A Survey of Energy-Efficient Scheduling Mechanisms in Sensor Networks

1. A Survey of Energy-Efficient Scheduling Mechanisms inSensor Networks Author：Lan Wang·Yang Xiao(2006) Presented by Yi Cheng Lin

2. Introduction Classification methodology Design assumptions Design objectives Energy saving modes of sensors Distributed scheduling mechanisms in non-hierarchical networks Classification Outline

3. Introduction • Sensor networks have a variety of application in both military and civil environment • These sensors usually operate on limited battery power • An important design objective: minimizing energy consumed by sensing and communication to extend the lifetime

4. Design assumptions

5. Design objectives

6. Energy saving modes of sensors

7. Distributed scheduling mechanisms in non-hierarchical networks • Random independent scheduling (RIS) • Time is divided into cycles based on time synchronization method • Active with probability p or go to sleep with probability 1-p (p determines the network life) • Sensor deployment strategies • Grid, random, uniform, and 2-dimensional Poisson

9. Sponsored sector • Preserving sensing coverage • Off- duty sponsors, sponsored sector • Use neighbor’s location information and sensing range

10. Maximization of sensor network life (MSNL) • K-coverage • Three states: active, idle or vulnerable • Nodes need to broadcast their state and energy level

11. Lightweight deployment-aware scheduling (LDAS) • No need location information • Each working node has a mechanism to know the number of working nodes in its neighbor

12. Probing environment and adaptive sensing (PEAS) • High-density sensor network in a harsh environment • Conserve energy by separating all the working nodes by a minimum distance of c • Unbalanced energy consumption • Optimal geographic density control (OGDC) • Maximize the number of sleeping sensor • Ensure 1-coverage and 1-connectivity • Minimize the overlapping area

13. Coverage configuration protocol (CCP) • Maintain K-coverage and K-connectivity • Combine CCP and SPAN • Three modes: ACTIVE, LISTEN, SLEEP

14. Adaptive self-configuring sensor networks topologies (ASCENT) • Goal: Maintain certain data delivery ratio • Unfair energy consumption

15. Probing environment and collaborating adaptive sleeping (PECAS) • Probe message • Prevent the occurrence of blind spots • Energy saving lower than PEAS

16. Classification based on assumption

17. Classification based on objectives