APs operating at excessive transmit power can create:
Excessive cell overlap
Co-channel interference
Poor roaming behavior
Higher channel utilization
Unnecessary RF noise
The objective should not be to install the largest possible number of access points.
The objective should be to install the correct number of APs, in the correct locations, using the correct antennas and RF configuration.
8. Coverage Is Only Part of the Design
Seeing a strong WiFi signal icon does not necessarily mean the network is performing well.
Professional warehouse WiFi design considers multiple RF and network characteristics, including:
Signal Strength (RSSI)
Is sufficient signal available at the client device?
Signal-to-Noise Ratio (SNR)
Can the device clearly distinguish the desired wireless signal from background noise?
Interference
Are other networks or RF sources affecting performance?
Channel Utilization
How busy is the wireless channel?
Cell Overlap
Is there sufficient coverage between neighboring access points to support mobility without creating excessive interference?
Capacity
Can the network support the required number of devices and applications?
Roaming
Can mobile devices transition effectively between coverage cells?
A professional warehouse wireless design considers all of these factors together.
9. Predictive Design Alone May Not Be Enough
Predictive RF modeling is extremely useful.
Warehouse floor plans can be imported into professional wireless design software, building materials can be modeled and proposed access points can be positioned before installation begins.
But software models are still models.
A warehouse containing thousands of pallets, metal racks, machinery and unusual construction materials can behave differently from the predictive model.
For critical warehouse environments, real-world validation can therefore be extremely valuable.
One method is an AP-on-a-Stick survey.
A temporary access point using the proposed antenna can be positioned at the intended installation location and height.
Wireless measurements are then collected throughout the surrounding aisles.
This allows engineers to validate assumptions about:
AP placement
Mounting height
Antenna selection
Coverage
Cell overlap
Signal propagation
Changes can then be made before permanent cabling and installation.
10. Warehouse WiFi Should Be Validated After Installation
A wireless project should not necessarily finish when the final access point is mounted.
After deployment, a post-installation validation survey can measure how the completed network actually performs.
Engineers can verify:
Coverage
Signal strength
SNR
Interference
Channel utilization
Cell overlap
Roaming
Throughput
Critical operational areas
The results can then be compared with the original design objectives.
Where required, access point transmit power, channels, antenna orientation or other RF parameters can be adjusted.
This creates an important engineering cycle:
Survey → Design → Validate → Install → Test → Optimize
Office WiFi vs Warehouse WiFi
The fundamental wireless technology may be the same, but the engineering requirements can be very different.
Office WiFiWarehouse WiFiRelatively predictable environmentComplex and changing RF environmentLower ceilingsHigh ceilingsDrywall and office furnitureMetal racks and dense inventoryMostly stationary usersHighly mobile users and equipmentLaptops and smartphonesScanners, forklifts, AGVs and AMRsMostly omnidirectional coverageDirectional coverage may be requiredModerate roaming requirementsRoaming can be operationally criticalRelatively stable layoutInventory and layouts may changeCoverage and capacity focusedCoverage, mobility and reliability focused
Neither environment is necessarily simple.
But warehouses introduce a combination of RF, mobility and operational challenges that require a different design methodology.
Warehouse WiFi Is an Engineering Project
Reliable warehouse WiFi doesn't come from simply installing access points throughout the building.
It comes from understanding:
The building
The racking
The inventory
The client devices
The applications
The operational workflow
The RF environment
Only then can access point locations, antennas, channels, transmit power and network architecture be designed appropriately.
Don't guess where access points should go. Engineer the wireless environment.
Need Help With Your Warehouse WiFi?
WiFiMax USA provides professional Warehouse WiFi site surveys, RF design, installation, upgrades and post-deployment validation for warehouses, distribution centers and industrial facilities.
Whether you're planning a new deployment or trying to solve an existing wireless problem, our engineers can assess the environment and develop a solution based on real operational requirements.