Push the Limit of WiFi based Localization for Smartphones

safetroubledMobile - Wireless

Nov 24, 2013 (3 years and 9 months ago)

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ECE Department



Push the Limit of WiFi based
Localization for Smartphones


BY
Hongbo Liu

Ph.D candidate of Electrical and Computer Engineering

Stevens Institute of Technology



ABSTRACT

Indoor localization is a critical enabler for location based smartphone
applications. In many environments (e.g., airport terminals, railway stations and
shopping malls), the location helps users access navigation, merchandise and
promotion information; bu
sinesses need it to understand the patterns of customer
visit and stay. Although there have been some recent commercial offerings and a
plethora of academic work on indoor localization, highly accurate indoor
localization on smartphones remains elusive. Ba
sed on our empirical
investigation of the suitability of WiFi localization, we find that although
reasonable accuracy (e.g., 3~4m) can be achieved, there always exist large
errors (e.g., 6~8m) unacceptable for many scenarios. The root cause is the
existenc
e of distinct locations with similar signatures, which is a fundamental limit
of pure WiFi based methods. We also observe that smartphones are gradually
woven into our social life and usually a high density of them exist in public
spaces. The relative posi
tions of nearby peer devices could be used as physical
constraints on the possible location of a smartphone. Inspired by high densities
of smartphones in public spaces, we propose a peer assisted localization
approach to eliminate such large errors. It obt
ains accurate acoustic ranging
estimates among peer phones, then maps their locations jointly against WiFi
signature map subjecting to ranging constraints. We devise techniques for fast
acoustic ranging among multiple phones and build a prototype. Experime
nts
show that it can reduce the maximum and 80
-
percentile errors to as small as 2m
and 1m, in time no longer than the original WiFi scanning, with negligible impact
on battery lifetime.


BIOGRAPHY

Hongbo Liu is a Ph.D. candidate of the Electrical and Compu
ter Engineering
Department at Stevens Institute of Technology. His research interests include
information security & privacy, mobile computing and wireless localization
systems, wireless and sensor networks, and digital signal processing. He is
currently w
orking in the Data Analysis and Information SecuritY (DAISY) Lab with
Prof. Yingying Chen. He received his Bachelor's and Master’s degree in
Communication Engineering from Department of Communication and Information
Engineering at University of Electronic
Science and Technology of China in 2005
and 2008 respectively. He was the recipient of the Best Paper Award from the
ACM International Conference on Mobile Computing and Networking (MobiCom)
2011. He was also the recipient of the Outstanding Undergraduate
Student
Thesis Award 2005.






EVENT DETAILS


DATE:

Wednesday
,
Sep

1
9
th
, 2012


TIME:

3
:00PM


4
:00
PM


LOCATION:

Babbio

Center, Room
319

Stevens Institute of

Technology


ATTENDANCE:

This event is open to all.
Stevens’ Faculty,

Students,
Staff and Invited
Guests


RSVP:

For more informati
on contact

Prof.
Yingying Chen

yingying.chen@stevens.edu