Reverse Direction Transmissions and Network Coding for Energy-Efficient Wi-Fi Networks

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1 Reverse Direction Transmissions and Network Coding for Energy-Efficient Wi-Fi Networks Raul Palacios a, Dzmitry Kliazovich b, Fabrizio Granelli a a University of Trento, Trento, Italy b University of Luxermbourg, Luxemrboug, December,

2 Outline Problem Network Coding COPE IEEE 802. DCF MAC Cross-layer Efficiency issues Solution BidCode Reverse Direction TXs Transmit after receive Result Energy Efficiency Analysis & Simulation Vs. Load Vs. Packet Vs. Rate 2

3 Network Coding (NC) Intermediate wireless nodes Reduce number of transmissions Transmit combined information Network Coding Add overhead for decoding

4 NC A&B Scenario Store and forward 4 A R B 2 NC enabled A R B 2 4

5 NC Cross Scenario Store and forward C NC enabled C A R B 2 A R B D D 5

6 NC Types Inter-session NC Combine information from different sources e.g. COPE Intra-session NC Combine information from the same source e.g. MORE 6

7 COPE IP NC MAC PHY COPE First on Wi-Fi Opportunistic listening Opportunistic coding Neighbor-state learning Pseudobroadcast Asynchronous ACK 7

8 IEEE 802. MAC/PHY Spec. DCF MAC DCF CSMA/CA BEB Basic OFDM PHY RTS/CTS 8

9 COPE A&B DIFS+BO DIFS: DCF Inter Frame Space : Short Inter Frame Space BO: Back-off period RTS: Request-To- Send CTS: Clear-To-Send A a b RTS CTS a ACK CTS ACK RTS a b a DIFS+BO R a b CTS ACK RTS CTS b ACK RTS CTS a b ACK B b a DIFS+BO 9

10 NC and 802. MAC Fairness A&B: / share for R Cross: /5 share for R / / / 2 A R B 0

NC-Aware MAC Priority State of the Art []-[4] State of

Adjust CW size Probabilistic priority only [] Xie et al,

Content Distribution in Ad Hoc Networks, in IEEE PIMRC,

and Network Coding for Single-Relay Multi-User Wireless

[] De Coppi et al, Network Coding Aware Queue Management

[4] Paramanathan et al, On the Need of Novel Medium Access

11 NC-Aware MAC Priority State of the Art []-[4] State of channel contention Network Coding info Level of congestion Adjust CW size Probabilistic priority only [] Xie et al, Popularity Aware Scheduling for Network Coding based Content Distribution in Ad Hoc Networks, in IEEE PIMRC, 2007, pp. 5. [2] Umehara et al, Enhancement of IEEE 802. and Network Coding for Single-Relay Multi-User Wireless Networks, in IEEE ICSPCS, 200, pp. 9. [] De Coppi et al, Network Coding Aware Queue Management in Multi-Rate Wireless Networks, in IEEE ICCCN, 202, pp. 7. [4] Paramanathan et al, On the Need of Novel Medium Access Control Schemes for Network Coding enabled Wireless Mesh Networks, in IEEE ICC, 20, pp. 6.

12 BidCode [5] Transmit after receive BidCode Coded data packets only Backwards compatible Low overhead Absolute priority [5] R. Palacios, F. Granelli, A. Paramanathan, J. Heide, and F. H. P. Fitzek, Coding-aware MAC: Providing Channel Access Priority for Network Coding with Reverse Direction DCF in IEEE 802.-based Wireless Networks, in IEEE ICC 204, 0-4 June 204, pp

13 BidCode A&B DIFS+BO DIFS: DCF Inter Frame Space : Short Inter Frame Space BO: Back-off period RTS: Request-To- Send CTS: Clear-To-Send A R B a b RTS CTS a ACK CTS a b a CTS ACK RTS CTS b a b ACK b a DIFS+BO

14 Contributions of The Paper Anlys Comprehensive performance assessment of BidCode Simul 4

15 Evaluation Framework BidCode A R B Alice and Bob C! COPE A R B 802.g DCF MAC D Cross!! GREENET Tutorial 5

16 General Assumptions Theoretical Analysis Error-free/Collisionfree channel Constant packet length Always data to transmit No packet losses for queue overflow Negligible coding time & energy Python simulator Ideal channel Poisson traffic generation Constant packet length Unbounded transmit queue Negligible coding time & energy GREENET Tutorial 6

17 DCF and BidMAC. There is one data transmission from BidCode Energy Efficiency Analysis: An Example Bob to the relay node through a DCF transmission slot. O data transmissions from Alice and Bob, there is a bidirecti sion similar to BidMAC but there is a coded data transmi relay node instead of a single data transmission. Hence, th TDIFS TBO TRTS T TCTS T TDATA T TACK TDIFS TBO TRTS T TCTS T TDATA T TXORDATA T TACK time ratio that results in the saturation network throughput DIFS DIFS Pt expressed as P CHAPTER 5. NETWORK CODING-AWARE ENERGY-EFFICIENT MAC r Pi PROTOCOLS net sat TBidCode = 2 (TDIF S +TBO +TRT S +TCT S +TDAT A +T 2 NAV The A energy consumed in the energy consumption in CTS Pt Pr (TXORDAT A +7 TSIF S ) Pi a data transmission through DCF and a bidirectional transmission+with 2 a M ODES AND T RANSMISSION T IMES DATA coded packet similar to BidMAC. There are 2 transmission slots in ERP-OFDM which PHY ERP-OFDM PHY M ODES AND T RANSMISSION T IMES CTS ACK CTS RTS DATA a >R combines BidCode RTS ACK Energy Efficiency >B the 2 source nodes transmit twice, the relay nodeb.transmits once and re- a b R Mode Modulation Code rate Data rate NDBP S TR Mode Modulation Code rate Data rate NDBP S TR P t BPSK /2 6 Mbps 24 5 P r Pi ceives twice, a source node receives once, the hidden node is idle twice, BPSK /2 6 Mbps 24 The energy2 efficiency x ( x ) is BPSK of a given /4 protocol 9 Mbps 6 defined5 2 BPSK /4 9 Mbps 6 ratio QPSK 2 Mbps 48 and the nodes are idle twice. Hence, the energyofconsumption that ban MSDU/2 DATA QPSK /2 2by Mbps 48 bits contained in divided the energy cons4 4 QPSK /4 8 Mbps 72 4 QPSK /4 8 Mbps 72 NAV CTSenergy efficiency is expressed >R6-QAM corresponds to the saturation network as /2 packet 24 Mbps 96 (Ex ) required55to transmit that includes the B 6-QAM the data /2 24 Mbps QAM 6-QAM 64-QAM 64-QAM 64-QAM 64-QAM /4 6 Mbps /4 6 Mbps 2/ 48 Mbps 2/ 48 M Mbps 8 L SDU /4 54 Mbps x [Mb/J]= /4 54 Mbps net sat EBidCode = (Et +Er +Ei ) 2 Ex Et = (2 (TRT S +TCT S +TDAT A +TACK ) +TXORDAT A ) Pt S =TSIF S +2T where LM SDU denotes the Tbyte-length anslot MSDU and E TDIF DIF S =TSIFof S +2T slot CW Er = (2 (TRT S +2 TCT S +TDAT A +TXORDAT Athe ) + T min spent in transm ACK ) P product ofr power consumed and CWtime min Tslot TTBO = = Tslot BO 22 Ei = ( (2 (TDIF S +TBO ) +7 TSIF S ) +2 (TRTtotal ) Pi amount transmitted data packets and is split into S +TDAT A ) +Tof ACK 2) Based 2) BD-DCF: BD-DCF: Based on on Fig. Fig. 2b, 2b, aa transmission transmission cy cy (5.) BD-DCF contains the same as that of DCF but it includ BD-DCF contains the same 27 as that of DCF but it inclu additional data transmission and additional data transmission and aa interval. interval. To To co co the maximum throughput of BD-DCF, we assume th the maximum throughput of BD-DCF, we assume th 5.. Cross Scenario IEEE CAMAD 204a STA, has receiver receiver of of aa data data packet, packet, either either the the AP AP or or a STA, has Greece packet ready to send to theathens, transmitter. Therefore, 7aa pp packet ready to send to the transmitter. Therefore, packets can be exchanged within a BD-DCF transmi The throughputs and energy efficiencies of the protocolsdata under evalua-

18 System Parameters* Parameter Value Parameter Value Slot time 9 us XOR header 40 bytes interval 0 us Payload length 500 bytes DIFS interval 28 us FCS length 4 bytes EIFS interval 88 us PHY data rate 54 Mbps Min CW size 5 PHY control rate 24 Mbps Max CW size 02 RTS TX time 0 us Preamble time 6 us CTS/ACK TX time 4 us Signal time 4 us DATA TX time 254 us OFDM symbol time 4 us XORDATA TX time 262 us Signal extension 6 us Transmit power cons..65 Watts Service bits 6 bits Receive power cons..4 Watts Tail bits 6 bits Idle power cons..5 Watts RTS length 20 bytes Holding time 0 ms CTS/ACK length 4 bytes Simulation time 20 s MAC header 0 bytes Number of iterations 0 *IEEE 802.g MAC/PHY spec. 8

19 A&B Energy Efficiency Vs. Traffic Load Network energy efficiency (Mb/J) DCF-Analytical DCF-Simulation COPE-Analytical COPE-Simualtion BidCode-Analytical BidCode-Simulation Total offered traffic load (Mbps) 9

20 A&B Energy Efficiency Vs. PHY Data Payload Length Network energy efficiency (Mb/J) DCF-Analytical DCF-Simulation COPE-Analytical COPE-Simualtion BidCode-Analytical BidCode-Simulation MAC Service Data Unit (MSDU) length (Bytes) 20

21 A&B Energy Efficiency Vs. Data Rate Network energy efficiency (Mb/J) DCF-Analytical DCF-Simulation COPE-Analytical COPE-Simualtion BidCode-Analytical BidCode-Simulation PHY data rate (Mbps) 2

22 A&B Max. Gains Vs. Data Payload Length Data Payload Length (Bytes) Energy Efficiency BidCode vs. DCF BidCode vs. COPE 50 70% 6% % % % 26% % 2% 000 9% 20% 250 4% 8% 500 % 6% % 5% % 4% % % Vs. PHY Data Rate PHY Data Rate (Mbps) Energy Efficiency BidCode vs. DCF BidCode vs. COPE 6 06% 4% 9 09% 5% 2 0% 6% 8 5% 8% 24 8% 0% 6 25% % 48 0% 5% 54 % 6% 22

23 Cross Energy Efficiency Vs. Traffic Load Network energy efficiency (Mb/J),5 2,5 2,5 0,5 DCF-Analytical DCF-Simulation COPE-Analytical COPE-Simualtion BidCode-Analytical BidCode-Simulation Total offered traffic load (Mbps) 2

24 Cross Energy Efficiency Vs. PHY Data Payload Length Network energy efficiency (Mb/J) 4,5 2,5 2,5 0,5 DCF-Analytical DCF-Simulation COPE-Analytical COPE-Simualtion BidCode-Analytical BidCode-Simulation MAC Service Data Unit (MSDU) length (Bytes) 24

25 Cross Energy Efficiency Vs. Data Rate Network energy efficiency (Mb/J),5 2,5 2,5 0,5 DCF-Analytical DCF-Simulation COPE-Analytical COPE-Simualtion BidCode-Analytical BidCode-Simulation PHY data rate (Mbps) 25

26 Cross Max. Gains Vs. Data Payload Length Data Payload Length (Bytes) Energy Efficiency BidCode vs. DCF BidCode vs. COPE 50 52% 27% 250 5% 9% 500 2% % 750 % 06% 000 0% 02% % 98% % 95% % 9% % 9% % 89% Vs. PHY Data Rate PHY Data Rate (Mbps) Energy Efficiency BidCode vs. DCF BidCode vs. COPE 6 244% 7% 9 249% 75% 2 252% 77% 8 260% 8% % 84% 6 277% 89% % 9% % 95% 26

Summary Problem Solution Contribution Result

Only probabilistic priority BidCode: Transmit a

data packet Energy efficiency analysis and

A&B: 70% vs. DCF, 40% vs. COPE Cross: 50% vs.

27 Summary Problem Solution Contribution Result Ongoing Wi-Fi: Lack of MAC priority for NC SoA: Only probabilistic priority BidCode: Transmit a coded data packet immediately after receiving a data packet Energy efficiency analysis and computerbased simulation for BidCode evaluation A&B: 70% vs. DCF, 40% vs. COPE Cross: 50% vs. DCF, 0% vs. COPE Analysis and modeling, GLOBECOM 4 Experimentation on WARP v nodes 27

28 WARP v Experiment Framework WARP v node WARP v network Energino meter Energino software 28

29 Some Preliminary Results Energy Efficiency Vs. Traffic Load Energy Efficiency Vs. Data Rate 0,4 0,45 Network energy efficiency (Mb/J) 0,5 0, 0,25 0,2 0,5 0, 0,05 4% % DCF-Experiment COPE-Experiment BidCode-Experiment Saturation network energy efficiency (Mb/J) 0,4 0,5 0, 0,25 0,2 0,5 0, 0,05 DCF-Experiment COPE-Experiment BidCode-Experiment 4% 5% Total offered traffic load (Mbps) PHY data rate (Mbps) 29

30 Thanks for your kind attention! Raul Palacios 0

Performance Analysis of Energy-Efficient MAC Protocols using Bidirectional Transmissions and Sleep Periods in IEEE 802.

Performance Analysis of Energy-Efficient MAC otocols using Bidirectional Transmissions and Sleep Periods in IEEE 82.-based WLANs* Raul Palacios a, El Moatez Billah Larbaa a, Jesus Alonso-Zarate b and Fabrizio