Zigbee’s New Bluetooth Integration Suits Smart Buildings more than Smart Homes

In April, the Connectivity Standards Alliance (CSA), announced the release of the latest version of the Zigbee protocol stack—Zigbee PRO 2023. The new version brings significant extensions to protocols capabilities, but some of the long-standing issues for Zigbee remain. Even so, key new features should help prolong and extend the value of Zigbee, particularly in the smart building market.

Zigbee PRO 2023 extends the frequencies supported, security enhancements, and, crucially, tackles a key issue in its competition with Bluetooth LE in the developing smart buildings and, in particular, the Network Controlled Lighting market.

For the first time, the new stack supports Zigbee outside of the 2.4 GHz spectrum. Sub-gigahertz frequencies, such as 800 MHz for use in Europe and 900 MHz in North America, offer greater signal strength and range with the ability to better penetrate building structures supporting more use cases.

Additional security is offered through the new Dynamic Link Key, Device Interview, and Trust Center Swap Out features. The Dynamic Link Key replaces existing static key support dynamic public/private key pairing. Device Interview enables user tests for devices based on ecosystem requirements before allowing them onto a network. The Trust Center Swap-Out feature allows changing out the core gateway or hub without requiring all attached devices to be recommissioned. Leveraging features already supported in the Zigbee Smart Energy stack this means that Zigbee PRO 2023 devices can be integrated with Smart Metering networks already using the Smart Energy Zigbee version.

Support for Zigbee Direct provides a way for BT LE embedded devices—smartphones, tablet, etc.—to be used to commission and manage Zigbee devices and networks simplifying device onboarding and management.

The CSA has positioned the new Zigbee capabilities as a boost for both smart home and commercial building applications, but while the new features broadly speak to both markets, the real potential skews towards the commercial market.

In residential smart homes, Zigbee faces the significant challenge of Thread. With the CSA stewardship, Thread, which uses the same silicon 802.15.4 silicon as Zigbee, has significant support of inclusion in the Matter specification which Zigbee does not. Without that support, Zigbee’s place in smart home technology is increasingly threatened. The CSA is also pushing the potential of Matter in the commercial building space, too.

However, in the commercial space, Zigbee already supports significant long-term vendor and end-user investments. In addition, this is a market with less emphasis on multi-vendor interoperability or consumer-level ease of use. Instead, premiums such as longevity, functionality, and existing Original Equipment Manufacturer (OEM) and channel investment all continue to support Zigbee adoption. More than one billion Zigbee chipsets have shipped with hundreds of companies continuing to build and deploy products. According to the CSA, more than 4,700 devices have been Zigbee certified to date, including over four hundred Zigbee products and platforms in 2022 alone.

These new features also speak to growing competition from Bluetooth (BT) in the smart building space and, most particularly, smart lighting applications. In the Network Lighting Control (NLC) market, Bluetooth Mesh is an increasingly popular rival approach to Zigbee. So far, much of that threat has been driven by a key feature of BT Mesh over Zigbee—the ability to simplify installation and commissioning using mobile devices and apps leveraging Bluetooth Low Energy (BLE) presence in smart devices. This feature also allows for luminaire level lighting control topologies where systems can be deployed without the need for gateways and hubs. Instead, the lighting network can leverage connectivity to smart devices via BLE for commissioning and maintenance. Support for similar capabilities in Zigbee PRO 2023 extends the value and potential for the specification significantly, especially as simplified installation and implementation is key to driving smart lighting deployments into smaller buildings and projects.

With regard to the new spectrum capabilities, Zigbee is not alone in extending into sub-GHz spectrum. In the smart home market, Z-Wave has long operated in 900 MHz, while Wi-Fi with HaLow and standard and proprietary LoRa offerings also use the band. Furthermore, NLC platform player Wirepas supports 900MHz as well as 2.4 GHz.

However, despite these key developments, Zigbee PRO 2023, suffers from an Achilles heel that has long hampered adoption—the lack of single specification and the greater interoperability that enables. The new specification will not apply across all Zigbee implementations. Instead support for the new protocol features is optional. End-users looking to deploy multi-vendor Zigbee networks will require each potential supplier to have upgraded their offerings to the new specification. In addition, new features, such as new spectrum and BT LE support, require new hardware and certification and so broad vendor support is likely to be a drawn-out process.

At present, the smart building lighting market is one dominated by vendor proprietary implementations even where standard silicon has been leveraged, such as with BT Mesh. However, standard implementations will become increasingly valuable as end-users increasingly seek multi-vendor implementations and interoperability. This is an area examined in detail in ABI’s report on the subject (AN-5770). While Zigbee PRO 2023 does not bring features that will really ignite Zigbee’ uptake in the smart building market or, most crucially, in NLC, it does keep the specification competitive and in line with broad market direction, ensuring that those to vendors already invested and supporting Zigbee in their offerings will continue to have a feature set and offerings that can embrace much of the functionality of rival approaches.