Self-Orienting Wireless Multimedia Sensor Networks for Maximizing Multimedia Coverage Nurcan Tezcan and Wenye Wang Department of Electrical and Computer Engineering North Carolina State University ICC 2008

Outline Introduction Self-Orientation Algorithm Performance Evaluation Conclusion

Introduction A common sensor network use the omni-directional sensing. the coverage problem Covered a plane by arranging the circles

Introduction In the multimedia sensor network The sensors have the unique feature of capturing direction-sensitive multimedia content

In the multimedia sensor network The video sensor can only capture the useful image in line of sight. The sensing area limited by the obstacles

Introduction Goal Each sensor node determines the most beneficial orientation Maximum multimedia sensing coverage Occlusion-free coverage

Multimedia Coverage Defined the FOV Field of View Visible Field of View Overlapping Field of View Occluded Field of View

Multimedia Coverage

Self-Orientation Algorithm Step 1 Step 2 Step 3 Step 4

Step 1 Sensor nodes send HOLLO_MSG Node ID Node location vFOV (visible FOV) New sensor node build the list of neighbor vFOV

Step 2 S i performs the Perimeter Test Pass S i selects the beneficial pose S i sends the POSE_ADV_MSG to the neighbors Fail Go to the next step 3

Perimeter Test

Perimeter Test (1 Test) The Example

Step 2 S i performs the Perimeter Test Pass S i selects the beneficial pose S i sends the POSE_ADV_MSG to the neighbors Fail Go to the next step 3 To check S i which has the visible FOV or not

Step 3 S i performs the Neighbor-Distance Test Pass S i sends the CANDIDATE_ACK_MSG To the neighbors who pass the N-D test If no xFOV occurs The S d send the ACK_POSE_MSG to the S i Fail go to the next step 4

Neighbor-Distance Test

If S i has visible FOV ( ) There is the overlapping field Neighbor-Distance Test D(1,5) d(1,5) d(1,4) d(1,3) d(1,2) S1S1 S2S2 S3S3 S4S4 S5S5 A G B C F H

Step 3 S i performs the Neighbor-Distance Test Pass S i sends the CANDIDATE_ACK_MSG To the neighbors who pass the N-D test The S d send the ACK_POSE_MSG to the S i Fail go to the next step 4

Step 4 If the perimeter test and neighbor-distance test are failed perform the Obstacle-Distance Test Select the beneficial pose

Obstacle-Distance Test

Performance Evaluation Simulator : NS2 Placement : random Sensing filed : 250 x 250 m 2 Node number : 50, 100, 150 Sensing range (Rs) : 30, 60 m

Performance Evaluation

Conclusion This paper propose a self-orienting algorithm Maximum multimedia sensing coverage Occlusion-free coverage Even in sparse network, the coverage is increased by using self-orienting algorithm instead random-orienting alorithm