Utility-Based Resource Allocation for Layer-Encoded IPTV Multicast Service

in Wireless Relay Networks

Shi-Sheng Sun, Yi-Chun Chen, Wanjiun Liao

Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan Graduate Institute of Communication Engineering, National Taiwan University, Taipei, Taiwan

IEEE ICC 2011

OutlineIntroductionSystem modelProblem formulationAlgorithmSimulationsConclusions

2

IntroductionIPTV multicasting is an important service for residential users in WiMAX.

3

MS1 MS2MS3

BS

IntroductionAccording to the audiovisual spec., the original video can be converted into different files with different resolution.

4

H.264/SVC

Data Resolution Req.

Base Layer

Enhancement Layer 1

Base Layer

Enhancement Layers 1

Base Layer

Enhancement Layers 2

Enhancement Layers 3

IntroductionThe deployment of relay stations is considered as a cost-effective solution to

improve the network throughputextend cell coverage

5

BS

MS1

RS

RS

MS2

RS

MS2

Introduction

6

RS

MS1

MS2

BS

A: 5 ts

E: 16 ts

D: 10 ts

C: 9 ts

B: 7 ts

multicast service is more complicated than unicast services.

forwarding strategy should be considered when allocating resources for multicast services.

Unicast :

Multicast :

MS1 : E (16)MS2 : D (10)

> 26

D(10)+ B(7) : 17E(16) : 16A(5) + C(9) : 14

Assume the system operates under OFDMA transmission scheme.the system components in a cell include

one base station (BS) multiple fixed relay stations (RSs)N mobile stations (MSs)

System model

BS

7

MS2

RS

RS

MS1

Relay link : BS-RS / RS-RS Access link : BS-MS / RS-MS

Assume the system operates under OFDMA transmission scheme.the system components in a cell include

one base station (BS) multiple fixed relay stations (RSs)N mobile stations (MSs)

System model

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Spatial reuse(i) RSs are divided into R non-interfering groups.

(ii)Each non-interfering group consists of RSs that do not interfere with each other.

BS

RS

MS

Problem formulationsN usersR non-interfering groups of RSs in the single cell systemP : the number of video programs L : the number of layers in a programT : the total resource in terms of timeslots in a frameburst profile (bp) : B kinds of burst profiles (i.e.,modulation), bp1 > bp2 >……> bp B

9

Problem formulations

up,l : the amount of utility gained when a user receives the l-th layer of program p

E = [l, p, r] : the utility gained for receiving layer l of program p using non-interfering group r

UE : total utility

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Layer Utility (Program I) Utility (Program II)

1 0.80 0.55

2 0.15 0.30

3 0.05 0.15

u1,l

u1,2

u1,3

u2,l

u2,2

u2,3

E = [l, p, r] = [2,1,r] = 0.80 + 0.15 = 0.95

UE = 0.95 * 13 users = 12.35

Problem formulations : the number of timeslots allocated to transmit the l-th layer of program p from non-interfering group r in relay link.

: the number of timeslots allocated to transmit the l-th layer of program p from non-interfering group r in access link.

: the number of timeslots required to transmit the l-th layer of program p from RS s-1 to RS s in relay link.

: the number of timeslots required to transmit the l-th layer of program p from RS s to user n in access link.

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relaysslpv ,1,,

accessnslpv ,,,

relayrlpt ,,

accessrlpt ,,

Problem formulations

12

otherwise,0

program oflayer th thereceive toable is user ,1,, pln

w nlp

otherwise,0

program oflayer th the transmit toresources

sufficient allocated is s RS toBS thefrompath relay the,1

,,

plCov relay

slp

otherwise,0

andiff,1 ,,,,,

access

nslpaccess

rlpaccess vtrs

otherwise,0

and11iff,1 ,1,,1,,

relaysslp

relayrlprelay vtrs

GoalFind the allocation of timeslots to different transmitting entities such that the total utility over all users is maximized.

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Subject to

ss-1

…

MU-RMSMaximum Utility resource allocation for Relayed Multicast Services (MU-RMS)

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Step1 Find Emax

Step2 Allocate the additional timeslots

Step3 Removes & updates

MU-RMS

15

Step1 Find Emax

BS

RS

RS

MS3

MS2

MS4

bp1bp2bp3

RS

MS1

E = [l, p, r]E1 = [1, p, r] { MS1, MS2, MS3, MS4 }

E2 = [2, p, r] { MS1, MS2, MS3 }

E3 = [3, p, r] { MS1, MS3 }

consumed timeslotsofnumber

utility totaltheE

MU-RMS

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Step1 Find Emax

LayerUtility

(Program)

1 0.80

2 0.15

3 0.05

bp Layer 1 Layer 2 Layer 3

MS1

bp1 10 7 3

bp2 15 10 6

bp3 25 15 10

MS2

bp1 - - -

bp2 - - -

bp3 25 15 -

MS3

bp1 - - -

bp2 15 10 6

bp3 25 15 10

MS4

bp1 - - -

bp2 15 - -

bp3 25 - -

(timeslots)

1525

3*15.04*8.0 :bp3 3,12E

MU-RMST = 35 (total timeslots in a frame)

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Step1 Find Emax

consumed timeslotsofnumber

utility totaltheE

Layer 1

Layer 1+2

Layer 1+2+3

08.010

1*8.0 :bp1 1,1 E

16.015

3*8.0 :bp2 2,1 E

128.025

4*8.0 :bp3 3,1 E

056.0710

1*15.01*8.0 :bp1 1,12

E

108.01015

2*15.03*8.0 :bp2 2,12

E

X> 35

05.03710

1*05.01*15.01*8.0 :bp1 1,123

E

09.061015

2*05.02*15.03*8.0 :bp2 2,123

E

16.015

3*8.0 :bp2 2,1 E

MU-RMS

Emax= E1,2 = 0.16

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Step2 Allocate the additional timeslots

Allocate 15 timeslots

( Layer 1 : MS1, MS3, MS4 )

MU-RMS

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Step3 Removes & updates

E = [l, p, r]E1 = [1, p, r] { MS1, MS2, MS3, MS4 }

E2 = [2, p, r] { MS1, MS2, MS3 }

E3 = [3, p, r] { MS1, MS3 }

E = [l, p, r]E1 = [1, p, r] { MS2 }

E2 = [2, p, r] { MS1, MS2, MS3 }

E3 = [3, p, r] { MS1, MS3 }

MU-RMST = 35-15 = 20 (total timeslots in a frame)

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Step1 Find Emax

Layer 1

Layer 2

Layer 2+3

25

1*8.0 :bp3 3,1E X

> 20

..

. E = [l, p, r]

Simulations

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Simulations

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Simulations

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Simulations

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ConclusionsPropose a scheme that can allocate the limited resources effectively for layer-encoded IPTV such that the total utility over all users is maximized.

The simulation results show that our scheme can achieve high total utility.

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Thanks for your attention !!!