energy-delay tradeoffs for underwater acoustic sensor networks (blackseacom2013)

Tuesday, April 11, 2023BlackSeaCom2013 Batumi, Georgia1

Energy-Delay Tradeoffs for Underwater Acoustic Sensor Networks

Muhamad Felemban (Purdue University)Emad Felemban (Um Al Qura University)


Outline Introduction and motivation

Contribution

Underwater Communication Model

Energy-Delay Tradeoffs

Conclusion


Introduction Most of the Earth is covered by water Underwater operations are difficult Monitoring tasks:

pipelines Underwater cables Countries borderlines


Motivation AUV Limitations:

Off-line configuration Non real-time monitoring Limited Bandwidth and high propagation delays

Use Underwater Acoustic Sensor Network to over come theses limitations

But Large power consumption High end-to-end delay High cost deployment


Outline Introduction

Contribution



Conclusion


Contribution Present a comprehensive analytical model of

underwater acoustic communication Investigate the delay-energy tradeoffs in

string topology networks Find the number of hops in network based on

delay and energy consumption requirements


String Network Topology Multi-hops string topology N sends data to Gateway (GW) via hops h1 h2

h3 .. hn

Nh1

h2

h3hn

GW



Contribution



Conclusion


Passive Sonar Equation Underwater sound propagation is modeled by

many forms of Sonar equations Passive sonar equation is used to compute the

source level of omitted sound [Urick]

DI is directivity index We assume omni-directional directivity

€

SL(d, f ) = A(d, f ) +N( f ) + SNR −DI


Source Level SL(d,f) SL(d,f) is the ratio of the intensity of omitted

signal to some reference intensity [Urick]

Reference intensity has a value of 0.67x10-18

It is calculated using transmission power Ptx

Where d is water depth in meters

€

SL(d, f ) =10log(ItI0)

€

It =Ptx

2π ×1m × d


Underwater Path Loss A(d,f) Path loss A(d,f)

Two factors Energy spreading

K = 15 Wave absorption

α(f) is computed using Ainslie and McColm model [Ainslie&McColm]temperature, frequency, depth, salinity, and acidity

€

A(d, f ) = k log(d) +α ( f )r ×10−3


Underwater Ambient Noise N(f) Overall p.s.d of underwater ambient noise is

given [Coates]

Nt models the water turbulence Ns models surface-ship Nth models thermal noise Nw models breaking wave

€

N( f ) = N t ( f ) +Ns( f ) +N th ( f ) +Nw ( f )


Frequency-Dependent Path Loss A(d,f) + N(f) in passive sonar equation are

frequency-dependent Observation: Minimum A(d,f) + N(f) is achieved at

certain frequencies of various depths


Signal-to-Noise Ratio (SNR) Using Orthogonal Frequency Division Model

(OFDM), Bit Error Rate (BER) is computed [Proakis]

€

Pb =3

2kerfc(

k

10

Eb

N0

)

€

Eb /N0 = SNRBN

R


Acoustic Propagation Delay Acoustic wave propagation in water is much

slower than electromagnetic propagation in air

Empirical formula of acoustic propagation velocity is given by [Marczak]

€

c =1.402385 ×103 +5.038813T

−5.799136 ×10−2T 2 + 3.287156 ×10−4T 3

−1.398845 ×10−6T 4 +2.787860 ×10−9T 5



Contribution



Conclusion


Network Energy Consumption 1000m Deep and BER of 10-9


Network Energy Consumption 100m Deep and BER of 10-9


Energy Reduction


End-to-End Delay End-to-end delay of multi-hops string network

is given [Cui etc]

€

Delay = n(t prop(i,i+1) + t pkt )


Energy-Delay Tradeoffs By specifying the delay and energy

consumption requirements, the number of middle hops can be found For example: 3-hops path over 1000m and depth

of 1000m has 4 seconds delay and needs 11 Watts transmission power


Conclusion Comprehensive analytical model of

underwater communication for string topology networks

Energy consumption is reduced as the number of hops increases 5 hops reduce 80% of network energy at 1000m

deep and 60% at 100m End-to-end delay linearly increases when

more hops is introduced


References [Urick] R. Urick, “Principles of underwater sound,” New York,

1983. [Ainslie&McColm] M. Ainslie and J. McColm, “A simplified formula

for viscous and chemical absorption in sea water,” Journal of the Acoustical Society of America, vol. 103, no. 3, pp. 1671–1672, 1998.

[Coates] Underwater acoustic systems. Halsted Pr, 1989. [Proakis] “Digital communications,,” 1995. [Marczak] “Water as a standard in the measurements of speed of

sound in liquids,” the Journal of the Acoustical Society of America,vol. 102, p. 2776, 1997.

[Cui etc] “Energy-delay tradeoffs for data collection in tdma-based sensor networks,” in Communications, 2005. ICC 2005. 2005 IEEE International Conference on, vol. 5. IEEE, 2005, pp. 3278–3284.


Acknowledgment This work is funded by the National Science

Technology and Innovation Plan (NSTIP) of King Abdulaziz City of Science and Technology (KACST) in Saudi Arabia


Energy-Delay Tradeoffs for Underwater Acoustic Sensor Networks

Muhamad Felemban (Purdue University) and

Emad Felemban (Um Al Qura University)

energy-delay tradeoffs for underwater acoustic sensor networks (blackseacom2013)

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