1. Efficient Deployment Algorithms for Prolonging Network Lifetime and Ensuring Coverage in Wireless Sensor Networks Yong-hwan Kim cherish@kut.ac.kr Korea University of Technology and Education Laboratory of Intelligent Networks http://link.kut.ac.kr

2. Abstract Sensor deployment Initial sensor deployment Sensor relocation A goal of this paper 1. Extend the network lifetime 2. guarantee the coverage 2/8

3. Contents 1. Introduction 2. The sensor balanced deployment scheme 3. The proposed two-phased sensor deployment scheme 4. Simulation results 5. Conclusion 3/8

4. Introduction 4/8

5. Introduction Environment Consist of sensors, a sink node, sensing area Sensors can not able to be replaced or recharged Sensor devices are homogeneous Sing-hop or multi-hop transmission for the collected data Cluster structure 5/8

6. Introduction Motivation Previous work [7]  Move sensors from an initial unbalanced state to a balanced state  Balanced state – the number of sensors in each cluster is equal But, balanced state may not meet the goal of prolonging the network lifetime since the nodes that are near the sink may consume more energy than others 6/8

7. The sensor balanced deployment scheme 7/8

8. The sensor balanced deployment scheme N be the total number of sensor devices An r X r sensing region(area) The sink node is located at the lower left corner Euclidean coordinates (xi, yi), where 1<i<n and 0<xi,yi<r 8/8

9. The proposed two-phased sensor deployment scheme 9/8

10. The proposed scheme Previous work[1] 1. partition the sensing region into square areas  Each with equal size 10/8

11. The proposed scheme Previous work[2] 2. Create the communication graph  The vertex set  Each vertex corresponds to square area  represents the sink node  Let be the transmission range of sensor devices  Any two vertices are said to be existed an edge in If Euclidian distance( ) < 11/8

12. The proposed scheme The first phase [1] 1. Determine the energy consumption load function  denotes the expectation of energy consumption rate for square area within one event task is performed 2. Based on function, the sensor deploying function  denotes the number of sensors that will be deployed in  12/8

13. The proposed scheme The first phase [2] Determine the deployed number of sensor devices in each square area Based on these simulating results The simulation step 1. abnormal events occur in each square area 2. the routing path ( ) from 1’ square to sink node 3. the amount of energy consumption can be estimated 13/8

14. The proposed scheme The first phase [3] Events occur in each square area follows the uniform distribution  : the probability of an event occurring in The routing path is obtained the given static routing algorithm denote the energy consumption of node when node detects an event The energy consumption load function 14/8

15. The proposed scheme The first phase [4] The coefficient of sensor deploying ( ) with respect to each square area Based on the energy consumption load function  The sensor deploying function based on  The first condition is the coverage guarantee ( )  Let be the sensing range of a sensor device  the coverage lover bound of a square area 15/8

16. The first phase [5] - Example If data transmission energy = 4, others = 0 N = 80, = 15 The proposed scheme v1v2 v4v3 v0 16/8

17. The first phase [6] The proposed scheme 17/8

18. The proposed scheme The two phase Uniformly deploy sensor device into Using the sensor balanced deployment scheme Treating the square area as the whole sensing region The coordinate is located at the bottom left corner of the square area 18/8

19. Simulation results 19/8

20. Simulation results 20/8

21. Simulation results 21/8

22. Simulation results 22/8