SENSOR NETWORKS

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SENSOR NETWORKS

• BY
• Umesh Shah
• Mayuresh Patil
• G P Reddy
• GUIDES
• Prof U.B.Desai
• Prof S.N.Merchant

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Outline Of Presentation

• Introduction to Sensor NetworksUmesh
• Overview of protocols G P Reddy
• Localization Mayuresh
• Work done future plans Umesh

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Outline Of My Presentation

• Introduction to Sensor Networks.
• Characteristics features.
• Applications.
• Communication protocols issues.
• Physical layer for sensor networks.

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What is sensor network ?

• Large number of nodes randomly deployed.
• Node localizes itelf collects data.
• Nodes collaborate send the data to base
  station/sink.
• Sink communicates with task manager.

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Typical sensor network
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Features of sensor networks

• Sensor nodes are very small in size, limited in
  power, computational capacities, and memory.
• Sensor networks topology changes very
  frequently. Nodes may be mobile .
• Sensor nodes use broadcast communication paradigm
  in general.

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Features (Contd)

• Sensor nodes are very prone to failures.
• Nodes dont have global identification .
• Nodes are large in number densely deployed.

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Applications

• Habitat monitoring.
• Climate monitoring.
• Defence applications battle field
  surveillance, treaty monitoring, missile hunting.
• Warehouse inventory tracking.
• Vehicle tracking and detection.
• Monitoring dangerous areas.

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Applications(cont)

• Transportation.
• Health care.
• Disaster recovery.
• Warfare.
• Security .

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Applications(cont)

•  Space exploration. 
•  Patient monitoring.
•  Robot control and guidance in automatic
  manufacturing environments.

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Typical application
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Design factors

• Scalability
• Fault Tolerance
• Node Hardware
• Energy/Power Consumption
• Localization Network Topology
• Cost
• Environment medium

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Limitations

• Energy
• Computation
• Communication

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Energy/power consumption

• Battery lifetime/system life time
• Design of power-aware protocols and algorithms
• Node originator router
• Power consumption sensing, communication, and
  data processing

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Energy consumption(cont..)

• Communication v/s processing
• Multihop network
• Sleeping node
• Data aggregation

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Localization Network Topology

• Large no of nodes close to one other.
• Node should localize itself get into network.
• Creating maintaining routing information.
• Additional nodes mobile nodes.

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Routing protocol design targets

• They must be power efficient.
• It must be reliable .
• Delays must be low
• Power emanation must be low .

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Communication protocols

• Current architecture cant be used as
• Large number of nodes
• Nodes are simpler less complex
• Nodes fail frequently
• Nodes small in size power
• Header may be too long
• Acknowledgement packet energy inefficient

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Communication protocol

• New architecture should
• Combine power and routing awareness
• Integrate data with networking protocols
• Communicate power efficiently through the
  wireless medium
• Share tasks among neighbors

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PROTOCOL STACK
Task management plane
Application layer
Mobility management plane
Transport layer
Power management plane
Network layer
Data link layer
Physical layer
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Protocol stack (cont..)

• Physical layer simple robust sensing,
  modulation, transmission, and receiving
  techniques
• MAC Protocol must be power aware and able to
  minimize collision
• Network layer routing the data supplied by the
  transport layer
• application layer to meet user requirements

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Management planes

• monitor the power, movement, and task
  distribution among the sensor nodes
• The power management plane manages how sensor
  node uses its power
• The mobility management plane detects and
  registers the movement of sensor nodes
• The task management plane balances and schedules
  the sensing tasks

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Energy trade-offs

• Energy trade-offs in
• MAC Protocols.
• Routing protocol.

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• PHYSICAL
• LAYER

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Responsibilities

• Frequency selection.
• Carrier frequency generation.
• Signal detection.
• Modulation.
• Channel coding/decoding.
• Data encryption .

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Sensor node

• Sensor should
• Sense, process transmit the data in most energy
  efficient way.
• Be of very small size.
• Use very small power.
• Extract power from the environment.
• Work unattended for long time.

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Sensor node design

• Following points should be note
• Integrated ckts strictly designed for sensor
  node .
• Node not a black box.
• Application specific processors .
• Low data rate redundancy should be exploited.
• Short data packets and transmission distances

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Sensor node design(cont)

• Low duty cycle radio electronics.
• Startup time energy.
• Protocols must be designed considering
• Energy,impact on hardware.

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TYPICAL NODE
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Typical node(cont)

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Radio

• Avg power consumption depends upon
• Average number of times per second the
  transmitter/receiver is used.
• Power consumption of the Tx/Rx operation.
• ON time .
• Startup time.
• MAC protocol used .
• Modulation scheme used .

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Radio(cont)

• For energy efficiency should note
• Startup time .
• Startup energy.
• Active transmit time .
• Packet size .

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Modulation schemes

• Binary modulation schemes.
• M-ARY modulation schemes.
• Compare performance on basis of complexity , data
  rate , power consumption, transmit on time.
• Startup power dominant conditions, the binary
  modulation scheme is more energy-efficient than
  M-ary scheme.

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Power modes

• Perodic sleep mode for node.
• Other subsystems can also be turned off when not
  in use.
• SubsystemsProcessor,Sensor ADC , Radio.
• Latency Energy overhead.
• State selection policy.

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Research issues

• Design of Sensor node.
• Modulation schemes.
• Hardware design.
• Channel Coding.
• Strategies to overcome signal propagation effect.

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Summary

• Physical layer research is driven by power aware
  modulation and hardware design rather than
  targeting high data rates
• Adaptive transmit power,dynamic voltage scaling
  ability to go to sleep mode are very important
  energy efficient techniques.
• Miniaturization, integration, and customization
  will be required to achieve this

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References

• A Survey on Sensor Networks ,Ian F. Akyildiz,
  Weilian Su,IEEE communications Magazine August
  2002.
• E. Shih et al., Physical Layer Driven Protocol
  and Algorithm Design for Energy-Efficient
  Wireless Sensor Networks, Proc. ACM MobiCom 01.
• A. Woo, and D. Culler, A Transmission Control
  Scheme for Media Access in Sensor Networks,
  Proc. ACM MobiCom 01.

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• Thanks .

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