One problem with emerging standards is the licensing and certification issues that arise as the technology and organizations surrounding the standards mature. The ZigBee Alliance is the keeper of the ZigBee standard that is based on 802.15.4. ZigBee adds a significant number of features like mesh networking. It is an alternative to other 802.15.4 enhancements like Crossbow Technology’s MoteWorks (see “LabVIEW Celebration; and Robots Too!,” ED Online 13267).
A number of licensing and certification question arose a the recent ZigBee Developers Conference (see “Zigbee Surprise,” ED Online 12812) in Chicago. The questions I noted were of major interest to Electronic Design readers. The ZigBee Alliance was good enough to address many of these issues. For example, a major question who must be a member of the alliance when they are employing ZigBee technology. The short answer is:
Any organization that is simply reselling, distributing, installing or using a product based on ZigBee technology does not need to be a member.
The following is the detailed discussion with the ZigBee Alliance.
The ZigBee Interview
ED: The licensing and membership issues involved with utilizing ZigBee arose at the recent ZigBee Developers Conference. What is the boundary between those that must be members of the ZigBee Alliance and non-members that utilize the technology? It appears that a distributor such as Digikey would not need to be a member to sell ZigBee products like ZigBee modules but it is unclear whether a developer that purchased such a module to be used in their own product needs to be a member of the Alliance.
ZigBee (Alliance): Any organization that is simply reselling, distributing, installing or using a product based on ZigBee technology does not need to be a member. Any organization who adds something to a module before selling or is integrating the module or ZigBee technology into another product they intend to sell needs to be a member. Any organization building a product or subassembly for use in a ZigBee Network is strongly encouraged to participate in one of the quarterly interoperability test events. If a product or subassembly works at the interoperability test, it greatly increases the chance of passing qualification testing at a test house with a minimum of time and effort.
ED: Could you let us know what the requirements and costs are for the following classes:
a. ZigBee stack vendor
ZigBee: The ZigBee Alliance does not test for compliance at the stack level. It performs tests at the platform or product level only. If a software stack company wishes to sell a stack based on the ZigBee standard, they must be an alliance member. If they wish to develop a stack to provide it for free, then they would not be required to be a member.
b. ZigBee-capable chip vendor
ZigBee: Assuming you mean suppliers of ZigBee Compliant Platforms (ZCP) at the chip level, a vendor would need to be at least an Adopter member ($3500). A vendor would need to be either an Adopter or Participant member depending on how it implements the stack. If that vendor was getting its stack from a Participant member, then it could be an Adopter member because Participants members have access to the latest ZigBee updates. If it is unable to obtain the stack from a current Participant member, then that vendor would want to be a Participant member. The vendor needs to have its platform certified for ZigBee compliance. Given the general purpose nature of these devices, the testing is comprehensive and could take several days of test house time depending on the initial quality of the implementation. This higher testing cost though is spread out over a much higher volumes of parts. There are currently 13 vendors with ZigBee Compliant Platforms.
c. ZigBee tool vendor
ZigBee: There is no requirement for tool vendors to be members unless they are incorporating ZigBee directly into their products as part of the tool. As with the stack developers, it is advantageous for them to be members in any event. Assuming they are incorporating ZigBee into their product and used a ZigBee Compliant Platform (ZCP) the only additional testing necessary is ZigBee Certified Product testing. This testing is required if the company wishes to promote its product with a ZigBee logo. This test is low cost (~half day of test house time). If they are an Adopter member, there would be an additional $1,000 logo admin fee for the first product ($500 thereafter). There is no logo fee for Participant members.
d. ZigBee module vendor
ZigBee: A module vendors need to be a member. Assuming they use an already certified ZCP chip set and stack solution then testing is similar to c) above. Otherwise they would fall under the same category as b).
e. Developers incorporating the module into an end product
ZigBee: This type of entity must be a member, as either an Adopter or Participant. They must also obtain ZigBee product certification if they wish to use the logo on their product. Product testing is defined and straight forward. If they are an adopter member, there would be an additional $1,000 logo admin fee for the first product ($500 thereafter). There is no logo fee for Participant members.
f. Developers incorporating a self-contained ZigBee product within a product
ZigBee: If it is contained within the product then this case is treated the same as e). If it is already a ZigBee Certified Product and can be separately packaged as an accessory and plugged in to a PCI slot, USB port or other I/O by the end user, then no membership or additional testing is required.
ED: Do the requirements change if you use ZigBee technology within a product but in a proprietary fashion so the ZigBee name and logo are not used in the product, its documentation or marketing?
ZigBee: To be covered under the member agreement the vendor must have a complete ZigBee implementation or else they are not covered by the agreement and may be subject to royalty payments to other member companies.
ED: Open source, open source licensing and membership in the ZigBee Alliance are different things but it is possible for them to coexist. For example, it may be possible to release aspects of ZigBee technology as open source with a requirement that its use be only by an Alliance member. How does the current Alliance policy mesh with open source and GPL for commercial, versus academic, purposes?
ZigBee: The Alliance strongly encourages the open source and academic communities to produce stack and application implementations. There will be an approximate six-month time lag between releases to members of the Alliance and subsequent public releases.
ED: What is ZigBee certification?
ZigBee: Testing product or platforms for compliance to the ZigBee standards.
ED: Is ZigBee certification required? What does it cost? How is it performed?
ZigBee: Certification is required if you plan to use the ZigBee logo and name to market your product. With the exception of ZigBee Compliant Platform certification testing, which by its nature is far more involved, ZigBee Certified Product tests are expected to be relatively straightforward and therefore low cost. ZigBee has currently authorized two test houses for testing to ensure competition.
ED: Do all ZigBee products require certification? If not, what is the impact of being or not being certified?
ZigBee: Only those products where the member company wishes to use the ZigBee name and logo and benefit from the Alliance's marketing programs. Products not certified will not be promoted by the Alliance and may not use the ZigBee name and logo.
ED: Certification is based on an SKU. If I have 10 products, each with an SKU, that uses the same ZigBee module and software does that mean I need to certify it 10 times?
ZigBee: If products have distinct SKUs and differ in any way other than the color of the product/package and name on the product then yes, they must be tested individually. Different packages and developer software used in combination with the same modules can produce unexpected results if not implemented properly. The Alliance provides product certification to ensure products work as promised and to let end-users know they can buy ZigBee products with confidence.
ED: The Alliance's recertification note indicates "Modifications requiring recertification include but are not limited to any hardware changes, software updates and form factor modifications." Does set of changes apply to only the ZigBee related hardware and software or any change to my product. For example, if I maintain the portion of the PCB and software used for ZigBee support but make changes for other parts of my application will the entire system need to be recertified because of this change?
ZigBee: If it is a new SKU then yes. Re-testing is proportional to the extent of the changes. If the changes are as you describe, testing should be minimal and low cost.
ED: What is the ZigBee Certification logo? Is this different than the ZigBee logo? What documentation can I use the ZigBee logo with if a product is not certified?
ZigBee: It is the basic "red circle Z" ZigBee logo along with the word ZigBee. (art available). Products must be certified to use the ZigBee name or logo.
ED: The ZigBee Alliance has done an impressive job organizing the technology and certification process. What is the current status of the specification and certification process and what is its future timeline look like?
ZigBee: Alliance members are moving several products through the certification process over the next several months.
I would like thank the members of the ZigBee alliance for providing such a detailed response to my initial inquiries. Hopefully this information will help ZigBee developers understand what is involved in delivering a product that incorporates ZigBee. More details can be found at the ZigBee Alliance website and you can contact them directly or via email.
Let me know what you think about ZigBee, their plans and the tools you are using. I will have another ZigBee toolkit review later this fall.