Why 2.4GHz Wi-Fi is both the savior and the scourge of the smart home
This morning, my dog Gus took his big furry head and gave me a solid nudge. He looked at me and then at his food bowl. “Mom,” he said (telepathically, natch). “The Wi-Fi on my pet feeder is borked. Again.”
Gus is a smart-home dog. He’s used to letting me know when his food didn’t dispense on schedule because his smart pet feeder dropped off the Wi-Fi network — and I’m accustomed to doing the reconnection dance that follows.
If you’ve owned any type of smart home gadget — smart plug, bulb, security camera, garage door controller, or pet feeder — you know the steps: figure out how to reset the device, get out your phone, open the app, navigate to its Wi-Fi settings, swap to your phone’s settings, join your Wi-Fi network, go back to the app. Stand there for a few minutes while it tries to connect and invariably fails. Start again.
All the gadgets that regularly drop off my network share one common factor: they connect over 2.4GHz Wi-Fi
In my decade-plus of owning smart devices, I’ve done this dance countless times. And all the gadgets that regularly drop off my network or misbehave share one common factor: they connect over 2.4GHz Wi-Fi. This outdated, 1990s-era, low-bandwidth protocol is slow, congested, prone to interference from other household appliances, and just generally unreliable.
It’s 2023. Smart home device makers should put 5GHz Wi-Fi chips in their gadgets — right?
Here’s a look at why 2.4GHz Wi-Fi is so ubiquitous in today’s smart home, how we can learn to live with it, and whether there are better solutions out there.
What is 2.4GHz Wi-Fi, and why do so many smart home devices use it?
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.”
But now we’ve got problems…
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.
To begin with, all those devices using 2.4GHz Wi-Fi and everything else on the same slice of spectrum crowd the frequency. And all their incessant chatter makes it hard for any single device to be heard. “Congestion on 2.4GHz Wi-Fi is like there are 40 people in a room, and all of them are talking, but you can’t hear one specific person because all 40 people are talking,” explains Lin.
On a congested network, things move more slowly, leading to reduced performance, latency, and, potentially, failure. For example, you ask a voice assistant in a smart speaker to turn the lights on, and it happens 30 seconds later, with each bulb “popping” on one by one rather than at once.
In the case of my pet feeder, it’s probably trying to shout over all the noise, not being heard, and then just giving up. Here’s where poor software becomes a factor. If a company hasn’t put the work in to optimize its Wi-Fi connectivity, it will end up at the bottom of the pile, bleating pathetically. “2.4 doesn’t have a lot of spectrum to make use of, which becomes a problem,” says Weaver. “Couple that interference with bad software — a lot of cheap 2.4 devices don’t handle failure really well and produce a ton of retries to get back on a network, causing more interferences — and you end up with storms of broadcast traffic.”
So, how are we gonna solve this?
With the advent of the 5GHz and, more recently, 6GHz Wi-Fi bands, your smart home’s Wi-Fi has more room to breathe — specifically, more spectrum. As the bands go up, each lane gets wider — with 6GHz bringing us a whopping 1,200MHz of spectrum.
These new bands open up a swath of fast lanes for the Wi-Fi-connected devices in your home. Think of Wi-Fi like a highway, with specific lanes for specific functions. 2.4GHz is the bike lane for your slow but steady smart home gadgets, and 5GHz — with its wider bands and faster top speeds — is the main freeway for your high-bandwidth devices like security cameras, laptops, tablets, and streaming boxes.
“2.4GHz Wi-Fi is table stakes. It’s one of the most important parts of the smart home.”
The 6GHz band, which arrived with Wi-Fi 6E in 2021, is your HOV lane. Only select, super-fast gadgets that have paid for the privilege (with a more expensive chipset) can take this road. Unfortunately, today there aren’t many devices that use 6GHz — Apple doesn’t support it in any of its products — and 6E routers are expensive. But as more companies adopt 6GHz and the cost of the tech falls, it can start to take even more pressure off 2.4.
“The solution to the crowded room problem is to move the 10 loudest people away so now you can hear the remaining 30 quieter ones better,” says Lin. The simplest thing you can do to help with congestion in your smart home network is to move your high bandwidth devices like security cameras, laptops, and streaming sticks to 5GHz and even 6GHz, so that your 2.4GHz gadgets have more room to breathe. (It should go without saying that to reduce Wi-Fi congestion, you should hardwire anything that you can, such as desktop computers, televisions, streaming sticks, and other stationary bandwidth hogs.)
Most modern Wi-Fi routers offer band steering that moves dual-band devices to 5GHz automatically. Mesh router systems also help — if you have multiple access points across your house, your laptop and smartphone can stay connected to 5 or 6GHz wherever you are and avoid dropping down into that crowded 2.4GHz band.
If you have a smart home, you want Wi-Fi 6
Netgear, TP-Link, and others have started introducing dedicated “smart home / IoT” networks on their higher-end routers, such as the Deco XE75 Pro 3 pack and Netgear’s Orbi line. These keep all your low-bandwidth devices on a secure 2.4GHz network without you having to faff with setting up a guest network or splitting bands manually (no one buys a connected pet feeder hoping to learn how to be a network engineer). However, even Netgear’s Henry admits you shouldn’t need to use these. The band-steering technology should make everything work with just one network.
A new router is also an opportunity to upgrade to Wi-Fi 6. Wi-Fi 6 was specifically designed to improve the performance of a Wi-Fi network when a bunch of devices are connected to it. It’s basically a Wi-Fi upgrade for the smart home. If you have a smart home, you want Wi-Fi 6. Eero and Google Nest all have Wi-Fi 6 router options, as do Netgear, TP-Link, and others. If you are buying a new router today, Wi-Fi 6 should be a prerequisite.
Keep in mind, though, that Wi-Fi 6 is different from 6GHz; it doesn’t come with that extra 6GHz band. You only get 6GHz with the aforementioned Wi-Fi 6E (the whole naming convention is just silly).
Shouldn’t all smart home devices just use 5GHz so we can abandon 2.4?
While it makes sense for bigger, more bandwidth-eating smart devices like cameras and smart displays to use 5GHz, it doesn’t make sense to switch smaller, less intensive gadgets to the 5GHz band. “Why move all the bicycles into the faster lanes? Keep them in their own lane,” says Meross’ Lin.
While you may curse the heavens when your laptop is running on slow 2.4GHz while you’re trying to catch up on Succession, most smart devices send and receive very little data, making the slower data transfer speeds of 2.4GHz a non-issue. “Your door lock, sprinkler system, and Nest thermostat don’t need 5GHz,” says Henry. “They’re not streaming video, they can be battery powered, and they are often far away from your router.”
“I don’t think 2.4 Wi-Fi ever goes away … Turning it off would be not worth the pain.”
Additionally, making devices like smart plugs compatible with 5GHz would require dual-band Wi-Fi chips and more antennas, making “these small appliances more expensive and reducing their connection distance,” says Elin Zhao of TP-Link, which manufactures both smart home devices and Wi-Fi routers.
I buy the argument that 5GHz is currently overkill for most smart home devices that don’t stream audio or video. Adding 5GHz will make small, simple smart home gadgets chunkier, costlier, and more complex — not features you look for in, say, a smart plug. But as Wi-Fi matures, surely 2.4 will become obsolete. Shouldn’t we be future-proofing? “I don’t think 2.4 Wi-Fi ever goes away,” says Henry. “There’s just so many devices out there that use it. Turning it off would be not worth the pain — and dollars — compared to keeping it on.”
Is there a better solution?
While 2.4GHz Wi-Fi may be here to stay, it doesn’t mean smart home device makers need to use it. They have other options. Z-Wave, Zigbee, and Thread are all technologies more obviously suited to smart home gadgets, primarily because they use mesh networking. This allows each device to extend connectivity, so your smart plug can help your smart bulb stay connected. The more devices you have, the further the network reaches. Z-Wave uses the 900 megahertz band and is out of the whole congestion calamity entirely. This is one of the reasons it’s found in home security systems: it’s reliable and not as prone to interference.
These mesh protocol options also fix the issue of the massive power drain Wi-Fi has on battery-powered devices (there’s a reason you can’t find a decent Wi-Fi motion or door-window sensor anywhere). “Thanks to Zigbee, the battery-powered devices from Aqara have an ultra-long battery life of up to 5 years,” says Filipp Shved of Aqara. Zigbee can also scale, with one Aqara hub capable of handling up to 128 Zigbee devices. Standard Z-Wave hubs can handle 232 devices and Thread upwards of 250.
“Over the very long arc of the smart home, I think we’ll see a migration to technologies like Thread…”
But all these protocols require a hub or bridge of some sort to connect to the internet, adding to the cost and complexity — which many manufacturers are trying to avoid as they look to sell you lots of small, smart devices for your home. “The 2.4 Wi-Fi chipset is the best for IoT right now, cost-wise,” says Meross’ Lin. “Thread devices chipset could double or triple cost for us, and the price to the consumer will go up.”
In addition, Lin says the appetite is just not there from smart home users. “Matter is coming out — which uses Thread. But consumers are not wanting to buy the Matter devices at double the price.” A single Meross Matter plug costs $20. A four-pack of the same plug on 2.4GHz Wi-Fi is around $30. “The sales data tells the truth — customers aren’t buying for Matter.”
“Over the very long arc of the smart home, I think we’ll see a migration to technologies like Thread for low-bandwidth, high-quantity devices, such as lights, sensors, and battery-operated devices,” says Eero’s Weaver. “It still runs on 2.4GHz, but Thread is much more efficient than Wi-Fi from a packet overhead perspective. It doesn’t have the overhead of Wi-Fi negotiation, consuming less airtime with every device.” Thread offers better reliability, better network performance, and better range than 2.4GHz Wi-Fi, he says.
Thread-powered devices also don’t require a proprietary bridge or hub. Instead, they can use any Thread border router to connect to the internet. A Thread border router is a powered device with an internet connection and a Thread radio. It can be anything from a smart speaker, a thermostat, a light fixture or even be inside your Wi-Fi router. If you have a smart home, you may already have a Thread border router — Eero Wi-Fi routers, Apple HomePods, and some Google Nest and Amazon Echo smart speakers are Thread border routers.
While Thread’s infrastructure is beginning to arrive, there are still comparatively few devices that use Thread. And until it’s as cheap for manufacturers to build with Thread as it is with 2.4GHz Wi-Fi, it won’t replace Wi-Fi as the dominant smart home connectivity protocol. But if there’s one thing I’m sure of, it’s that my next smart pet feeder will use Thread.