The Connectivity Standards Alliance (CSA) has officially unveiled Zigbee 4.0 along with a new long-range sub-GHz mesh technology, now branded as Suzi. Here’s what integrators, custom installers, and specifiers need to know.
What’s New in Zigbee 4.0
Interoperability and Performance
According to the CSA, Zigbee 4.0 is meant to lay the groundwork for greater interoperability between traditional Zigbee and Smart Energy devices. Part of that groundwork involves simplifying the certification process while supporting more unified information exchange.
Some new features have also been added to tighten network communication between devices in general. Standardized network-level retries, more reliable data polling for sleepy end devices and expanded use of APS acknowledgements increase overall network performance and reduce message loss between devices.
Coordinated Sample Listening (CSL) supports sleepy-to-sleepy communication, for low-power exchanges between devices.
The new standard is also designed to be fully backward compatible with Zigbee 3.0 and Smart Energy, ensuring continuity for the massive install base of Zigbee devices already deployed globally.
Security
Beyond that, Zigbee 4.0 introduces a slew of new security features as well, with several new mechanisms having been added to strengthen network protection such as Unique Link Key Monitoring and Trust Center Connectivity.
There’s also the Advanced Frame Counter Synchronization feature, which is designed to prevent replay attacks while also improving routing features and rejoin behavior.
New tools like Restricted Mode also help prevent unauthorized changes, while Trust Center Swap Out allows users to replace Trust Centers more efficiently compared to previous standards.
Setup
Zigbee 4.0 also adds the option to onboard Zigbee devices through Bluetooth Low Energy (BLE), allowing for setup without the need for a hub. The new standard even includes a Batch Commissioning feature to simplify the setup of multiple devices on a network.
Enter ‘Suzi’ and Zigbee’s Foray into Sub-GHz
Central to the release of Zigbee 4.0, however, is the new support for Sub-GHz communications. The latest standard introduces baked-in support for the European 800 MHz and North American 900 MHz bands, which is ultimately meant to provide greater range, better penetration and more robust coverage (think Z-Wave Long Rage (ZWLR)).
The added Sub-GHz support also ties in with the introduction of Suzi: a Sub-GHz mesh network built on the Zigbee network layer.
According to the CSA, Suzi leverages sub-1 GHz frequencies to deliver that extended reach, while also operating at a lower power, which tends to show its strengths in larger deployments, as well as outdoor environments.
It being built on the Zigbee network layer, the Suzi network enjoys much of the same security features as Zigbee, as well, while theoretically being able to work with all the same devices that would naturally work with Zigbee.
It’s only “theoretically,” though, as Zigbee devices will still need to pass certification to affirm they will support the Suzi mesh.
The Suzi Certification Program is slated to open in the first half of 2026.
