Print this article

Comment

1 April 2005

ZigBee sensors live on five-year battery

ZigBee is a network architecture focusing on low-power networks for less demanding performance applications such as home automation, industrial automation, building automation, and toys.

While the integrity of the network is important, the emphasis is more upon power conservation for battery or other power-sensitive applications.

The ZigBee Alliance has supported the development of IEEE 802.15.4 for its purposes. Along the way, the former HomeRF Consortium dissolved and many of its former sponsors moved to support ZigBee.

Unlike other standards

The Wall Street Journal reported that thanks in part to this whimsically named wireless connection technology, homes, PCs, automobiles, and even certain branches of government may all function very differently in the not-too-distant future.

ZigBee is a new networking standard that allows a variety of low-power devices to communicate over an unregulated portion of the radio spectrum. It stands to join a crowded wireless technology field that already includes cellular phones, Bluetooth, Wi-Fi, and others.

But unlike those other standards, ZigBee can run for years on inexpensive batteries, eliminating the need to plug into electrical power. Hence, it holds huge promise in areas like energy conservation, automation, and agriculture.

Although ZigBee's underlying radio-communication technology isn't revolutionary, it goes well beyond single-purpose wireless devices, such as garage door openers and The Clapper that turns light on and off.

It allows wireless two-way communications between lights and switches, thermostats and furnaces, hotel-room air conditioners and the front desk, and central command posts.

It travels across greater distances and handles many sensors that linkup to perform different tasks.

Because ZigBee consumes very little power, a sensor and transmitter that report whether a door is open or closed, for example, can run for up to five years on a single double-A (AA) battery.

Soon, ZigBee will allow different manufacturers to create wireless sensors that one can manage over a single network. Remote controls powered by ZigBee don't need line-of-sight as infrared controllers do. Home PCs or independent wireless controllers can manage ZigBee networks.

ZigBee received a big boost late last year, when more than 100 companies including Honeywell International Inc., Philips Electronics NV, Samsung Electronics Co., and Motorola Inc., agreed to make new devices that can communicate using the technology. Already, it's catching on big time.

Analysts estimate the number of ZigBee devices sold this year will be up tenfold over last year with further rapid growth through 2010.

One user is oil giant BP

Potential applications for ZigBee, on both the home and business fronts, are numerous.

U.K.-based Raymarine Ltd. unveiled a $1,100 a ZigBee-based remote controller for its small-boat autopilots that will allow sport fishermen to change course without leaving their fishing chairs.

Even the government is bullish on the technology. In February, the U.S. Energy Department hired Dust Networks to examine how wireless dimmers could cut electricity use. Blanketing offices with the controls could reduce commercial building light use by 30%, saving $8 billion a year, the department estimates.

Crossbow Technology Inc., of San Jose, Calif., builds motes containing wireless sensors and low-power radios that can work for a variety of commercial applications. Michael Horton, Crossbow's president, says some companies' managers have installed its low-priced, tiny temperature sensors and accelerometers on expensive machines to send alerts when equipment starts vibrating too much or overheats. One user is oil giant BP PLC, which uses Crossbow motes to monitor machinery on its tankers.

ZigBee is even helping scientists glean information about the little-known Leach's storm petrel. Sensors placed in 150 underground nests on Great Duck Island, off the coast of Maine, transmit otherwise unobtainable data wirelessly and have revealed the birds dig burrows that maintain precise temperatures and high humidity, which may be needed because their fragile eggs take a long time to hatch.

As prices drop, sensor makers including ZigBee are hoping to sell farmers on deploying the devices to monitor soil humidity and start irrigation just when crops need it, thus saving water.

One Crossbow customer has nailed temperature sensors to stakes every 200 yards to keep track of the micro-climates in the vineyard and to have a better idea of precisely when to pick grapes for maximum sugar content.

Nicholas Sheble (nsheble@isa.org) edits the Sensors department.