Protocols for SelfOrganization of a Wireless Sensor Network

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Protocols for Self-Organization of a Wireless
Sensor Network

• Written By
• Katayoun Sohrabi, Jay Gao, Vishal Ailawadhi, and
• Gregory J. Pottie, UCLA
• Presented By
• Joe Zendejas

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General Operational Requirements

• Wireless ad hoc networks that can connect
• Embedded sensors Actuators - Processors
• Form multihop networks with broadcast and
  multicast operation modes
• Development of algorithms with
• Scalable large number of mainly static nodes
• High constrained energy resources
• Maintain a network, with high routing efficiency
• Robust unattended operation at Startup, Steady
  state, and Failure scenarios

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Wireless Sensor Node
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Wireless Sensor Networks are a New Family of
Networks

• Mobile ad hoc networks (MANET)
• Peer to peer network / 10s-100s nodes / Range lt
  100s m / replaceable battery
• Cellular networks
• Vast network of stationary and mobile nodes
• Provide high QoS BW / unlimited power
• Short range wireless local area networks
• All nodes are connected to a master / 10m range
• Sensor networks
• 100s 1000s of nodes / Prolong network lifetime

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Various Wireless Networks
Mobile node
Wireless link
Mobile cluster head
Wireless link
Wired link
Base station
Mobile user
Base station
Wireless link
Mobile sensor
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Energy-Conserving Techniques in Sensor Networks

• Energy consumption occurs in
• Sensing / Data processing / Communications
• Communications is the major energy consumer
• Ex. Radio Transmission Vs. Data Processing
• Therefore, local processing is key

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Our Developed Protocols

• Self-Organization Medium Access Control for
  Sensor Networks (SMACS)
• Network startup and link layer
• Eavesdrop-And-Register (EAR) Algorithm
• Seamless interconnection of mobile nodes in the
  field of stationary wireless nodes (mobility
  management)
• Sequential Assignment Routing (SAR)
• Facilitates multihop routing
• Single Winner Election (SWE) and Multi-Winner
  Election (MWE)
• Facilitates local cooperative information
  processing

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Link-Layer Issues

• Link layer topology and regulation of channel
  access among the nodes
• Channel contention Vs. time/freq/code domains
• Description of the stationary MAC and Startup
  Procedure (organized scheme)
• 1st attempts to determine network radio
  connectivity, 2nd assign collision free channels
  to links

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Mobile MAC Issues

• The Ear algorithms motivation
• Offers continuous service to mobile nodes in
  either mobile or stationary constraints
• Network constraints
• EAR algorithm
• Broadcast Invite (BI)
• The stationary node invites other nodes to join.
• Mobile Invite (MI)
• The mobile responds to BI to request a
  connection.
• Mobile Response (MR)
• The stationary node accepts the MI response.
• Mobile Disconnect (MD)
• The mobile informs the stationary node of a
  disconnect no response is needed.

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General Mobile Activity
Stationary not in registry
Stationary neighbor, Possible future
connection
Mobile
BI message
Stationary connection
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Adaptive Local Routing for Cooperative Signal
Processing

• Routing of networks refers specifically to a
  connection set of sensors that detected a common
  target
• Noncoherent cooperative function
• Processing network formation process
• P1 Target detection, data collection,
  preprocessing
• P2 Membership declaration
• P3 Central node (CN) election (SWE or MWE)
• Coherent cooperative function

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Single Winner Election (SWE) Process
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Simulation Implementation

• A radio propagation model complete with shadowing
  and path loss was implemented in Parsec
• Network of 45 randomly scattered nodes having a
  density of 0.04 nodes/m2
• 1mW transmit power, Tframe 8.0s
• 100 frequency bands are available

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Conclusion Critique

• Algorithms with the ability to maintain
  connectivity to a wireless sensor network
• Great energy conservation schemes and network
  scalability
• Exploitation of low mobility and abundant
  bandwidth
• Evaluation with assumption that a greater amount
  of nodes were static.
• No evaluation with specific energy capacities
• Distribution/Management of TDMA freq. slots