Sensor%20Network%20Architectures

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Sensor Network Architectures
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Objectives

• Be familiar with how application needs impact
  deployment strategies
• Understand key benefits/costs associated with
  different topologies.
• Understand key benefits/costs associated with
  homogeneous and heterogeneous node deployments

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Objectives (cont.)

• Apply simple metrics to assess network
  connectivity
• Understand common routing protocols
• Synthesize these concepts to ascertain the energy
  requirements for various network topologies

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Outline

• Deployment strategies
• Network topologies
• Connectivity and Coverage
• Routing protocols
• Example Application Energy use for various
  topologies

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Deployment Strategies

• Motivation
• Application needs?

Deployment
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Random vs. Structured

• Random

• Structured

Deployment
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Incremental vs. Over-deployment

• Incremental

• Over-deployment

Deployment
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Outline

• Deployment strategies
• Network topologies
• Connectivity and Coverage
• Routing protocols
• Example Application Energy use for various
  topologies

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Network Topologies

• Motivation
• Star single hop
• Flat mesh multi-hop
• Tiered multi-hop

Topologies
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Star
Topologies
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Mesh
Topologies
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Tiered
Topologies
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Node Capabilities

• Homogeneous

• Heterogeneous

Topologies
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Single vs. Multi-hop

• Single hop

• Multi-hop

Topologies
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Outline

• Deployment strategies
• Network topologies
• Connectivity and Coverage
• Routing protocols
• Example Application Energy use for various
  topologies

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Connectivity

• Motivation
• Graph Theory Tools

Connectivity
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Random Graph Model

• G(n,R)

Connectivity
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Graph Connectivity
Connectivity
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Problem with Random Graph Model

• Propagation environments are not isotropic

Connectivity
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K-connectivity
Connectivity
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Improving connectivity

• Approaches

• Costs

Connectivity
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Outline

• Deployment strategies
• Network topologies
• Connectivity and Coverage
• Routing protocols
• Example Application Energy use for various
  topologies

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Coverage

• Motivation
• Tools

Coverage
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Voronoi Diagram
Coverage
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K-coverage
Coverage
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Example
Coverage
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Problems with Coverage Metrics
Coverage
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Topology Control

• Idea
• Motivation

Topology Control
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Method 1 PEAS
Topology Control
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Method 2 ACK
Topology Control
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Outline

• Deployment strategies
• Network topologies
• Connectivity and Coverage
• Routing protocols
• Example Application Energy use for various
  topologies

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Routing protocols

• Motivation
• Metric-based
• Diversity-based

Routing protocols
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Greedy Forwarding
Routing protocols
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ETX Metric
Routing protocols
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Opportunistic (ExOR)
Routing protocols
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Gradient-based
Routing protocols
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Lifetime and Load-balancing

• Lifetime

• Load

Routing protocols
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Data Mules
Routing protocols
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Outline

• Deployment strategies
• Network topologies
• Connectivity and Coverage
• Routing protocols
• Example Application Energy use for various
  topologies

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Comparison Single-hop vs. Double-hop
Networking Energy
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Scenario 2 Single-hop vs. Double-hop
Networking Energy
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Conclusions

• Multi-hop networks promise broader coverage and
  robustness at the cost of increased complexity
• Homogeneous node architectures simplify
  deployment strategies but may require more
  capable hardware
• Node connectivity is dependent on the node
  placement and the communication channel

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Conclusions - 2

• Network coverage requirements may not coincide
  with network connectivity requirements
• Routing schemes depend on defining an appropriate
  cost metric
• Network architectures drive node and system
  design and therefore energy and bandwidth
  requirements

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Want to learn more?

• B. Krishnamachari, Networking Wireless Sensors,
  Cambridge Press (2005).
• H. Karl and A. Willig, Protocols and
  Architectures for Wireless Sensor Networks, Wiley
  (2007).