Deployment Analysis in Underwater Acoustic Wireless Sensor Networks
Dario Pompili, Tommaso Melodia, lan F. AkyildizACM WUWNet’06
2008. 12. 9.Ahn Jung-Sang
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Content
• Introduction
• Communication Architectures
• Deployment Strategies in 2D
• Deployment Strategies in 3D
• Conclusion
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Introduction
• Underwater Acoustic Sensor Network (UW-ASN)– Challenges
• Harsh environment• Limited bandwidth• High & variable propagation delay, error rates• Etc.
• This Paper– Propose a mathematical & hydrodynamics model in 2D
• Considering depth, current, and so on.• Determine the minimum number of sensors• Provide guidelines on how to choose the optimal deploy-
ment– And extend this 3D briefly
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Communication Architec-tures
• 2D Architecture
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Communication Architec-tures
• 3D Architecture
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Deployment in 2D
• Triangular-grid Coverage Properties– Sensors with same sensing range r– Optimal deployment to cover a 2D area with minimum
number of sensors
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Deployment in 2D
• Triangular-grid Coverage Properties– Sensing coverage η
– We can estimate d/r when we set η.• In this paper, η=0.95, and corresponding d/r = 1.95
Overlap
Non-overlap
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Deployment in 2D
• Triangular-grid Coverage Properties
Coverage=0.95
Ratio of sensor distance and sensing range=d/r=1.95
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Deployment in 2D
• Triangular-grid Coverage Properties
100 x 100 m^2 300 x 200 m^2
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Deployment in 2D
• Trajectory of a Sinking Object
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Deployment in 2D
• Trajectory of a Sinking Object
– Assumptions in this paper:• No vertical movement of ocean water• The considered area is neither an upwelling nor a down-
welling• The velocity of the ocean current depends on depth
– H: # of different ocean current layers– Current in each layer has a fixed module and angular
deviation (with known statistics)– Thermohaline Circulation (ocean’s conveyor belt)
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Deployment in 2D
• Trajectory of a Sinking Object– Kind of Hydrodynamics
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Deployment in 2D
• Trajectory of a Sinking Object
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Deployment in 2D
• Communication Properties of 2D UW-ASNs– Every sensed data should pass gate-way– Sensor & gate-way have different weights
• Gate-way is heavier than sensor
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Deployment in 2D
• Deployment Surface Area: Side Margins
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Deployment in 3D
• 3 Strategies– 3D-random
• The simplest strategy.• Random deploy, random depth.
– Bottom-random• Random deploy.• Surface station calculates the depth for each sensor.
– Bottom-gird• Assisted by one or multiple AUV• Grid deploy.• Assigned a desired depth by the AUV
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Deployment in 3D
• 3 Strategies
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Conclusion
• Deployment strategies for 2D and 3D architec-tures for UW-ASNs
• Deployment analysis in order to:– Determine the minimum number of sensors– Provide guidelines on how to choose the deployment– Determine the minimum number of uw-gateways, given
some desired communication properties of clusters