Energy-Efficient Protocol for Cooperative Networks
IEEE/ACM Transactions on Networking, Apr. 2011Mohamed Elhawary, Zygmunt J. Haas
Yong Zhou2012-07-19
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Outline
IntroductionCooperative ProtocolProtocol Robustness and Energy EfficiencySimulation ResultsConclusions
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Introduction
Wireless sensor networks: limited energy resources
Cooperative transmission: • Virtual antenna array
• Diversity gain
• Energy efficient
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Cooperative Protocol - CwR
Cluster head, sending cluster, receiving cluster Path width Two phases: routing (AODV), recruiting-and-transmit
ting
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Assumptions
Sending nodes are synchronized Receiving power is the sum of all the signal p
owers coming from all the senders
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CAN
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Recruiting Phase
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BER-MISO
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Protocol Robustness (1)
Denote the transmission pattern of nodes in a sending cluster by a binary representation bm-1 … b1 b0 according to which node j transmits if bj = 1 and does not transmit if bj = 0.
Similarly, denote the reception status of nodes in a receiving cluster by a binary representation bm-1 … b1
b0 according to which node j correctly receives the packet if bj = 1 and receives the packet in error if bj = 0.
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Protocol Robustness (2)
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Protocol Robustness (3)
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Other Protocols
Disjoint-paths:
One-Path
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Failure Probability
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Energy Consumption
To make the comparison of energy consumption of any two schemes meaningful, the failure probability needs to be kept equal for the compared schemes.
Thus, the needed transmission power for each case can be calculated according to the analysis of robustness.
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Power Ratio
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Conclusions
Propose an energy-efficient cooperative protocol
Analyze the robustness and energy consumption of the protocol