Design and Performance Evaluation of Underwater Data Dissemination Strategies using Interference Avoidance and Network Coding

Transcription

1 Design nd Performnce Evlution of Underwter Dt Dissemintion Strtegies using Interference Avoidnce nd Network Coding Rúl Plcios Fbrizio Grnelli University of Trento, Itly Jnus Heide Frnk H.P. Fitzek Alborg University, Denmrk

2 Outline Underwter Chnnel Medium Access Problem Solution Interference Avoidnce Network Coding Evlution Summry Future work Result 2 23

3 PROBLEM Underwter Acoustic Link Pth loss Bndwidth Dely 3 23

4 PROBLEM Medium ccess control Crrier sense multiple ccess with collision voidnce (CSMA/CA) well-estblished in ir DIFS SIFS Source RTS SIFS Dt SIFS Destintion CTS ACK DIFS Other sttions NAV RTS NAV CTS NAV Dt Time New ccess 4 23

5 PROBLEM Medium ccess control Crrier sense multiple ccess with collision voidnce (CSMA/CA) inefficient under wter DIFS Dely Source RTS Dely Dt Dely Destintion CTS ACK DIFS Other sttions NAV RTS NAV CTS NAV Dt Time New ccess 5 23

6 SOLUTION Contributions CSMA/CA-bsed medium ccess scheme with Interference Avoidnce (IA) full-duplex communiction Network coding (NC) combintion of dt Exploit the underwter coustic chnnel Increse efficiency of dt trnsmission 6 23

7 Bsic scheme: Two nodes SOLUTION Interference Avoidnce inter-nodl distnce A Tx Dt A Dt B Tx B ) Both trnsmit. A Tx Rx Dt A Dt B Rx Tx B b) Stop sending nd strt receiving. A Rx Dt B Dt A Rx B c) Both hve lmost received the dt. 7 23

8 Extended scheme: Three nodes SOLUTION Interference Avoidnce inter-nodl distnce inter-nodl distnce A Tx Dt A B Tx Dt B C ) A-B trnsmit. A Tx Dt A Rx B Tx Dt B Rx C b) A-B stop sending nd B-C strt receiving. A Dt A Rx B Dt B Rx C c) B-C hve lmost received the dt. 8 23

9 Requirements SOLUTION Interference Avoidnce - propgtion dely prop. Time = Tx. Time - sttionry networks fixed or move slowly - intelligent collision redefine RTS/CTS - precise synchroniztion Gurd bits sequence 9 23

10 Liner network coding (NC) opertion 1. A trnsmits 2. B trnsmits b 3. C forwrds +b 4. A-B retrieve b, with +b SOLUTION Network Coding A C B Time A C B Time b 1 b 1 b, 2,b b b 2,b b b, 3,b +b,b +b b, 3,b b,b b b, 4 ) Without network coding. b) With network coding

11 SOLUTION Physicl-lyer Network Coding Physicl-lyer network coding (PNC) opertion 1. A-B trnsmit,b 2. C forwrds +b 3. A-B retrieve b, with +b A C B Time A C B Time b 1 +b b b 1,b b b 2,b +b +b +b b, 2,b +b,b +b b, 3 ) With network coding. b) With pyshicl-lyer network coding

12 SOLUTION Network Coding Requirements - dditionl functionlities coding/decoding coding opportunities - optiml MAC functions bck-off RTS/CTS frgmenttion power control collision/retrnsmission 12 23

13 Exmple with 3 nodes ) CSMA b) IA + NC c) IA + PNC A,b b C,b,b,b b b B Time b 1 b b, b, ) CSMA/CA A,b A,b SOLUTION Combined strtegies +b x +b x B,b,b +b b) IA + NC. B,b c) IA + PNC. C Time b 1 b b 2 b +b bx b, C 3 Time b 1,b

14 RESULT Evlution String topology network 14 23

15 Time slots RESULT Evlution Dissemintion time (8 nodes) CSMA/CA IA NC PNC IA+NC IA+PNC No. of pckets 15 23

16 Time slots RESULT Evlution Dissemintion time (8 nodes) CSMA/CA IA+NC IA+PNC No. of pckets -50% 16 23

17 RESULT Evlution Energy sving gin bsed on CSMA/CA (5 nodes) 17% IA NC PNC IA+NC IA+PNC 28% 30% 31% 26% 24% 25% 25% 21% 22% 17% 7% No. of pckets 17 23

18 RESULT Summry Pth loss Bndwidth Dely 18 23

19 Summry Limited bndwidth Combine multiple pckets into single encoded pcket Long dely Bidirectionl concurrent trnsmission RESULT Energy nd throughput improvements 19 23

20 RESULT Future work From underwter to ir Reserch ctivity. Integrte Interference Avoidnce nd Network Coding into rel systems, bsed on CSMA/CA. Expected outcome. Reduce energy consumption in wireless networks, while the qulity-of-service is gurnteed

21 RESULT Future work 1 st ctivity: pply Interference Avoidnce to CSMA/CA-bsed wireless networks. Bidirectionl dt pcket in exchnge A successful RTS/CTS hndshke cn be used to communicte bidirectionl dt. Scenrio: mobile d hoc network (MANET). Performnce metrics: energy consumption [Joule/bit] nd throughput [bit/second]

22 RESULT Future work 2 nd ctivity: combine bidirectionl trnsmissions with network coding. Optimize CSMA/CA prmeters to mximize the opportunities for both bidirectionl trnsmissions nd network coding. Scenrio: mobile d hoc network (MANET). Performnce metrics: energy consumption [Joule/bit] nd throughput [bit/second]

23 Thnk you very much for your kind ttention! Any question?

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25 RESULT Bckup Evlution Simultion prmeters Prmeter Vlue Prmeter Vlue Dt Tx. rte 9600bps Rx./Idle Power 0.8W Length of links 1000m Sleep Power 8mW Speed of sound 1500m/s Bit Error Rte 10-5 Prop. Time ms Pcket Error Rte Tx. Time ms No. of nodes 2 5,8,10,20,30 Mx. Pcket size 800bytes No. of pckets 2,4,10,20,50,100 Tx. Power 2W No. of runs 100

26 RESULT Bckup Future work Bidirectionl dt pcket exchnge Source Destintion Other sttions DIFS RTS SIFS CTS SIFS Dt SIFS ACK NAV RTS NAV CTS NAV Dt DIFS RTS SIFS Defer ccess ) Stndrd DCF. CTS SIFS Dt SIFS ACK NAV RTS NAV CTS NAV Dt DIFS Time New ccess DIFS SIFS SIFS Source RTS SIFS Dt SIFS ACK Destintion Other sttions CTS DATA IN EXCHANGE NAV RTS ACK Dt (ACK) NAV CTS NAV Dt REPLACED BY DATA DIFS Time New ccess b) Modified DCF with bidirectionl trnsmissions.