What is Zigbee? Why is it important for your smart home?

Smart home connections include not only familiar technologies such as Wi-Fi and Bluetooth, but also some industry-specific protocols that are more suitable for smart home applications, such as Zigbee, Z-Wave and Thread.

When it comes to home automation, there are a wide range of products on the market that allow you to easily control everything from lighting to heating. Thanks to the popularity of voice assistants like Alexa, Google Assistant and Siri, you can even ensure that devices from different manufacturers work together.

That's thanks in part to wireless standards like Zigbee, Z-Wave, and Thread, which allow commands (like a smart light bulb turning on a certain color at a certain time) to be sent to multiple devices at once, provided you have a compatible smart home hub that can communicate with all your smart home devices.

Unlike Wi-Fi, these smart home standards use very little power, which means many smart home devices can be used without frequent battery replacements, and some may not require replacement for years.

What is Zigbee?

As we have already mentioned, Zigbee is a wireless networking standard whose specifications are maintained and updated by the Zigbee Alliance (now renamed the Connectivity Standards Alliance), a non-profit organization founded in 2002. More than 400 technology companies support the standard, including IT giants like Apple, Amazon and Google, as well as many well-known brands such as Belkin, Huawei, IKEA, Intel, Qualcomm and Signify.

Zigbee can transmit data wirelessly over a distance of approximately 75 to 100 meters indoors or approximately 300 meters in the open air, which means it can easily provide strong, stable coverage throughout the home.

How does Zigbee work?

Zigbee sends commands between smart home devices, such as from a smart speaker to a light bulb, or from a switch to a light bulb - without first going through a central control hub, such as a Wi-Fi router. The signal can also be sent and understood by the receiving device. It doesn't matter which manufacturer it was made by. As long as they all support Zigbee, they can understand the same language.

Zigbee operates in a mesh network, which means that commands can be sent between devices connected to the same Zigbee network. In theory, each device acts as a node, receiving and transmitting data to every other device, helping the command data spread further, and the smart home network can cover a large area.

With Wi-Fi, however, the signal weakens with distance or may be blocked entirely by the thick walls of an older home, meaning commands may not reach the farthest smart home devices at all.

The mesh structure of a Zigbee network also means there is no single point of failure in the network. For example, if your home is filled with Zigbee-compatible smart light bulbs, you probably want them all to be lit at the same time. If one of them isn't working properly, the mesh ensures that the command will still be able to be delivered to every other light bulb in the network.

In reality, however, this may not be the case. While many Zigbee-enabled smart home devices act as repeaters that pass commands across the network, some devices can send and receive commands but are unable to forward them.

As a general rule, devices powered by the mains act as repeaters, broadcasting all signals they receive from other nodes on the network. Battery-powered Zigbee devices do not typically do this; instead, they simply send and receive commands.

This is where a Zigbee-enabled hub comes into play, as it ensures that commands are relayed to all the right devices without having to rely on the Zigbee mesh alone to deliver them. Some Zigbee products come with their own hubs, however, Zigbee-enabled smart home devices can also connect to third-party Zigbee-enabled hubs, such as the Amazon Echo smart speaker or Samsung SmartThings hub, making the solution more affordable and ensuring that your home doesn’t have redundant devices.

Is Zigbee better than Wi-Fi and Z-Wave?

Zigbee uses the IEEE's 802.15.4 personal area network standard for communication and operates on the 2.4GHz, 90MHz, and 868MHz frequencies. Its data transfer rate is only 250kB/s, which is much slower than any Wi-Fi network. But because only a small amount of data is transmitted, Zigbee's slow speed is not a big deal.

There is a limit to the number of devices, or nodes, that can be connected to a Zigbee network. But smart home users don’t need to worry, because that number goes up to 65,000 nodes. So unless you’ve somehow built a truly gigantic house, everything should be connected to a single Zigbee network.

By comparison, another wireless smart home technology, Z-Wave, is limited to 232 devices (or nodes) per hub. For this reason, Zigbee offers better smart home technology, but only if you have a particularly large house and plan to fill it with more than 232 smart devices.

Z-Wave can transmit data farther, about 100 feet, while Zigbee has a range of between 30 and 60 feet, but Z-Wave is slower, with data transmission speeds between 10 and 100 kilobytes per second, compared to Zigbee's 40 to 250kbps. They are both much slower than Wi-Fi, which is measured in megabits per second and can transmit data between about 150 and 300 feet, depending on obstructions.

Which smart home products support Zigbee?

Zigbee may not be as ubiquitous as Wi-Fi, but it’s also in a staggering number of products; the Connectivity Standards Alliance has more than 400 members from 35 countries. The alliance also says there are more than 2,500 Zigbee-certified products, with more than 300 million units produced to date.

In many cases, Zigbee is a technology that runs quietly in the background of your smart home. You might have a Philips Hue smart lighting system installed, controlled by the Hue Bridge, and not know that the wireless technology powering it is Zigbee. This is partly the point of standards like Zigbee (and Z-Wave), because they just keep working without you having to configure them like you would with Wi-Fi.