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Two-Relay-Based Cooperative MAC Protocol for Wireless Ad hoc Networks. Murad Khalid, Yufeng Wang, In-ho Ra, and Ravi Sankar University of South Florida IEEE Transactions On Vehicular Technology , VOL. 60, NO. 7, SEPTEMBER 2011. Outline. Introduction Goal 2rcMAC protocol Simulation
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Two-Relay-Based Cooperative MAC Protocolfor Wireless Ad hoc Networks Murad Khalid, Yufeng Wang, In-ho Ra, and Ravi Sankar University of South Florida IEEE Transactions On Vehicular Technology, VOL. 60, NO. 7, SEPTEMBER 2011
Outline Introduction Goal 2rcMAC protocol Simulation Conclusion
Introduction 20s 20s 60s • The cooperative communication approach effective uses of spatial diversity in wireless ad hoc networks • Improved throughput • Delay performance
Related Work Its performance deteriorates under fading conditions due to lower direct path or relay path reliability CoopMACI
Related Work Not fully benefit from higher throughput relay path(compared with the direct path) since it uses relay path only as asecondary backup path UTD MAC
Goal • We propose a 2rcMAC protocol • Better transmission reliability • Higher throughputthrough the relay path • Higher performance underfast-fading conditions
System Model • 2rcMAC protocol • Single-channel/Single-hopad hoc network • Multiple data rates of 1, 2, 5.5, and 11 Mb/s • Control packets and headers are transmitted at 1 Mb/s
2rcMAC protocol r1 S D 2Mbps 2Mbps 11Mbps 11Mbps 2Mbps 2Mbps 5.5Mbps 5.5Mbps 1Mbps 1Mbps r2
2rcMAC protocol D S CTS RTS • RR frame • Eight-slot frame • 7 bits per slot
2rcMAC protocol Total transmission time First best relay Second best relay • The source node searches for the two best relay • Start from the (11,11) rate category
2rcMAC protocol • Four cases • Two best relays • Only one best relay • No best relay • No relay feedback
2rcMAC protocol • MAC header • Only onerelay • Pick Relay • NAV Adaptation
Simulation SIMULATION PARAMENTERS