LowPower Wireless Multihop Network Design

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Low-Power Wireless Multihop Network Design

• Danny Patel
• Jan Rabaey
• BWRC
• University of California
• Berkeley

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Goals

• Explore energy efficiency of candidate ad-hoc
  routing protocols for the PicoRadio applications.
• Parameterize network routing properties in terms
  of Energy for use in protocol design flow.
• Develop a design space for the rapid testing and
  implementation in Simulink.

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Ad-Hoc Protocols

• Possible candidates for PicoNode Network
• DSDV
• simplest , requires periodic updates, large
  amount of overhead
• DSR
• complex, intermediate nodes do not require
  up-to-date information
• AODV
• a hybrid of DSDV and DSR

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Energy Concerns

• Routing overhead will lead to significant energy
  usage with channel contention
• Tradeoff exists between bandwidth utilization,
  energy, and data consistency.
• Energy Cost function will be influenced by
  received power, power computation per node, and
  mobile mobility.
• Distributed nature may be compromised in order to
  save energy.
• Energy saving for a net or node more important?

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Tool Environments

• Tools Considered
• VINT NS2
• Rich TCP and Network libraries, but CMU wireless
  extensions are still being integrated
• Very Flexible environment for developing and
  simulation.
• Requires considerable self-maintenance.
• Parsec/GloMoSim -- current favorite
• Geared toward ad-hoc network simulations. Work is
  being done to import CMU network protocols
• Intended to be used for testing for deployment.
• OpNet
• Rich and detailed models of existing protocols
  and hardware
• Not popular among Network research community

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Parsec/GloMoSim Simulator

• Parsec
• UCLAs Discrete - Event Parallel simulation
  engine
• GloMoSim -library of modules for wireless
  networks
• Source Code is written primarily in C and uses
  the Parsec compiler to create executable.

Coming soon Not in distribution
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Experiment Setup

• Option of custom node placement or random is
  available with a selection of mobility patterns.
  Experiment setup is configured through a text
  file.

Parameters Routing Protocol Basic
Bellman-Ford Number of Nodes 30 Power Range
10m Free-Space Periodic Update Interval 10s Run
Time 100s Mobile Speed 1m/5s No Collisions!
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Simulation Results

• Simulation done in Parsec/GloMoSim.
• Forwarding tables and layer-specific statistics
  also available.

Red - 1 mobile moving only Green - all nodes
stationary Blue - 1 new mobile going online
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Future Work

• Use mobilitys movement as a metric in link cost.
• Include MAC and a detailed Physical Channel to
  investigate energy consumption at different
  layers.
• Investigate DSRs on-demand routing.
• Investigate advantages of using a single-hop
  uplink and multi-hop downlink network.