#wifi interference

By Dr Chris Spencer, CTA, GlobalReach Technology

Ever noticed that your home Wi-Fi signal becomes patchy over the festive break?  We have. 

Unfortunately, your fantastic Xmas LED light show could be to blame. And, while your thought that bigger was better, the problem is all down to some basic principles of physics.

But, before you break your children’s hearts and tear down the tree, so that you can stream ‘Bad Santa’ without interruption, the answer might be a room re-arrangement to reduce the distance between your Wi-Fi router (or access points), your holiday lights and any sparkling strands.

The Science Behind the Sparkle

Wi-Fi uses radio waves to communicate. Radio waves fall into the radiant energy family, we call this the electromagnetic spectrum. Microwaves, infrared beams, visible light, ultraviolet rays, and gamma rays are all part of this radiant energy family. Unfortunately for us, these waves interfere with each other.

Not isolated to Christmas lights, your microwave is actually the biggest nuisance to a decent home Wi-Fi signal. If your router sits next to a microwave, you’ll probably notice a few blips in connectivity when you warm up your turkey sandwich...

High-powered microwaves often operate at a frequency around 2.4GHz  - which is the same as the frequency used by most home Wi-Fi devices. Switch on the microwave, and your laptop can no longer distinguish between the Wi-Fi signals and energy being produced by heating your turkey stuffing. Mobile phones, Bluetooth gadgets, some baby monitors, and cordless phones can create similar problems and interfere with your overall connectivity. Something to think of before you try and to stream the Queen’s Christmas speech.

Back to the reasons why our pretty twinkly holiday lights cause havoc with our Wi-Fi. Today’s throwaway culture has made the likelihood of these interruptions more frequent. Most of our lights are now light-emitting LED bulbs. and the quality of their wires is typically unshielded. This means that the electromagnetic radiation created by electricity pulsing through the cable produces a very weak electromagnetic field.

Moreover, the more lights in the string may mean a stronger electromagnetic field, thanks to a physical concept called linear superposition. In essence, you’ve weaponized your Christmas tree and turned it into a giant electromagnetic pulse (EMP) emitter, and it’s the reason why your Wi-Fi is struggling.

Light waves, like all forms of electromagnetic radiation, moves in waves, best visualized as waves of water on a shoreline.

If two or more of those waves arrive at the same point and at the same time, their strength can combine and we see a much bigger wave. Turn that back to our subject here, those corresponding light waves create a stronger magnetic field.

Visible light from your holiday lights isn’t messing with your Wi-Fi because the two don’t actually work on the same frequency. The primary culprit is the electromagnetic radiation from the wires or LED electronics powering or driving those, which can create interference in the range of radio and Wi-Fi frequencies. Remember the microwave oven effect? Well, literally that...

What’s the Answer to a Connected Christmas?

It’s hard to predict the exact points where electromagnetic waves from those twinkling lights may join or merge, but electromagnetic field strength diminishes with distance. An obvious solution, therefore, is to move your Wi-Fi router or laptop desk away from your freshly decorated Christmas tree. Alternatively, dig out the strange short HDMI extender that came in the box with your new Firestick to move your streaming adapter. It can be used to move your streaming device or change its orientation. Sometimes just a few centimeters is enough to move it out of range of the electromagnetic waves affecting your Wi-Fi connection...

Experiment by moving your router to different areas around your house and then check your connection speed from a speedtest site.

The Future

Engineers are designing materials that will protect Wi-Fi and other communication devices from electromagnetic issues. These shields will only permit intended Wi-Fi signals to interact with a device while blocking all other interference. Many government agencies, research facilities, and even NASA are already researching and creating shielding materials behind the scenes, because of the impact that electromagnetic waves have on major military applications.