The 2.4GHz radio frequency was released by the FCC way back in 1985 for unlicensed communication use — meaning people didn’t have to pay to use it. This made it the obvious choice in 1997, when the first version of the Wi-Fi protocol 802.11 was released. And thus, 2.4GHz Wi-Fi was born.
Only it wasn’t alone. Everything else in our homes that wanted to communicate wirelessly jumped on the free 2.4GHz band, from cordless phones and garage door openers to baby monitors — and microwave ovens were already using 2.4GHz waves for cooking food. With other smart home protocols, like Bluetooth, Zigbee, and now Thread, also on the frequency, the 2.4GHz house party has gotten very crowded very quickly.
“2.4GHz is so much better than 5GHz for the smart home because … 2.4 is perfect!”
Today, 2.4GHz Wi-Fi is the most popular protocol for smart home devices. If you have a smart plug or smart bulb in your home, the chances are it’s using 2.4GHz Wi-Fi. Talk to any smart home device maker — and I talked to many for this article — and they will sing the praises of 2.4GHz. It’s the cheapest to deploy of all the protocols and has the widest compatibility — everyone who buys a smart home device has a Wi-Fi router that supports 2.4GHz.
“2.4GHz is so much better than 5GHz for the smart home because it provides longer coverage and [goes through] walls more strongly. 2.4 is perfect!” says Wesly Lin, a former TP-Link engineer and current associate general manager of Meross, a Chinese manufacturer of smart plugs, switches, and bulbs. “That’s the core reason why manufacturers use 2.4. They don’t want users suffering more drop-offs. They don’t want complaints that their devices aren’t working in corners or downstairs in the basement.”
While 2.4GHz is much slower than its siblings 5GHz and 6GHz, it brings range. “2.4GHz spectrum is very narrow, so data doesn’t go fast, but because it’s a low frequency, it can go a very long way and penetrate walls better than 5GHz or 6GHz,” explains David Henry, president of connected home products at router manufacturer Netgear. This helps connect devices like smart garage door controllers, pet feeders, and thermostats that may be further from your Wi-Fi router.
2.4GHz also doesn’t need a mesh network to enable its reach, which most other wireless protocols in the smart home do. “2.4GHz Wi-Fi is table stakes. It’s one of the most important parts of the smart home,” Nick Weaver, CEO and founder of mesh Wi-Fi router company Eero, tells me. “Not everyone has 5GHz or 6GHz infrastructure in their home, and 2.4 is great for low bandwidth devices where you need range.”
However, being cheap and easy to deploy has made 2.4GHz Wi-Fi way too popular. With popularity comes problems. For 2.4GHz, these are twofold. First, there can be interference and congestion caused by overcrowding on the frequency’s narrow spectrum. And second: bad firmware.