1. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Advantages of Dual Channel MAC for Wireless Sensor Networks Antonio G. Ruzzelli, Gregory O’Hare, Raja Jurdak † and Richard Tynan School of Informatics and Computer Science University College Dublin Dublin, Ireland {ruzzelli,richard.tynan,gregory.ohare}@ucd.ie †Bren School of Information and Computer Sciences University of California Irvine CA 92697 rjurdak@ics.uci.edu

2. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan Summary

3. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan Background Traditional low cost radios for wireless sensors operate with one frequency channel at any given time A profusion of MAC protocols focus on energy efficiency over one frequency channels

4. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan Unique frequency channel issues MACs like IEEE802.11, SMAC, TRAMA or BMAC suffer from: – High latency (e.g. due to RTS/CTS/ACK in CSMA/CA) –Low flexibility (Difficult to release slots unused in TDMA) –Inefficient usage of the wireless channel (e.g. the ETP problem in CSMA/CA)

5. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan Advances in WSNs Novel transceivers can operate with two channels simultaneously with a relative small increase of energy consumption e.g. nRF2401 Supply current one channel in receive 18 mA Supply current two channels in receive23 mA nRF2401 is effectively mounted on the motes developed in Cork

6. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan DCMA/AP: Dual channel multiple access with adaptive preamble Channel Cd used for data Channel Cc used for notifications

7. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan DCMA transmission mechanism (1)

8. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan DCMA mechanism (2)

9. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan The exposed terminal problem removal

10. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan Adaptive Preamble mechanism

11. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan Opportunistic Crossover mechanism During ongoing transmission, the next scheduled RX node is notified through the alternative channel Cc. TX RX Next RX Channel Cd Channel Cc

12. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan Related work

13. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan Timing Analysis against BMAC

14. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan Implementation

15. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan Preliminary results

16. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan Future works

17. UNIVERSITY COLLEGE DUBLINDUBLIN CITY UNIVERSITY SMI || NCSR || CDVP Ruzzelli, O’Hare, Jurdak, Tynan Conclusion