The Connectivity Standards Alliance (CSA) has announced Zigbee 4.0 and Suzi, the new brand for Zigbee’s sub-GHz feature.

The CSA sees these as two major milestones in advancing the foundation of secure, interoperable and scalable IoT connectivity with a range of optional features, enabling product manufacturers to choose the specific set that best fits their product’s use case and needs.

Zigbee 4.0 lays the groundwork for harmonising traditional Zigbee and smart energy devices, delivering more interoperability across universal networks. This release simplifies certification processes and supports enhanced information exchange, creating a more complete smart home offering.

Comprehensive and proactive security updates aligned with evolving international security standards implement cryptographic agility and additional mechanisms to protect the network. Extending its capabilities beyond the 2.4GHz band, Zigbee 4.0 introduces support for the European 800MHz and North American 900MHz phy, providing increased signal strength, range and coverage. Fully backwards compatible with Zigbee 3.0, it ensures continuity with more than a billion Zigbee devices already deployed worldwide while introducing improvements to network stability, user experience and device commissioning in dense networks.

Delivering security enhancements aligned with evolving global standards, the latest release reinforces Zigbee’s position for secure, modern connectivity. Capabilities such as dynamic link key, device interview and smart energy authentication level control improve control and resilience across connected networks. These capabilities strengthen device authentication, enable selective communication based on security levels and ensure only trusted devices join the network.

New tools such as restricted mode, secured channel, pan ID changes and trust centre swap out offer improved flexibility and management for ecosystems and installers by enhancing protection, allowing efficient trust centre replacement, and preventing unauthorised network changes.

With frame counter synchronisation, Zigbee 4.0 prevents replay attacks and synchronises precise message validation between endpoints. Improvements such as standard 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.

Features such as formalised parent selection, unique link key monitoring and trust centre connectivity improve network resilience, ensuring that devices maintain secure connections, can re-join when necessary and operate even in complex network environments.

Elevating usability and scalability, Zigbee 4.0 is designed to simplify and strengthen device interoperability. Through Zigbee Direct, users can seamlessly onboard and control devices via Bluetooth Low Energy (BLE) without a hub. Batch commissioning enables efficient, simultaneous setup of multiple devices, simplifying residential and commercial deployments.

Additionally, sleepy-to-sleepy communication using coordinated sample listening (CSL) allows direct, low-power exchanges between devices, optimising energy and further extending battery life. Collectively, these advancements position Zigbee 4.0 as a forward-looking standard, continuing to evolve with industry needs and future market requirements.

Alongside Zigbee 4.0, the alliance has introduced Suzi (csa-iot.org/all-solutions/suzi/), the new brand for the standards-based wireless technology that extends the reach and reliability of IoT connectivity through long-range, sub-GHz mesh networking.

Built on the proven Zigbee network layer, Suzi combines long-range performance, low power consumption and multi-vendor interoperability to unlock opportunities in residential, commercial and industrial applications. From connecting outdoor living spaces to enabling large-scale networks in buildings and cities, Suzi delivers robust, efficient communications in environments demanding extended coverage and low interference.

Adhering to the same security principles that define all CSA technologies, Suzi aligns with international standards to ensure a secure and trusted ecosystem. Its framework allows developers, manufacturers and consumers the freedom to build and deploy interoperable devices from a global ecosystem of trusted suppliers.

The Suzi certification programme is planned to open in the first half of 2026, enabling manufacturers to begin certifying products that bring the benefits of long-range, low-power mesh networking to the connected world.

Together, Zigbee 4.0 (csa-iot.org/all-solutions/zigbee/) and Suzi, by combining enhanced security, simplified onboarding and extended range, expand the reach and resilience of the smart ecosystem, making secure, intelligent connectivity more accessible.

Established in 2002, the CSA (www.csa-iot.org) has wide-ranging global membership to create and evolve universal open standards.