In a surprising move, the Connectivity Standards Alliance has announced Zigbee 4.0, an evolution of the smart home and IoT communication standard. As a component of what makes a Matter smart home work with specific hardware, this is a key development, ahead of the rumored Matter 1.5.
In addition, a new name for Zigbee’s sub-GHz feature has been unveiled: Suzi.
What is Zigbee?
Intended for smart home devices in the pre-Matter era, Zigbee is a wireless protocol introduced for smart lights, plugs, sensors, and switches. It creates a personal area network (PAN) using mesh technology for remotes and physical triggers, and can be used with a wider selection of hardware than Matter can currently handle using Wi-Fi or Thread. Zigbee is typically used to monitor energy use through smart devices, too, using the Smart Energy protocol Zigbee SE.
For use with Matter, Zigbee devices require a Matter Bridge, like the IKEA Dirigera (which now works as a Matter hub).
Our guide explaining what Zigbee is will fill in the blanks for you.
How Zigbee 4 improves Zigbee
Perhaps the most important element of Zigbee 4.0 is its backward compatibility with Zigbee 3.0 and Smart Energy devices.
Improved interoperability between Zigbee and Smart Energy should be possible, but I think the main improvement beyond improved compatibility is security. Proactive security updates, cryptographic agility, and security features like Dynamic Link Key and Smart Energy Authentication Level Control are important additions that ensure Zigbee 4.0 is capable of handling the challenges of keeping modern smart home and IoT hardware safe from unauthorized, external control.
New resilience features, improved stability, and Zigbee Direct (hubless onboarding via Bluetooth Low Energy) makes Zigbee 4.0 pretty robust new standard.
What about Suzi?
Built on the Zigbee network layer, Suzi is designed to improve reliability of IoT connectivity using sub-GHz mesh networking over a long range. Specifically, it will extend wireless reach beyond the 2.4GHz band, and include the European 800 MHz and North American 900 MHz PHY.
It is low power, and intended for residential, commercial, and industrial applications. As with other protocols overseen by the CSA, a certification program will be in place for Suzi, which will start in the first half of 2026.
How will you know if you’re using Zigbee 4?
In most cases, you won’t. Unless you’re a developer or smart home enthusiast who uses Home Assistant rather than an Apple/Google/Amazon/Samsung etc. solution for Matter, the version of Zigbee running on your new sensors or lamps or security software won’t be of any significance.
But based on the information released by the CSA today, it will improve your smart home experience.
