Four or five years ago, ZigBee had a burst of publicity. Why has it gone quiet since then?

ZigBee promised to integrate wireless sensors - light switches, burglar alarms and just about everything else - into mesh networks, using economical low-power, low-speed connections. Using links defined by IEEE 802.15.4, it promised networked devices with a battery life of five or ten years, that could be installed and left to run.

But what's happened? We've yet to see any ZigBee installations, and we keep hearing of competitors, including proprietary technology like Z-Wave's Zensys, new systems that use IP over 802.15.4, and from Ultra-Low Power Bluetooth, formerly known as WiBree.

We asked Bob Heile, chair of the ZigBee Alliance what is going on.

We haven't heard much about ZigBee for the last couple of years. Is it just progressing rather quietly?

We're moving to complete the specification, and building support in the automation space. It's been very exciting over the last year and a half. We've had a lot of adoption in our core areas.

The most exciting thing has been the discovery of ZigBee by the energy industry. They are looking for a ready made standard in-building solution, for electricity meters. They want to do load control, and have an infrastructure which can start to slow growth in electric demand, using real time pricing information, in lieu of building more power plants than they could ever build.

Have there been any deployments?

There are big deployments in Sweden from the electricity side, since Sweden modified its regulations. Two years ago the Swedes only required electricity meters to be read once a year. They decided to increase that to once a month. To meet this, and accomplish other goals, the utilities are moving aggressively to using interactive, two-directional communications.

A lot of cities and towns are moving in the direction of interactive meters. Gothenburg is rolling out ZigBee-enabled meters across the entire city. They will network inside and outside buildings, and tie up every 200 metres in a communication point. This will be complete and up and running, by June 2009.

There are other projects in Ontario, and Texas. There could look be 500,000 to 600,000 ZigBee enabled meters this year, and there are a lot of trials going on. Over the next three years, there are over 70 million meters under RFP, and a good chunk could go to ZigBee technology.