Wireless Sensor Networks

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Wireless Sensor Networks

• Nuwan Gajaweera
• Research Engineer

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Outline

• Motes Wireless Sensor Networks
• WSN Applications
• TinyOS
• WSN research at the Dialog Lab

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Motes Wireless Sensor Networks
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Mote

• 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)

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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

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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

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WSN Applications

• Environmental/Habitat monitoring
• Acoustic detection
• Seismic Detection
• Military surveillance
• Inventory tracking
• Medical monitoring
• Smart spaces
• Process Monitoring

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Habitat Monitoring on Great Duck Island

• http//www.greatduckisland.net/
• 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

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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.

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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,

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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

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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 1.1.15
• 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

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Different Targets
mica mica2 mica2dot micaz
telos telosb rene2 pc
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Mica2

• Extremely popular mote
• 8-bit AVR Controller
• FSK radio
• Data-logger flash

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Our contributions to the WSN world
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Mica2 Clone
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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

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Data Mule
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Data Mule
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Data Mule
Base Station
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Data Mule - Applications

• Collecting a data in a sparse sensor network
• Tracking movement of mobile elements
• Vehicles
• Livestock
• Wild Animals

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Data Mule
Base Station
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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

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Thank you..