1 / 30

Introduction to Theory and Applications of Self Organizing Wireless Sensor Networks

Introduction to Theory and Applications of Self Organizing Wireless Sensor Networks. Vijay K. Devabhaktuni & James W. Haslett Department of Electrical and Computer Engineering University of Calgary 13 July 2004. Agenda. Introduction Self Organizing Wireless Sensor Networks

torie
Download Presentation

Introduction to Theory and Applications of Self Organizing Wireless Sensor Networks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Introduction to Theory and Applications of Self Organizing Wireless Sensor Networks Vijay K. Devabhaktuni & James W. Haslett Department of Electrical and Computer Engineering University of Calgary 13 July 2004

  2. Agenda • Introduction • Self Organizing Wireless Sensor Networks • Experimental System • Wireless Sensor Networks in Patient Monitoring • Demonstration • Summary

  3. Wireless Sensor Network (WSN) A wireless sensor network consists of a large number of nodes deployed in the environment being sensed and controlled through wireless communication. Typically, a WSN consists of • A number of remote nodes (we refer to them as motes) • Base station

  4. Self Organizing WSN Routing Tree Link Connectivity Features: The remote nodes self-assemble into a network. The sensor information is propagated to the base station. Nodes collaborate i.e. intermediate nodes assist distant nodes to reach the base station. Base Station

  5. Application Domains Highlights • Micro-sensors, on-board processing and wireless interface are all possible at very small scale! • WSN are able to monitor a phenomena up-close • Spatio-temporally dense environmental monitoring becomes a reality • Networked sensing can reveal certain previously unobservable phenomena of our nature Seismic structure response Contaminant transportation Eco-system’s biocomplexity Marine microorganisms

  6. Sensor Radio ADC Battery In-node processing Wireless communication with other nodes & base Event detection Mote: Structure & Function

  7. Enabling Technologies Technological advances have facilitated • Smaller & cheaper electronic components • Systems on a single chip • Integrated low-power communication modules The above trends enabled WSN characterized by • Smaller physical size • Multi-functional behavior & concurrent operation • Wireless communication

  8. It’s Just a Beginning UCLA, 1996 UCLA, 1998 UCB, 2000 (Crossbow Tech.) Sensoria, 2001

  9. Roadmap Number crunching Data storage Mainframe Minicomputer Productivity Interactive Workstation PC Laptop PDA log (people per computer) “Streaming information to/from physical world” Time

  10. A Dream Network! • Flexible integration of sensors • Low-cost & energy-efficient processors • Robust communication over radio • Lifetime source with each mote 

  11. Experimental Hardware Mote to PC Interface and Programming Board (MIB500) 4× Mica2Dot Motes 4× Mica2 Motes 3× Sensor Boards (MTS300) 2× Prototyping Boards (MDA500)

  12. Generations of Crossbow Motes

  13. Mica2dot • Battery • Memory and Processor • Sensor modules (externally integrated) • 916/433 radio transceiver • 10-bit ADC

  14. Base Station Base station includes an interface board that allows • Mote connectivity • RS-232 serial programming interface • Aggregation of network data on a PC

  15. Required Software Services • Sensor interfacing • Radio messaging • Routing • Power management • Time • Debug

  16. Tiny Operating System (TinyOS) Developed taking the following aspects into account • Efficient resource utilization • Small foot print to run on small processors Key Features: • Set of services • Simple operating system • Open-source development environment • nesC programming language

  17. TinyOS Architecture • Designed for low-power ad hoc WSN Responsive to stimuli, event oriented, scaleable • Key elements Sensing, computation, communication, power • Resource constrained Power, memory, processing • Adapt to changing technology Modularity & re-use

  18. nesC - The TinyOS Language • Dialect of C • TOS syntax and structure aware • Variables, tasks, calls, events, signals • Component wiring • A pre-processor • nesC output is a c program file, which is compiled and linked using gcc tool

  19. Application ExampleA Wireless Patient Monitoring System for the Ward of the 21st Centuryof the Calgary Foothills Hospital

  20. Patient’s Vital Medical Parameters Doctors wish to continuously monitor variations in • Temperature • Heart rate • Blood oxygenation • Respiratory rate Toward this end, we developed a wireless framework.

  21. The Comprehensive Wireless Framework

  22. Key Features The framework includes • Real-time sensing of patient’s vital parameters using precision-sensors interfaced to the motes • Wireless transmission of such critical information over radio frequencies to the base-station • Subsequent data processing on a PC to allow detection of medical emergencies and alerting of medical staff Note: Emergency detection is enabled using neural networks

  23. Deliverables • A self-organizing wireless system capable of continuous patient-monitoring • Patients can move about in the hospital space, thanks to the “multi-hop” feature of WSN • A smart hospital bed with automation in terms of emergency detection

  24. Temperature Sensor Ear temperature is quick to read and reliable! Our initial temperature sensor design involved: • Thermistor modeling • Linearization of output voltage • Initial prototype is operational • Future work will include packaging of thermistor using a silicon enclosure to protect from ear wax, and other non-intrusive methods of measuring body temperature

  25. Heart Rate & Blood Oxygenation This instrument is being interfaced to a wireless mote

  26. Low-Power Transceivers • Potential applications for Ad hoc WSN are vast • Low-power transceiver designs become essential • “Low-power” versus “Performance” • Fully-integrated low-power relaxation VCO • Ken Townsend presented measured results

  27. Concept Demonstration • ADXL202AE dual-axis accelerometers (±2g) from Analog Devices are interfaced to the motes • Mica2dot motes are programmed to read sensor data via ADC3 and wirelessly transmit such data • Nominal reading of sensors is +1500mV at 0g. Sensitivity characteristic is ±150mV/g • Targeted application is the R&D of 6-axis motion of human feet that helps understand Parkinson’s

  28. Future of Power Management (1324,1245) Two types of nodes • Tripwire nodes that always sense • Low-power presence sensing • Tracker nodes that sense on-demand

  29. Acknowledgements • NSERC • iCORE • TRLabs • Calgary Health Region

  30. Conclusions • In this project, WSN technology is exploited for developing a framework for wireless patient-monitoring. • Results are expected to significantly help the healthcare personnel to cope with today’s shortage of resources. • The WSN paradigm and its advancements promise many other key applications in the healthcare sector. • The research area opens the doors for novel R&D activities in the microelectronics arena.

More Related