1. A Cooperative Lifetime Extension MAC Protocol in Duty Cycle Enabled Wireless Sensor Networks Hongzhi Jiaot, Mary Ann Ingram, Frank Y. Li Milcom 2011

2.  Introduction  Problem  Goal  Proposed protocol  CDC-MAC  Simulation  Conclusion Outline

3.  Duty cycle  Long Network Lifetime Introduction Dormant State Active state

4.  Duty cycle MAC  Synchronous  S-MAC  DW-MAC  Asynchronous  RI-MAC Introduction

5.  Cooperative transmission works only when there are mul­tiple active neighboring senders  Successful transmission of the necessary control messages and copies of the data  Ex. OC-MAC Introduction

6. Problem C C D D E E B B A A

7.  Using virtual multiple-input-single-output(MISO) transmission Problem C C D D E E B B A A Cooperative transmission

8.  We also discuss the main goals and challenges of integrating cooperative transmission into a duty cycle MAC protocol  Balance the energy consumption Goal

9.  CDC-MAC  Rendezvous selection for data transmission  Phase 1: network initialization and rendezvous  Phase 2: Data transmission  Energy-Balance-Oriented scheduling  CDC-MAC-1  CDC-MAC-2 Proposed protocol

10. CDC-MAC C C D D B B A A

11.  Rendezvous selection for data transmission  Phase 1: network initialization and rendezvous CDC-MAC C C D D B B Sync ACK Active window ACK Sync W B,0 W B,1 W B,2 W B,3 W B,0

12. CDC-MAC C C D D B B W B,0 W B,1 W A,1 A A W B,0 W A,1

13.  Rendezvous selection for data transmission  Phase 2: Data transmission (Non-cooperative transmission) CDC-MAC-1 C C D D B B W B,0 W B,1 W A,1 A A W B,0 W A,1 Data transmissionCooperative decision and competition for channel access

14.  Energy-Balance-Oriented scheduling  CDC-MAC (regular transmission) CDC-MAC-1

15.  Rendezvous selection for data transmission  Phase 2: Data transmission (cooperative transmission) CDC-MAC-1 C C D D B B W B,0 W A,1 A A Data transmissionCooperative decision and competition for channel access

16.  Energy-Balance-Oriented scheduling  CDC-MAC (cooperative transmission) CDC-MAC-1

17.  Energy-Balance-Oriented scheduling  CDC-MAC-2 (cooperative transmission)  Residual energy CDC-MAC-2

18.  Area: 500 m x 250m  The energy consumption ratios: 0:1:1.05:1.4 (sleep:idle:reception:transmission) Simulation

19.  OC-MAC Simulation

22.  In this paper, a cooperative duty cycle MAC protocol CDC- MAC has been proposed to extend the network lifetime of WSNs  Balance energy consumption  Prolong network lifetime Conclusion