Zigbee Updates Its Green Power Certification Process

Tom Lombardo posted 2019-12-09

My first home automation system included a set of “smart” outlets and an X10 controller that sent messages over the house power lines. The budding home automation market that existed back in the mid-1990s flourished into a $46 billion smart home industry by 2017 and is expected to exceed $100 billion by 2025. Unlike X10, which relied on devices being plugged into a wall outlet, many of today’s home automation and IoT products are powered by batteries or energy-harvesting technology. These systems rely on low-cost, low-power communication systems such as Zigbee, a wireless protocol based on the IEEE 802.15.4 standard.

A Zigbee-based smart home. (Image courtesy of the Zigbee Alliance.)

The Zigbee Alliance recently announced changes to its Green Power certification process, which ensures that Zigbee-based devices are compatible with each other and adaptable enough to work in multiprotocol networks. Certified products are eligible to use the new Zigbee Green Power logo, which helps customers identify devices that will easily mesh with their Zigbee networks.

Zigbee Green Power logo. (Image courtesy of the Zigbee Alliance.)

Jon Harros, director of Certification & Testing at the Zigbee Alliance, walked me through a pair of case studies that highlight the Zigbee Green Power Certification process.

Case 1

Overview

This product, a low-power temperature and humidity sensor, followed the more traditional route of testing which is open to manufacturers that are already members of the Zigbee Alliance (ZA). The battery-powered sensor was designed as an “end device,” a product located at the periphery of the network.

Certification Process

  1. The manufacturer obtained the latest Zigbee Green Power Specification from the ZA.

  2. As a member company of the ZA, the manufacturer was also able to obtain access to:
    1. Additional relevant documentation (e.g., test specifications, etc.)
    2. Test tools (e.g., the official ZA Green Power Test Tool) to assist with the design/development of the product and make it ready for formal testing.

  3. Once the design was ready for assessment, the company contacted one of the ZA Appointed Test Suppliers (ATS) and booked a slot to have its product tested for compliance.

  4. The manufacturer completed a form called the Protocol Information Conformity Statement (PICS). This is a formal technical declaration that details all of the features that the product supports. This form is used by the ATS to confirm that all mandatory functions have been implemented prior to testing and to then ensure that the correct tests are performed on the product.

  5. Technicians at the ATS tested the product against the applicable test cases detailed in the ZA Green Power Test Specification using the official ZA Green Power Test Tool. This protocol testing confirmed the correctness of the frames being transmitted wirelessly. It included checking the content, structure, and transmission timing of the frames to ensure that they complied with the requirements of the specification.

  6. Once the product was shown to be fully compliant, the ATS generated a formal Test Report, which it issued directly to the ZA.

  7. Both the manufacturer and the ATS signed the Declaration of Conformity (DoC) to state that the product complies with the applicable requirements of the Green Power specification.

  8. The manufacturer submitted the DoC, PICS, product description, and product photograph to the ZA using the online Certification Application portal on the ZA website.

  9. The Certification Team within the ZA reviewed the Test Report, DoC, PICS, and product description to confirm that all applicable aspects had been covered and were correctly shown as compliant.

  10. ZA issued a formal Certificate with the specific product information and detailing its compliance with the Zigbee Green Power Specification.
Zigbee Certification Process. (Image courtesy of the Zigbee Alliance.)

Case 2

Overview

This four-button switch to control lighting systems followed a different path to certification: It used the Certification Transfer Program (CTP), which allows one manufacturer to rebrand a “white-labeled” version of an already certified product from another manufacturer. The switch is powered by energy harvesting technology (an electrodynamic generator) instead of batteries.

Certification Process

  1. The original “white-label” product manufacturer (“Manufacturer A”) obtained full certification of the product using a process similar to that detailed in Case A above.

  2. Manufacturer A registered this product with the ZA as being available for the Certification Transfer Program (CTP).

  3. The final “rebranded” product manufacturer (“Manufacturer B”) selected the white-label product from the CTP list and contacted Manufacturer A to enter into a commercial contract.

  4. Manufacturer B applied for certification of the rebranded version of the product using CTP via the online Certification Application portal on the ZA website. The application included details of the original white-label product and the rebranding changes made from the original white-label version.

  5. The ZA Certification Team reviewed the details of the original white-label product and the rebranded changes to ensure that they did not alter the original certification.

  6. ZA issued a formal Certificate with the specific rebranded product information and detailing its compliance with the Zigbee Green Power Specification.

Over half a billion Zigbee chipsets currently operate in various devices, with more being released every day. Products that earn Zigbee certification are more likely to integrate seamlessly into home automation and other IoT networks, giving the system designer one less complication to worry about. To date, more than 3,200 products, devices and platforms are Zigbee certified, with an average of 460 new products becoming certified each year. Will your product be next?