Broadcast Scheduling in Interference Environment.ppt - Copy

8/4/2019 Broadcast Scheduling in Interference Environment.ppt - Copy

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.WELCOME.WELCOME


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CIENCEND TECHNOLOGYathupally


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TECHNICAL

SEMINAR


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BroadcastScheduling in

Interference Environment

resented By.Uday simha07C61A0530&Department of Computer Science &Department of Computer Science

EngineeEnginee


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Abstract

Broadcast is a fundamental operation in, wireless networks and na ve flooding is not

,practical because it cannot dealwith.interference

Scheduling is a good way of avoiding

,interference but previous studies on broadcastscheduling algorithms allassume highlytheoretical models such as the unit disk graph

.model ,In this work we reinvestigate this problem by

-using the 2 Disk- - - - -and the signal to interference plus noise ratio

( ) .SINR models


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CONTENTS Introduction

Related Work

Interference Models,Assumptions,And

Problem Definition Tessellation of Hexagons

Braodcast Scheduling Algorithms

Analysis Simulation Results

Conclusion


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INTRODUCTION

Braodcast is probably the most fundamental yetChallenging operation among all operations ofwireless ad

.Hoc networks

[ ]The broadcast storm problem 26 tells us

,that na ve flooding is simply not practical,because it causes severe contention

, .collision and congestion


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RELATED WORK

Broadcast was studied extensively in theliterature.They also designed a centralized

distributed broadcast algorithm

-Minimum latency broadcast schedule hasbeen extensively studied in the

literature


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, ,INTERFERENCE MODELS ASSUMPTIONS

ANDPROBLEM DEFINITION

,In this section we introduce two,interference models

, - .namely the 2 Disk and SINR models -The descriptions of the 2 Disk model are

:given as follows A wireless network ismodeled as a set of nodes V arbitrarily

.located in a 2D euclidean space


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TESSELLATION OF HEXAGONS

A tessellation of the entire plane is

(a way of partitioning into equal or) .similar pieces

. . ( ) - . ( ) -Fig 2 a Three coloring k 1 b Three

.coloring filling up the plane


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BROADCAST SCHEDULING ALGORITHM

, -In this section we first look at the 2Disk model and design a broadcast

scheduling algorithm of approximation ratio

, .6d2 3 rI rT 2e2 which is a constant

We consider the transmission graph GT ; .V ET generated by rT and V To define

,the broadcast schedule we first need toconstruct a virtual backbone as follows


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. . ( ) - . ( )Fig 3 a Twelve coloring k 2 b.Twelve coloring filling up the plane


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. . ( ) . ( ) . ( ) . ( )Fig 6 a GT s topology b Layered MIS c BFS tree d.Virtual backbone


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ANALYSIS

: ) We prove two assumptions 1 each node will receivesuccessfully before it is scheduled to transmit and

) , .2 in the end all nodes receive successfully ,Algorithm 3 begins with the source s transmission

,and since there is only one node transmitting there

,will be no collision .and all nodes of L1 will receive successfully ,Now we prove that all nodes of Li1 will receive

. ,successfully from Li for all 1 i R 1 First weshow that all nodes of BLACKi1 will receive

. .successfully from BLUEi This is straightforward


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. . ( ) . ( ) ; .Fig 8 a Concentric disks at v b Annulus Ar1 r2


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SIMULATION RESULTS

Simulations have been performed in Matlab to

evaluate .the latency of our proposed scheme ,In these simulations in nodes were distributed

,randomly into a square region of size X by Ywhere X and Y are normalized to the transmission

.range rTThe transmission latency was then measuredafter our proposed scheme is employed.


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. .Fig 10 Transmission latency for different numbers of.nodes k 3


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CONCLUSION

Many highly theoretical models were used inall previous

.works on broadcast scheduling

, ,Instead we have used two Surprisingly we have

found that we can apply the same method to both- .models and obtain low latency schedules


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. . .HANK YOU

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Broadcast Scheduling in Interference Environment.ppt - Copy