When it comes to building a smart home, there are four wireless technologies you need to be aware of. The first two are the well-known Wi-Fi and Bluetooth standards, of which you will already be aware. But the latter two are the relatively unheard of Zigbee and Z-Wave.
These connect devices together wirelessly, but work in a different way to Wi-Fi and Bluetooth. This is because, instead of creating a direct connection between a hub or router and a device, Zigbee and Z-Wave use mesh networks, where signals and data are sent from the hub to one device, then from that device to another, and another. This way, the signal can reach devices which would usually be out of range of the hub, because it hops along a pathway created by each device acting as a repeater.
Zigbee and Z-Wave devices use very little power, and in some cases can last for years before their batteries need replacing. Devices which use these technologies include sensors (motion or water, for example), smart thermostats, door locks, switches, light bulbs, smart plugs, and hubs like the Samsung SmartThings, Amazon Echo Plus and Wink.
Zigbee is an open standard controlled by the Zigbee Alliance (established in 2002) and was originally created for commercial use before transitioning to the smart home. Meanwhile, Z-Wave was first developed by Danish company Zensys in 2001. Created specifically for the smart home, Z-Wave was sold to Sigma Designs in 2009, which then sold it to Silicon Labs in 2018 for $240 million.
What is a mesh network?
Mesh networks can cover an area (your home and garden, for example) more thoroughly than a Wi-Fi network. This is because a Wi-Fi network only sends data to and from a single hub, your router, and so devices placed further away have a weaker signal, which can cause connection problems. Owners of old houses with thick walls will also be aware of the limitations of Wi-Fi, when a router struggles to make its signal heard several rooms away, potentially leaving entire rooms out of range.
A mesh network overcomes this by taking a signal from the hub (a light bulb being asked to switch on, for example) and relays this message via other devices in the network. This way, an instruction to turn the light on at the other end of the house still gets there, because it has been relayed by several other Zigbee or Z-Wave devices along the way.
What all this means is that smart home devices will talk clearly to each other throughout your home, and the more devices you install the better the network's coverage will be.
The only real difference between how Zigbee and Z-Wave operate their mesh networks is that Z-Wave allows a signal or piece of data to be relayed four times across the network, while for Zigbee there is no limit.
The technical differences between Zigbee and Z-Wave
Although Zigbee and Z-Wave work in a similar way, sending messages to smart home devices over a mesh network, there are some differences regarding their capabilities. For example, Zigbee uses the 915 MHz and 2.4GHz radio frequencies, and you may recognize the latter as it is shared with Wi-Fi. This, in theory, can cause interference issues in homes with a large number of Zigbee and Wi-Fi devices all fighting to be heard in the same space.
Z-Wave doesn't suffer from Wi-Fi interference because it operates at the lower (and less congested) 800-900MHz frequency range.
Other differences include the amount of data each technology can transfer at once. Zigbee wins this one, offering data transfer speeds of between 40 and 250 kilobytes per second, compared to Z-Wave's 10-100kbps. Although this is technically a victory, these speeds are still incredibly slow compared to Wi-Fi and cellular connections - that's because Zigbee and Z-Wave are only used to transmit very small piece of data, like instructions for a device to perform an action, or readings from a sensor.
More meaningfully, Zigbee also wins when it comes to how many devices (or 'nodes') you can have connected to the same mesh network at once - 65,000, compared to Z-Wave's limit of 232 devices. In reality, it is unlikely that your smart home will have more than 232 devices in it, but if you happen to have a mansion filled with smart lights in every room, then you might want to use a Zigbee lighting product instead.
The technologies also differ when it comes to how far each device can transmit data. Zigbee's range falls between 33 and 66 feet, while Z-Wave is 100 feet. However, both of these figures depend on where the devices are, if walls are nearby, how thick the walls are, and various other factors. But, given the mesh networking we explained earlier, it is highly likely that another smart devices is just a few feet away and able to repeat the signal before it falls out of range.
Finally, both technologies use the same AES-128 encryption to keep your smart home safe - especially important when using devices like smart door locks and motion sensors for alarm systems.
Which products work with Zigbee?
Some of the biggest and most well-known families of smart home devices work with Zigbee, like Philips Hue lights, the Samsung SmartThings system of hubs and sensors, and LG's new ThinQ smart home portfolio. Others include:
- Philips Hue
- Ikea Tradfri smart lights
- Samsung SmartThings devices
- LG ThinQ devices
- GE Appliances
- Somfy window blind motors
- Honeywell smart thermostats
- Yale smart locks
Which products would with Z-Wave?
Devices which use Z-Wave include:
- August smart locks
- Schlage smart locks
- Kwikset smart locks
- Ring doorbells
- Fibaro water leak detector
- Aeotec water, door and window sensors
- First Alert smoke alarm
- GoControl lights and wall switches
Can I use Zigbee and Z-Wave devices in my smart home?
Yes, an important thing to remember when building your smart home is that a good range of devices work with both Zigbee and Z-Wave, so you won't find yourself tied to one technology or the other. For example, hubs by Wink and Samsung SmartThings work with both standards, and so too do Honey thermostats, Yale smart locks, products by GE Appliances, and the LG ThinQ ecosystem.
It is also worth bearing in mind that Zigbee and Z-Wave devices can play nice in the same smart home, even if they don't walk to each other. For example, Philips Hue smart lights use Zigbee, bu they also connect to the Hue Bridge, which then hooks up to your Wi-Fi router. That way, you can control the bulbs directly from a Zigbee hub, or from a smart speaker like the Amazon Echo or Google Home via the Bridge.
If you plan to fill your home with a lot of smart devices, then a hub which talks to everything - like the Wink or SmartThings - is a safe bet, as these cater for both Zigbee and Z-Wave.