in Wireless Sensor Networks

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21 Νοε 2013 (πριν από 3 χρόνια και 11 μήνες)

77 εμφανίσεις


Enhancing RSSI
-
based

Tracking Accuracy

in Wireless Sensor Networks



Bracha Hod

Based on a joint work with:

Gaddi Blumrosen, Dr. Tal Anker,

Prof. Danny Dolev and Prof. Boris Rubinsky

Motivation


Precise tracking systems in an indoor environment
are important in many fields, such as sports and
medicine


Wireless sensor networks can provide motion and
location tracking



RSSI
-
based Tracking


RSSI (Received Signal Strength Indicator) is a
measurement of the signal power on a radio link


RSSI
-
based tracking includes two steps


Range estimation

between pairs of nodes based on
RSSI measurements


Location estimation

using geometric or statistical
methods applied on the information from all nodes


Simple and cheap, widely used, low
-
power
consumption, and not suffer from any drift

Contribution


Existing RSSI
-
based tracking systems provide
a tracking accuracy in the scale of a meter


Variations in the wireless medium, reflections,
scatterers, multi
-
paths interference



Our RSSI
-
based tracking system


achieves an accuracy in


the order of a few centimeters


Close
-
proximity


High transmission rate

Setup


The mobile node transmits data packets


The static sensor nodes receive packets from
the mobile node and calculate the RSSI


The computer processes the information and
estimates the mobile node’s location


Close
-
proximity


Spatial
-
Temporal Correlation









Interpolation


Low
-
pass filter

Spatial
-
Temporal Correlation






Before post
-
processing





After median filter







After low
-
pass filter

High Transmission Rate


Error Analysis


Summary


We proposed a new RSSI
-
based tracking system
that achieves a high accuracy


Close
-
proximity


High transmission rate


Future work


Integration of RSSI measurements


with other motion sensors


More extensive experiments


Thank You!