InSitu Habitat and Environmental Monitoring

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In-Situ Habitat and Environmental
Monitoring Alan Mainwaring, Joe Polastre and Rob
Szewczyk Intel Research - Berkeley Lablet
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Talk Outline

• Introduction to habitat monitoring
• Field sites and application requirements
• Establishing the design context
• Summer milestones and wrap-up
• Demo live data from two networks

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Introduction

• Habitat monitoring represents a class of sensor
  network applications enormous potential impact
  for scientific communities and society as a
  whole.
• Instrumentation of natural spaces enables
  long-term data collection at scales and
  resolutions that are difficult, if not
  impossible, to obtain otherwise.
• Intimate connection with physical environment
  allows sensor networks to provide local
  information that complements macroscopic remote
  sensing.

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Application-Driven Sensor Network Research

• Benefits to others
• Computer scientists help life scientists
• Small steps for us can be revolutionary for
  others
• Provides design context
• Eliminates some issues, constrains others
• Can add new ones, e.g., packaging
• Prioritizes issues
• Low-power communication stacks
• Run-time systems and VMs for re-tasking
• Health and status monitoring systems
• Tools deployment and on-site interaction

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Habitat Monitoring

• Goal Remote, in-situ system consisting of
• Sensor networks in scientifically interesting
  areas
• WLANs link sensor networks to base station (DB)
• Internet link remote users to local resources
• Access models
• Remote DB, admin, health and status monitoring
• Continuous data logger to DB for long-term
  analysis
• Interactive inspection of sensor nodes (near
  real-time)
• Sensors of interest too many to list
• E,g., light, temperature, relative humidity,
  barometric pressure, infrared, O2, CO2, soil
  moisture, fluid flow, chemical detection, weight,
  sound pressure levels, vibration
• Need both relative and absolute measurements with
  units

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Field Sites and Application Requirements
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Habitat Monitoring Field Sites
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Application Requirements I

• Internet access
• 24x7
• 3 to 4 sensor networks (habitats)
• network of sensor networks
• 128 stationary motes per network
• 50 may miss interesting phenomena
• 1 year lifetime -- minimum
• standalone data-loggers run 1 to 10 years
• Change and adaptation may take days
• Static node locations, infrequent occlusions
• Off-the-grid power its off, its big, or its
  solar
• Disconnected operation possible at all levels

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Application Requirements II

• Field re-tasking (local or remote)
• Adjust sampling rates, operational parameters,
• Remote management (one site visit per year)
• 1 person can locate/touch/service all motes in 1
  week
• Inconspicuous packaging and operation
• No bright colors, no sounds (buzzing) or blinking
  lights
• Pack it out cannot deploy and forget
• Must find motes in field after year(s) of
  operation
• Cant leave 1000s of leaking Li/Cd batteries
• Users want predictable system operation
• Cannot burden users with more complexity

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Sensing Requirements Weather Board
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Some Non-Requirements

• Localization
• Oftentimes nodes are precisely placed
• Data aggregation
• Of readings on node (yes), across nodes (no)
• Precise time synchronization (yet)
• Depends on what precise means
• Instantaneous adaptation to change
• Prompt detection but not reaction
• Object tracking
• Unless its passive and over large distances

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Establishing the Design Context
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Design ContextPower Budget Basics

• Batteries
• 2xAA 2850 mAhr (est. 75 usable)
• daily 5.86 mAhr (365 day target lifetime)
• What can the mica do with 5.86 mAhr?
• Compute for 46 minutes
• Or send 70320 messages
• Or take 281000 temp readings

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Design ContextSensing Demands

• Sensor frequency bytes/day compressed
• Photo 1 min 2800 144 (95)
• I2C temp 15 min 192 192
• Baro/pressure 15 min 192 192
• Baro/temp 15 min 192 192
• RH 15 min 192 192
• IR thermopile second 172800 8640 (95)
• Thermistor second 172800 8640 (95)
• Totals
• 0.04 mAhr for sensing
• 349KB/day or 11600 msgs
• 18KB/day or 600 msgs (compressed)

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Design Context TwoCommunications Budgets

• (1) Low-power listening (2) Global scheduling
• 98 idle 1.17 mAhr 99 idle 1.188 mAhr
• 1 listen 3.60 mAhr listen time n/a
• 1 runtime 1.08 mAhr 1 runtime 4.668 mAhr
• sensing 0.044 mAhr sensing 0.044 mAhr
• for comm 1.036 mAhr for comm 4.624 mAhr
• Whats 1 mAhr worth? And 4.6 mAhr?
• 12431 msg opportunities 55487 msg opportunities
• 1 msg every 7 seconds 1 msg every 1.5 seconds
• In 128 node network, In 128 node network,
• 32 msgs/leaf-node/day 144
  msgs/leaf-node/day

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Communications Design Challenge

• Want network to last 1 year
• Want uniform amount of data from motes
• Route 18KB from each sensor to DB
• 1 mAhr communication budget (low-power listening)
• 4 mAhr communication budget (global scheduling)
• The key design challenge for habitat monitoring
  with sensor networks is resolving the trade-off
  between globally-scheduled approaches to
  communications and alternative approaches based
  on local information.

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Summer Milestones
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Summer Milestones

• June
• Weather sensor board debug and SW
• Low-power multi-hop routing for 1 duty cycle
• Setup lab network with new sensors and SW (6/27)
• July
• Upgrade Great Duck Island network (7/8 7/12)
• Upgrade James Reserve network (7/24 7/25)
• Monitor data collection, begin evaluation
• August
• Invited talk COA board of trustees (8/1)
• TR experiences and initial evaluation (8/25)
• NPR segment / National Geographic article (tbd)

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Conclusions

• Habitat monitoring is broadly representative of a
  seemingly simple class of sensor network
  applications.
• Reference for benchmarking and comparison
• The habitat monitoring application domain makes
  some systems issues concrete yet leaves others
  open.
• no mobility, 1 year longevity, resource budgets
• We can pursue sensor network systems research
  while delivering significant value to life
  scientists, today.
• whats trivial to one can be revolutionary to
  another
• We need robust multi-hop routing on spanning
  trees
• Youve got 1 to 4 mAhr per day to accomplish it

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Demo?