This paper is included in the Proceedings of the
13th USENIX Symposium on Networked Systems
Design and Implementation (NSDI ’16).
March 16–18, 2016 • Santa Clara, CA, USA
Abstract – We present Chronos, a system that enables
a single WiFi access point to localize clients to within tens
of centimeters. Such a system can bring indoor positioning
to homes and small businesses which typically have a
single access point.
The key enabler underlying Chronos is a novel algorithm
that can compute sub-nanosecond time-of-flight using
commodity WiFi cards. By multiplying the time-of-
flight with the speed of light, a MIMO access point computes
the distance between each of its antennas and the
client, hence localizing it. Our implementation on commodity
WiFi cards demonstrates that Chronos’s accuracy
is comparable to state-of-the-art localization systems,
which use four or five access points.