Finding and Mending Barrier Gaps in Wireless Sensor Networks Anwar Saipulla Benyuan Liu Jie Wang Department of Computer Science University of Massachusetts Lowell Lowell, MA 01854, USA IEEE Globecom 2010

Outline Introduction Network model Two-phase algorithm Simulation Finding Mending Simulation Conclusion

Introduction Barrier coverage has been studied intensively in recent years Military operations Homeland security Hazardous area

Introduction Barrier coverage using wireless sensor networks aims at detecting intruders that attempt to cross the network Area A Area B

Introduction-motivation Barrier gap Malfunctioning Run out of power Environmental factor Barrier gap Barrier gap

Introduction-goal Forming new barrier coverage Finding barrier gaps Relocating mobile sensors to the desired locations

Network model

Network model ns stationary nm mobile sensors Sensing range = r i-th sensor’s target landing point w l Ex: n = ns + nm 1 2 3 4 5 6 7 8 9 5 15 25 35 45 l = 50

Network model P(any crossing path is covered) = 1 w l

Finding Mending

Find barrier gaps Finding Mending s t

Find barrier gaps s t x x1 y y1 Gap (x,y) Gap (x1,y1) Finding Mending Dist>2r s t Dist>2r Gap (x,y) Gap (x1,y1)

Mend barrier gaps Finding Mending Ex: grid point = 4 x y g1 g2 g3 g4

Mend barrier gaps Finding Mending m1 m3 m4 x y m2 m5

Mend barrier gaps 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 S D Finding Mending S 1 1 1 1 1 m1 m3 m2 m4 m5 1 1 1 1 1 1 1 1 1 1 1 1 1 D

Mend barrier gaps Finding Mending m1 m3 m4 x y m2 m5

Mend barrier gaps 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 S D Finding Mending S 1 1 1 1 1 m1 m3 m2 m4 m5 1 1 1 1 1 1 1 1 1 1 1 1 1 D

Mend barrier gaps Finding Mending m1 m3 m4 x y m2 m5

Simulation

Simulation Parameter Value Filed size 1000*300 Sensing range 10 Stationary sensors 100 Offset variances 10, 30, 50

Simulation result

Simulation result

Conclusion The authors devise a two-phase algorithm First finding barrier gaps in the network Then relocating mobile sensors to desirable locations to fill the gaps Simulation results show that our algorithm can effectively improve barrier coverage of a wireless sensor networks

Wireless Access and Networking Technology Lab (WANT Lab) Thanks for your attention n t n u f r y n h o t