Dotdot 1.0 Enables Zigbee and Thread IP to Speak the Same Language

The Zigbee Alliance predicts the release of its new specification will unleash creativity in developers since it enables Zigbee-based home-automation and smart-lighting products to operate with IP networks, while Wi-Fi is the next potential interoperability target.
Published: February 8, 2019

Internet of Things (IoT) interoperability received a recent boost with the release of a new specification created in a collaboration between the Zigbee Alliance and the Thread Group, known as Dotdot 1.0. This application layer for Zigbee-based products can now run over the Thread Mesh network.

For developers, the result is the ability to more easily create solutions using the Zigbee standard, with an interoperability language that will automatically speak to systems based on Internet Protocol (IP) v6. With the new specification, the Zigbee Alliance is announcing its Dotdot over Thread certification program for product developers, opening in the first quarter of this year, to validate technologies before they are commercialized.

The Zigbee Alliance’s Victor Berrios

Several companies are already developing home-automation products and smart lighting systems that take advantage of the interoperability between the Zigbee application layer and Thread’s Internet Protocol. Thread is a low-power mesh-networking technology, based on the IEEE 802.15.4 standard, that brings IP connectivity to wireless IoT devices. It traditionally competes with other IoT protocols, including Zigbee, Wi-Fi, Bluetooth 5 and Z-Wave.

Zigbee, which is also an IEEE 802.15.4-based protocol, is used for home-automation devices, medical devices and smart lighting. It was standardized in 2004 to provide intermittent data transmissions from and to sensors. Since its revision in 2006, Zigbee has had an application layer that enables products to interoperate over its mesh network. However, says Victor Berrios, the Zigbee Alliance’s VP of technology, “A couple of years ago, the board made the decision that we wanted to unlock that value that was nascent in our application layer.”

The new agreement makes all Zigbee and Thread Mesh devices compatible via the application layer. This will be the first of many such interoperability specifications, Berrios says, adding, “We have completed the work now so that the Zigbee application layer runs over the Thread network. The first time is always the hardest. It moves us now down the path that we can very quickly do the work to have it operating on other networks.”

The Alliance expects to open up the new specification to Zigbee developers within a few months. Berrios likens the use of Zigbee with other 802.15.4 devices to the installation of a wireless printer. When a printer is installed, he explains, both the printer and the computer can recognize each other via Wi-Fi or Bluetooth. In order for them to operate together, however, proprietary software and drivers must be installed.

With the Dotdot application layer now added to Thread products, that connection can be made automatically between Thread and Zigbee devices. To assist this, the Zigbee Alliance uses its own existing commissioning mobile application, extended from the Thread commissioning application to include application-level configuration of devices on a Thread network. This mobile application, as well as the Zigbee Cluster Library, is now enabled to run over IP networks.

These efforts are a response to the recent growth in IoT deployments. When Zigbee was first released, the Internet of Things did not yet exist and companies were seeking vertical solutions that consisted of a wireless sensor system for a single use case. “They were built to serve a specific function alongside other technologies,” Berrios explains. Since that time, the advent of the IoT has resulted in many Zigbee-based products using wireless networks to transmit data. Zigbee is commonly used in smart-home and automated-lighting deployments, and there is a more horizontal focus these days, in that companies are seeking more functionality available on the same network, utilizing a variety of technologies and application layers.

Throughout the past year, the Zigbee Alliance has been conducting testing of Dotdot 1.0 to ensure that the specification is complete. Several members have been testing the technology, Berrios says, and are expected to release lighting and consumer home-automation products later this year.

Once the testing with the Zigbee Alliance is complete, several member companies expect to expedite Dotdot over Thread product development. For those using a traditional IP-based network, Berrios notes, Dotdot 1.0 now serves as a standard application layer that a business can lay on top of that network.

The Zigbee Alliance has a roadmap that continues interoperability plans with other networks, Berrios says, adding, “We’re in conversations with other networks that are not IP-based.” The group is presently in talks with the Wi-Fi Alliance to enable interoperability with Wi-Fi devices. “Wi-Fi is ubiquitous,” he states, “so by bringing our application protocol to that particular transport, we will get a wider audience.”

As IoT solutions continue to proliferate, Berrios predicts, “It will be hard to have a single technology meet all real-world needs.” He adds, “We feel Dotdot could be that first layer that unifies everyone speaking that language. That will unleash a wave of creativity.”