1. Abdul Wahid, Sungwon Lee, Dongkyun Kim Kyungpook National University ， Korea IEEE Oceans 2011

2.  INTRODUCTION  RELATED WORK  ERP 2 R  SIMULATION  CONCLUSION

3.  Underwater wireless sensor networks (UWSNs) in order to support variousapplication ◦ soil/gas spills monitoring ◦ offshore exploration ◦ disaster prevention ◦ submarine detection

4.  UWSNs constraints ◦ propagation delay ◦ low bandwidth ◦ high noise ratio Sink node Sensor node Flooding Direction Data Collection Direction

5.  Drawback ◦ network lifetime  exchanging many control messages  a lot of broadcasting activities for the same packets

6.  Routing protocols for UWSNs ◦ VBF ◦ HHVBF ◦ FBR ◦ DFR ◦ DBR

7.  VBF P. Xie, JH. Cui, L. Lao, “VBF: vector-based forwarding protocol for Underwater Sensor Networks” In proc. of IFIP Networking, Coimbra, Portugal, May 2006

8.  HHVBF ◦ Need all node localization information  FBR ◦ Need sink location information ◦ Use RTS/CTS  DFR ◦ Need all node localization information

9.  DBR

11.  Assumption ◦ distances to their neighbors ◦ ToA(Time of Arrival) Vijay Chandrasekhar, Yoo Sang Choo, “Localization in Underwater Sensor Networks – Survey and Challenges” In proc. of WUWNet’06, Los Angeles, California, USA, September 2006. John Heidemann, Wei Ye, Jack Wills, Affan Syed,, Yuan Li, “Research Challenges and Applications for Underwater Sensor Networking” In proc. of WCNC 2006, Las Vegas, NV, USA, April 2006.

12.  ERP 2 R two phase: ◦ Cost establishment phase with knowledge acquisition of residual energy ◦ Data forwarding phase

13.  Cost establishment phase with knowledge acquisition of residual energy Hello ID Sequence number Residual energy COST

14.  Cost establishment phase with knowledge acquisition of residual energy 10 12 25 17 22 23 29 16 12 34 12 18 27 18 27 17 14 10 15 27 12 10 39 45 53 30 57 32 27 56 72 66 35

15. ◦ Data forwarding phase 12 10 39 45 53 30 57 32 27 56 72 66 9 9 11 12 8 10 6 5 7 15

16. ◦ Data forwarding phase 12 10 39 45 53 30 57 32 27 56 72 66 9 9 9 5 7 8 10 4 5 7 15 priorityID 1C 2D A B D C E G F ordered list priorityID 1G 2E 3F ordered list

17. ◦ Data forwarding phase  Hold time 12 10 39 45 53 30 57 32 27 56 72 66 9 9 9 5 7 8 10 4 5 7 15 A B D C E G F T = ((1(4/10))/100)+5 =5.006

18. ParameterValue SimulatorNS-2 Node25,49,100,225 400 Source Node2 Data packet generated15 sec Data packet sizes64 bytes

22.  lightweight and energy efficient routing protocol (named ERP 2 R) for UWSNs.  uses physical distance for reducing unnecessary retransmissions and the residual energy for energy balancing