Smart home connectivity involves more than just familiar technologies like Wi-Fi and Bluetooth. There are also industry-specific protocols that are more suitable for smart home applications, such as Zigbee, Z-Wave, and Thread.
When it comes to home automation, the market offers a wide variety of products 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 seamlessly.
This is partly thanks to wireless standards such as Zigbee, Z-Wave, and Thread. These standards allow commands (such as turning on a smart light bulb of a certain color at a specific time) to be sent to multiple devices at once, provided you have a compatible smart home gateway that can communicate with all your smart home devices.
Unlike Wi-Fi, these smart home standards use very little power, meaning that many smart home devices can operate without frequent battery replacements, and some may not even need replacements for several years.
What is Zigbee?
As we have already mentioned, Zigbee is a wireless network standard whose specifications are maintained and updated by the Zigbee Consortium (now renamed the Connectivity Standards Consortium), 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 wirelessly transmit data at a distance of approximately 75 to 100 meters indoors or approximately 300 meters outdoors, meaning it can easily provide strong, stable coverage in 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, regardless of its manufacturer. As long as they all support Zigbee, they can understand the same language.
Zigbee operates as a mesh network, meaning 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 to further propagate command data, allowing smart home networks to cover large areas.
However, with Wi-Fi, the signal weakens with distance or may be completely blocked by the thick walls of an old house, meaning commands may not reach the furthest smart home devices at all.
The mesh structure of Zigbee networks also means there are no single points of failure. For example, if your home is full of Zigbee-compatible smart bulbs, you might want them to be lit simultaneously. If one of them malfunctions, the mesh ensures that commands will still be able to reach every other bulb in the network.
However, in reality, this may not be the case. While many Zigbee-enabled smart home devices act as repeaters for transmitting commands over the network, some devices can send and receive commands but cannot forward them.
As a general rule, electrically powered devices act as repeaters, broadcasting all signals they receive from other nodes on the network. Battery-powered Zigbee devices typically do not do this; instead, they simply send and receive commands.
This is where Zigbee-enabled hubs come in, as they ensure commands are relayed to all the correct devices without relying solely on the Zigbee mesh to pass them. Some Zigbee products come with their own hubs, but Zigbee-enabled smart home devices can also connect to Zigbee-enabled third-party hubs, such as the Amazon Echo smart speaker or the Samsung SmartThings hub, which solves more problems, makes things more affordable, and ensures there aren't unnecessary devices in your home.
Is Zigbee better than Wi-Fi and Z-Wave?
Zigbee uses the IEEE 802.15.4 personal area network standard for communication and operates at frequencies of 2.4 GHz, 90 MHz, and 868 MHz. Its data transfer rate is only 250 kB/s, much slower than any Wi-Fi network. However, because it only transmits small amounts of data, Zigbee's slow speed is not a significant factor.
There is a limit to the number of devices or nodes that can connect to a Zigbee network. But smart home users don't need to worry, as the number can reach up to 65,000 nodes. So, unless you're building a truly massive house, everything should be connected to a single Zigbee network.
In contrast, 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 over a much greater distance, approximately 100 feet, while Zigbee's transmission range is between 30 and 60 feet. However, Z-Wave is slower than Zigbee's 40 to 250 kbps, with data transfer speeds between 10 and 100 KB per second. Both are significantly slower than Wi-Fi, which transmits data in megabits per second and can reach distances of approximately 150 to 300 feet, depending on obstacles.
Which smart home products support Zigbee?
Zigbee may not be as ubiquitous as Wi-Fi, but it's used in a staggering number of products; the Connectivity Standards Alliance has over 400 members from 35 countries. The alliance also states that there are currently over 2,500 Zigbee-certified products, with over 300 million units manufactured to date.
In many cases, Zigbee is a technology that operates quietly in the background of a smart home. You might have installed a Philips Hue smart lighting system controlled by Hue Bridge, but be unaware that the wireless technology powering it is Zigbee. This is part of the appeal of standards like Zigbee (and Z-Wave), because they simply continue to function without requiring you to configure them like you would with Wi-Fi.
