MAGNETIC SENSORS TURN CELL PHONES INTO LOCATORS
By Jeff Karoub
Small Times Staff Writer
Aug. 4, 2004 - You're stuck in traffic in an unfamiliar town on a business trip. The Middle Eastern restaurant just up the street looks nice, but how do you know if its shish kabob is succulent or the tabbouleh is to-die-for? How do you know if you can afford an entrée, much less an appetizer?
You reach for your mobile phone to call, but what do you think they're going to say? Don't put the phone away; just point it at the joint. Then, presto: The phone's display shows a few good reviews, a reasonably priced menu, and an electronic coupon. Dinner is a done deal. You park that rental car and dig in, bon appetit , or, as the host may say as you walk in, sahtein .
Cell phones are starting to provide similar gastronomic assistance, thanks to the emerging field of location-based services.
Honeywell International has developed micromachined magnetic sensors for mobile phones as part of an electronic compass and navigation system. Honeywell’s Solid State Electronics Center in Plymouth, Minn., is making millions of the anisotropic magneto-resistive (AMR) sensors for several unidentified but major mobile phone makers.
The sensor-enabled phones are being launched this year – first in Europe, followed closely by Asia. Eventually, the technology will make its way in phones manufactured in North America.
“I like to think of location-based services as a Yellow Pages book in your phone,” said Mark Amundson, an applications engineer for magnetic sensors at Honeywell. “We’re providing the hardware nuts and bolts to enable these services.”
Inside a wireless phone, AMR sensors use the surrounding magnetic field to determine direction. The phone sends the data to the phone service provider, which can determine the targeted business, and transfer desired content back to the phone.
The sensor, which is made using MEMS fabrication techniques, also benefits by having microscale sensing kin on board. By integrating AMR with two- or three-axis tilt sensors, the phones can be pointed in any direction. That’s unlike traditional compasses, which must be held flat.
Amundson said the technology isn't new. Honeywell has been making AMR sensors for automotive compasses for years, but the wireless industry has demanded smaller and more accurate sensors. The new application area also promises much higher volumes, he said.
It also compels competitors. Royal Philips Electronics makes its own AMR sensors. California-based Pharos Science and Applications Inc. offers Smart Navigator , a subscriber-based system that combines real-time traffic data and points-of-interest lookup.
Amundson said that service up until now has been subscriber-based. Broad acceptance would require a model that gets the businesses and others to buy into the database.
“Customers don't want to pay for that service. People who will pay are businesses, much like they pay for Yellow Pages ads,” he said. “This is the money trail. … You’re not going to get people to knock down your door unless there’s someone wanting to do that.