Wireless Sensor Networks for Habitat Monitoring Jennifer Yick Network Seminar October 10, 2003

Outline Habitat monitoring Requirements System Architecture Hardware and Design Network and Application Interface Results

Habitat monitoring Objective: monitor seabird nesting environment and behavior Key fact: Seabird colonies are very sensitive to disturbance. Repeated disturbance will lead to abandonment of the colony. Major Problem: The impact of human presence repeatedly can distort results by changing behavioral patterns and destroy sensitive populations. Solution: Deployment of a sensor network

Great Duck Island and requirements Great Duck Island is a remote island south of Mount Desert Island, Maine Requirements Internet access: to allow remote interactions Internet access: to allow remote interactions Hierarchical network: to provide enough connectivity over several kilometer Hierarchical network: to provide enough connectivity over several kilometer Sensor network duration: at least 9 months on non-rechargeable battery Sensor network duration: at least 9 months on non-rechargeable battery

Requirements con’t Inconspicuous operation: habitat monitoring should not disrupt the natural process or behavior under study Sensor network: should be stable, predictable, and repeatable behavior if necessary Local interaction: PDA assist with direct sensor query, adjust operational parameters or assist in locating devices Sensor type: sense light, temperature, infrared, relative humidity, and barometric pressure Data compression: archive sensor readings

System Architecture

Sensor Node UC Berkeley mote family called Mica Uses a single channel 916 MHz radio from RF monolithic to provide bidirectional communication Uses a single channel 916 MHz radio from RF monolithic to provide bidirectional communication Uses 2 AA batteries and a DC boost converter to stable voltage source Uses 2 AA batteries and a DC boost converter to stable voltage source Small in size (approx. 2.0x1.5x0.5 inches) Small in size (approx. 2.0x1.5x0.5 inches)

Sensor node functionality Each sensor node contains a computational module (a programmable unit) which provides computation ability, storage, and bidirectional communication with other nodes in the system Two advantages: They can be re-task in the field They can be re-task in the field Easily communicate with the rest of the network Easily communicate with the rest of the network

Gateway Each sensor patch contains a gateway node Each gateway node can communicate with the sensor network and provides connectivity to the transit network

Transit Network Can consist of a single hop link or a series of networked wireless nodes Each transit network design has different characteristics Robustness Robustness Bandwidth Bandwidth Energy efficiency Energy efficiency Cost Cost Manageability Manageability

Base Station Data storage for the collection of sensor patches WAN connectivity will be wireless Base-Remote link connection to the internet

Possibility of Disconnection There is a possibility of disconnection at every level Each layer (sensor nodes, gateways, base station) has storage against data loss (power failure) Each layer has data management Sensor nodes – data logging Sensor nodes – data logging Gateway – some database storing services Gateway – some database storing services Base station – database services Base station – database services

Sensor Deployment 32 sensor nodes were deployed using Mica motes with Mica Weather Boards Mica motes Battery case integrated with the main processing and sensor boards Battery case integrated with the main processing and sensor boards Weather proof case First enclosed by a 10 micron parylene sealant to protect it from electrical contact First enclosed by a 10 micron parylene sealant to protect it from electrical contact Then enclosed by a transparent acrylic enclosure Then enclosed by a transparent acrylic enclosure

Gateway – a single hop mote to mote network over CerfCube 1 (an embedded linux system equipped with a compact flash adapter [1]Cerfcube embedded StrongARM system. Intrinsyc Corporation, Vancouver BC Canada Chosen hardware

Base Station Base station – a laptop Each group of sensors communicates with a laptop which stores the data in a database Each group of sensors communicates with a laptop which stores the data in a database

Base Station An external antenna permits communication from the sensor patch to the laptop-a distance of over 350 feet. A satellite transciever is then used to replicate the data in the database to the research facilities – a distance of over 50,000 miles

Data Management and User Interface Base station uses a SQL database which stores the time-stamped readings from the sensors Database is replicated every fifteen minutes Database is replicated every fifteen minutes User Interface is implemented on top of the sensor network database Matlab to analyze the data Matlab to analyze the data Java Applet to display Java Applet to display

RESULTS

Conclusion Define the core application requirements Constraints on the sensor nodes have defined energy budget for all other services This study can be a representation of many applications in this area

References A. Mainwaring, J. Polastre, R. Szewczyk, D. Culler, J. Anderson, “Wireless Sensor Networks for Habitat Monitoring,” ACM International Workshop on Wireless Sensor Networks and Applications, Sept. 2002