Wireless sensors ready to go global?

But that day is approaching, the chief executive officer of sensor network company Crossbow Technology told a conference here Tuesday. Crossbow CEO Mike Horton likened the power of widespread sensor networks to a tornado.

"This tornado is very much going to come," Horton said.

Wireless sensor networks are made up of sensors of varying types, radios and equipment for processing the information gathered. Thanks to factors such as smaller sensors and tiny, relatively cheap radios being built into computer chips, networks of wireless sensors are seen as having a promising future in areas including building maintenance and homeland security.

Earlier this year, research firm ON World predictedthat more than a half-billion "nodes" will ship for wireless sensor applications in 2010 for a market worth more than $7 billion.

But many obstacles stand in the way of such a rosy future, according to speakers at the conference, which was sponsored by the Institute of Electrical and Electronics Engineers Communications Society.

Among the roadblocks to wireless sensor networks is making them easy to use, said Suresh Singh, professor of computer science at Portland State University. "You can't really expect the users to do what the technical people do in setting up wireless networks," Singh said.

Privacy questions and a lack of standards in the field are other concerns. So is the ability of remote sensors to scrimp on energy, argued Robert Poor, chief technology officer of Ember, which makes semiconductors for wireless networks. "You really need to make systems that last for a very long time on batteries," he said.

Despite the challenges, Crossbow is seeing some success. The company has shipped more than 500,000 wireless sensors, which sell for about $25 to $150, depending on volume and product type. Crossbow's sensors perform tasks ranging from tracking bird behavior on a remote island to monitoring engine equipment on a British Petroleum oil tanker.

At the conference, a Crossbow official showed off one of the company's sensor "motes." Smaller than a computer mouse, the device combines a radio transceiver and processor chip with a "sensor board" that can include sensors for such things as light, temperature and movement. The company, formed in 1995, has been profitable for the past two years, Horton said.

Tuesday's conference also focused on so-called ad-hoc wireless networks. Such networks, sometimes referred to as "mesh" networks, involve devices communicating with each other through a chain of links, rather than relying on a central control point. The concept is similar to the way peer-to-peer file-sharing programs work on the Internet.

Conference attendees heard a bullish prognosis for mesh networks from Scott Burke, vice president of engineering at PacketHop, which makes applications for wireless mesh networks. Burke said mesh technology threatens conventional hub-and-spoke arrangements, which would include Internet access points connecting wirelessly to a number of computers. "These models don't make sense when you can use peer-to-peer (communications)," he said.