1. Wireless Sensor Networks Haywood Ho http://inst-eecs.berkeley.edu/~haywood

2. August 4, 2002Wireless Sensor Networks Introduction What are wireless sensor networks? What’s the big deal?

3. August 4, 2002Wireless Sensor Networks ‘Smart Dust’ MICA ATMEL ATMEGA103 4MHz processor 512 KB flash memory, 4 KB RAM A/D converter Network reprogramming Battery Radio (916 MHz)

4. August 4, 2002Wireless Sensor Networks

5. August 4, 2002Wireless Sensor Networks Operating System for ‘Smart Dust’ Requirements –Consume little memory –Dynamic reprogramming –Robust and reliable performance Windows 98?

6. August 4, 2002Wireless Sensor Networks TinyOS Tiny microthreaded Operating System Instead of in Windows XP, all based on threads, two levels of scheduling is used –Commands –Tasks Clock can wake mote, and then signal commands to be carried out

7. August 4, 2002Wireless Sensor Networks Networking How do we network all the motes together?

8. August 4, 2002Wireless Sensor Networks Network Discovery: Radio Cells

9. August 4, 2002Wireless Sensor Networks Network Discovery

10. August 4, 2002Wireless Sensor Networks What’s the Big Deal? Tons of applications! –Prof Pister’s predictions for 2010: Augmented reality displays Color laser projection systems Virtual keyboards, guitars Smart homes and offices

11. August 4, 2002Wireless Sensor Networks What is the nearest available conference room? How many people are in the gym? Is the treadmill free? Motion Sensor: Room 3201 is Empty What is the average temperature on the second floor? Smart Office

12. August 4, 2002Wireless Sensor Networks Applications Three applications currently under active research: –Defense-related sensor networks –Energy conservation –Real-time monitoring of structural safety of buildings

13. August 4, 2002Wireless Sensor Networks Defense-Related Sensor Networks 29 Palms Fixed/Mobile Experiment –Deploy a sensor network onto a road from an unmanned aerial vehicle (UAV) –Establish communication among nodes –Detect and track vehicles passing through –Transfer information from network to UAV –Transfer information from UAV to observer at base camp

14. August 4, 2002Wireless Sensor Networks Flight Path UAV

15. August 4, 2002Wireless Sensor Networks Energy Conservation Replace faulty and obsolete sensors Introducing light sensors would allow lighting power consumption by 40% Cory Hall Demonstration (22 May 2001)

16. August 4, 2002Wireless Sensor Networks Next Steps As a first step, instrument every room in a number of buildings on campus and collect data Later, real-time monitoring and control of power systems on campus

17. August 4, 2002Wireless Sensor Networks Real-time Monitoring of Structural Safety of Buildings Difficult to discover hidden failures in structures Need to ensure safety may require lengthy inspection periods when buildings are closed Self-monitoring structures!

18. August 4, 2002Wireless Sensor Networks Motes clustered around critical points in structure Processing in mote network, allows transmission of only useful information

19. August 4, 2002Wireless Sensor Networks Wiring for traditional accelerometer sensors

20. August 4, 2002Wireless Sensor Networks Instrumenting the Golden Gate Bridge!

21. August 4, 2002Wireless Sensor Networks Conclusion Vast sensor networks would allow everyday objects to become “smart” Pervasive computing

22. August 4, 2002Wireless Sensor Networks Mote management Long battery life required for practical implementations Control of power consumption crucial Power consumption: –100 mW (on) –30 µW (sleep)

23. August 4, 2002Wireless Sensor Networks Defense-Related Sensor Networks Battlefield surveillance Transportation monitoring Scud hunting in Iraq