1. Network and Systems Laboratory nslab.ee.ntu.edu.tw Polly@NTU Copyright © 2008 1 Wireless Sensor Networks: Overview & Application Polly Huang Department of Electrical Engineering National Taiwan University http://cc.ee.ntu.edu.tw/~phuang phuang@cc.ee.ntu.edu.tw

2. Network and Systems Laboratory nslab.ee.ntu.edu.tw Road Map Overview What is a sensor network? Applications How can the sensor network be useful? Polly@NTU2 Copyright © 2008

3. Network and Systems Laboratory nslab.ee.ntu.edu.tw Sensor Network Polly@NTU3 Copyright © 2008

4. Network and Systems Laboratory nslab.ee.ntu.edu.tw Sensors? Also the biomedical sensors: EMG, EKG, pulses, emotions, etc camera mic accelerometer gyro pressure thermal GPS Polly@NTU4 Copyright © 2008

5. Network and Systems Laboratory nslab.ee.ntu.edu.tw Sensor Nodes Today MICA, 2001-2002 5.7cm X 3.18cm 4 MHz CPU 128K ROM 512K RAM 40kbps Radio range x00 feet Sensors, battery not included Spec, March 2003 2mm X 2.5mm CPU, memory, RF transceiver Sensors, battery, antenna not included < 1 dollar if mass-produced Polly@NTU5 Copyright © 2008

6. Network and Systems Laboratory nslab.ee.ntu.edu.tw Embedded Sensor Node Intel® Xscale CPU Analog and digital radio Flash and SRAM memory Sensors Polly@NTU6 Copyright © 2008

7. Network and Systems Laboratory nslab.ee.ntu.edu.tw Embedded Sensor Network Polly@NTU7 Copyright © 2008

8. Network and Systems Laboratory nslab.ee.ntu.edu.tw Applications Home, Office, Healthcare, Science & Nature, Agriculture Polly@NTU8 Copyright © 2008

9. Network and Systems Laboratory nslab.ee.ntu.edu.tw Intel Digital Home Polly@NTU9 Copyright © 2008

10. Network and Systems Laboratory nslab.ee.ntu.edu.tw UCSB Bren School of Environmental Science and Management Day-lighting controls Operable windows control taking advantage of on- site ocean breezes Airflow controls based on CO 2 level Polly@NTU10 Copyright © 2008

11. Network and Systems Laboratory nslab.ee.ntu.edu.tw Long-Term Nursing Home Accelerometers Pressure sensor Muscle activity Camera Orientation sensor Fall detection Vital sign monitoring Dietary/exercise monitoring Polly@NTU11

12. Network and Systems Laboratory nslab.ee.ntu.edu.tw The Channel Islands Fox Polly@NTU12 Copyright © 2008

13. Network and Systems Laboratory nslab.ee.ntu.edu.tw Fancy Californian Winemaking Temperature Soil moisture Pest/disease Polly@NTU13 Copyright © 2008

14. Network and Systems Laboratory nslab.ee.ntu.edu.tw Taiwan Value! Home: Security (Crime Rate) Industry: IC (Energy crises) Healthcare: Elder Care ( 健保 Burden) Agriculture: Orchid Growing (Big Export Business) Polly@NTU14 Copyright © 2008

15. Network and Systems Laboratory nslab.ee.ntu.edu.tw Our Applications Maria (chronic disease) BL-Live (smart building) Ubiquitous Care (patient safety) Polly@NTU15 Copyright © 2008

16. Network and Systems Laboratory nslab.ee.ntu.edu.tw MicaZ Sensor Node Xscale-based Embedded System Maria: The Elder ’ s Companion WiFi GPRS Sensor Network Full-Fledged Server Polly@NTU16

17. Network and Systems Laboratory nslab.ee.ntu.edu.tw BL-Live: Elevator Report Sensor Network Polly@NTU17 Copyright © 2008

18. Network and Systems Laboratory nslab.ee.ntu.edu.tw U-Care: Localization Polly@NTU18 Copyright © 2008

19. Network and Systems Laboratory nslab.ee.ntu.edu.tw Sensor Network Problems 1. Network and Communication 2. Information or Signal Processing Polly@NTU19 Copyright © 2008

20. Network and Systems Laboratory nslab.ee.ntu.edu.tw Wireless Technologies Mote PicoNet IEEE 802.15.4 bluetoothWLAN Rangex m 10 m100 m Max BW40 kbps224 kbps723 kbps11Mbps Band310, 433, 868/916M Hz 868-928 MHz, 2.4GHz 2.4GHz Power (data mode) (1mA)(10mA)30mA250mA Polly@NTU20 Copyright © 2008

21. Network and Systems Laboratory nslab.ee.ntu.edu.tw Indoor Wireless Transmission Source Polly@NTU21

22. Network and Systems Laboratory nslab.ee.ntu.edu.tw Packet Reception Rate Good linkGrey linkBad link Polly@NTU22 Copyright © 2008

23. Network and Systems Laboratory nslab.ee.ntu.edu.tw Problems in Networking No one node can reach every other node Need multiple routing Each node can reach a high number of other nodes Need MAC with collision avoidance No link is 100% reliable Need (quasi-)reliable data transport Polly@NTU Copyright © 2008 23

24. Network and Systems Laboratory nslab.ee.ntu.edu.tw (Used to be) Hot Topics MAC Energy efficient MAC Data Dissemination Data-centric routing Energy efficient routing Hop-by-hope retransmission Polly@NTU Copyright © 2008 24

25. Network and Systems Laboratory nslab.ee.ntu.edu.tw Sensor Signals - Accelerometer Polly@NTU Copyright © 2008 25 MariaBL-Live Identify period of time where there is no activity Identify the direction/duration of the elevator moving

26. Network and Systems Laboratory nslab.ee.ntu.edu.tw Problem in Signal Processing Information to derive Very application dependent Signals come with noise Need filters Computation Cost Compute on board or else Polly@NTU Copyright © 2008 26

27. Network and Systems Laboratory nslab.ee.ntu.edu.tw (Used to be) Hot Topics In-network processing Do signal processing on board or with the help of other nodes Collaborative signal processing Derive information with the help of sensor data from multiple nodes Ranging-based localization Localize mobile nodes by triangulation Polly@NTU Copyright © 2008 27

28. Network and Systems Laboratory nslab.ee.ntu.edu.tw Road Map Zigbee Stack Designed for indoor home appliances AODV, CSMA-like MAC Classic Protocols Designed for outdoor sensor networks Directed diffusion, S-MAC In-Trend Protocols Designed for better QoS Magnetic diffusion, newer MAC Polly@NTU Copyright © 2008 28

29. Network and Systems Laboratory nslab.ee.ntu.edu.tw Polly@NTU Copyright © 2008 29 Questions?