If you’re an electrician with even a bit of experience on Wi-Fi installations, chances are you’ve hit a snag with network interference before. Put your access points (APs) too close together, and they can end up fighting with each other for bandwidth – but too far, and you end up with dead zones where your client’s device connectivity (and satisfaction) hit rock bottom. Knowing how to place your APs is as much art as it is science…and it’ll often feel like you need a lot of both.

However, you don’t need to go back to school as a network engineer to cut the interference in your Wi-Fi deployment. Here’s how you can do so.

What IS network interference?

Knowing the enemy is half the battle. Interference happens when two devices (in range of one another) transmit at the same frequency, causing dramatic drops in performance. This can be caused by non-Wi-Fi devices (like microwaves or baby monitors), which aren’t usually as much of an issue: Aruba Instant ON APs for example will either automatically switch channels or talk “over” the less powerful appliances.

The more common issue stems from other Wi-Fi devices using the same “channel” (or segment of wireless frequency). Wi-Fi APs are notoriously polite: if one AP is “talking” on a particular channel, others won’t interrupt it – and they’ll never get their turn on the network. A bit of careful planning, however, can make sure every device gets its fair share of connectivity.

Social distancing for a speedier network

You can cut out a lot of interference by following these simple steps:

  1. Use the 5GHz range. 5GHz APs offer a lot more available channels and less causes of interference than their 2.4GHz counterparts. Aruba Instant ON APs offer both 5GHz and 2.4GHz, but make sure you design for a 5GHz network (leaving 2.4GHz for legacy device support). You’ll want to check that your client’s devices support 5GHz though.
  2. Space things out. Put your APs closer to the devices they’re connecting to. When you do so, you’ll usually end up naturally containing your APs in their own unique zone with enough distance between. Remember the CLOSE rule as you set your APs: Closer + Line of Sight (to your devices) = Effective.
  3. Choose the right AP. Aruba Instant ON APs will automatically scan the network to see what channels other APs are using – even if they’re not from Aruba, like the neighbour’s wireless router. The AP will then select a different channel to minimise interference and simplify the install process. That’s a feature worth looking out for when setting up any network.
  4. Cable where you can. Wireless extenders and mesh networks use up extra channels on the Wi-Fi spectrum – increasing the chances of interference between the very APs they’re connecting. In other words, connect your APs to the network with cables wherever you can. Aruba Instant ON APs do offer mesh networking for more challenging design situations where cables can’t reach, but you’ll get much better connectivity with the faithful Cat5/Cat6.

Sometimes, less is more

What do you do if you’re still getting interference? There may simply be too many access points or devices crowding up the site, so that they’re overlapping no matter how good you are at playing Tetris with your plan. If that’s the case, why not remove some access points or even wire up some of the higher-bandwidth devices? This can free up the airwaves while still giving the client the coverage they need – and even reducing their total cost.

As a rule of thumb, one access point per room or per 10 devices should give ample coverage. If you want to test the range for potential overlap, fire up an access point then connect to it with your smartphone and walk around the room. Your phone’s signal bar should give you a decent idea where the coverage starts to drop.

Final thoughts: don’t fail to plan

Network interference can put a real dampener on an otherwise successful Wi-Fi installation. In most cases, a bit of planning and understanding can help reduce the risk of interference and avoid clashes with unhappy clients. It also helps to know your product’s recommended usage settings and features that could help you in a pinch, like how to switch frequencies or toggle mesh networking. You don’t need to be a network engineer to fix interference, but a bit of common sense is certainly worth packing!

Check out the other blog posts for more tips on Wi-Fi installation practices for sparkies.