Programming Sensor Networks

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Programming Sensor Networks

• Andrew Chien
• CSE291
• Spring 2003
• May 6, 2003

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Outline

• Applications Requirements
• Programming Challenges
• Technology Challenges
• Current Approaches
• New Directions

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Applications Requirements

• Broad and Amorphous
• Tremendous breadth
• No single design point
• What are some example requirements

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Static Sensing Mission

• Examples industrial, bridge, civil
  infrastructure, environmental monitoring
• Static Deployment of Sensor network
• Limited mission change, evolution
• Update dominated by management and failure/repair
• Slow adaptation, configuration acceptable
• Monitor and Activate in response to stimuli
• Capture data and process
• Stream to base station systems

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Dynamic Sensing Mission

• Examples disaster response, military or police
  search, surveillance
• Dynamic deployment of sensor network
• Rapid mission change, rapid evolution on command
• Update limited due to short intense missions, but
  reconfiguration to changing mission
• Fast adaptation, configuration critical
• Monitor and Activate in response to stimuli
• Capture data and process
• Process in network and actuate or Stream to base
  station systems

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Dynamic Network Structure

• Examples airborne, water born, vehicle born,
  zebra born sensornets
• Coastal Sensor Networks
• Dynamic deployment of sensor network
• Slow mission change, evolution
• Rapid network structure change due to physical
  movement, environment change, or failures
• Fast adaptation, configuration critical
• Monitor and Activate in response to stimuli
• Capture data and process
• Process in network and actuate or Stream to base
  station systems

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Sensor Network Programming Challenges

• Describe the distributed computation and sensing
  structures
• Manage/Tolerate the irregular and changing
  network structure to achieve the computational
  goal
• Reflect the accuracy / capability with which the
  sensor network can achieve mission
• Detect needs for reconfiguration and repair
• Enable optimization of program structure by
  automatic tools
• Enable adaptation of program structure to new
  configurations with automatic tools
• Enable gracefully degrading behavior with loss of
  resources and same source program
• Enable energy/resource conservation with
  techniques such as sleep/idle
• Others?

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Relevant Technologies

• Raise the level
• High Level and Declarative Programming
• Tolerance to change, portability
• Parallel computation
• Management of Computation/Communication,
  Concurrency, and Distribution
• Aggressive compiler control of behavior/implementa
  tion

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Relevant Foundations

• Distributed Systems and FT community
• Protocols, algorithms, implementation knowledge,
  programming techniques
• Embedded and RT systems community
• Local tools
• Managing resource requirements

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Technology Challenges

• Powered and Limited power
• Limited interconnectivity (link, bisection),
  external connectivity
• Limited coordination
• Limited memory
• Unreliable nodes
• Network evolution (upgrades and failures)

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Current Approaches

• C and Embedded SW Engineering
• NesC
• TinyDB

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C Embedded SW Engin.
C

• Cyclic executive or Priority Driven scheduler
• Collection of real-time tasks
• Manually Manage (some tools)
• Concurrency and correctness
• Memory constraints
• Distributed application structure
• Irregular sensor node distribution
• Sensor network change/evolution

C
C
C
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NesC

• TinyOS like interface with
• Call/Event Pairs
• Concurrency safety conditions
• Type Checking
• Manually Manage
• concurrency and correctness (some help)
• memory constraints
• distributed application structure
• Irregular sensor node distribution
• Sensornetwork change/evolution

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TinyDB

• Relational Model (table of sensor data sources)
• Simple Operators
• Semantics for transformation / implementation of
  Queries
• Optimize deployment and implementation for power
• Acquisitional Query processing
• Optimize implementation and data acquisition for
  power
• Manually Manage
• concurrency and correctness (some help)
• memory constraints
• distributed application structure (some help)
• Irregular sensor node distribution (some help)
• Sensornetwork change/evolution (some help)

Global Queries
Query Plan and Map
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New Directions
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Spatial Programming
Global Program

• Spatial structures (processor array) in
  programming systems
• Spatial structure lt-gt physical space ?
• Fortran D / HPF (imperative, spatial, explicit
  optimization/communication management)

Partition Data, Map/Optimize
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Collection Programming
Global Program

• Collection structures lt-gt sensor collections?
• Nesl
• CA/ICC
• Object-oriented Simulation models
• Elements
• Collection oriented naming
• Collection structuring, indexing
• Programmed cooperative behavior
• Presumed distribution and optimization

Map/Optimize
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Data/Communication Oriented

• Local program communication models which
  support asynchronous interactions
• Tuple Spaces (Linda)
• Publish-subscribe
• Bulletin Boards
• Data dissemination systems content-based query
  systems
• Peer to peer systems (gnutella, freenet, etc.)
  Content Filtering/ranking systems (OpenCola,
  others)
• TinyDB implementation techniques or different
  semantic framework?
• -gt we wont focus on these

Pub- Sub
Bulletin Boards
Tuple Space
Point To Point




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Summary / Discussion

• Just scratched the surface on the programming
  problem
• Low-level mechanisms and relational model provide
  starting point
• Higher level models common threads
• Global views
• Imperative control
• Explicit decoupling of expression from underlying
  resources
• Expose distribution for compiler managed
  communication
• Support for asynchrony
• Will explore over coming weeks

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