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
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

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!