CONSTRUCTING LOAD-BALANCED DATA AGGREGATION

TREES IN PROBABILISTIC WIRELESS SENSOR NETWORKS

Jing (Selena) He, Shouling Ji, Yi Pan, Yingshu LiDepartment of Computer Science

Georgia State University

OUTLINE

Motivation

Solution Overview

Problem Formulation and Analysis

Performance Evaulation

Conclusion2

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Motivation• Probabilistic Network Model• Load Balanced Data Aggregation Tree• Challenges

TRANSITIONAL REGION PHENOMENONMotivation

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Link Length 0 – 2.6 M 2.6 – 6 M > 6 Mλ > 80% 7 8 0

Total 8 27 15

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PROBABILISTIC NETWORK MODELMotivation

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LOAD-BALANCED DATA AGGREGATION TREE (LBDAT)

Motivation

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CHALLENGESHow to measure the traffic load of each node under

Probabilistic Network Model (PNM)? Potential load Actual load

How to find a Load-Balanced Data Aggregation Tree (LBDAT)?

NP-Complete

Motivation

OUTLINE

Motivation

Solution Overview

Problem Formulation and Analysis

Performance Evaluation

Conclusion8

SOLUTION OVERVIEW

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9Load-Balanced Maximal Independent Set (LBMIS)Connected Maximal Independent Set (CMIS)Load-Balanced Parent Node Assignment (LBPNA)Load-Balanced Data Aggregation Tree (LBDAT)

OUTLINE

Motivation

Solution Overview

Problem Formulation and Analysis

Performance Evaluation

Conclusion10

LOAD-BALANCED MAXIMAL INDEPENDENT SET (LBMIS)

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DS Property Constraint

IS Property Constraint

linearization

Relaxing

(quadratic)

ωi1 vi is a dominator0 otherwise

APPROXIMATION ALGORITHM (RANDOM ROUNDING)

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Due to the relaxation enlarged the optimization space, the solution of LP*

LBMIS corresponds to a lower bound to the objective of INPLBMIS .

LOAD-BALANCED MAXIMAL INDEPENDENT SET (LBMIS)

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CONNECTED MAXIMAL INDEPENDENT SET (CMIS)

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Relaxing

LOAD-BALANCED PARENT NODE ASSIGNMENT (LBPNA)

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Each dominatee can be allocated to only one dominator

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LOAD-BALANCED PARENT NODE ASSIGNMENT (LBPNA)

OUTLINE

Motivation

Solution Overview

Problem Formulation and Analysis

Performance Evaluation

Conclusion17

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PERFORMANCE EVALUATION

Our method

Other’s Method

LBDAT prolong network lifetime by 42% on average compared with DAT

OUTLINE

Motivation

Solution Overview

Problem Formulation and Analysis

Performance Evaluation

Conclusion19

CONCLUSIONS

LBDAT is NP-Complete, constructed in three steps:Load-Balanced Maximal Independent Set (MDMIS)Connected Maximal Independent Set (CMIS)Load-Balanced Parent Node Allocation (LBPNA)

Approximation algorithms and performance ratio analysis are presented.

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Q & A