1. An Adaptive Coordinated Medium Access Control for Wireless Sensor Networks Jing Ai, Jingfei Kong, Damla Turgut Networking and Mobile Computing (NetMoC) Research Laboratory School of Electrical Engineering and Computer Science, University of Central Florida IEEE ISCC2004 Speaker: Yung-Lin Yu

2. Outline Introduction AC-MAC Protocol Design –Motivation –Synchronization and virtual clustering –Adaptive duty cycle Simulation Study –Latency –Throughput –Energy Conclusion And Future Work

3. Introduction Our protocol, AC-MAC, is extended from S-MAC AC-MAC introduces adaptive duty cycle to the traffic loads AC-MAC designed to provide more optimized trade-offs than S-MAC

4. AC-MAC Protocol Design (1/5) Motivation –S-MAC provide a limited adaptability to a range of traffic loads Fixed parameters for S-MAC’s duty cycle Parameters must tuned for specific application Incompatible parameters will incur large latency and low throughput

5. AC-MAC Protocol Design(2/5) Synchronization and virtual clustering

6. AC-MAC Protocol Design(3/5) Adaptive duty cycle AC-MAC uses the number of packets queued at the buffer indication of the traffic load –Ni: Packets in the buffer of node i –Ri: The number of new duty cycle –F(˙): An application-specific function

7. AC-MAC Protocol Design(4/5) New T frame – Define R i max –

8. AC-MAC Protocol Design(5/5) Announce R value via RTS/CTS –Node i append the R i to the RTS packet –Each node within one-hop away will learn R i –Receiver node append R i to the CTS packet –Thus, all node will learn new duty cycle

9. Simulation Study (1/4) Simulation tool –NS-2 Topology – The source node sends 50 msgs each with 50 bytes Changing the packet inter-arrival time from 1s to 15s

10. Simulation Study (2/4)

11. Simulation Study (3/4)

12. Simulation Study (4/4)

13. Conclusion And Future Work Simulation results show that AC-MAC –Achieves better latency and throughput in wide range of traffic loads compared to S-MAC –Maintains the same level of energy-efficiency as S-MAC Future work –The virtual clustering technique –Suitable topology mechanisms