Newswise — Because faint signals don’t penetrate buildings well, you can’t easily find your way around indoors using the Global Positioning System (or other satellite-based navigation systems). But there are radiolocation systems that can help. The most developed scheme at this point uses Wi-Fi access points as beacons of opportunity, computing position based on which access points are detected and how strong their signals are. But there are other, more precise methods available, including ultrawideband systems, which in theory can ascertain positions to within 10 centimeters. Most likely, though, in the future your smartphone will help you find your way around indoors using a combination of sensor measurements, some not involving radiolocation at all.

For a faxed copy of the article (“You Are Here,” by David Schneider, IEEE Spectrum, December 2013) or to arrange an interview, contact: Nancy T. Hantman, 212 419 7561, [email protected]