1. DISSense: An Adaptive Ultralow-power Communication Protocol for Wireless Sensor Networks Ugo Maria Colesanti*, Silvia Santini°, Andrea Vitaletti* * Dipartimento di Informatica e Sistemistica, “Sapienza” Università di Roma ° Department of Computer Science, ETH Zurich

2. Periodical Environmental Monitoring WSN deployed over large area Monitors physical phenomena Periodic samples collected by a sink

3. Periodical Environmental Monitoring Nodes10-100 Expected lifetime1-10 years Delivery ratio> 95% Periodic samples1 – 60 minutes Packets1/node Common requirements Node with radio at 100% duty cycle + 2 x AA Batteries 2000mAh ≈ 4-5 days Expected lifetime = Per mille duty cycle: Duty Cycle: 100 % => <1% Lifetime: 4-5 days => >1 year

4. DISSense Adaptive cross layer communication protocol Designed for environmental monitoring applications GTRIDCIGTRIDCIGTDCI Sampling period (1-60 minutes) sleep Radio fully on (duty cycle 100%) Low Power Listening (duty cycle 0.1%) Guard Time Interval Resynchronization Interval Data Collection Interval Issues: Length of GT, RI, DCI? How often resync is needed? Synchronization algorithm? Collection protocol? Dissemination of the schedule? Active

5. DISSense GTRIDCIGTRIDCIGTDCI sleep Collection Tree Protocol (CTP) [3] CTP Beacons Issues: Length of GT, RI, DCI? How often resync is needed? Synchronization algorithm? Collection protocol? Dissemination of the schedule?

6. DISSense GTRIDCIGTRIDCIGTDCI sleep CTP Beacons + Packet timestamping (footer) + Schedule updates (footer) When parent selected: Resync Values shared No additional time for Resync and dissemination Issues: Length of GT, RI, DCI? How often resync is needed? Synchronization algorithm? Collection protocol? Dissemination of the schedule?

7. DISSense Adaptive Engine Sampling Period Time To Resync Time To Collect Data GT RI DCI Skip GTRIDCIGTRIDCIGTDCI sleep Issues: Length of GT, RI, DCI? How often resync is needed? Synchronization algorithm? Collection protocol? Dissemination of the schedule? For how many sampling period resync is NOT required

8. DISSense Some formulas… GTRIDCIGTDCI sleep Protocol Duty Cycle

9. Experiments Testbed – Indoor, 4 months – 1,15,60 minutes sampling period – 15 TelosB motes – TinyOS operating system Simulations – TOSSIM simulation environment – 1,2,5 minutes sampling period – 10,20,30,40 and 50 nodes – 20 random deployments each Metrics: – Duty Cycle (%) – Data Delivery Ratio (%)

10. Testbed Results Adaptive EnginePerformance

11. Simulation Results

12. Simulation results Multi-sink DISSense (topology #1)

13. Comparison to related work DISSenseDozer [1]Koala [2] Duty Cycle0.1% - 4%0.168%0.1% - 1% D.D.R.98-99% > 99.99% Latency< 5 secondsminutesdays Platform Dependencynoyesno Open Sourceyesnoyes Adaptationyesno

14. DISSense for Structural Monitoring B1 Underground Construction (Conca d’Oro – Jonio) Planned: DISSense 12 sensing nodes 28 relay nodes 1 hour sampling period

15. DISSense for Structural Monitoring Tunnel Boring Machine Concrete Mounting Holes Instrumentation Box

16. References [1] Nicolas Burri, Pascal von Rickenbach, and Roger Wattenhofer. Dozer: Ultra-low power data gathering in sensor networks. In Proceedings of the Sixth International Conference on Information Processing in Sensor Networks, Cambridge, MA, USA, April 2007. [2] R. Musaloiu-E, C.-J.M. Liang, and A. Terzis. Koala: Ultra-low power data retrieval in wireless sensor networks. In Information Processing in Sensor Networks, 2008. IPSN '08. International Conference on, pages 421 - 432, 2008. [3] Omprakash Gnawali, Rodrigo Fonseca, Kyle Jamieson, David Moss, and Philip Levis. Collection tree protocol. In Proceedings of the 7th ACM Conference on Embedded Networked Sensor Systems (SenSys 2009), November 2009

17. Thank You!

18. Questions?