The Art of AP Placement

Hi all, I’m the

Today we will talk about where and how to place APs in an indoor environment.

Often times I see a WLAN network ruined because of how and where the APs are placed. In such a case, IT staff will usually go buy and add more APs. This isn’t always the answer, and often it adds a different set of problems. Sometimes the solution may be something as simple as relocating APs.

Here are the tips that will help you with your AP placement:

1) Line of sight is your friend. While WiFi can and does travel through obstacles such as walls and furniture, it’s always best to try and place the APs in line of sight if possible. Think of this like talking to someone in the next room over – with both of your doors closed. You will likely be able to hear each other, but would have to yell, talk slower and say “WHAT??” a lot. Not the best way to communicate. If you can, position your APs with a line of sight to where you want coverage.

2) Generally, the best mounting position of APs is on the ceiling. There are quite a few exceptions to this such are warehouses and establishments with very high ceilings. Most of the time however, ceiling mounting will be optimal for horizontal coverage.

3) If you are placing the AP on top of a suspended ceiling, make sure to place the AP face down. While putting the APs above the ceiling tiles will create an extra barrier for the signal to go through, it is a far smaller factor than if you were to place the AP face up. It is a very common rookie mistake to lay the APs with the shiny side up and if you do, you end up with a very poor coverage on your floor, and are sending all the signal to whoever is on the floor above you. Place the APs face down.

4) Do not place APs on desks. Desks are considered one of the worst spots to put your AP, because they get blocked by other furniture and cluttered with items. Sources of interference such as phones, Bluetooth devices, and others always manage to find their way on the same desk your AP is on. All these will diminish your WiFi signal.

5) Do not put the APs in closets. Even if line of sight placement is not possible, it doesn’t mean you should say “well since there are obstructions anyway, I might as well place it in my server closet because it is convenient.” Putting your APs in a closet will diminish your coverage, and throughput – usually by a lot. Mount the APs on ceilings or walls, and avoid those closets.

6) Be mindful of metal obstructions. Metal objects act like mirrors for WiFi and reflect the signal. Avoid placing your AP inside or next to a metal shelf, behind metal doors, and others alike. Otherwise areas on the other side the metal obstacles will be shielded from WiFi signal.

7) Avoid sources of interference. This goes for both APs and clients connected to the APs. Most common sources of interference are microwave ovens, fluorescent light bulbs, cordless phones, electrical motors, Bluetooth devices, and other WLAN networks. Some interferences like neighboring WLAN networks, cordless phones, fluorescent lighting, etc. cannot be avoided and you have to live with them. Others such as microwave ovens and cordless phones can be taken in account, and therefor avoided. If you put your AP or client device in the kitchen next to a microwave oven, anytime someone is heating up food you will see your signal diminished or dropped. I cannot stress this enough: Beware of the microwave ovens!

8) If your AP has external antennas, do not point all of them in the same direction. The most common set up I see is pointing all the antennas up – and while this looks nice and organized, it is not optimal. Set the antennas to different tilt patterns. This will help with the polarization, and special stream differentiation if your AP and devices support it. Generally, the most effective setups are what I call the “turtle” and “fly” configurations. See the examples below, and depending on how many antennas your devices has, set the according configuration.

Often AP placement makes or breaks the WLAN. Hopefully the above tips will help you otimize your wireless network.

Just as a note, keep in mind the above Dos and Don’ts are *generally* best practices, but may vary in unique situations.

If you like more information on any of the above, please, do ask away!

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Peter Yordanov, Signing Out.