a cooperative multicast scheduling scheme for multicast services in ieee 802.16 networks fen hou,...

A Cooperative Multicast Scheduling Scheme for A Cooperative Multicast Scheduling Scheme for Multicast Services in IEEE 802.16 NetworksMulticast Services in IEEE 802.16 Networks

Fen Hou, Pin-Han Ho, and Lin X CaiFen Hou, Pin-Han Ho, and Lin X Cai

Dept. of Electrical and Computer Engineering, Waterloo UniversityDept. of Electrical and Computer Engineering, Waterloo University

IEEE Transactions on Wireless Communications, Vol. 8, No 3, March, 2009IEEE Transactions on Wireless Communications, Vol. 8, No 3, March, 2009

22

Speaker : Chi-Tao Chiang (蔣季陶 )

Meeting 報告簡報

AgendaAgenda

IntroductionIntroduction Cooperative Multicast Scheduling SchemeCooperative Multicast Scheduling Scheme Performance AnalysisPerformance Analysis Simulation ResultsSimulation Results ConclusionsConclusions

33



IntroductionIntroduction

Multicast communicationMulticast communication An efficient mechanism for one-to-many transmissions ovAn efficient mechanism for one-to-many transmissions ov

er wireless channeler wireless channel Users’ requests are the sameUsers’ requests are the same

Multicast group (MGroup)Multicast group (MGroup) ApplicationsApplications

Emergency alert Emergency alert Internet Protocol Television (IPTV)Internet Protocol Television (IPTV) Mobile TV Mobile TV

44



IntroductionIntroduction-Motivation-Motivation

MGroupsMGroups

Lag !!

Lag !!

Lag !!

Lag !!

55



IntroductionIntroduction-Motivation-Motivation

Scheduling mechanismScheduling mechanism Fairness considerationFairness consideration

Round-robin for each MgroupRound-robin for each Mgroup Ex. CDMA 2000 1xEx-Do networks : 204.8 kbpsEx. CDMA 2000 1xEx-Do networks : 204.8 kbps

Robust considerationRobust consideration Minimal supported rate of all Mgroup membersMinimal supported rate of all Mgroup members

Group member with the worst channel condition becomes bottlenGroup member with the worst channel condition becomes bottleneckeck

Inefficient to most users in good channel conditionsInefficient to most users in good channel conditions

66



IntroductionIntroduction-Goal-Goal

Cooperative multicast communicationsCooperative multicast communications Achieve high throughput for all group membersAchieve high throughput for all group members Maintain good fairness performanceMaintain good fairness performance

77



Cooperative Multicast Scheduling SchemeCooperative Multicast Scheduling Scheme

Multicast group selectionMulticast group selection Decide which groups should be served at each frameDecide which groups should be served at each frame

Cooperative multicast transmissionCooperative multicast transmission Decide how to multicast data to the selected group Decide how to multicast data to the selected group

membersmembers

88



Multicast group selectionMulticast group selection

Random MGroup SelectionRandom MGroup Selection BS randomly selects an MGroup for service with a pre-defBS randomly selects an MGroup for service with a pre-def

ined probabilityined probability The same probability for each MGroupThe same probability for each MGroup Service differentiation Service differentiation

99



Multicast group selectionMulticast group selection

Channel-aware MGroup SelectionChannel-aware MGroup Selection Normalized relative channel condition Normalized relative channel condition XXi i for MGroupsfor MGroups

Normalized relative channel condition of MGroup i

Total number of group members in MGroup i

Instantaneous SNR of the j-th group members in MGroup i

Avg. SNR of the j-th group members in MGroup iThe set of all group mem

bers in MGroup i

1010



Cooperative Multicast TransmissionCooperative Multicast Transmission

DilemmaDilemma

64-QAM

16-QAM

QPSK

64-QAM

16-QAM

QPSK

64-QAM QPSKToo fast !!

Too fast !!

Oh! Cool! Too

Slow !!Too

Slow !!

Oh! Cool!

1111




Two-phase transmission schemeTwo-phase transmission scheme

Downlink Burst # i

Phase 1 ( ) 2iR Phase 1 ( ) 2

iR

64-QAM 16-QAM

1212




AdvantagesAdvantages Higher throughput than conservative rateHigher throughput than conservative rate

Group members with good channel conditionsGroup members with good channel conditions Group members with bad channel conditionsGroup members with bad channel conditions

ExtensionsExtensions m-m-phase transmissionsphase transmissions Larger Larger mm, lager computation and control overhead, lager computation and control overhead

1313



Performance AnalysisPerformance Analysis

Service probability of each MGroupService probability of each MGroup Throughput of each user Throughput of each user Throughput of each MGroupThroughput of each MGroup Throughput of the whole networksThroughput of the whole networks

1414



Service Probability of Each MGroupService Probability of Each MGroup

DefinitionDefinition The probability than an MGroup is selected for service in The probability than an MGroup is selected for service in

a MAC frame when the system is stablea MAC frame when the system is stable

1515



Throughput of each MGroupThroughput of each MGroup

Given and , the probability that a group meGiven and , the probability that a group member in MGroup mber in MGroup i i , SS, SSii,,j j can receive the data in Phacan receive the data in Phase 1se 1

)1(log)1(log0

1,

221

N

ECSNRCR ji

i

)1(220

1,1

N

E jiCRi 01. )12(

1

NE iRji

jBiiR

iiiENSNRSNRR

ji eeNE ,0

11 /))12((/

01, ))12(Pr( jBi

iRiii

ENSNRSNRRji eeNE ,0

11 /))12((/

01, ))12(Pr(

(Shannon Capacity)

The avg. received power for SSi,j from BS

1616




Given and , the probability that a group meGiven and , the probability that a group member in MGroup mber in MGroup i i , the set of all possible for SSi,, the set of all possible for SSi,j j

121

||1

1

1,

i

i

N

k

Niji k

NC

giG

Example: Suppose MGroup i contains SSi,1, SSi,2, SSi,3, SSi,4. The possible group members that can be transmitter in phase 2 are SSi,2, SSi,3, SSi,4.The number of possible are

giG

3

1, 7

3||

kji k

C

SSi,2 SSi,3 SSi,4

SSi,2 SSi,3 SSi,2 SSi,4SSi,3 SSi,4

SSi,2 SSi,3 SSi,4

1717




Given and , the probability that a group meGiven and , the probability that a group member in MGroup mber in MGroup i i , SS, SSii,,j j cannot receive the data in Pcannot receive the data in Phase 1, but can receive the data in Phase 2hase 1, but can receive the data in Phase 2

1818



Throughput for SSThroughput for SSi,ji,j


Throughput of each MGroupThroughput of each MGroupPhase 1 Successful

Phase 1 Failure, Phase 2 Successful

1919



Simulation ResultsSimulation Results

2020




2121




2222




2323




2424



ConclusionConclusion

Cooperative multicast scheduling scheme for multimCooperative multicast scheduling scheme for multimedia services in IEEE 802.16 networksedia services in IEEE 802.16 networks

Simulation results shows that Simulation results shows that Analysis and the proposed scheme are similar in terms ofAnalysis and the proposed scheme are similar in terms of

Throughput Throughput Service probabilityService probability

Higher throughput Higher throughput

a cooperative multicast scheduling scheme for multicast services in ieee 802.16 networks fen hou,...

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