ZigBee Mesh Networking Radio Comes of Age?

By Ollie Smith, Telegesis

ZigBee has been a bit of a buzz word among engineers looking for wireless solutions over the past eighteen months or more. ZigBee low power mesh networking radio technology is its more accurate — if somewhat cumbersome — description for those who have yet to encounter it. But despite being a prominent topic of conversation among engineers looking for a robust wireless solution across a wide cross section of markets and applications, there has been a perception that up till now, ZigBee has been “unfinished” and not yet ready for use in the real world environment.

It can be argued that this perception has been partially valid as ZigBee has made its way along the road to its ultimate goal of a truly international and interoperable protocol. However, the stated aim of the ZigBee Alliance — the association of companies working together to achieve an open global standard for the technology — is now tangible. With the ratification of ZigBee PRO at their September meeting in Beijing, the final steps are now being taken to deliver a truly “finished” standard to which all can comply.

In fact, over the past two years or so, many early adopters have already begun to use ZigBee in its earlier iterations to address widely differing applications. And it would be wrong to suppose that ZigBee hasn’t been robust enough to provide genuine solutions to real world problems before now. There are many examples of solutions which are based upon the technology.

ZigBee has already made inroads into a wide range of market verticals — notably Home Automation, Industrial Control and Environmental Monitoring. However, the largest and fastest growing arena which ZigBee has made its own is that of the Automatic Meter Reading (AMR) and Advanced Metering Infrastructure (AMI) projects that are now springing up worldwide.

Hundreds of thousands of ZigBee chipsets and modules are being deployed around the world in meter reading pilots and energy use monitoring schemes — not only across the United States but in Europe and elsewhere. The interest has been truly international and almost simultaneous up to and including whole cities that have “gone ZigBee” as Gothenburg, Sweden has done.

Utility companies already committed to ZigBee technology include CenterPoint Energy, Göteborg Energi, Southern California Edison and Sempra Utilities with many others joining the movement on an almost weekly basis.

Partially in response to the utility uptake, products & services providers and manufacturers have also been moving in. These include Cellnet, Eaton, Energy Optimisers, Itron, Phillips, Schneider Electric, Siemens, Comverge, Control4, DCSI, Golden Power, Johnson Controls, Legrand, Nivis, Nuri Telecom, Sensus Metering, Silver Spring Networks, Site Controls, Talon Communications, Tendril, Trilliant Networks, Tritech Technology, Viconics …the list is impressive and is extending daily.

The energy technology market — increasingly referred to by its American soubriquet, ener tech — is certainly the killer volume application that will see ZigBee reach rapid maturity with all the benefits to end users that that process entails. These benefits can be summarized as a robust technology tried and tested in widely varied and sometimes difficult radio environments available to all users at lower prices.

So if ZigBee has been forging ahead already what, you may ask, does ZigBee PRO bring to the party?

Well, to begin with, ZigBee PRO will provide the platform for certifiable ZigBee end products to be marketed bearing the ZigBee logo. Many products have been waiting in the wings for the opportunity to gain ZigBee status before being unveiled to their markets and you can expect to see a rapid proliferation of ZigBee products during the first quarter of 2008 and onwards.

And ZigBee PRO brings real benefits and additional functionality to the previous proprietary iterations of the technology. In a nutshell it enables larger, denser, sleepier, more mobile, more secure and more resilient ZigBee networks. (An explanation for some of these terms follows below.)

ZigBee PRO will form the basis of all ZigBee mesh networking technology in the future whether it is released by TI/Chipcon, Ember Corporation, AirBee, Freescale, ST Microelectronics or any of the other manufacturers of ZigBee system-on-chip technology.

According to Ember Corporation — a founder member of the ZigBee Alliance and the market leader in design and implementation of ZigBee technology — their newly released EmberZnet PRO 3.1 mesh networking platform is “the most robust and reliable ZigBee platform available today.”

Announced in Boston, US on October 30, 2007, EmberZnet PRO 3.1 is Ember’s third-generation mesh networking software. Their stack combines the increased scalability, security and resilience of the ZigBee PRO Feature Set with compatible Ember-specific innovations for denser networks, “sleepy” (i.e. power saving) nodes and mobile nodes.

EmberZnet PRO 3.1 innovations mean:

  • Larger networks, scaling to potentially thousands of nodes enabled by the Stochastic Addressing, Many-to-One / Source Routing and Asymmetric Link Handling features in ZigBee PRO
  • Denser networks, enabled by Ember’s Intelligent Table Management that assures network stability even when dozens of routing nodes are within close proximity
  • “Sleepier” networks, extending the power-saving benefits of sleepy end devices through compatible Ember enhancements
  • More mobile networks, offering explicit handling of end nodes that may move within the ZigBee network topology, such as remote controls and key fobs
  • Highly secure networks, implementing many of the optional ZigBee PRO security extensions for advanced network encryption and device security
  • More resilient networks, allowing the ability for entire ZigBee networks to change channels in the face of interference through ZigBee PRO’s Frequency Agility features

Ember is also offering tools that help to accelerate the ZigBee approval of products by simulating the test house routines that manufacturers will face when they submit their end products to ZigBee listed test houses for official ZigBee PRO certification.

Others ZigBee houses are sure to follow suit and Q1 2008 should see a proliferation of comparable, compatible offerings based upon the ZigBee PRO standard.

So when will all this technology actually be available? Well Ember Corporation will almost certainly be first out of the blocks and they are finishing beta testing of EmberZnet PRO 3.1 right now. Their version of ZigBee PRO will come bundled free with their EM250 ZigBee system-on-chip and EM260 ZigBee network co-processors. As with previous Ember products selected as ZigBee “Golden Node” platforms, EmberZNet PRO 3.1 will be a ZigBee Certified Platform upon completion of formal testing by the ZigBee Alliance.

That final process is expected to occur around Christmas together with the release of an increasing number of other ZigBee PRO products from the other serious players in the ZigBee mesh networking technology market throughout Q1 2008.

So if you were waiting for ZigBee to arrive then you need wait no more. It is here and it is “finished.”

About Telegesis
Telegesis is the UK’s leading designer and manufacturer of ZigBee module technology. Telegesis ZigBee products are based upon Ember mesh networking technology and built around the EM250 chip from Ember Corporation and the SN250 chip from STMicroelectronics. All Telegesis products carry the acclaimed Telegesis AT style command interface for direct access to the ZigBee functionality.

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Ember, Ember Enabled, EmberZNet and the Ember logo are trademarks of Ember Corporation. ZigBee is a trademark of the ZigBee Alliance. Telegesis is the trademark of Telegesis UK Ltd.