1. 1 Reorganization in OCO Presented By: Aiyaz Amin Paniwala Saurav Kumar Bengani

2. 2 Outline Introduction to Reorganization in WSN Introduction to Reorganization in WSN Importance of Reorganization in WSN Importance of Reorganization in WSN OCO in WSN OCO in WSN OCO Reorganization Algorithm OCO Reorganization Algorithm Conditions for the Algorithm Conditions for the Algorithm References References

3. 3 Introduction to Reorganization in WSN Nodes have limited resources for power Nodes have limited resources for power Nodes are exposed to natural and deliberate damages Nodes are exposed to natural and deliberate damages Node positions could change Node positions could change Overall network topology changes Overall network topology changes Reorganization provides methods to adjust to these changes Reorganization provides methods to adjust to these changes

4. 4 Importance of Reorganization in WSN Nodes may get exhausted, dead or repositioned Nodes may get exhausted, dead or repositioned WSN may become partially non functional WSN may become partially non functional Reorganization ensures recovery Reorganization ensures recovery Reorganization utilizes the redundancy in WSN Reorganization utilizes the redundancy in WSN Non-functional nodes can be replaced by Reorganizing the WSN Non-functional nodes can be replaced by Reorganizing the WSN

5. 5 OCO in WSN Consists of 4 phases Consists of 4 phases Position Collection Position Collection Processing Processing Tracking Tracking Maintenance Maintenance

6. 6 OCO Reorganization Algorithm Maintenance phase provides Reorganization Maintenance phase provides Reorganization Algorithms have been designed to handle different node failures Algorithms have been designed to handle different node failures Reorganization in OCO can be achieved by Reorganization in OCO can be achieved by Local Reorganization of Border Nodes Local Reorganization of Border Nodes Local Reorganization of Forwarding Nodes Local Reorganization of Forwarding Nodes Global Reorganization Global Reorganization

7. 7 Conditions for the Algorithm This part describes three conditions in which algorithm runs This part describes three conditions in which algorithm runs The conditions are : The conditions are : The dead node is a forwarding node The dead node is a forwarding node The dead node is a border node The dead node is a border node Several nodes in the network are dead Several nodes in the network are dead

8. 8 References “Maintenance Efficient Routing in Wireless Sensor Networks” Barroso, A.; Roedig, U.; Sreenan, C.; Embedded Networked Sensors, 2005. EmNetS-II. The Second IEEE Workshop on 30-31 May 2005 Page(s):97 - 106Embedded Networked Sensors, 2005. EmNetS-II. The Second IEEE Workshop on “Loop-Based Topology Maintenance in Wireless Sensor Networks” Volume 3619/2005 ISBN 978-3-540-28102-3 “Location-free Coverage Maintenance in Wireless Sensor Networks” Rong Zhengy, Guanghui Hezand Xue Liuz Department of Computer Science University of Houston Technical Report Number UH-CS-05-15, July 21, 2005