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