Researchers at the IMDEA Networks Institute in Madrid, Spain, say they have come up with a way to improve indoor location positioning by using time-of-flight (ToF) measurements and adding software upgrades to commercial off-the-shelf 802.11 chipsets integrated into access points.
The solution reduces system implementation costs by using $6 Wi-Fi chipsets to collect and filter measurements, and it features a novel filtering technique that requires just a few samples to estimate the distance range, according to the research institute.
In this case, ToF is a measurement of time it takes a radio wave to move from the access points to the smartphone--a known concept but one that hasn't always been easy to get right. The researchers also say they're solving problems that arise with multipath reflections in indoor environments. Article