Wi-Fi equipment manufacturers are well known for advertising “long range wireless” or “with our system you’ll need the fewest number of access points” or “our access point can cover 10,000 sq. ft.” Or whatever the latest marketing lingo is to tell you that you’ll need less of their equipment than anyone else’s.
To me, this is like the drug commercials on TV that advertise to help you with a problem, but the known side effect is that it may cause another problem that is much worse (even death!). Before you rush out to buy some wireless access points for your warehouse wifi network, it’s important to read the fine print, or this case, understand the side effects of the poor wireless design.
Here are a few industrial wireless network design principles that you should consider before your next wireless deployment.
1) Wireless communication is a two way medium
Yes, you absolutely can cover a 10,000 sq. ft. space with a wi-fi signal from one wireless access point assuming there are no obstructions (which there typically are in a warehouse). But the question isn’t just “can the access point cover a large area?” The question is “do the wireless devices have enough power to communicate back to the access point?” If you and I were standing on opposite ends of a football field and I have a bullhorn but you do not. I can talk through the bullhorn and you can hear me, but if you talk back without a bullhorn I can’t hear you. We wouldn’t be able to have a very effective conversation, matter of fact, we’d both be frustrated. The same goes for a big industrial wireless access point trying to talk to a small hand held scanner on the other side of the warehouse. The scanner can “hear” the access point, but the access point can hear the scanner.
2) With high power comes high interference
In large industrial environments, the solution for the manufactures is to just crank up the power settings to their highest level. This is how they advertise so few access points. The problem with this answer to the coverage problem is that your warehouse wifi system needs to be designed to have communications with each device in the facility. Think of this as having a conversation with an individual face to face. When you’re talking to them one on one it’s easy, but have you ever tried to have a conversation while listening to other conversations at the same time? You can’t do it effectively. When all of the access points are turned up to their highest power, they interfere with the conversations each of them are having with the end user devices and you end up with bad communication ending in crappy performance.
3) The fewer AP’s you have the fewer Wi-Fi services you have
Wi-Fi is not just for data access anymore. In a large warehouse environment you can use Wi-Fi for wireless voice over IP or other things like real time location services, i.e. locating things using your Wi-Fi network similar to the way GPS works in your car. But those services won’t work properly when you don’t have the proper number of access points. Voice handsets need to be close to the access points because they’re typically very low power devices (back to point #1). Location services need to be able to triangulate using the access points which is hard to do when you don’t have access points spread throughout your facility. So if you’re looking for more advanced wi-fi services you’ll need to be very strategic in your access point density and placement.
Warehouses wireless is not as simple as throwing up some long range access points and forgetting it. Planning wireless for any industrial environment has a very unique set of challenges. The starting point is to think about how your system will be used now and in the future. Then you’ll need a wireless plan that selects the right wireless system to support your needs and incorporates industry standards for planning and AP placement. If you need a wireless expert to work with you feel free to contact us to talk to someone who can help.
