1. 1/24 Experimental Analysis of Area Localization Scheme for Sensor Networks Vijay Chandrasekhar 1, Zhi Ang Eu 1, Winston K.G. Seah 1,2 and Arumugam Pillai Venkatesh 2 1 Network Technology Department Institute For Infocomm Research, A*STAR, Singapore 2 National University of Singapore WCNC2007

2. 2/24 Outline Introduction Related Work Enhancement To Area Localization Scheme Experimental Setup and Results Conclusions

3. 3/24 Introduction The location information is important for a large wireless sensor network. To identify the exact location of every sensor may not be feasible or necessary.

4. 4/24 Introduction Localization algorithm Range based Add additional hardware (e.g: GPS) Range-free based Location information can be obtained RSSI Time of arrival or time difference of arrival Angle of arrival measurements Probabilistic techniques

5. 5/24 Related Work- ALS Algorithm Q. Yao, S.K. Tan, Y. Ge, B.S. Yeo, Q. Yin, “An Area Localization Scheme for Large Wireless Sensor Networks”,Proceedings of the IEEE 61st Semiannual Vehicular Technology Conference (VTC2005-Spring), May 30 - Jun 1, 2005, Stockholm, Sweden.

6. 6/24 Related Work- ALS Algorithm There are three types of nodes in ALS Reference nodes Sensor nodes Sinks

7. 7/24 Related Work- ALS Algorithm Reference nodes Send out beacon signal to help the sensor nodes construct their signal coordinates. Equipped with GPS or placed in pre- determined locations.

8. 8/24 Related Work- ALS Algorithm Sensor nodes Monitor environment. Use a simple signal coordinate to indicate their information to the sinks. Only knows its own signal coordinate and attach this to the data. Example:

9. 9/24 Related Work- ALS Algorithm Sinks Charge of collecting information from sensor node and then processing the information. Knows the location of all the reference node and there respective transmitted power level.

10. 10/24 Related Work- ALS Algorithm A BC D Reference node Power Level 1 Power Level 2

11. 11/24 Related Work- ALS Algorithm

12. 12/24 Related Work- ALS Algorithm Ideal propagation model ALS only functions in an ideal radio channel.

13. 13/24 Enhancement To ALS Shadowing Propagation model

14. 14/24 Enhancement To ALS

15. 15/24 Enhancement To ALS

16. 16/24 Enhancement To ALS Shadow and fading effects ALS did not consider shadowing and fading. Use overlapping ranges to construct the signal map.

17. 17/24 Experimental Setup and Results Nodes :MicaZ motes Area size: Indoor 10m x 10m Multi-purpose hall (MPH) Outdoor 30m x 30m Open field Park 35 Sensors indoor 30 Sensors outdoor 8 reference nodes

18. 18/24 Experimental Setup and Results The circular ring between radii √(A/π) and 2√(A/π) is defined as the 1-hop neighboring region of the node.

19. 19/24 Experimental Setup and Results Summary of experimental results

20. 20/24 Experimental Setup and Results Actual versus Estimated Locations of Sensors (MPH)

21. 21/24 Experimental Setup and Results Actual versus Estimated Locations of Sensors (Open Field)

22. 22/24 Experimental Setup and Results Actual versus Estimated Locations of Sensors (Park with obstacles)

23. 23/24 Experimental Setup and Results

24. 24/24 Conclusions In this paper, they Modified and implemented the ALS algorithm on a experimental study. ALS is comparable or better than other implemented localization scheme, and ALS has lower complexity. Future works They will incorporate routing protocols on ALS algorithm.

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