SpinLoc: Indoor localization
Spin once to know your location
Souvik Sen
Duke University
souvik.sen@duke.edu
Romit Roy Choudhury
Duke University
romit.rc@duke.edu
Srihari Nelakuditi
University of South Carolina
srihari@cse.sc.edu
Presented by
Mallika Kogatam
mkogatam@cs.odu.edu
Indoor Localization
• Localization: To locate a device.
• Why not GPS?
• Wardriving/ Warwalking: Searching for a Wi-fi
network while changing location.
• Cost and human effort associated with other
indoor localization methods.
SpinLoc: Introduction
• Hypothesis: Maximum attenuation is observed
when the human is in between the device and
the AP.
Signal Transmission in Indoor environment
• EDP (Energy of Direct Path) Vs RSSS (Receiving
signal strength)
EDP Vs RSSS
Filtering the signal
EDP Vs Orientation
• In all cases, we have least EDP at 180 degrees.
Choosing APs based on signal strength
Performance Evaluation
• Angle error reduces with increasing SNR
• Error reduces with increasing APs
Spinloc Limitations and future research
• Requires user to spin once.
• Depends on availability of atleast 3 APs with
high SNR.
• Results could vary with increasing crowd.
• Need to be able to localize based on turns
instead of 360 degree rotation.
• Should be able to constantly localize without
user making full rotation.
Queries??
Thanks and regards
Mallika Kogatam