11

QoS Model and Resource QoS Model and Resource Management Issues for Management Issues for IEEIEE

E Std. 802.16E Std. 802.16Chen-Nien TsaiChen-Nien Tsai

Institute of Computer Science and InformatiInstitute of Computer Science and Information Engineeringon Engineering

National Taipei University of TechnologyNational Taipei University of Technology2007.11.192007.11.19

2

OutlineOutline► IntroductionIntroduction►QoS ModelQoS Model

Service FlowService Flow Service Flow ManagementService Flow Management Scheduling ServicesScheduling Services

►Resource Management IssuesResource Management Issues Packet SchedulingPacket Scheduling Bandwidth AllocationBandwidth Allocation Admission ControlAdmission Control

3

IntroductionIntroduction

► IEEE 802.16-2004 defines several QoS relatIEEE 802.16-2004 defines several QoS related concepts:ed concepts: Service Flow QoS SchedulingService Flow QoS Scheduling

►But do not specify how to do it.But do not specify how to do it. Dynamic Service ManagementDynamic Service Management

►DSA/DSC/DSD messages.DSA/DSC/DSD messages.►BS-initiated and SS-initiatedBS-initiated and SS-initiated

Two-phase Activation ModelTwo-phase Activation Model►It is often utilized in telephony applications.It is often utilized in telephony applications.

4

IntroductionIntroduction

►DOCSISDOCSIS Data-Over-Cable Service Interface SpecificationData-Over-Cable Service Interface Specification

s.s.►The QoS description and name conventions The QoS description and name conventions

from DOCSIS were chosen as the basis for dfrom DOCSIS were chosen as the basis for describing QoS in IEEE Std 802.16.escribing QoS in IEEE Std 802.16. Service flowService flow

►Provisioned, admitted, and active.Provisioned, admitted, and active. Authorization Model EnvelopesAuthorization Model Envelopes QoS parameter setsQoS parameter sets

5

Service FlowService Flow

►A service flow is a unidirectional flow of paA service flow is a unidirectional flow of packets that is provided a particular QoS.ckets that is provided a particular QoS.

►Service flows exist in both UL and DL direcService flows exist in both UL and DL direction and exist without actually being activtion and exist without actually being activated to carry traffic.ated to carry traffic.

►All service flows have a 32-bit SFID; All service flows have a 32-bit SFID; admittedadmitted and and activeactive service flows also hav service flows also have a 16-bit CID.e a 16-bit CID.

6

Object ModelObject Model

7

Service Flow AttributesService Flow Attributes►Service flow ID (SFID)Service flow ID (SFID)►Connection ID (CID)Connection ID (CID)

Mapping to an SFID that exists only when the Mapping to an SFID that exists only when the connection has an admitted or active service fconnection has an admitted or active service flow.low.

►ProvisionedQoSParamSetProvisionedQoSParamSet A QoS parameter set provisioned via means oA QoS parameter set provisioned via means o

utside of the scope of this standard.utside of the scope of this standard.►AdmittedQoSParamSetAdmittedQoSParamSet

A set of QoS parameters for which BS and SS aA set of QoS parameters for which BS and SS are reserving resources.re reserving resources.

8

Service Flow AttributesService Flow Attributes

►ActiveQoSParamSetActiveQoSParamSet A set of QoS parameters defining the service aA set of QoS parameters defining the service a

ctually being provided to the service flow.ctually being provided to the service flow.►Authorization ModuleAuthorization Module

A logical function within BS that approves or dA logical function within BS that approves or denies every change to QoS parameters and claenies every change to QoS parameters and classifiers associated with a service flow.ssifiers associated with a service flow.

Provisioned authorization module.Provisioned authorization module. Dynamic authorization module.Dynamic authorization module.

9

Types of Service FlowsTypes of Service Flows►Provisioned service flowProvisioned service flow

It is known via provisioning by the network mIt is known via provisioning by the network management system.anagement system.

AdmittedQoSParamSet and ActiveQoSParamAdmittedQoSParamSet and ActiveQoSParamSet are both null.Set are both null.

►Admitted service flowAdmitted service flow It has resources reserved by the BS for its AdmIt has resources reserved by the BS for its Adm

ittedQoSParamSet, but these parameters are ittedQoSParamSet, but these parameters are not active.not active.

ActiveQoSParamSet is null.ActiveQoSParamSet is null.

10

Types of Service FlowsTypes of Service Flows

►Active service flowActive service flow It has resources committed by the BS for its AIt has resources committed by the BS for its A

ctiveQoSParamSet.ctiveQoSParamSet. ActiveQoSParamSet is not null.ActiveQoSParamSet is not null. For example, BS is actively sending maps contFor example, BS is actively sending maps cont

aining unsolicited grants for a UGS-based servaining unsolicited grants for a UGS-based service flow.ice flow.

11

Service ClassService Class►An optional object that may be implementeAn optional object that may be implemente

d at the BS to have a particular QoS Paramed at the BS to have a particular QoS Parameter Set.ter Set.

►Allow higher-layer protocols to create a serAllow higher-layer protocols to create a service flow by its Service Class Name.vice flow by its Service Class Name. G711 for telephone signaling.G711 for telephone signaling.

►Service flow contains either a full definition Service flow contains either a full definition of QoS parameters or a service Class Name.of QoS parameters or a service Class Name.

►When a Service Class name is used, the servWhen a Service Class name is used, the service flow can modify the parameters of the Sice flow can modify the parameters of the Service Class.ervice Class.

12

Service ClassService ClassSS BS

DSA-REQService Class =

G711

DSC-REQ

Wireless channel

.

.

Maximum Sustained Traffic Rate = X’Maximum Latency= Y’

DSA-REQ

DSC-REQ

.

.

Maximum Sustained Traffic Rate = X’Maximum Latency= Y’

Maximum Sustained Traffic Rate = XMaximum Latency= Y

13

Scheduling ServicesScheduling Services

►Scheduling services represent the data haScheduling services represent the data handling mechanisms supported by the MAC ndling mechanisms supported by the MAC scheduler for data transport on a connectischeduler for data transport on a connection.on. Unsolicited Grant Service (UGS)Unsolicited Grant Service (UGS) Real-time Polling Service (rtPS)Real-time Polling Service (rtPS) Extended rtPS (ertPS)Extended rtPS (ertPS) Non-real-time Polling Service (nrtPS)Non-real-time Polling Service (nrtPS) Best Effort (BE)Best Effort (BE)

14

Unsolicited Grant ServiceUnsolicited Grant Service►The UGS scheduling service type is The UGS scheduling service type is

designed to support real-time data designed to support real-time data streams consisting of fixed-size data streams consisting of fixed-size data packets issued at periodic intervals.packets issued at periodic intervals.

15

Real-time Polling ServiceReal-time Polling Service►The rtPS scheduling service type is designThe rtPS scheduling service type is design

ed to support real-time data streams consed to support real-time data streams consisting of variable-sized data packets that aisting of variable-sized data packets that are issued at periodic intervals.re issued at periodic intervals.

16

Extended rtPSExtended rtPS► It was added by the 802.16e amendment.It was added by the 802.16e amendment.►ertPS is a scheduling mechanism that builertPS is a scheduling mechanism that buil

ds on the efficiency of both UGS and rtPS.ds on the efficiency of both UGS and rtPS. provides unicast grants in an unsolicited manprovides unicast grants in an unsolicited man

ner like in UGS.ner like in UGS. ertPS allocations are dynamic.ertPS allocations are dynamic.

►The ertPS is suitable for variable rate real-The ertPS is suitable for variable rate real-time applications that have data rate and time applications that have data rate and delay requirements.delay requirements.

17

Non-real-time Polling ServiceNon-real-time Polling Service

►The nrtPS is designed to support delay-tolThe nrtPS is designed to support delay-tolerant data streams consisting of variable-erant data streams consisting of variable-size data packets for which a minimum dasize data packets for which a minimum data rate is required.ta rate is required.

18

Best EffortBest Effort►The BE service is designed to support The BE service is designed to support

data streams for which no minimum data streams for which no minimum service guarantees are required.service guarantees are required.

►A long period can run without A long period can run without transmitting any BE packets. transmitting any BE packets.

19

Usage RulesUsage Rules

ScheduliScheduling ng ServiceService

PollingPollingContentioContention n RequestsRequests

PiggyBack RPiggyBack Requestsequests

Bandwidth Bandwidth StealingStealing

UGSUGS PM bitPM bit Not Not allowedallowed Not allowedNot allowed Not Not

allowed allowed

rtPSrtPS UnicasUnicastt

Not Not allowedallowed AllowedAllowed AllowedAllowed

ertPSertPS UnicasUnicastt AllowedAllowed Extended Extended

piggybackpiggyback AllowedAllowed

nrtPSnrtPS AllAll AllowedAllowed AllowedAllowed AllowedAllowed

BEBE AllAll AllowedAllowed AllowedAllowed AllowedAllowed

20

QoS ParametersQoS Parameters►Maximum Sustained Traffic RateMaximum Sustained Traffic Rate►Maximum LatencyMaximum Latency►Tolerated JitterTolerated Jitter►Request/Transmission PolicyRequest/Transmission Policy►Minimum Reserved Traffic RateMinimum Reserved Traffic Rate►Traffic PriorityTraffic Priority►Maximum Traffic BurstMaximum Traffic Burst►Minimum Tolerable Traffic RateMinimum Tolerable Traffic Rate

21

Mandatory QoS ParametersMandatory QoS ParametersScheduliScheduling ng ServiceService

Maximum Maximum Sustained Sustained

Traffic Traffic RateRate

Minimum Minimum Reserved Reserved

Traffic Traffic RateRate

Request/Request/transmissiotransmissio

n Policyn Policy

Tolerated Tolerated JitterJitter

MaximuMaximum m

LatencyLatency

Traffic Traffic PriorityPriority

UGSUGS ★★(Can be (Can be presented)presented) ★★ ★★ ★★

rtPSrtPS ★★ ★★ ★★ ★★

ertPSertPS ★★ ★★ ★★ ★★

nrtPSnrtPS ★★ ★★ ★★ ★★

BEBE ★★ ★★ ★★

2222

Service Flow Service Flow ManagementManagement

23

Service Flow ManagementService Flow Management►CreationCreation

Pre-provisioned service flowPre-provisioned service flow►It is done via means outside of the scope of this Std.It is done via means outside of the scope of this Std.►Admitted or activated during Network Entry Admitted or activated during Network Entry

procedures.procedures.

Dynamic service flowDynamic service flow►Managed by DSA (add) message.Managed by DSA (add) message.

►ModificationModification Managed by DSC (change) message.Managed by DSC (change) message.

►DeletionDeletion Managed by DSD (delete) message.Managed by DSD (delete) message.

24

Dynamic Service Flow Dynamic Service Flow CreationCreation

►Creation of a service flow may be Creation of a service flow may be initiated initiated by the BS (mandatory capability) by the BS (mandatory capability) by the SS (optional capability)by the SS (optional capability)

►The DSA messages are used to create a The DSA messages are used to create a new service flow (either uplink or new service flow (either uplink or downlink).downlink).

►The general format of The general format of DSA-REQDSA-REQ, , DSA-RSPDSA-RSP, and , and DSA-ACKDSA-ACK messages: messages:

25

Dynamic Service Dynamic Service EstablishmentEstablishment

►SS-initialed DSASS-initialed DSA The standard does not go into details on The standard does not go into details on

what actually triggers the DSA.what actually triggers the DSA. Triggering is just assumed to happen, Triggering is just assumed to happen,

stimulated by the upper layers when needed.stimulated by the upper layers when needed.

SS BS

DSA-RSQ

DSX-RVD

Wireless channel

DSA-RSP

DSA-ACK

This allows BS to take it time determining whether to admin the service flow

26

Dynamic Service Flow CreationDynamic Service Flow Creation( SS-initialed DSA)( SS-initialed DSA)

SS BS

Receive DSA-REQ

Send DSX-RVD

Check whether SS is authorized Check whether QoS can be supportedCreate SFID

DSX-RVD

DSA-REQ

New service flow neededCheck if resources are available

Receive DSX-RVD

Send DSA-REQ

Wireless channel

If AdmittedQoSParamSet is non-null, map service flow to CID

If uplink ActiveQoSParamSet is non-null, enable reception of data on new service flow

27

Dynamic Service Flow CreationDynamic Service Flow Creation( SS-initialed DSA)( SS-initialed DSA)

SS BS

Send DSA-RSP

Send DSA-ACK

Wireless channel

DSA-RSP

DSA-ACK

Receive DSA-RSP

If ActiveQoSParamSet is non-null, enable transmission or reception of data on new service flow

If downlink ActiveQoSParamSet is non-null, enable transmission of data on new service flow

Receive DSA-ACK

28

Dynamic Service Dynamic Service EstablishmentEstablishment

►BS-initiatedBS-initiated

SS BSDSA-RSP

DSA-RSQ

Wireless channel

DSA-ACK

29

Dynamic Service Flow CreationDynamic Service Flow Creation( BS-initialed DSA)( BS-initialed DSA)

SS BS

Receive DSA-REQ

Send DSX-ACK

New service flow required for SSCheck whether SS is authorized Check whether QoS can be supportedCreate SFID

DSX-REQ

DSA-RSPSend DSX-RSP

Send DSA-REQ

Wireless channel

If AdmittedQoSParamSet is non-null, map service flow to CID

Enable transmission or reception of data on new service flow

Confirm the SS can support service flow

Add downlink SFID

Enable reception on new downlink service flow

Enable transmission on new uplink service flow

Receive DSA-ACK

DSX-ACK

Receive DSA-RSP

30

Dynamic Service Flow Dynamic Service Flow ModificationModification

►Created service flows are modified with thCreated service flows are modified with the DSC message.e DSC message. Change the admitted and active QoS parametChange the admitted and active QoS paramet

er sets of the flow.er sets of the flow.►QoS Parameter set typeQoS Parameter set type

31

QoS Parameter Set Type ValuesQoS Parameter Set Type Values

32

SS-Initiated DSCSS-Initiated DSCSS BS

Send DSX-RVD

Receive DSC-RSP

Wireless channel

DSC-RSP

DSC-ACK

Send DSC-RSQ

Service flow requires modifying

Validate RequestModify service flowIncrease channel bandwidth if required

Receive DSC-ACK

Modify service flow

Adjust payload bandwidth

Send DSC-ACK

DSC-REQ

DSX-RVD

Receive DSC-RSQ

Receive DSX-RVD

Send DSC-RSP

33

BS-Initiated DSCBS-Initiated DSCSS BS

Receive DSC-RSP

Wireless channel

DSC-RSP

DSC-ACK

Send DSC-RSQ

Service flow requires modifying

Validate RequestModify service flowDecrease payload bandwidth if required

Receive DSC-ACK

Modify service flow

Adjust channel bandwidthSend DSC-ACK

DSC-REQReceive DSC-RSQ

Send DSC-RSP

Increase payload bandwidth if required

34

Dynamic Service Flow Dynamic Service Flow DeletionDeletion

►Any service flow can be deleted with Any service flow can be deleted with the DSD messages.the DSD messages.

►When a service flow is deleted, all When a service flow is deleted, all resources associated with it are resources associated with it are released.released.

35

SS-Initiated DSDSS-Initiated DSDSS BS

Receive DSD-RSP

Wireless channel

DSD-RSP

Send DSD-RSQ

Service flow no longer needed

Delete service flow

Verify SS is service flow owner

Delete service flow

DSD-REQ

Receive DSD-RSQ

Send DSD-RSP

36

BS-Initiated DSDBS-Initiated DSDSS BS

Receive DSC-RSP

Wireless channel

DSD-RSP

Send DSD-RSQ

Service flow no longer needed

Delete service flow

Determine associated SS for this service flow

Delete service flow

DSD-REQ

Receive DSD-RSQ

Send DSC-RSP

37

Two-phase Activation ModelTwo-phase Activation Model

►The resource for a call are first The resource for a call are first admittedadmitted, , and then once the end-to-end negotiation and then once the end-to-end negotiation is completed, the resources are is completed, the resources are activatedactivated..

►The purposes:The purposes: Conserving network resources until a complete Conserving network resources until a complete

end-to-end connection has been established.end-to-end connection has been established. Performing policy check and admission control Performing policy check and admission control

on resources as quickly as possible.on resources as quickly as possible.

38

Example 1Example 1

SS BS

DSA-REQAdmitted MSTR = A’s

requestActive MSTR = 0

Perform admission control

DSC-REQ

Higher-level flow A is pending.

Wireless channel

Higher-level flow A is active.

.

.

.

.

Active MSTR = A’s requestIf active MSTR within the range of the previous reservation, this DSC-REQ is guaranteed to succeed.

►Suppose that an upper-layer service Suppose that an upper-layer service were using UGS.were using UGS.

►MSTR = Maximum Sustained Traffic RateMSTR = Maximum Sustained Traffic Rate

39

Example 2Example 2

►Suppose there are 4 higher-lever flows Suppose there are 4 higher-lever flows which are classified in a service flow.which are classified in a service flow.

SS BS

DSA-REQAdmitted MSTR = all flows’

requestActive MSTR = 0

Perform admission control

DSC-REQ

All flows are pending

Wireless channel

Higher-level flow A is active.

.

.

.

.

Admitted MSTR = all flows’ requestActive MSTR = A’s request

If active MSTR within the range of the previous reservation, this DSC-REQ is guaranteed to succeed.

4040

Resource Management Resource Management IssuesIssues

41

Resource Management Resource Management IssuesIssues

►BSBS Contention Slot AllocationContention Slot Allocation Admission ControlAdmission Control Uplink Scheduling and Bandwidth AllocationUplink Scheduling and Bandwidth Allocation Downlink Packet SchedulingDownlink Packet Scheduling

►SSSS Uplink Packet SchedulingUplink Packet Scheduling

►BS & SSBS & SS Contention Resolution AlgorithmContention Resolution Algorithm

►Binary exponential backoff. (specified in the Std.)Binary exponential backoff. (specified in the Std.)

42

Contention Slot AllocationContention Slot Allocation

►BS can dynamically adjust the ratio of BS can dynamically adjust the ratio of the bandwidth allocated to the the bandwidth allocated to the contention slots.contention slots. Too few contention slotsToo few contention slots

►Increase the chances of bandwidth request Increase the chances of bandwidth request collision.collision.

►Reduce the amount of data that can be Reduce the amount of data that can be transmitted.transmitted.

Too many contention slotsToo many contention slots►Reduce the bandwidth left for data transmission.Reduce the bandwidth left for data transmission.

43

SC Frame StructureSC Frame Structure

44

TDD Uplink SubframeTDD Uplink Subframe

45

Uplink TransmissionUplink Transmission

►Three classes of bursts may be transmitteThree classes of bursts may be transmitted in a UL subframe:d in a UL subframe: Contention opportunities for initial ranging.Contention opportunities for initial ranging. Contention opportunities for BW requests.Contention opportunities for BW requests. Contention-free periods assigned by BS to indContention-free periods assigned by BS to ind

ividual SSs.ividual SSs.

46

Contention Slot AllocationContention Slot Allocation Proposed in [1] Proposed in [1]

►NN SSs in the system and backoff window si SSs in the system and backoff window size is ze is BB..

►The probability of choosing a given slot isThe probability of choosing a given slot is

►The system throughput (no collision)The system throughput (no collision)

1p B

11( )NthP Np p

47

►To maximize system throughputTo maximize system throughput

►The maximum throughput can be The maximum throughput can be obtained when obtained when BB = = NN..

1 21 1 1 0

1 1

( ) ( )( )N NthdPN p Np N p

dp

pN B

N B

48

Packet SchedulingPacket Scheduling

►Three main scheduling pointsThree main scheduling points Scheduling of the UL by the BS.Scheduling of the UL by the BS.

►Generates UL-MAPGenerates UL-MAP

Scheduling of the DL by the BS.Scheduling of the DL by the BS.►Generates DL-MAPGenerates DL-MAP

Scheduling of the UL by the SS.Scheduling of the UL by the SS.

49

QoS Architecture Proposed in QoS Architecture Proposed in [2][2]

BS’s DL Scheduler

50

Packet SchedulingPacket Scheduling

►Scheduler in the BSScheduler in the BS Creates and distributes UL/DL MAP Creates and distributes UL/DL MAP

messages.messages. Must consider BW requests, polling, PHY Must consider BW requests, polling, PHY

maintenance needs, and current PHY maintenance needs, and current PHY mode.mode.

►Scheduler in the SSScheduler in the SS SS runs a scheduling algorithm but limited SS runs a scheduling algorithm but limited

in scope to its own services.in scope to its own services.

51

Scheduler in the BSScheduler in the BS► It is the role of the BS scheduler to It is the role of the BS scheduler to

determine the burst profile and the determine the burst profile and the transmission periods for each connection.transmission periods for each connection. UL/DL-MAPUL/DL-MAP

52

Scheduling of the Different Scheduling of the Different ServicesServices

►Recall that:Recall that: Each connection is assigned a scheduling servEach connection is assigned a scheduling serv

ice (via service flow).ice (via service flow). Packets are classified in Convergence SublayePackets are classified in Convergence Sublaye

r.r.►So…So…

The connection which the packets are placed The connection which the packets are placed is chosen based on the QoS requirements, whiis chosen based on the QoS requirements, which specify in the service flow.ch specify in the service flow.

53

Scheduling Service for Some Scheduling Service for Some ServicesServices

►Some of these services are mentioned Some of these services are mentioned in the standard.in the standard.

54

BS Scheduler Operation for the BS Scheduler Operation for the ULUL

55

BS Scheduler Operation for the BS Scheduler Operation for the DLDL

56

57

Scheduling AlgorithmsScheduling Algorithms

►Scheduling algorithms were intentionally Scheduling algorithms were intentionally left outside the scope of the IEEE Std. left outside the scope of the IEEE Std. 802.16.802.16.

►Any of the known scheduling algorithms can Any of the known scheduling algorithms can be used:be used: Round RobinRound Robin Weighted Round RobinWeighted Round Robin Weighted Fair QueuingWeighted Fair Queuing

►Many scheduling algorithms are being Many scheduling algorithms are being proposed for WIMAX/802.16 in the proposed for WIMAX/802.16 in the literature.literature.

58

Scheduling Algorithms Scheduling Algorithms Proposed in [2]Proposed in [2]

►BS’s uplink scheduler (creates UL-MAP)BS’s uplink scheduler (creates UL-MAP) Weighted Round Robin (WRR).Weighted Round Robin (WRR).

►SS’s scheduling strategySS’s scheduling strategy

PriorityPriority Service TypeService Type Queuing PolicyQueuing Policy

11 UGSUGS Wireless Fair Wireless Fair QueuingQueuing

22 rtPSrtPS Wireless Fair Wireless Fair QueuingQueuing

33 nrtPSnrtPS WRR SchedulerWRR Scheduler

44 BEBE FIFOFIFO

59

Admission ControlAdmission Control

►Admission control is used to limit the numAdmission control is used to limit the number of connections/flows admitted into thber of connections/flows admitted into the network.e network. Individual connection/flow can get its desired Individual connection/flow can get its desired

QoS.QoS.►Note that the types of services flows areNote that the types of services flows are

ProvisionedProvisioned AdmittedAdmitted ActiveActive

Perform admission control when a service flow requests to change to one of these two types.

60

Admission Control PolicyAdmission Control Policy►Admission control policy can be simpleAdmission control policy can be simple

First-In-First-Serve.First-In-First-Serve. Considers only one QoS parameter.Considers only one QoS parameter.

►Maximum Sustained Traffic RateMaximum Sustained Traffic Rate►Admission control policy can be complexAdmission control policy can be complex

Considers multiple QoS parameter.Considers multiple QoS parameter. Advanced mechanismsAdvanced mechanisms

►Combines with bandwidth allocation.Combines with bandwidth allocation.►Dynamically adjust BW allocated to users.Dynamically adjust BW allocated to users.►PreemptivePreemptive

61

Admission Control Proposed Admission Control Proposed in [3]in [3]

►Consider multiple QoS parametersConsider multiple QoS parameters Maximum Sustained Traffic Rate for UGS, rtPS, aMaximum Sustained Traffic Rate for UGS, rtPS, a

nd nrtPS.nd nrtPS. Minimum Reserved Traffic Rate for nrtPS.Minimum Reserved Traffic Rate for nrtPS. BE connections are always admitted.BE connections are always admitted.

►Dynamic bandwidth allocation.Dynamic bandwidth allocation. For nrtPS only.For nrtPS only. BS can allocates BW to a nrtPS connection base BS can allocates BW to a nrtPS connection base

on the condition of the network.on the condition of the network.►Lower BW allocated = more users can admitted.Lower BW allocated = more users can admitted.

62

SummarySummary►The service flows and connections are imThe service flows and connections are im

portant concepts.portant concepts. Service flows Service flows

►Identify the right of an SS to certain system resourIdentify the right of an SS to certain system resources.ces.

►Define which of packets will be mapped to the corrDefine which of packets will be mapped to the corresponding connection.esponding connection.

Connections determineConnections determine►Which SS receives the data on the DL.Which SS receives the data on the DL.►What QoS and traffic parameters are associated wiWhat QoS and traffic parameters are associated wi

th the traffic.th the traffic.

63

SummarySummary

►Other issuesOther issues Rate ControlRate Control Power ControlPower Control Channel Assignment (OFDMA PHY)Channel Assignment (OFDMA PHY) Subcarrier Permutation (OFDMA PHY)Subcarrier Permutation (OFDMA PHY)

64

ReferencesReferences

[1] Dong-Hoon Cho, Jung-Hoon Song, Min-Su Kim, and Ki-Ju[1] Dong-Hoon Cho, Jung-Hoon Song, Min-Su Kim, and Ki-Jun Han, “Performance Analysis of the IEEE 802.16 Wireless n Han, “Performance Analysis of the IEEE 802.16 Wireless Metropolitan Area Network,” Metropolitan Area Network,” Proceedings of the First IntProceedings of the First International Conference on Distributed Frameworks for Mulernational Conference on Distributed Frameworks for Multimedia Applicationstimedia Applications ( (DFMA’05DFMA’05), Feb. 2005, pp130-136.), Feb. 2005, pp130-136.

[2] [2] GuoSong Chu, Deng Wang, and Shunliang Mei, "A GuoSong Chu, Deng Wang, and Shunliang Mei, "A QoS Architecture for the MAC Protocol of IEEE 802.16 QoS Architecture for the MAC Protocol of IEEE 802.16 BWA System," BWA System," IEEE 2002 International Conference on IEEE 2002 International Conference on Communications, Circuits and Systems and West Communications, Circuits and Systems and West Sino ExpositionsSino Expositions, , vvol. 1, June 2002, pp. 435-439.ol. 1, June 2002, pp. 435-439.

65

ReferencesReferences[3] Haitang Wang, Bing He, and Dharma P. Agrawal, “Abov[3] Haitang Wang, Bing He, and Dharma P. Agrawal, “Abov

e Packet Level Admission Control and Bandwidth Allocate Packet Level Admission Control and Bandwidth Allocation for IEEE 802.16 Wireless MAN,” ion for IEEE 802.16 Wireless MAN,” Simulation ModellinSimulation Modelling Practice and Theoryg Practice and Theory, vol. 15, issue 4, April 2007, pp. 36, vol. 15, issue 4, April 2007, pp. 366-382.6-382.

[4] IEE Std 802.16-2004, IEEE Standard for Local and Metro[4] IEE Std 802.16-2004, IEEE Standard for Local and Metropolitan Area Networks—Part 16: Air Interface for Fixed Bpolitan Area Networks—Part 16: Air Interface for Fixed Broadband Wireless Accessroadband Wireless Access..

[5] Carl Eklund [5] Carl Eklund et alet al., ., WirelessMAN: Inside the IEEE 802.16 SWirelessMAN: Inside the IEEE 802.16 Standard for Wireless Metropolitan Area Networkstandard for Wireless Metropolitan Area Networks, IEEE P, IEEE Press, 2006.ress, 2006.

[6] Loutfi Nuaymi, WiMAX: [6] Loutfi Nuaymi, WiMAX: Technology for Broadband WirelTechnology for Broadband Wireless Accessess Access, John Wiley & Sons, 2007., John Wiley & Sons, 2007.

6666

The EndThe End

6767

Backup MaterialsBackup Materials

68

DSA-REQ and DSA-RSPDSA-REQ and DSA-RSP

69

DSA-ACK and DSX-RVDDSA-ACK and DSX-RVD

70

Service Flow EncodingsService Flow Encodings

71

Confirmation CodeConfirmation Code

72

AuthorizationAuthorization

►Every change to the service flow QoS ParaEvery change to the service flow QoS Parameters shall be approved by an authorizatmeters shall be approved by an authorization module.ion module. DSA-REQ message and DSC-REQ message.DSA-REQ message and DSC-REQ message.

►Such changes include requestingSuch changes include requesting admission control decision (setting the Admitadmission control decision (setting the Admit

tedQoSParamSet).tedQoSParamSet). activation of a service flow (setting the Activeactivation of a service flow (setting the Active

QoSParamSet).QoSParamSet).

73

Provisioned Authorization Provisioned Authorization ModelModel

►The module stores the provisioned status of The module stores the provisioned status of all deferred service flows.all deferred service flows.

►Admission and activation requests for those sAdmission and activation requests for those services flows are permitted as long aservices flows are permitted as long as AdmittedQoSParamSet ProvisionedQoSParamAdmittedQoSParamSet ProvisionedQoSParam

SetSet ActiveQoSParamSet AdmittedQoSParamSetActiveQoSParamSet AdmittedQoSParamSet

74

Provisioned Authorization Provisioned Authorization ModelModel

►Those requests are refused:Those requests are refused: Changing the ProvisionedQoSParamSetChanging the ProvisionedQoSParamSet Creating new service flowsCreating new service flows

►This defines a static system where all possThis defines a static system where all possible services are defined in the initial confiible services are defined in the initial configuration of each SS.guration of each SS.

75

Dynamic Authorization ModelDynamic Authorization Model

►The module communicates to an independThe module communicates to an independent policy server.ent policy server. Policy server specifies the proper authorization Policy server specifies the proper authorization

action to be taken on requests.action to be taken on requests.►BS retrieves the ProvisionedQoSParamSet fBS retrieves the ProvisionedQoSParamSet f

or an SS prior to initial connection setup.or an SS prior to initial connection setup. It is handed to the authorization model.It is handed to the authorization model. BS use this information to authorize dynamic flBS use this information to authorize dynamic fl

ows.ows.

76

Dynamic Authorization ModelDynamic Authorization Model

►Admission and activation requests from aAdmission and activation requests from an SSn SS Are permitted if that are signaled in advance bAre permitted if that are signaled in advance b

y the external policy server.y the external policy server. May result in a real-time query to the policy seMay result in a real-time query to the policy se

rver if that are not presignaled by the external rver if that are not presignaled by the external policy server.policy server.

77

Model EnvelopesModel EnvelopesAuthorization Module

78

Related TermsRelated Terms

►ConnectionsConnections►Service FlowService Flow

Service flow IDService flow ID Provisioned, Admitted, Active.Provisioned, Admitted, Active. QoS parameter sets QoS parameter sets

►Service ClassService Class►Scheduling ServiceScheduling Service

79

►Admission control and provisioningAdmission control and provisioning►Traffic classificationTraffic classification►Shaping and policingShaping and policing►Traffic schedulingTraffic scheduling

80

OFDM Frame StructureOFDM Frame Structure

81

OFDMA Frame StructureOFDMA Frame Structure

82

Scheduling Algorithms in Scheduling Algorithms in Packet NetworksPacket Networks

►FIFO (First In, First Out)FIFO (First In, First Out) FIFO +FIFO + No fairness and protection.No fairness and protection.

►Round-RobinRound-Robin Weighted round-robinWeighted round-robin Provides fairness and protection.Provides fairness and protection.

►Stop-And-GoStop-And-Go

83

Scheduling MethodsScheduling Methods

►Round robinRound robin►Proportional fairProportional fair►Max CINRMax CINR►Fair throughputFair throughput►Early deadline firstEarly deadline first

84

WirelessMAN-SC/SCa PHYWirelessMAN-SC/SCa PHY►Time is slotted. (Physical slots and minislots)Time is slotted. (Physical slots and minislots)►Uplink Uplink

TDMA.TDMA.►DownlinkDownlink

TDMTDM►Granularity of bandwidth allocationGranularity of bandwidth allocation

One PS for DLOne PS for DL One minislot for UL. One minislot for UL. 1 minislot = 21 minislot = 2mm PS (0≦ PS (0≦mm ≦7) ≦7)

85

86

QoS ArchitectureQoS Architecture

87

QoS Architecture Proposed in QoS Architecture Proposed in [2][2]

88

Uplink Bandwidth Allocation Uplink Bandwidth Allocation Proposed in [1]Proposed in [1]

►UGSUGS BS always allocates bandwidth for UGS conneBS always allocates bandwidth for UGS conne

ctions.ctions.►rtPSrtPS

BS polls the SS according to the deadline.BS polls the SS according to the deadline.►nrtPSnrtPS

Uses either contention-free mode (low prioritUses either contention-free mode (low priority) or contention mode.y) or contention mode.

►BEBE Uses contention mode only.Uses contention mode only.

89

Uplink Bandwidth Allocation Uplink Bandwidth Allocation Proposed in [1]Proposed in [1]

Service TypeService Type Contention-free Contention-free modemode Contention modeContention mode

UGSUGS N/AN/A N/AN/A

rtPSrtPS High priorityHigh priority N/AN/A

nrtPSnrtPS Low priorityLow priority High priorityHigh priority

BEBE N/AN/A Low priorityLow priority