1. 後卓越計畫進度報告 中央大學許健平教授 淡江大學張志勇教授 94/06/05 Obstacle-Free Routing for WSNs

2. Motivation Obstacles are existed in WSNs Unbalanced deployment Some sensor nodes are failure after working for a long time Animus interference Natural effects river and mountain Packet transmission is inefficient or blocked if the obstacle is encountered

3. Obstacle Detection Phase (1st) Goal: find minimal number of border nodes sensor Node border nodes

4. Normalization Phase(2nd) sensor node border node corner node Goal: Normalize the obstacle shape

5. Forbidden Region Construction Phase(3rd) Sensor Sink A B J K L sensor node border node corner node forbidden boundary node Goal: Construct a forbidden region to avoid the packet entering obstacle region.

6. Packet Guiding Phase(4th) Sensor Node Routing Path 1 Routing Path 2 Sensor Sink

7. Future Research Sensor O2O2 Sink O1O1 Multiple Obstacles At time t o, O 2 exists, optimal routing path is R 2 At time t 1, O 1 dynamically exists, optimal routing path is R 1 R1R1 R2R2 R3R3 R4R4