Warehouses have very special requirements when it comes to providing Wi-Fi coverage, for a whole host of reasons.
They are a challenging environment in RF terms - there's often high ceilings, lots and lots of metal racking, RF attenuation is constantly changing (shelves filling and emptying, forklifts moving loads around and so on) and small devices which need good coverage.
The devices themselves are varied, but are used to provide high efficiency for staff in their work. From devices which provide an audio stream to detail what should be collected from the shelves to the workhorse barcode scanner, there's an array of devices in use. Some use 2.4GHz, some use 5GHz and some may have small antennas or old chipsets. Devices are often used in real time in the warehouse environment, with staff receiving details of the items to pick over the Wi-Fi network and using scanners to record as the items are selected.
Warehouse Wi-Fi: Lessons Learnt
It's an environment that’s difficult to get right. So, there’s a number of best practices and lessons learnt to take into account:
- Firstly, figure out the weakest transmitting device – that’s the benchmark and none of your APs should be running at a power higher than that
- A mix of directional and omni-directional APs are needed – one size does not fit all in a warehouse and its needs a mix of directional antennas to reach down aisles and omni’s for open areas
- A predictive survey is a must of course – if you don’t design it properly, it's not going to work
- The AP height is important – it’s a compromise between providing a wider arc of coverage the higher you deploy the AP and reducing the received power
- The antenna types are important – while some APs will be the internal antenna type, for some spots, external antennas will be required – size, gain, height and angle are all important
Warehouse Wi-Fi: Guidelines
The access point type, placement, angle, power and channel are all critical. Illustrated on the left is an option for mounting an AP and using a downtilt to cover an area.
With many APs in a changing environment, it makes most sense to use the built in tuning features of the WLAN network - RRM and DCA. The trick is to ensure that both settings are properly configured, based on the device types in use (i.e. don't use channels your clients can't use and set the max transmit power to match your weakest client).
Final word should go to surveys. As with every WLAN install, a predictive, site survey and post-install survey are critical elements. You have to design, measure, adjust and improve the design. Its an iterative process, but one that can be used to achieve reliable Wi-Fi in a difficult environment.
Of course, following the guidelines doesn't mean it will all work without a hitch. Devices with old chipsets are in use, so watch out for these.
Overall, you can get a highly reliable Wi-Fi network working in a warehouse - it just takes time to design and deploy correctly.
If you're suffering issues with your Warehouse Wi-Fi install, contact us as we can help! We've worked across lots of large warehouses and have the skills and techniques to get yours working properly.