improving throughput by tuning carrier sensing in 802.11 wireless networks

Improving throughput by tuning carrier sensing in 802.11 wireless networks

Computer Communications 2009

Qiang Shena, Xuming Fanga,

Rongshen Huangb, Pan Lib, Yuguang Fangb

a: Provincial Key Lab of Information Coding and Transmission, Southwest Jiaotong University b: Department of ECE, University of Florida

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Outline Introduction Wireless network models Solution to the blocking problem Performance evaluation Conclusions

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IntroductionIn 802.11 MAC protocol

Physical carrier sensing thresholdHidden terminal problem

Exposed terminal problem Spatial reuse

Tuning carrier sensing threshold(range) && Channel rateImprove the network throughput

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Wireless network models A successful reception

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Interference model Chain topology

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Wireless network models A successful reception

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How to determine the k

k = 3, S0=6.02

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Solution to the blocking problem Optimum sensing range for RTS Optimum sensing range for CTS Maximization of the achievable data

rate

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Optimum sensing range for RTS

SS RR11 22 33 44

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d

Optimum sensing range for CTS

SS RR11 22 33 44

IX

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Maximization of the achievable data rate

The relationship between the spatial reuse and the max achievable data rate

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Simulator: NS2Payload : 8000 bitsChain topologyK = 3rc = 6Mbps

Performance evaluation

11 22 33 44

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Out of TR

Throughput of node 1-2 and 4-3

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Throughput of Node 1-2 and 3-4

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End-to-end throughput with different values of k

Chain topology: 7 nodesAlleviate intra-flow contention

Increasing the RTS sensing range of the source node (IRSR)

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End-to-end throughput comparison of different methods

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Throughput comparison of IRSR and DAW

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Delay comparison of IRSR and DAW

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Conclusions In this paper

Tuning physical carrier sensing Maximizing channel rate

Improving network throughput Increasing spatial reuse

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Thank You!!

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