1. Wireless Sensor Networks
Nuwan Gajaweera
Research Engineer

2. Outline Motes & Wireless Sensor Networks WSN Applications TinyOS
WSN research at the Dialog Lab

3. Motes & Wireless Sensor Networks

4. Mote A very low cost low power computer Monitors one or more sensors
External Memory
Digital I/O ports
Radio Transceiver
Analog I/O Ports
Microcontroller
A/D
D/A
Sensor
A very low cost low power computer
Monitors one or more sensors
A Radio Link to the outside world
Are the building blocks of Wireless Sensor Networks (WSN)

5. Wireless Sensor Network
“A wireless sensor network (WSN) is a wireless network consisting of spatially distributed autonomous devices using sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants, at different locations.”
- Wikipedia

6. Wireless Sensor Networks
Formed by hundreds or thousands of motes that communicate with each other and pass data along from one to another
Research done in this area focus mostly on energy aware computing and distributed computing

7. WSN Applications Environmental/Habitat monitoring Acoustic detection
Seismic Detection
Military surveillance
Inventory tracking
Medical monitoring
Smart spaces
Process Monitoring

8. Habitat Monitoring on Great Duck Island
Intel Research Laboratory at Berkeley initiated a collaboration with the College of the Atlantic in Bar Harbor and the University of California at Berkeley to deploy wireless sensor networks on Great Duck Island, Maine (in 2002)
Monitor the microclimates in and around nesting burrows used by the Leach's Storm Petrel
Goal : habitat monitoring kit for researchers worldwide

9. FireBug Wildfire Instrumentation System Using Networked Sensors
Allows predictive analysis of evolving fire behavior
Firebugs: GPS-enabled, wireless thermal sensor motes based on TinyOS that self-organize into networks for collecting real time data in wild fire environments
Software architecture: Several interacting layers (Sensors, Processing of sensor data, Command center)
A project by University of California, Berkeley CA.
Sensors : Thermal, light, pressure, GPS, Accelerometer
More can be done here (overview of the protocol)

10. Preventive Maintenance on an Oil Tanker in the North Sea: The BP Experiment
Collaboration of Intel & BP
Use of sensor networks to support preventive maintenance on board an oil tanker in the North Sea.
A sensor network deployment onboard the ship
System gathered data reliably and recovered from errors when they occurred.
The project was recognized by InfoWorld as one of the top 100 IT projects in 2004,

11. “Cricket” Mote Basically a location-aware mote.
Includes an Ultrasound transmitter and receiver.
Uses the combination of RF and Ultrasound technologies to establish differential time of arrival and hence linear range estimates
Based on Cricket Indoor Location System developed by a MIT researcher Nissanka Bodhi Priyantha

12. TinyOS
What is TinyOS
open-source operating system
wireless embedded sensor networks
component-based architecture
Developed at UCB in collaboration with Intel Research
Current Stable Version is
TinyOS 2.0 (T2) released on 6/11
Main Ideas –
Low complexity
Conserve power – sleep as frequently as possible
Written in nesC – next generation C compiler

13. Different Targets
mica
mica2
mica2dot
micaz
telos
telosb
rene2 pc

14. Mica2 Extremely popular mote 8-bit AVR Controller FSK radio
Data-logger flash

15. Our contributions to the WSN world

16. Mica2 Clone

17. Data Mule
DataMule – a mobile entity present in the environment that will pick up data from the mote when in range, buffer it, and drop off the data at base station
ex: People, Vehicles, Livestock

18. Data Mule
Leaf Node
Base Station
Data Mule

19. Data Mule

20. Data Mule
Base Station

21. Data Mule - Applications
Collecting a data in a sparse sensor network
Tracking movement of mobile elements
Vehicles
Livestock
Wild Animals

22. Data Mule
Base Station

23. Data Mule - Research undertaken
Development of a TDMA/CSMA hybrid MAC
TinyOS currently has a CSMA MAC
Hope to improve throughput by employing TDMA
Time is divided into transmission periods and contention periods
Nodes will contend with each other to join “the transmission group” during the contention period.
Nodes in the transmission group will be allocated a time-slot in the transmission period.
Development of data storage engine optimized for fast retrieval

24. Thank you..