1 Wireless Sensor Networks by Craig Young and Chris Theodoridis

2 Context, Problem, and MotivationWSNs used when difficult or expensive to monitor data using wired sensors Environmental monitoring Military surveillance Inventory tracking Problems arise with responsiveness and battery consumption of nodes More efficient WSNs could save lives and prevent damages

3 Background Research MICAz2.4 to GHz IEEE compliant 250 kbps data rate Runs TinyOS and higher

4 Background Research Sensor Boards and Base StationSensor Boards(MTS300CA/MTS310CA) Light, temperature, and microphone sensors Compatible with MICA, MICA2, and MICAz Base Station Allows aggregation of sensor network data onto PC Any MICAz can act as a base station by plugging into a serial interface board

5 Work Outline Install necessary softwareCreate basic multi-hop network for testing Decrease update time for the motes Determine lowest threshold of performance Switch to an event-based system Create updated network for demo

6 Work Done InstallationInstallation of IBM Java Installation of Cygwin and TinyOS Installation of 5 RPM files Installation of MoteView 1.4 GUI to facilitate programming/reading motes Switch from SurgeReliable to XMesh

7 Work Done One-Hop NetworkOne-Hop network implemented Default refresh rate approximately 7 seconds SurgeM and Surge.h were altered in order to shorten the refresh rate Refresh rate shortened to approximately 1 second

8 Work Done Multi-Hop NetworkSynchronized Counter One node generates counter based on internal clock and flashes LEDs accordingly Other node synchronizes flashing of LEDs by receiving transmitted signal from first node Surge-Reliable Program Collection of data from sensor boards Problems: recognizing nodes, battery power

9 Work Done Decreasing the Update TimeXMesh permits 300 millisecond refresh rate No performance penalties Battery voltage dropped below 2.3V Sensors unable to communicate properly Not enough time to work on event-based system Battery voltage now at 3V

10 Results Surge Reliable Graphs

11 Results Voltage Readings

12 Results Dropped Packets

13 Results XServeterm

14 Results XServe Webpage

15 Summary Importance of Wireless Sensor Networks MICAz instead of MICA2XMesh instead of SurgeReliable Refresh rate lowered to 300 milliseconds Battery voltage must be above 2.3V

16 QUESTIONS???