1. 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 Two-Relay-Based Cooperative MAC Protocol for Wireless Ad hoc Networks

2. Outline Introduction Goal 2rcMAC protocol Simulation Conclusion

3. Introduction The cooperative communication approach effective uses of spatial diversity in wireless ad hoc networks Improved throughput Delay performance 60s 20s

4. Related Work CoopMAC I Its performance deteriorates under fading conditions due to lower direct path or relay path reliability

5. Related Work UTD MAC Not fully benefit from higher throughput relay path (compared with the direct path) since it uses relay path only as a secondary backup path

6. Goal We propose a 2rcMAC protocol Better transmission reliability Higher throughput through the relay path Higher performance under fast-fading conditions

7. System Model 2rcMAC protocol Single-channel / Single-hop ad hoc network Multiple data rates of 1, 2, 5.5, and 11 Mb/s Control packets and headers are transmitted at 1 Mb/s

8. 1Mbps 2Mbps 11Mbps 5.5Mbps 2Mbps 2rcMAC protocol 1Mbps 2Mbps 11Mbps 5.5Mbps 2Mbps D D S S r1 r2

9. 2rcMAC protocol RR frame Eight-slot frame 7 bits per slot S S D D RTS CTS

10. 2rcMAC protocol The source node searches for the two best relay Start from the (11,11) rate category Total transmission time First best relay Second best relay

11. 2rcMAC protocol Four cases Two best relays Only one best relay No best relay No relay feedback

12. 2rcMAC protocol MAC header Only one relay Pick Relay NAV Adaptation

13. Simulation ParameterValue Frequency2.4 GHz MAC header272 bits PHY header192 bits RTS/CTS/ACK160 bits/112 bits/112 bits Slots time20 us SIFS/DIFS10 us/50 us Payload1023 bytes CW max /CW min 1024/32 Rate for MAC, PHY header, RTS, CTS, ACK packtes1Mbps SIMULATION PARAMENTERS

14. Simulation

18. Thank You