January 2007: ZigBee specification update
ZigBee 2006 specification now available30-Jan-2007 — The long-anticipated ZigBee 2006 specification has been released and is available to the public on the ZigBee website (www.zigbee.org). This release has been accompanied by a rethinking of terminology around the specification, which, although it will make life easier for everyone in the long run, may have caused some confusion in the process. So, here's the story... From now on, the ZigBee Alliance will refer to public specification releases by the year in which they were released. Thus, the version that was released in 2004 will be called ZigBee 2004 and the current release is called ZigBee 2006. You can expect another release in 2007 and, in all likelihood, in 2008. From the beginning, the ZigBee specification, because of the wide range of intended applications, has contained a number of optional features. It was realized early on that this was an interoperability risk because it was pretty clear that two devices implementing different choices with respect to some of these options would not work together very well. In order to mitigate this risk and to make the task of testing ZigBee platforms more manageable, the Alliance also releases stack profile documents that further restrict the options into well-defined feature sets, and writes conformance test plans against those feature sets rather than against the specification as a whole. The original stack profile that was released along with the ZigBee 2004 specification was generally referred to as the "HA stack profile," or more informally "the home stack," the idea being that it was intended for Home Automation applications. It soon became clear, however, that this was kind of silly. Basically, there was nothing about "the home stack" that made it inherently suited to home automation applications and not suited to, say, applications in the controllers and peripherals market or the medical devices market. Thus, it was decided to stop labeling stacks with the names of applications. The stack profile formerly known as HA is now called the "ZigBee stack profile." Simple. Taken together, the 2006 specification and the ZigBee stack profile offer an update of the feature set that was available under the 2004 specification and the HA stack profile. As noted in the last newsletter, however, there have been some changes, notably:
The changes required to support these new features affect frames formats and other "over the air" behavior sufficiently that the 2006 specification mandates a new protocol version number. ZigBee devices are free to support both protocol versions, but may only support one at a time on a particular network. Once they get their hands on the 2006 specification, though, careful readers will notice something more. There are, in fact, a bunch of intriguing new features in the new specification. These include:
These features are the beginnings of an additional feature set or stack profile, known for now as ZigBee PRO, which is intended to address the larger, denser networks and heavier maintenance schedules that are associated with commercial and industrial applications. Work on this feature set has been ongoing since 2004 and will come to fruition with the release of the 2007 specification and the ZigBee PRO stack profile. It should be noted that, because of the forward compatibility work in the 2006 specification, the two feature sets are mutually compatible. |
Daintree's Chief Technology Officer, Zachary Smith, who is also technical editor of the ZigBee specification and the ZigBee network layer specification, provides a update about the state of the ZigBee specification and what new functionality to expect in the upcoming ZigBee PRO and ZigBee 2007 specification.