Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Wi-Fi Finds the Way

24.06.2004


In the concrete canyons of city centres, GPS satellite positioning systems often fail because high buildings block the signals they rely on. But an unlikely back-up for GPS is emerging: Wi-Fi. A Wi-Fi based positioning system developed in the US and the UK works best where GPS fails: in cities and inside cavernous complexes like shopping malls. And because cheap Wi-Fi technology is already appearing on a raft of gadgets like PDAs, cellphones and laptops faster than more expensive GPS receivers are, the developers predict that Wi-Fi could become central to new location-based applications.

They say emergency services in particular could find the system an essential back-up. Wi-Fi allows people to connect devices wirelessly to the internet. Base stations are springing up in coffee bars, libraries, universities, airports, phone booths and other public places. Each base station broadcasts a radio signal to announce its presence to devices within a range of around 100 metres. This signal incorporates a unique network address code that identifies the base station. Anthony LaMarca of the University of Washington in Seattle, and colleagues at Intel’s research labs in both the US and the UK, have developed software that constantly records the radio signal strengths from nearby base stations. It can identify the origin of the signal from a database giving the location of 26,000 Wi-Fi base stations in the US and the UK. Using the signal strength from at least three base stations, it can then triangulate the user’s location. "This is a poor man’s GPS," says team member Bill Schilit of Intel Research in Santa Clara, California.

At the moment, the new system, called Place Lab, is not as precise as GPS. It can provide accuracy to within 20 to 30 metres, whereas the GPS average is 8 to 10 metres. But with improved algorithms that take into account, say, the height of the base station above the ground, or the building materials in the vicinity, LaMarca says "we could get on a par with GPS" in an area as densely served with Wi-Fi as downtown Seattle. The growth of Wi-Fi means all urban areas should one day have similar blanket coverage. Once a user has Wi-Fi they won’t have to buy extra hardware to use Place Lab, and the software can be downloaded for free from http://www.placelab.org. Increasingly, laptops, cellphones and PDAs are being sold with Wi-Fi capability already installed for around an extra $30. "This is not the case with GPS," LaMarca points out.



Researchers at the University of Glasgow in the UK are planning to test Place Lab’s positioning ability on volunteers equipped with Wi-Fi enabled PDAs during this year’s Edinburgh Festival in August - despite the city’s patchy Wi-Fi coverage. And next year, new software for the PDAs will help people find their way around Edinburgh and keep track of their friends. Place Lab is not the first software to use Wi-Fi for positioning but- belying its name- it is the first to bring the idea out of the lab and into the real world. "Microsoft once set up arrays of access points in a lab, but we are using the existing Wi-Fi infrastructure," LaMarca says. Place Lab has already been tested in Berkeley, San Diego, Seattle, Manhattan and Cambridge in the UK, among other cities. The Place Lab team have other applications in the works. Jason Hong, a computer scientist at the University of California, Berkeley, is developing a "location-aware" version of Microsoft’s Instant Messenger software. This will allow users to transmit their Place Lab data so that "buddy lists" will not only reveal when friends are online, but also where they are. It could also be used to direct a user to the nearest petrol station or coffee bar, remind them their books are overdue as they pass the library, or warn them of traffic congestion ahead.

| newswise
Further information:
http://www.newscientist.com

More articles from Information Technology:

nachricht Study suggests buried Internet infrastructure at risk as sea levels rise
18.07.2018 | University of Wisconsin-Madison

nachricht Microscopic trampoline may help create networks of quantum computers
17.07.2018 | University of Colorado at Boulder

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>