Just like it’s easy to misunderstand a message when someone’s shouting from the other end of the house, wireless messages can get distorted between your smart hub and smart home devices if they’re far apart and they don’t have strong signals. But strengthening the signal can cause interference in your Wi-Fi signal and other wireless devices. What’s a smart hub to do?
Enter mesh networks like Z-Wave and Zigbee. A mesh network is designed to help your smart devices talk to each other across long distances without using much extra power. We’ll explain how Zigbee and Z-Wave protocols work—and how they’re different—to help you decide which is right for your smart home.
What Zigbee and Z-Wave Do
Remember the game of Telephone you used to play when you were a kid where one person whispers into someone’s ear and that person whispers into someone else’s ear until the original message is completely lost? Both Z-Wave and Zigbee work like a game of Telephone with your smart home devices as the players. But since the hub and smart devices share the same radio frequency, the target device always receives the message loud and clear.
Both protocols use one or more hubs that act like the person at the beginning of the Telephone line. If the hub wants to relay a message to a smart device close to the hub, the hub talks directly to that device. If the device is farther away, the hub uses other smart home devices located in between as “repeaters” to pass the message along until it reaches the target device. Both Zigbee and Z-Wave refer to this process as “hopping.”
Both Z-Wave and Zigbee use AES-128 encryption (the same level of encryption that banks use) to ensure that no one cuts into your home’s game of Telephone. And both have hubs and devices that use unique network IDs, so you can rest assured that your neighbor’s Z-Wave hub won’t be sending random home automation messages to your Z-Wave smart home devices.
How Zigbee and Z-Wave Are Different
A game of Telephone wouldn’t work very well if one player were speaking English and another were speaking Spanish, and smart home platforms are the same way. Zigbee and Z-Wave each use different frequencies. It’s like each protocol speaks a different language, so they can’t understand each other.
That’s the bad news—they’re not interchangeable. The good news is that many smart home devices and hubs are created to be “bilingual,” so they can work with either a Z-Wave or Zigbee protocol. The catch is that once they start speaking one language (i.e., are tuned in to one frequency), they have to stick to it.
2. Code and Products
The Z-Wave protocol has a proprietary code, so it keeps its technology hush-hush. Even so, Z-Wave has an alliance made up of over 700 companies offering more than 2,400 products. It’s the top choice for most security companies, like ADT, Honeywell, and First Alert. Z-Wave’s unified standard means that all Z-Wave smart devices will work with all other past, present, and future Z-Wave devices, so you’ll never have to worry about incompatibility if you want to add on to your smart home system in the future.
The Zigbee protocol is designed with open source code, which means that any manufacturer who wants to make Zigbee-enabled smart devices can freely access the code and make them. Zigbee has an alliance made up of over 400 companies and 2,500 smart devices that support the Zigbee platform. In the past this has led to different protocols for different types of Zigbee smart home devices, and not all of them worked together. The recent addition of Zigbee 3.0 created a unified standard that works more like Z-Wave’s.
Curious about which protocol your devices use? Here’s a sampling of top brands and devices and their protocol compatibility:
Zigbee uses either a powerful 2.4 GHz frequency or a lower power 915 MHz frequency. Its 2.4 GHz frequency uses more power and works much faster than the 915 MHz, but it might interfere with your Wi-Fi network or your microwave. The low-power, wireless 915 MHz frequency offers less interference but will only give you a speed of 40 kbps, compared to the 250 kbps from the stronger signal.
Z-Wave uses a frequency of 908.42 MHz, which won’t interfere with your Wi-Fi, but it might cause some interference in your cordless landline phones or baby monitors (if you have them). It delivers up to 100 kbps of speed.
4. Number of Supported Devices
Z-Wave can support up to 232 smart devices on its mesh network, while the Zigbee protocol can handle a whopping 65,000, making it a better option for larger businesses that might be packed with smart devices. But these two platforms have different rules: Z-Wave allows only four hops between a device and a hub, while Zigbee allows unlimited hops. For the average-size home, four hops are plenty. A larger business might need Zigbee’s unlimited capacity.
The Bottom Line
Both Zigbee and Z-Wave create strong mesh networks for home automation. Zigbee’s capability for a longer range and unlimited expansion makes it the better choice when it comes to busy offices or large spaces where a lot of wireless smart devices will be used on the same network.
Z-Wave devices are slightly more expensive than Zigbee, but they’re guaranteed to stand the test of time—even as technology keeps changing. They’re a good choice for the average person who doesn’t want to worry about upgrades later on.
Z-Wave technology is also generally considered to be more user-friendly than Zigbee, but that’s become less of an issue as Zigbee has recently made changes to make its network more approachable for the average DIYer. The two Z’s are close enough cousins that either one is a good choice for home automation. If you already have devices you like that work with one and not the other, your best bet is to stick with the protocol that works for you and build your smart home system around it. If you’re not in the groove with any particular system yet, we recommend starting your Z-Wave and Zigbee journey by shopping around for a hub that has the features you’re looking for and going from there.