1 7 th IEEE International Conference on Mobile Ad-hoc and Sensor Systems IEEE MASS 2010 San Francisco, CA (United States), November 8 – 12, 2010 Optimization

1

7th IEEE International Conference on Mobile Ad-hoc and Sensor Systems

IEEE MASS 2010San Francisco, CA (United States), November 8 – 12, 2010

Optimization of Critical Data Synchronization via Link Overlay RNG in Mobile Ad hoc Networks

Emmanuel Baccelli Juan Antonio Cordero Philippe Jacquet

Équipe Hipercom, INRIA Saclay (France)

MASS

2

Agenda

Optimization of Critical Data Synchronization via Link Overlay RNG in Mobile Ad hoc Networks IEEE MASS 2010

Rationale

Our Proposal: SLO-T

An SLO-T Overlay Example

SLO-T Analysis

Application: SLO-T in OSPF

Rationale

3

Rationale (1)

Reliable communication of critical datain MANETs

Synchronized Overlay


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MANET link synchronization is costly

Overlay requirements:

Low overlay density

Low overlay link change rate

Rationale (and 2)


5

Agenda

Rationale

Our Proposal: SLO-T


SLO-T Analysis



6

Our Proposal: SLO-T

Synchronized Link Overlay – Triangular (SLOT)

SLOTUniform Costs

SLOTDistance-based Costs

Relative Neighborhood Graph (RNG)


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Our ProposalRelative Neighbor Graph (RNG)

Mathematical definition (Toussaint, 1980)

Intuitive definition

yxxym and between distanceEuclidean )(


u v

))}()(),(:,,(:{)(

}in verticesofset { 2

uvmwvmuvmSwSvuuvSRNG

S

R

8

Distance-based cost (SLOT-D)

C

A

B

3

54

C

A

B

3

54

Our ProposalSynchronized Link Overlay – Triangular (SLOT)

Mathematical definition


unit

distm(·,·)

SLOT-D

SLOT-U

Unit cost (SLOT-U)

13

42

37

13

42

37


)(),()(

)()(:)(

wvmuwmuvm

vNuNwVwGSLOTuv

9

Agenda

Rationale

Our Proposal: SLO-T


SLO-T Analysis



10

Synchronized Link Overlay – Triangular Example (1)

Network graph

N: 30 nodes

Grid: 400x400m

Radio range: 150 m

Network link

SLOT-U link

SLOT-D link


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SLOT-Usubgraph

Network link

SLOT-U link

SLOT-D link


12


SLOT-Dsubgraph

Network link

SLOT-U link

SLOT-D link


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Synchronized Link Overlay – Triangular Example (and 4)

Network link

SLOT-U link

SLOT-D link

SLOT-Dsubgraph

(distance-based metrics)


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Agenda

Rationale

Our Proposal: SLO-T


SLO-T Analysis



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Synchronized Link Overlay – TriangularAnalytical Model

Graph model: Unit disk graph (UDG)

Speed: Constant node speed s

Node distribution: Uniform node density

Mobility: Independent, isotropic random walk


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Synchronized Link Overlay – Triangular Analysis 2D (1)

Avg. number of links per node

All links

SLOT-D

SLOT-U

3,60

2,56


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Synchronized Link Overlay – Triangular Analysis 2D (and 2)

Avg. rate of link creation

sec

u5s

All links

SLOT-D

SLOT-U

for a fixed node speed s


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Synchronized Link Overlay – TriangularAnalysis Summary

Avg number of overlay links

2

2,56

2,94

2,77

3,60

2,50

Avg rate of link creation

2

2,73

1,02

2

3,60

1,44

)(s

)(s

)(3 s

)(s

)(s

)(s

dim

1

2

3

1

2

3

SL

OT

-DS

LO

T-U

()


19

Agenda

Rationale

Our Proposal: SLO-T


SLO-T Analysis



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Application: SLOT in OSPF

OSPF: Link-state routing protocol

MANET extension: RFC 5449

Components:

Topology selection

LSA flooding

LSDB synchronization (Adjacencies)

SLOT for Unit Cost(SLOT-U)

13

42

37

13

42

37


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Application: SLOT in OSPF Adjacencies (synchronized links)


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Application: SLOT in OSPF Control Traffic Overhead


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Application: SLOT in OSPF Data Delivery Ratio


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Conclusions & Future Work

Synchronized overlay requirements: low density / low link change rate

SLOT: number of overlay links/node is independent from density

SLOT-OSPF: overhead reduction leads to better behaviors in dense networks

SLOT-D better than SLOT-U (in terms of overlay size)

But requires a distance-based metric

factor in link formation rate


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Questions ?

E-mail: [email protected]


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Backup Slides


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Impact of Distance in SLOT Link Selection

Optimization of Critical Data Synchornization via Link Overlay RNG in Mobile Ad hoc NetworksIEEE MASS 2010

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Synchronized Link Overlay (SLO)


Mathematical definition


A B

C1 C2

10

2

2

2

)(),...,(),()(

)()(,:,...,,)(

),(

21121 vcmccmucmuvm

vNuNcniVcccGSLOuv

EVG

n

in

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Analytical Model Formulae (1)


SLOT with distance-based metrics

rrrB

eOs

drersV

eOdreM

B

r

r

r

d

Br

r

r

d

distanceat disksbetween on Intersecti)(

)()()3

2sin

32(

3

4

2)(3

4

)(56.22

)|1(|23

2

1

0

)3

2sin

32(

22

)|1(|1

0

)3

2sin

32(

2

2

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Analytical Model Formulae (2)

SLOT with unit-cost metrics

ssV

sOds

esddxsV

OexdrdxM

su

x

x

u

x

x

r

r

r

u

15.4),(

)(

)2sin2(

2sin)(32

)2sin(32)·(·),(

160.3)1(22)(

ct

2

3

2

1

0

2

3

)3

2sin

32(

2

1

0

1

0

)3

2sin

32(2


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Analytical Model Formulae (and 3)

Further details

E. Baccelli, J. A. Cordero, P. Jacquet: Optimization of Critical Data Synchronization via Link Overlay RNG in Mobile Ad Hoc Networks.

INRIA Research Report RR-7272.

April 2010.

(publicly available in the Internet: http://hal.inria.fr/docs/00/47/96/89/PDF/RR-7272.pdf )


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The SLO-T Algorithm

Relative Neighbor Graph (RNG)A B

C1

C2

C3

Synchronized Link Overlay, Triangle eliminationA B

C

SLO-T (unit cost)13

42

37


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Documentation of OSPF MANET Extensions

Simulations run over the Georgia Tech Network Simulator (GTNetS)

Implementation based on the Quagga/Zebra OSPFv3 daemon (ospf6d)

Source code for OSPF MANET extensions

Following the IETF RFC 5449 “OSPF Multipoint Relay (MPR) Extension for Ad Hoc Networks” from E. Baccelli, P. Jacquet, D. Nguyen and T. Clausen

SLO-T mechanism following the INRIA Research Report n. 6148, by P. Jacquet.

Implementation provided by INRIA, publicly available in www.emmanuelbaccelli.org/ospf


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Simulation Environment

General Simulation Parameters

20 samples/experiment

Data traffic pattern Constant Bit Rate UDP flow Packet size: 1472 bytes Packet rate: 85 pkts/sec

Scenario Square grid Grid size: 400x400 m

Node configuration Radio range: 150 m MAC protocol: IEEE 802.11b

Node mobility Random waypoint model Pause: 40 sec Speed: 0, 5, 10, 15 m/s

(constant)

Performed Experiments

Fixed size grid

OSPF Configuration

Standard Parameters HelloInterval: 2 sec DeadInterval: 6 sec RxmtInterval: 5 sec MinLSInterval: 5 sec MinLSArrival: 1 sec

RFC 5449 AckInterval: 1,8 sec Adj. persistency: Disabled

SLOT-OSPF AckInterval: 1,8 sec


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The α parameter

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

0 30 60 90 120 150

Link length (m)

Pro

ba

bili

ty o

f s

uc

es

s (

ov

er

1)

alpha=0

alpha=0,25

alpha=0,5

alpha=0,75

alpha=1


Documents

1 7 th IEEE International Conference on Mobile Ad-hoc and Sensor Systems IEEE MASS 2010 San Francisco, CA (United States), November 8 – 12, 2010 Optimization