1. Chinh T. Vu, Yingshu Li Computer Science Department Georgia State University IEEE percom 2009 Delaunay-triangulation based complete coverage in wireless sensor networks

2. Outline Introduction Protocol Simulation Conclusion

3. Introduction The coverage problems for sensor networks can be categorized into three broad types  Barrier Coverage  Target Coverage  Area Coverage A

4. Introduction The coverage problems for sensor networks can be categorized into three broad types  Barrier Coverage  Target Coverage  Area Coverage A Target point

5. Introduction The coverage problems for sensor networks can be categorized into three broad types  Barrier Coverage  Target Coverage  Area Coverage A

6. Introduction Equilateral triangulation with each edge as has the minimal redundant coverage A

7. Introduction Random sensor deployment and variable sensing radii A

8. Motivation Overlap Uncovered hole A B E D C A B E D C

9. Goal The monitored area can be completely covered. Minimize the energy consumption and extend the lifetime of networks.

10. IDT Algorithm Step 1. Build the local Delaunay triangulation Step 2. Determine weighted centroid of Delaunay triangulation Step 3. Sensors at border increase sensing ranges

11. Step 1. Delaunay Triangulation (DT) Empty Circle Property Nearest P1P1 P2P2 P4P4 P3P3 P1P1 P2P2 P4P4 P3P3

12. Step 1. Delaunay Triangulation (DT) Empty Circle Property Nearest A B E D C A B E D C

13. Step 1. P1P1 P4P4 P8P8 P5P5 P2P2 P3P3 P7P7 P6P6 P9P9

14. P1P1 P4P4 P8P8 P5P5 P2P2 P3P3 P7P7 P6P6 P9P9 Delaunay triangulation

15. Step 1. P1P1 P4P4 P8P8 P5P5 P2P2 P3P3 P7P7 P6P6 P9P9

16. Step 2. E(s) : sensor s’s current residual energy S x : x coordinate S y : y coordinate (1.5, 1.6) (2, 1)(1, 1) A BC IDE(s) A0.5 B C

17. Step 2. E(s) : sensor s’s current residual energy S x : x coordinate S y : y coordinate (1.5, 1.6) (2, 1)(1, 1) A BC IDE(s) A0.5 B C1

18. Step 2. E(s) : sensor s’s current residual energy S x : x coordinate S y : y coordinate (1.5, 1.6) (2, 1)(1, 1) A BC IDE(s) A0.5 B C0

19. Example A B E D C

20. Problem A B C boundary

21. Step 1. A B C D E G F

22. A B C D E G F

23. A B C D E G F

24. Step 2. A B C D E G F

25. A B C D E G F

26. A B C D E G F

27. Step 3. A B C D E G F

28. Define priority of a node as A B C D E G F E has the highest priority & NOT completely perimeter- covered G has the highest priority & NOT completely perimeter- covered

29. Simulation ParameterValue Network size800 m X 400 m Number of sensors100 ~ 500 Energy range100 ~ 120 mJoules Maximum sensing range100 m

30. Simulation

33. Conclusion They deal with the area coverage problem with variable sensing radii variable sensing radii in WSN Using variable sensing radii variable sensing radii in WSN by improving the energy balancing The monitored area can be completely covered

34. Thank you~