1. Power-Aware Topology Control for Wireless Ad-Hoc Networks Wonseok Baek and C.-C. Jay Kuo Department of Electrical Engineering University of Southern California Los Angeles, CA 90089, USA David S. L. Wei Department of Computer and Information Science Fordham University Bronx, NY 10458, USA WCNC 2006

2. Outline Introduction Related Works Proposed Algorithm Performance Evaluation

3. Introduction Topology control  Prolong the network life time  Improve the network throughput Topology control algorithms  Power-aware topology control  Power-efficient topology control

4. Related Works “Design and analysis of an MSTbased topology control algorithm,” IEEE INFOCOM 2003  Collect the location information of nodes within the maximum transmission range  Construct a local MST  Global connectivity  Node degree is bounded by 6

5. Related Works “SPT-based power-efficient topology control for wireless ad hoc Networks,” IEEE MILCOM 2004  Collect the location information of nodes  Construct a local SPT  The minimum-energy path  Global connectivity

6. Problem Description The power-efficient topology control algorithm  Uneven power consumption The power-aware routing algorithm  The complexity is high

7. Proposed Algorithm A class of power-efficient algorithm must satisfy the following requirement :  Distributed  Based on the link cost  Bi-directional links  Global connectivity

8. Proposed Algorithm Weighted Link cost Topology Construction through Power- Aware Node classification

9. Proposed Algorithm - Weighted Link cost Link cost : Weighted link cost :

10. Topology Construction through Power-Aware Node classification The core node set  The residual energy level is above the threshold  Form a virtual backbone A power-efficient topology control algorithm The weighted link cost

11. Topology Construction through Power-Aware Node classification The non-core node set  Active node set One core node is within its transmission range  Passive node set No core node is within its transmission range

12. Non-core node set Active node connectivity  Exchange the connectivity information with one-hop neighboring active nodes AC B D CB A A B C

13. Non-core node set Active node’s two properties  One-hop away from core node  Guarantee the connectivity

14. Non-core node set The procedure for passive node connectivity is the same as that of active node.

15. Performance Evaluation 50 nodes Area: 750m *750m Max transmission range: 250m Packet Size: fixed

16. Performance Evaluation Metrics  The network lifetime  The network partition time  The node decreasing time  The number of delivered packets  The number of dead nodes  The packet delivery ratio

17. Performance Evaluation The mean and standard deviation network lifetime

18. Performance Evaluation The network partition time

19. Performance Evaluation

20. Network lifetimeNetwork partition time