PRESENTED BY:
Vamshi Nadipelli
Preethi Tiwari

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Taking Sensor Networks from the Lab to the Jungle
What is a Sensor Network?
 Challenges
 Technical
 System
 Conclusion
 Introduction
 Chain Home - Britain’s Radar Network WWII
 Cold War:
 SOSUS – The Pacific Ocean
 NORAD – Cheyenne Mountain
 National Power Grid
 Involves
 Devices with multiple sensors
 Network via wireless/physical links
 Involved Technologies
 The Systems involved
 Sensor Node Internals
 Operating System
 Sensor Node Internals
 Operating System - TinyOS
 Custom built at UC, Berkeley for wireless sensor nodes
 Component-based architecture: ensures minimum code size
Component library includes:
 Network protocols
 Sensor drivers
 Data acquisition tools
 Distributed services
 Physical Size
Applications
 Border Monitoring
 Battlefield Observation
 Forest Fire Detection
 Environment and Habitat Monitoring
 Infrastructure security
 Industrial sensing
 Medical Applications
 Border Monitoring
 Most widely cited application
 US-Mexico Border (3100 km)
 Requires Full length Surveillance
 Detection can be based on sound or vibration
 With in a range of 10m
 Estimated need of 440,000 sensors
 Air dropped biannually (battery life 6months)
 Not cost effective
 Should distinguish humans from wild animals
 Battlefield surveillance
 Observing enemy activities in a battle field.
 Unmanned aerial vehicles (UAV)
 Coverage problem (limited radio range)
 10,000 nodes were required to monitor just 1 square kilometer
 For large areas:
 cost
 Many nodes implies large number of UAV’s operating simultaneously.
 Forest Fire Detection
 A sensor network is more feasible as an early warning system for forests.
 Carefully placing nodes (close to vulnerable areas such as hilltops)
 Reduce the number of sensors required to cover a large geographic area.
 Important aspect is lifetime
 Must operate for a very long period of time to discover a comparatively rare event
Environment and Habitat Monitoring
 Monitoring nesting
 Large number of burrows.
 Long time observation
 Over 100 sensor nodes.
 Long term observation
 Migration pattern of zebras
 They generally move in wide area
 Long term observation
 Sensors were integrated on to the zebra’s neck.
 Consisted of 2 radios.
 Long range (base station)
 Short range (neighbors)
 These were used to monitor the heart beat, body temperature and frequency of feeding
Infrastructure Security
Medical applications
 Heart rate
 Oxygen saturation
 Enhances emergency medical care.
 Challenges
 Power
 Communication
 Hostile Environments
 Cost
 Technical challenges
Changing network topology:
 Node failures
 Introduction of additional nodes variations in sensor location
 Changes to cluster allocations in response to network demands requires the adaptability of underlying network structures and operations.
Advanced communication protocols
 To support high level services and real-time operation
(to adapt rapidly to changes in network conditions).
Resource optimization:
 To minimize cost, power and network traffic loads
 Ensuring network reliability and adequate sensor resolution for data accuracy.
Limitations:
 Power, Memory, processing power, life-time. These physical constraints may be minimized through further technological breakthroughs in materials and sensor hardware designs.
Failure prone:
 Individual sensors are unreliable, particularly in harsh and unpredictable environments.
 Addressing sensor reliability can reduce the level of redundancy required for a network to operate with the same level of reliability.
Network congestion resulting from dense network deployment:
 The quantity of data gathered may exceed the requirements of the network and so evaluation of the data and transmission of only relevant and adequate information needs to be performed.
Self-organization
 Ability to adapt to dynamic environments as well as ad hoc distribution and connectivity scenarios.
Self-operating and self-maintaining
 This functionality is desired in order to minimize further human interaction beyond network deployment.
Security
 It is a critical factor in sensor networks.
 An effective compromise must be obtained, between the low bandwidth requirements of sensor network applications and security demands.
Conclusion
 Sensor networks are application specific
 Key application characteristics
Lifetime, cost, data rate, environment, network topology, user interaction
 Must address the system aspects of wireless sensor network design