Soon the world of GPS will be headed out of the parks and into shopping malls and buildings all over the country. Microsoft has released a study exploring technology they are currently researching to bring GPS indoors without the use of Wifi. According to the study, the solution to the indoor GPS problem is by attaching a steerable, high-gain, directional antenna to the front of the GPS receiver which helps attain location fixes using signal processing from the cloud with acquisition results from different directions over time.
The research team tested their theory with a 10×10 inch board with 16 antennas arranged in a ray in 31 random indoor single-story locations such as warehouses and shopping centers. They were able to obtain location fixes in 20 of them with a median error of less than 10 meters. According to Jie Liu, a principle researcher at Microsoft, this is a test that all conventional GPS receivers fail. With more research, Liu said he expected the technology to shrink to a more viable size.
Right now, indoor GPS is provided through a set of Wifi maps which infer user location based on the device-provided Wifi signature. The study states that they felt this method was time consuming and expensive, and the profiling is a continuing process because the number of Wifi access points change over time. However, with this new method, Microsoft would be able to pinpoint location without profiling or using unreliable Wifi connections–as long as the end device had the proper multiantenna configuration–with no additional infrastructure needed.
“People spend more than 80 percent of their time indoors,” Liu said in a blog post. “Location is key contextual information to enable smart services, such as Cortana. With GPS and Wifi-based solutions, people are taking outdoor location services for granted on mobile devices, but that experience has not been transformed to indoor environments.” The team did admit that not all indoor places can currently receive GPS signals and it is a work in progress.
This new research may completely change the way people use GPS. Someday soon it may be as common for shopping-mall lovers to GPS their way to the nearest Starbucks as it is for outdoor enthusiasts find their way around new trails.