A Flexible Resource Allocation and Scheduling Framework for Non-real-time Polling Service in IEEE 802.16 Networks Fen Hou, James She, Pin-Han Ho, and Xuemin

A Flexible Resource Allocation and Scheduling A Flexible Resource Allocation and Scheduling Framework for Non-real-time Polling Service Framework for Non-real-time Polling Service in IEEE 802.16 Networksin IEEE 802.16 NetworksFen Hou, James She, Pin-Han Ho, and Xuemin (Sherman) ShenFen Hou, James She, Pin-Han Ho, and Xuemin (Sherman) Shen

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

IEEE Transactions on Wireless Communications, Vol. 8, No 2, Feb. 2009IEEE Transactions on Wireless Communications, Vol. 8, No 2, Feb. 2009

22

Speaker : Chi-Tao Chiang (蔣季陶 )

Meeting 報告簡報

AgendaAgenda

IntroductionIntroduction Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling

FrameworkFramework Numerical ResultsNumerical Results ConclusionsConclusions

33



IntroductionIntroduction

Four types of services defined in IEEE 802.16 standFour types of services defined in IEEE 802.16 standardard Unsolicited Grant Service (UGS)Unsolicited Grant Service (UGS) Real-time Polling Service (rtPS)Real-time Polling Service (rtPS) Non-real-time Polling Service (nrtPS)Non-real-time Polling Service (nrtPS) Best Effort (BE)Best Effort (BE)

Other Types(20 %)

nrtPS (80 %)

Total Internet Bandwidth

C. Fraleigh, S. Moon, B. Lyles, et al., “Packet-level traffic measurements from the sprint IP backbone,” IEEE Network, vol. 17, no. 6, pp. 6-16, 2003.

44



Resource allocation and scheduling for nrtPSResource allocation and scheduling for nrtPS Minimum throughput requirementsMinimum throughput requirements Resource utilizationResource utilization Acceptable delayAcceptable delay

For 3GPP standard, the delay constraints for nrtPS is [50,300] msFor 3GPP standard, the delay constraints for nrtPS is [50,300] ms

HowHow A flexible and effective framework for nrtPS traffic in IEEE A flexible and effective framework for nrtPS traffic in IEEE

802.16 networks802.16 networks Analytical modelAnalytical model

Selective ARQ mechanism Selective ARQ mechanism AMC schemeAMC scheme

IntroductionIntroduction

Contradictory relation

55



Yes

Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework-Overview-Overview

How many SSs are scheduled in this frame

How many SSs are scheduled in this frame

How many bandwidth is granted to a connection


(1) Acceptable delay (2) Average channel condition

(1) Acceptable delay (2) Average channel condition

Minimum bandwidth requirement of a nrtPS connection

Minimum bandwidth requirement of a nrtPS connection

AVG. channel condition of

any SS change ?

AVG. channel condition of

any SS change ?

No

Acceptable delay of the connection change ?

Acceptable delay of the connection change ?

No

Min. BW requirement of the connection change ?

Min. BW requirement of the connection change ?

No



Yes

Yes

66



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework QuestionsQuestions

How many SSs are selected at each MAC frame (How many SSs are selected at each MAC frame (hh)) Resource utilization Resource utilization Packet delivery delay of each SSPacket delivery delay of each SS

How many bandwidth is granted for a served SS (How many bandwidth is granted for a served SS (LL)) Minimum bandwidth requirement of a nrtPS connectionMinimum bandwidth requirement of a nrtPS connection

77



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework AssumptionsAssumptions

Tagged SSs VS. Tagged QueueTagged SSs VS. Tagged Queue Each SDU is fragmented to Each SDU is fragmented to F F PDUs with an equal size of PDUs with an equal size of B B

bitsbits Feedback information is sent by SS in UL-ACK channelFeedback information is sent by SS in UL-ACK channel Resource are available for nrtPS traffic admitted into netResource are available for nrtPS traffic admitted into net

work at each MAC framework at each MAC frame When a queue is scheduled, it has PDUs waiting for transWhen a queue is scheduled, it has PDUs waiting for trans

missionmission

88



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework Wireless channel modelWireless channel model

FSMC (Finite State Markov Channel) modelFSMC (Finite State Markov Channel) model

99



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework

Gamma Function of mm: Nakagami fading parameterRaleigh fading channel: m=1

Complementary incomplete Gamma FunctionEx: If m=1, = b2, π(2)= e-1- e-2

1010



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework For a slow fading channel, the state transition matrix for For a slow fading channel, the state transition matrix for

the FSMC can be expressed as followthe FSMC can be expressed as follow

7767

676665

565554

454434

343332

232221

121110

0100

000000

00000

00000

00000

00000

00000

00000

000000

pp

ppp

ppp

ppp

ppp

ppp

ppp

pp

p

1111




TLnp nnn 11, )(

)(1

1, n

TLp n

nn

TLnp nnn )(1,

)(1, n

TLp n

nn

1212




7767

676665

565554

454434

343332

232221

121110

0100

000000

00000

00000

00000

00000

00000

00000

000000

pp

ppp

ppp

ppp

ppp

ppp

ppp

pp

p

1313



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework Analysis of service probability for an SSAnalysis of service probability for an SS

DefinitionDefinition The probability for an SS to obtain the service at a DL subframeThe probability for an SS to obtain the service at a DL subframe

Three groups for SSsThree groups for SSs Suppose the channel state of the tagged SSs is at state Suppose the channel state of the tagged SSs is at state nn

Group 1 (G1, Group 1 (G1, KK1) : SSs with channel condition better than state 1) : SSs with channel condition better than state nn Group 2 (G2, Group 2 (G2, KK2) :2) : SSs with the same channel condition as state SSs with the same channel condition as state nn Group 3 (G3, Group 3 (G3, KK3) : SSs with channel condition worse than state 3) : SSs with channel condition worse than state nn

How many SSs are selected at each MAC frame (How many SSs are selected at each MAC frame (hh))

1414



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework If (If (kk1>1>h h or or kk1=1=hh))

Number of SSs with better channel conditions (Number of SSs with better channel conditions (kk1) > or = 1) > or = Number of SSs selected in this frame (Number of SSs selected in this frame (hh))

All selected SSs should be come from G1All selected SSs should be come from G1

G1 G2 G3

K1=4 K2=3 K3=5

Scheduled Set

h=2

1515



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework If (If (kk1<1<hh))

Number of SSs with better channel conditions (Number of SSs with better channel conditions (kk1) < Nu1) < Number of SSs selected in this frame (mber of SSs selected in this frame (hh))

Selected SSs come from G1 and G2Selected SSs come from G1 and G2

G1 G2 G3

K1=4 K2=3 K3=5

Scheduled Set

h=6

1616



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework The probability of the tagged SS obtains TXOPThe probability of the tagged SS obtains TXOP

The probability that all SSs without tagged SS in G1, G2 and G3

1717



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework Assume Assume M M SSs in the networksSSs in the networks

αα1 1 is the number of possible combinations for selecting is the number of possible combinations for selecting kk1 1 from (from (MM-1)-1)

αα2 2 is the number of possible combinations for selecting (is the number of possible combinations for selecting (kk22-1)-1) frofrom (m (M-kM-k11--1)1)

11

1

k

M

1

1

2

12 k

kM

The total number of possible )( 1j

The total number of possible )( 2j

1818



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework The probability of the tagged SS obtains TXOPThe probability of the tagged SS obtains TXOP

1919



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework Analysis of inter-service timeAnalysis of inter-service time

State of the tagged SS obtains TXOP at state 1

State of the tagged SS losses TXOP at state 1

2020



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework The transition probability of the group states The transition probability of the group states

2121



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework Let Let mm denote the inter-service time denote the inter-service time

The duration (in unit of frame) between two successive The duration (in unit of frame) between two successive transmission chances for the tagged queuetransmission chances for the tagged queue

2222



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework Analysis of GoodputAnalysis of Goodput

2323



Resource Allocation and Packet Scheduling Resource Allocation and Packet Scheduling FrameworkFramework Analysis of Delivery Delay of a PDUAnalysis of Delivery Delay of a PDU

2424



Numerical ResultsNumerical Results

Simulation SettingsSimulation Settings Channel model : Rayleigh fading channel modelChannel model : Rayleigh fading channel model Number of SSs : 20 Number of SSs : 20

DL/UL subframe duration : 1.25 / 1.25 msDL/UL subframe duration : 1.25 / 1.25 ms OFDM symbol duration : 23.8 μsOFDM symbol duration : 23.8 μs Channel bandwidth : 10 MHzChannel bandwidth : 10 MHz

2525



PDU Delivery Delay VS. PDU Delivery Delay VS. hh

hh: Number of SSs selected at each MAC frame: Number of SSs selected at each MAC frame•SS1 : AVG. SNR = 10 db

•SS11 : AVG. SNR = 25 db


2626



Inter-service time VS. Inter-service time VS. hh

hh: Number of SSs selected at each MAC frame : Number of SSs selected at each MAC frame •SS1 : AVG. SNR = 10 db



2727



Resource Utilization VS. Resource Utilization VS. hh

hh: Number of SSs selected at each MAC frame : Number of SSs selected at each MAC frame

2828



Goodput VS. Goodput VS. hh

hh: Number of SSs selected at each MAC frame: Number of SSs selected at each MAC frame•SS1 : AVG. SNR = 10 db



2929



ConclusionConclusion

A efficient resource allocation and packet scheduling A efficient resource allocation and packet scheduling framework for nrtPS applications in IEEE 802.16 netframework for nrtPS applications in IEEE 802.16 networksworks

An analytical modelAn analytical model A practical guideline to select appropriate parameters for A practical guideline to select appropriate parameters for

satisfying the throughput requirement, delay and resourcsatisfying the throughput requirement, delay and resource utilizatione utilization

Thank You !!Thank You !!

Documents

A Flexible Resource Allocation and Scheduling Framework for Non-real-time Polling Service in IEEE 802.16 Networks Fen Hou, James She, Pin-Han Ho, and Xuemin