Wireless Sensor Networks for Habitat Monitoring

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Wireless Sensor Networks for Habitat Monitoring

• Presented by Jas Ahluwalia
• 4/15/03 (Doh! Tax Day)
• CSE291Programming Sensor Networks
• Prof. Andrew Chien

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Why Sensor Networks for Habitat Monitoring?

• Human presence messes things up!
• Can change the behavioral patterns that we are
  trying to monitor
• Can even destroy sensitive populations by
  reducing breeding success, causing shift to
  unsuitable habitats, introducing exotic elements,
  etc.
• Providing food and lodging for human researchers
  in such remote locations is costly.

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Why Sensor Networks for Habitat Monitoring? (Cont)

• Small sensors can be deployed during periods
  when sensitivity to human presence is minimal.
• Non-Breeding times
• When Plants are Dormant
• Implement a Deployem and Leaveem strategy.
• Broaden the scope of study sites which were
  previously limited by concerns of human presence
  or danger to humans.

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Goals Motivation

• Develop a specific habitat monitoring application
  that will represent all problems within this
  domain.
• Taking an application-driven approach quickly
  separates actual problems from potential ones and
  relevant issues from irrelevant ones.
• True or False?

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Great Duck Island

• 237 acre island 15 km south of Mount Desert
  Island.
• Wish to monitor the Leachs Storm Petrel
• Usage pattern of nesting burrows
• Environmental differences in burrow and on
  surface.
• Differences in micro-environments with and
  without large numbers of nesting petrels.
• Various data needs with various data acquisition
  rates.

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Great Duck Island Requirements

• Internet Access
• Support remote interactions with in-situ networks
• Hierarchical Network
• Discussed Later
• Sensor Network Longevity
• 9-12 months
• Operating Off-the-grid
• No wall sockets! Must operate on battery power,
  solar power, etc.

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Great Duck Island Requirements (Cont)

• Management at-a-distance
• Goal is zero on-site presence, including
  maintenance and administration.
• Inconspicuous Operation
• Invisibility as discussed by Prof. Chien.
• System Behavior
• Stable, predictable, and repeatable behavior. But
  is this possible in the physical world?
• In-Situ Interactions
• Some local interactions may be required via PDAs.
  Huh? What about the first bullet?

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Great Duck Island Requirements(Cont)

• Sensors and Sampling
• Light, temp, humidity, barometric pressure, etc.
• Data Archiving
• Archiving of data acquired by sensors for
  off-line data mining. Additionally, reliably
  offloading this acquired data to databases in the
  wired world.

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Planned System Architecture

• Sensor Nodes
• Perform general purpose computing, networking,
  and sensing.
• Sensor Patch
• Group of Sensor Nodes.
• Gateway
• Responsible for transmitting sensor data from
  patch through a local transit network.
• Transit Network
• Single hop link or series of networked wireless
  nodes in a path from gateway to base station.
• Base Station
• Provide Wide area connectivity and a Database
  Management System.

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Panned System Architecture (Cont)
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Planned System Architecture (Cont)

• Sensors form a multihop network by forwarding
  each others messages.
• Each Layer has some form of storage
• Sensor Level Data Logging
• Base Station Level Full Relational DBMS
• Gateway Level Something in between.

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Implementation

• So that was the plan, how did they implement a
  Sensor Network at Great Duck Island.

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Sensor Node

• Sensor Node
• MICA as discussed by Johann.

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The MICA Weather Board

• Provide the same functionality as a traditional
  weather station.
• Startup time dominates power consumption, not
  sample rate due to low duty cycle.
• Through calibration, interchangeability and
  accuracy can be reduced to below 1.

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The MICA Weather Board (Cont)
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Energy Budget

• Target Lifetime is Approx. 7-8 months
• Power Budget is 6.9 mAh/Day

Expected Lifetime (months)
Number of Operating Hours per Day
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Energy Budget (Cont)
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Sensor Deployment

• Coat entire sensor package with 10 micron
  parylene sealant to provide water protection.
• Sensors placed in protective packaging that
  minimally obstruct sensing functionality
  (ventilated).
• Sensors placed in burrows without protective
  packaging due to size constraints.

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Sensor Patch Network

• Single Patch Network of 32 Motes
• 9 of which are inside burrows
• Single Hop Model
• Broadcast to gateway during scheduled
  communication period.
• But didnt we say were going to be using a
  multihop network?

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Gateway

• 2 Designs
• CerfCube (solar power)
• Embedded Linux system.
• 1GB Storage Space.
• 802.11b
• Mote-To-Mote (solar power)
• Mote connected to Base Station and Mote in Sensor
  Patch.
• 14dbi directional 915MHZ Yagi antennae. 1200 ft
  range.
• Tests yielded equivalent identical packet
  reception rates.
• Mote-To-Mote solution chosen because less
  intrusive hardware and consumes far less power (2
  orders of magnitude).
• Do we still have Gateway and Transit Network
  levels of Hierarchies?

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Base Station

• Wide area connectivity provided through 2 way
  satellite.
• Laptop running relational database.

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DBMS

• PostGres SQL
• Replicated every 15 min over satellite link to DB
  in Berkley

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User Interfaces

• Various Database Interfaces
• Web based Interfaces
• Developed Java applet which provides access to
  habitat data.
• Gizmos not fully developed
• Experiments iPaq PDA running Linux.

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Results

• Verified that data collected by sensors is
  correct.
• When satellite goes down, data continues to be
  logged on the island and connectivity is brought
  up again, the secondary database is brought up to
  date.
• Power Management
• Calculated 7 months, expect 4
• Petrels are not Mote Neutral
• What does that mean?
• 50 km/hr winds knock equipment down
• 739,846 samples as of 9/23 (3 months after
  deployment), network is still running

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Future Work and Discussion

• Data Sampling and Collection
• Sampling rates, aggregate collection, etc.
• Communication
• Ad Hoc Routing
• Network Retaking
• Health and Status Monitoring
• Power Optimization/Conservation Techniques