1. 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

2. 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

3. 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

4. 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

5. 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

6. Close-proximity

7. Spatial-Temporal Correlation
Interpolation Low-pass filter

8. Spatial-Temporal Correlation
Before post-processing
After median filter
After low-pass filter

9. High Transmission Rate

10. Error Analysis

11. 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

12. Thank You!