Wireless Sensor Networks

1. Wireless Sensor Networks By Eric Anderson

2. Introduction • Wireless Sensor Network (WSN): An autonomous, ad hoc system consisting of a collective of networked sensor nodes designed to intercommunicate via wireless radio.

3. Introduction • Wireless – Communication via radio waves • Autonomous – Independent; self-directed • Ad hoc network – A network without a fixed, well-defined infrastructure • Sensor node – Device that produces a measurable response to a change in physical condition

4. Node Classification • Individually addressable • Each node is uniquely identified, facilitates object-based organization • Ex: Parking lot spaces • Network data is aggregated • Messages broadcast, reduction in network bandwidth • Ex: Temperature in room corner

5. Node Examples

6. WSN Goals • Tracking – Detect and track objects • Classification – Classify objects • Estimation – Estimate parameters and events of interest pertaining to objects • Determination – Determine the value of some parameter at a given location

7. WSN Requirements • Stationary or Mobile use • Low energy consumption • Self-organization and autonomy (locality) • Robust and scalable • Collaborative signal processing (emergent behavior through data fusion) • Querying ability (possible message routing via cluster head promotion)

8. Types of WSNs • Environmental • Medical • Military • Urban • Civic • Industrial • Residential

9. Environmental Usages • Search and rescue • Disaster relief • Climate monitoring (weather prediction) • Seismic detection (earthquakes, volcanos) • Pollution tracking (patterns, density) • Habitat monitoring (endangered species, www.greatduckisland.net) • Geophysical monitoring (forest fires, river currents, contaminants, global warming, farms, marine microorganisms)

10. Environmental Requirements • Energy efficiency (long battery life) • Intermittent connectivity • Schedule sleep mode for redundant sensors • Inexpensive nodes (large quantity needed) • Reduced size of nodes (small, microscopic) • Auto-configuration of sensors • Scalable network • Robust nodes to handle harsh environments (heat, water, snow, humidity, wind)

11. Medical Usages • Health care (insurance cards) • Patient monitors (pulse, heart rate, glucose levels, child tracking, eye implants, defibrillators) • Cybernetic enhancements • Information tags (allergies, severe reactions) • Medication notification system

12. Medical Requirements • Energy efficiency (long battery life, heat/kinetic/bio battery) • Hidden device (not visually detectable) • Biologically safe • Fault-tolerant, reliable • Encrypted bio information • Interference-safe (RF noise, 900 MHz)

13. Military Usages • Tactical surveillance (land, sea) • Tracking troop movement (both sides) • Ubiquitous, undetected smart mines • Battlefield communication • Detection of hazardous agents (explosive, nuclear, biological, poisonous, radioactive) • Environmental awareness (terrain mapping)

14. Military Requirements • Energy efficiency (long battery life) • Schedule sleep mode for redundant sensors • Ubiquitous and Undetectable • Auto-deployment and self-organization • Fault-tolerant, reliable • Strong Encryption (low overhead) • Auto-configuration of sensors • Scalable network • Robust nodes to handle harsh environments (heat, water, snow, humidity, wind)

15. Urban Usages • Civic • Transportation systems (traffic) • Auto-identification (drivers license) • Parking lot availability sensors • Security monitors (shopping malls, parking garages, city streets) • Child abduction prevention • Automated parking meter update

16. Urban Usages • Industrial • Hotel room smart service • Ubiquitous gambling cameras • Product distribution (UPS) • Inventory tracking/control • Worker efficiency and daily routine (company badges) • Quality assurance, process control

17. Urban Usages • Residential • Home security • Digital canvas • Smart appliances (lights, thermostat, television, stereo, etc.) • Life alert system (elderly, children near pool) • Pet tracking (angel alert proximity detector) • Dirt sensors (alert home owner when specific quadrants exceed dust/dirt quota)

18. Urban Requirements • Inexpensive nodes (large quantity needed) • Reduced size of nodes (small, medium) • Robust nodes to handle harsh environments (climate, people) • Diverse range of sensor types (audible, visual, location, etc.) • Interoperability (interface with home, commercial and government systems) • Highly customizable (diverse user base) • Scalable network (wide area of coverage)

19. References • http://www.cs.uno.edu/~golden/MobileBook/ • M. Kochhal, L. Schwiebert, Sandeep Gupta. Role-based Hierarchical Self Organization for Wireless Ad hoc Sensor Networks • J. Elson, K. Romer. Wireless Sensor Networks: A New Regime for Time Synchronization. ACM SIGCOMM Computer Communications Review, volume 33, January 2003. • Smart Sensor Networks. Advanced Network Technologies Division, Nation Institute of Standards and Technology. May 2001. • D. Estrin, R. Govindan, J. Heidemann. Embedding the Internet. Communications of the ACM, volume 43, May 2000. • A. Mainwaring, J. Polastre, R. Szewczyk, D. Culler, J. Anderson. Wireless Sensor Networks for Habitat Monitoring. WSNA ’02, September 2002. • K. Romer, O. Kasten, F. Mattern. Middleware Challenges for Wireless Sensor Networks. Mobile Computing and Communications Review, volume 6, July 2002.