3-D Optical Wireless Localization

1. 1 3-D Optical Wireless Localization Mehmet Bilgi, Murat Yuksel, and Nezih Pala mbilgi@cse.unr.edu, yuksem@cse.unr.edu, npala@fiu.edu Computer Science and Engineering University of Nevada, Reno Project Website: http://www.cse.unr.edu/~yuksem/fso-manet.htm

2. 2 Outline • Motivation • Literature Survey • Packet-Based Simulation for Multi-Transceiver Structures • Localization Results • Summary and Conclusions

3. Localization in MANETs: Motivation • Providing contextual (location) information to data (motion, light measurement) is important • Geographical routing protocols can use localization: ID-to-Location mapping

4. Localization Approaches • Range-only • Orientation-only • Using both • Using landmarks and mapping (by robotics community)

5. Localization Literature • Range-only: • estimate ranges using power loss measurements, • assume simple path RF propagation • 3 anchors in 2D, 4 in 3D • Saravese ‘02 introduced a tuning phase • Whitehouse ‘02 used both signal strength and acoustic time of flight

6. Localization Literature • Orientation-only: • Use bearing and sectoring devices • Assign a direction to incoming signal • Niculescu ‘03 used a set of ultrasound and an antenna array • Found: localization error increases as one goes away from the anchors • Hybrid: Akella ‘07 used FSO to achieve 100% localization extent in a connected graph

7. Alignment Lists Contributed FSO propagation Accounting for noise Packet-Based Simulation of FSO-MANETs • NS-2 extensions

8. AODV target [n] target [0] target [k] Default NS-2 mobile node design had only 1 interface linklayer linklayer linklayer mac mac mac downtarget downtarget downtarget interfacequeue interfacequeue interfacequeue • • • • • • downtarget downtarget downtarget uptarget uptarget uptarget MAC MAC MAC downtarget downtarget uptarget uptarget uptarget Introduced alignment lists for each interface alignment list alignment list wirelessphy wirelessphy wirelessphy channel channel channel uptarget uptarget uptarget wireless channel Introduced FSO propagation at wireless channel Packet-Based Simulation of FSO-MANETs downtarget

9. 9 Location Location Tx Normal Tx Normal 3-D FSO Localization • Orientation-only localization with two localized neighbors: • A third node can triangulate using the advertised normals received from two other GPS-enabled nodes.

10. 10 3-D FSO Localization: Heuristics Arrival Times Anchor Distance Angular Priority

11. 11 3-D FSO Localization • How to select 2 out of many neighbors? Acceptable, predictable error

12. Increasing Trend Decreasing Trend GPS-Enabled Node Effect

13. High localization extent with reasonable overhead Message Exchange Overhead

14. 14 Conclusions • Introduced optical-only 3-D localization techniques, • Provided accuracy results with respect to: • Node density • GPS-enabled node count • Localization overhead • Localization is possible using a direction-only approach without extra hardware

15. 15 Future Work • Introduce realistic 3-D terrain models • Experiment using the prototype

16. 16 THE END Thank you! Acknowledgments This work was supported by the U.S. National Science Foundation under awards 0721452 and 0721612 and DARPA under contract W31P4Q-08-C-0080