Improved Performance of Enhanced Receiver Initiated Packet Train (E-RIPT) for Underwater Acoustic Networks

Transcription

1 Improved Performance of Enhanced Receiver Initiated Packet Train (E-RIPT) for Underwater Acoustic Networks Nuttarit Leelapisut 1, Nitthita Chirdchoo 3, Teerawat Issariyakul 2, Lunchakorn Wuttisittikulkij 1 Department of Electrical Engineering,Chulalongkorn University 1, TOT Public Company Limited 2 ensor Network and Embedded ystem Research Unit,Nakhon Pathom Rajabhat University 3 1

2 Outline Introduction Protocol Design imulation & Results Conclusion 2

3 Introduction Why Underwater? The ocean covers 71% of the Earth's surface and contains 97% of the planet's water. More than 95% of the underwater world remains unexplored. Examples of Application in underwater Detect polluting chemical and biological substances Monitor oceanic wind and current Tsunami warning 3

4 Introduction What is the difference between terrestrial and underwater wireless networks? Terrestrial networks use radio wave but underwater use acoustic waves. Limit bandwidth Long propagation delay. Limited energy Examples of MAC in UAN MACA-U, RIPT, E-RIPT, MACA-APT 4

5 RIPT RIPT was proposed by Chirdchoo et al.(2008) is handshaking with Receiver-Initiated protocol. use packet-train that can send more than one DATA packet in each handshake round. 5

6 E-RIPT E-RIPT (2014) Use slot for reservation packet. Receive information before assign DATA slot. 6

7 ME-RIPT Dmax D t Firstslot t busy max D max Dmax B t out,b Handshake Period Data Reception REV REV-ACK ORDER Broadcasted NTF1 NTF2 DATA DATA Guard time (if necessary) ME-RIPT stands for Modify Enhanced Receiver- Initiated Packet Train Remove unnecessary control packet to alleviates exposed node problems of E-RIPT 7

8 ME-RIPT and E-RIPT ME-RIPT B Dmax D t Firstslot t busy max D max Dmax t out,b Handshake Period Data Reception E-RIPT t0 B O Dmax REV REV-ACK ORDER t NTF1 D t t Firstslot busy max REV REV-ACK ORDER Broadcasted NTF1 NTF2 DATA DATA tntf2 t t D rx,bstart out1 max Broadcasted NTF1 NTF2 DATA DATA Guard time (if necessary) Guard time (if necessary) t out,b 8

9 Node state RIPT, E-RIPT ME-RIPT 9

10 imulation Model The open source simulator N-3 version is deployed with UAN module. Network topology has 196 nodes, only data of 36 nodes in the center of network topology are collected

11 Throughput per node Normalized throughput per node RIPT M max E-RIPT M max E-RIPT M max = 50 MACA-U ME-RIPT M max ME-RIPT M max = Offered load per node 11

12 Delay Delay (s/packet) RIPT M max E-RIPT M max E-RIPT M max = 50 MACA-U ME-RIPT M max ME-RIPT M max = Offered load per node 12

13 Fairness (D of No. of transmission) tandard Division of Number transmission packets RIPT M max E-RIPT M max E-RIPT M max = 50 MACA-U ME-RIPT M max ME-RIPT M max = Offered load per node 13

14 Conclusion ME-RIPT alleviates exposed node problems that its predecessors RIPT and E-RIPT experience. The simulation results show the improvement in throughput, delay, and fairness. 14

15 Q & A 15

16 Thank you 16