- Authors
-
Andrew M. Ladd
Kostas E. Bekris
Algis Rudys
Lydia E. Kavraki
Dan S. Wallach
- Abstract
-
A key subproblem in the construction of location-aware systems is the
determination of the position of a mobile device. This article
describes the design, implementation and analysis of a system for
determining position inside a building from measured RF signal
strengths of packets on an IEEE 802.11b wireless Ethernet
network. Previous approaches to location-awareness with RF signals
have been severely hampered by non-Gaussian signals, noise, and
complex correlations due to multi-path effects, interference and
absorption. The design of our system begins with the observation that
determining position from complex, noisy and non-Gaussian signals is a
wellstudied problem in the field of robotics. Using only off-the-shelf
hardware, we achieve robust position estimation to within a meter in
our experimental context and after adequate training of our system. We
can also coarsely determine our orientation and can track our position
as we move. Our results show that we can localize a stationary device
to within 1.5 meters over 80% of the time and track a moving device to
within 1 meter over 50% of the time. Both localization and tracking
run in real-time. By applying recent advances in probabilistic
inference of position and sensor fusion from noisy signals, we show
that the RF emissions from base stations as measured by off-the-shelf
wireless Ethernet cards are sufficiently rich in information to permit
a mobile device to reliably track its location.
- Published
-
Wireless Networks, Volume 11, Number 1-2, January 2005, 189-204.
- BibTEX Entry
@Article{,
author = {Andrew M. Ladd and Kostas E. Bekris and Algis Rudys and Lydia E. Kavraki and Dan S. Wallach},
title = {Robotics-Based Location Sensing Using Wireless {Ethernet}},
journal = {Wireless Networks},
year = 2005,
volume = 11,
number = 1--2,
pages = {189--204},
month = jan
}