Energy-Efficient Protocol for Cooperative Networks IEEE/ACM Transactions on Networking, Apr Mohamed Elhawary, Zygmunt J. Haas Yong Zhou
2/16 Outline Introduction Cooperative Protocol Protocol Robustness and Energy Efficiency Simulation Results Conclusions
/16 Introduction Wireless sensor networks: limited energy resources Cooperative transmission: Virtual antenna array Diversity gain Energy efficient
/16 Cooperative Protocol - CwR Cluster head, sending cluster, receiving cluster Path width Two phases: routing (AODV), recruiting-and- transmitting
/16 Assumptions Sending nodes are synchronized Receiving power is the sum of all the signal powers coming from all the senders
/16 CAN
/16 Recruiting Phase
/16 BER-MISO
/16 Protocol Robustness (1) Denote the transmission pattern of nodes in a sending cluster by a binary representation b m-1 … b 1 b 0 according to which node j transmits if b j = 1 and does not transmit if b j = 0. Similarly, denote the reception status of nodes in a receiving cluster by a binary representation b m-1 … b 1 b 0 according to which node j correctly receives the packet if b j = 1 and receives the packet in error if b j = 0.
/16 Protocol Robustness (2)
/16 Protocol Robustness (3)
/16 Other Protocols Disjoint-paths: One-Path
/16 Failure Probability
/16 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.
/16 Power Ratio
/16 Conclusions Propose an energy-efficient cooperative protocol Analyze the robustness and energy consumption of the protocol