2000-01-13 working group on broadband wireless access · 2000. 11. 21. · 2000-01-13 [ieee...

[IEEE 802.16.1mp-00/05]2000-01-13

Ray W. Sanders, CircuitPath

Working Group on Broadband Wireless Access

Document Number:IEEE 802.16.1mp-00/05

Title:Proposed Amendments to MAC/PHY Layers to Include a Bandwidth-On-Demand MAC Sublayer

Date Submitted:2000-01-11

Source:Ray W. Sanders Voice: (310) 476-5063CircuitPath Network Systems Fax: (310) 471-7854P O Box 24950 E-mail: mailto:[email protected] Angeles, CA 90024

Venue:Session # 5 at Clarion Hotel in Richardson, Texas – January 10-14, 2000

Base Document:IEEE 802.16.1mc-00/05 and IEEE 802.16.1pc-00/06

Purpose:To propose adoption of the proposed amendments as an option to the base document for inclusion in 802.16.1 PHY standard.

Notice:This document has been prepared to assist the IEEE 802.16. It is offered as a basis for discussion and is not binding on thecontributing individual or organization. The material in this document is subject to change in form and content after further study.The contributor reserve the right to add, amend or withdraw material contained herein.

Release:The contributor acknowledges and accepts that this contribution may be made public by 802.16.

IEEE Patent Policy:

The contributor is familiar with the IEEE Patent Policy, which is set forth in the IEEE-SA Standards Board Bylaws<http://standards.ieee.org/guides/bylaws> and includes the statement: “IEEE standards may include the known use of patent(s),including patent applications, if there is technical justification in the opinion of the standards-developing committee and providedthe IEEE receives assurance from the patent holder that it will license applicants under reasonable terms and conditions for thepurpose of implementing the standard.”

[IEEE 802.16mp-00/05]2000-01-13


Study Group on Broadband Wireless Access

Presentation PurposePresentation Purpose

This presentation is made as a This presentation is made as a

friendly amendment tofriendly amendment to

other MAC & PHY proposalsother MAC & PHY proposals

submitted to 802.16.1submitted to 802.16.1

[IEEE 802.16mp-00/05]2000-01-13



Presentation OutlinePresentation Outline

•• Broadband Wireless AccessBroadband Wireless AccessMAC/PHY Basics (Generic)MAC/PHY Basics (Generic)

•• Proposed Data Channel AssignmentProposed Data Channel AssignmentApproachApproach

•• Proposed Next Generation BWAProposed Next Generation BWA–– Early market benefitsEarly market benefits

•• An unmet market needAn unmet market need•• Proposed ProgramProposed Program•• DiscussionDiscussion

[IEEE 802.16mp-00/05]2000-01-13



SomeSomeBroadband Wireless AccessBroadband Wireless Access

MAC/PHY BasicsMAC/PHY Basics(Generic)(Generic)

[IEEE 802.16mp-00/05]2000-01-13



Topics CoveredTopics Covered•• Reference ModelReference Model

•• Bandwidth-On-Demand SublayerBandwidth-On-Demand Sublayer

•• TDM/TDMATDM/TDMA

•• Common Signaling ChannelCommon Signaling Channel

•• Proposed ApproachProposed Approach

•• Factors Affecting Bandwidth EfficiencyFactors Affecting Bandwidth Efficiency–– PHY overhead PHY overhead vsvs delay delay

–– MAC overhead MAC overhead vs vs delaydelay

–– Asynchronous traffic bufferingAsynchronous traffic buffering

[IEEE 802.16mp-00/05]2000-01-13



ConventionalConventionalReference ModelReference Model

MAC Layer

PHY Layer

Data Link / Network Layers

[IEEE 802.16mp-00/05]2000-01-13



Proposed Reference ModelProposed Reference Model

MAC Layer

PHY Layer

Data Link / Network Layers

MAC Bandwidth-On-Demand Sublayer

[IEEE 802.16mp-00/05]2000-01-13



•• To provide a simple standardizedTo provide a simple standardizedinterconnection to interconnection to allall MAC and MAC andhigher network layer protocolshigher network layer protocols

•• To interconnect with the PHY layer inTo interconnect with the PHY layer ina manner thata manner that

–– uses available bandwidth efficientlyuses available bandwidth efficiently

–– minimizes delay, delay variation & jitterminimizes delay, delay variation & jitter

Role of the MACRole of the MACBandwidth-On-Demand SublayerBandwidth-On-Demand Sublayer

[IEEE 802.16mp-00/05]2000-01-13



Proposed MAC Sublayer /Proposed MAC Sublayer /PHY Interface SchematicPHY Interface Schematic

Bandwidth-On-Demand

MAC Sublayer

PHY Layer

Send Clock/ Frame

Receive Data Common

Signaling

Channel

API Request Receive

Clock/ Frame

Send Data

API Response

Upper MAC and Network Layers

[IEEE 802.16mp-00/05]2000-01-13



Delay Delay vs vs BandwidthBandwidth(for various payload block sizes)(for various payload block sizes)

0

1

10

100

1,000

Payload Bandwidth

Mea

n D

elay

(m

sec)

0.11 Kbps 10 Kbps 100 Kbps 1 Mbps 10 Mbps 100 Mbps

Payload Block Size (Bytes)1,0241 4 16 64 256

Payload Size (Bytes)

48 184 1,500

G.72x DS0 384 T1/E1 OC1

[IEEE 802.16mp-00/05]2000-01-13



Average Payload Rate Per UserAverage Payload Rate Per Uservs vs Aggregate Rate & Aggregate Rate & Nbr Nbr UsersUsers

Note Attached

Ag

gre

gat

e P

aylo

ad D

ata

Rat

e (M

bp

s)

Average Payload Rate Per User (Kbps)

1

10

100

1 10 100 1,000 10,000

10,000 Users

1 User

1,000 Users

100 Users

10 Users

50,000 20,000 5,000 2,000 500 200 50 20 5 2

200

50

20

5

2

[IEEE 802.16mp-00/05]2000-01-13



Bandwidth-On-DemandBandwidth-On-DemandMAC/PHY FunctionalityMAC/PHY Functionality

•• Assign bandwidth to flowsAssign bandwidth to flows•• Flows may be single session orFlows may be single session or

aggregations thereofaggregations thereof•• Advantages includeAdvantages include

–– Low transport delay & delay variationLow transport delay & delay variation•• Delay is inversely proportional to channel bandwidthDelay is inversely proportional to channel bandwidth

–– Low (and bounded) jitterLow (and bounded) jitter–– MAC & Network Protocol IndependenceMAC & Network Protocol Independence–– SimplicitySimplicity

[IEEE 802.16mp-00/05]2000-01-13



Dealing with FlowsDealing with Flows

1 1 0 1 0 0 1 ,0 0 0 1 0 ,0 0 0 1 0 0 ,0 0 0

Flo

w D

ura

tio

n (

seco

nd

s)

1 0 B

1 0 0 B

1 K B

1 0 K B

1 0 0 K B

1 M B

1 0 M B

1 0 0 M B

1 G B

1 0 G B

G 7 2 x D S 0 D S 3 , O C 1 c 6 x D S 0 T 1 , E 1

P a y lo a d B a n d w id t h ( K i lo b i t s p e r s e c o n d )

1 h o u r

1 m in u t e

1 s e c o n d

1 m s e c

1 0 , 0 0 0

1 , 0 0 0

1 0 0

1 0

1

0 . 1

0 . 0 1

0 . 0 0 1

Note Attached

[IEEE 802.16mp-00/05]2000-01-13



The Specific ApproachThe Specific Approach

•• Define the PHY layer as a single TDMDefine the PHY layer as a single TDMstream of fixed size “cell slots” —stream of fixed size “cell slots” —((cc bits per cell slot) bits per cell slot)

•• The size of TDM frames is based onThe size of TDM frames is based onGCD of all supported data ratesGCD of all supported data rates

•• TDM frame size can be a fieldTDM frame size can be a fieldprogrammable parameter assuringprogrammable parameter assuringnon-obsolescencenon-obsolescence

[IEEE 802.16mp-00/05]2000-01-13



The Specific ApproachThe Specific Approach

•• Bandwidth is assignable in increments ofBandwidth is assignable in increments ofone cell slot (one cell slot (cc bits) per frame bits) per frame–– i.e., channel bandwidth = i.e., channel bandwidth = cc times number of times number of

assigned cell slots per frame times frame rateassigned cell slots per frame times frame rate

•• Define two ways by which individual cellDefine two ways by which individual cellslots are identifiedslots are identified–– A logical (Element Address) domainA logical (Element Address) domain–– A physical time division address (OrdinalA physical time division address (Ordinal

Position Number) domainPosition Number) domain

[IEEE 802.16mp-00/05]2000-01-13



ExamplesExamples

•• For a cell slot size of 1 byteFor a cell slot size of 1 byte–– Frame size of 8 msec allows bandwidthFrame size of 8 msec allows bandwidth

granularity of 1,000 bpsgranularity of 1,000 bps–– Frame size of 6 msec allows bandwidthFrame size of 6 msec allows bandwidth

granularity of 1,333.33 bps and cangranularity of 1,333.33 bps and cansupport TDM cells that support ATM forsupport TDM cells that support ATM forn*DS0’s with minimum transport delayn*DS0’s with minimum transport delay

–– Frame size of 24 msec supports bothFrame size of 24 msec supports both

[IEEE 802.16mp-00/05]2000-01-13



Function of the DomainsFunction of the Domains

•• The Element Address (Logical) domainThe Element Address (Logical) domain–– Contiguous Element Addresses can be used toContiguous Element Addresses can be used to

assign cell slots to a channelassign cell slots to a channel

•• The Ordinal Position Number (TimeThe Ordinal Position Number (TimeDivision) domainDivision) domain–– Cell slots for a channel are nearly uniformlyCell slots for a channel are nearly uniformly

spaced throughout a framespaced throughout a frame

•• A simple-to-implement transformA simple-to-implement transformtranslates cell slot assignment addressestranslates cell slot assignment addressesfrom one domain to the otherfrom one domain to the other

[IEEE 802.16mp-00/05]2000-01-13



Element Address DomainElement Address Domain

•• Each Element Address denotes a singleEach Element Address denotes a singlecell slot within a framecell slot within a frame

•• An entire frame can be divided intoAn entire frame can be divided intopartitions of contiguous elementpartitions of contiguous elementaddresses, each of which denotes aaddresses, each of which denotes aparticular class of serviceparticular class of service

•• Each partition can be subdivided intoEach partition can be subdivided intoindividual channelsindividual channels

[IEEE 802.16mp-00/05]2000-01-13



EAs

Signaling

CBR

Voice

Spare

IP

VBR

TDM Frame

Signaling CBR Voice Spare IP VBR

MAC Sublayer - Partition Assignment (Element Address) Domain

PHY Layer - Time Division Mulitplex (Ordinal Position Number) Domain

Element Address / OrdinalElement Address / OrdinalPosition Number ExamplePosition Number Example

[IEEE 802.16mp-00/05]2000-01-13



Channels Embedded inChannels Embedded inCBR PartitionCBR Partition

CBR

EAs

TDM Frame

MAC Sublayer - Partition & Channel Assignment (Element Address) Domain

PHY Layer - Time Division Mulitplex (Ordinal Position Number) Domain

All CBR

CBR:1

CBR:8

CBR:2

CBR:3

CBR:4

CBR:5

CBR:6

CBR:7

[IEEE 802.16mp-00/05]2000-01-13



Technique can be applied toTechnique can be applied toFDD, TDD and H-TDDFDD, TDD and H-TDD

In TDD and H-FDD, domains areIn TDD and H-FDD, domains arepartitioned in time as well as bypartitioned in time as well as by

Element AddressElement Address

[IEEE 802.16mp-00/05]2000-01-13



The Two-Unit Case WithThe Two-Unit Case WithSynchronized SchedulersSynchronized Schedulers

I/O

I/O

I/O

I/O

Scheduler

Link I/O

I/O

I/O

I/O

I/O

Scheduler

Link I/O

[IEEE 802.16mp-00/05]2000-01-13



Common Signaling ChannelCommon Signaling Channel

Using a Common Signaling Channel Using a Common Signaling Channel

within a TDM environmentwithin a TDM environment

increasesincreases

bandwidth utilization efficiencybandwidth utilization efficiency

[IEEE 802.16mp-00/05]2000-01-13




•• A Base Station to Subscriber StationA Base Station to Subscriber StationCommon Signaling Channel is usedCommon Signaling Channel is usedfor basic system controlfor basic system control

•• It need be of the order of 2% to 4% ofIt need be of the order of 2% to 4% oftotal base station payload bandwidthtotal base station payload bandwidth

•• Channel BER is engineered to beChannel BER is engineered to beless than 10less than 10-11-11

[IEEE 802.16mp-00/05]2000-01-13




•• Subscriber Station to Base StationSubscriber Station to Base Station

Common Signaling Channel is sharedCommon Signaling Channel is shared

among all Subscriber Stations under Baseamong all Subscriber Stations under Base

Station control, i.e., access to theStation control, i.e., access to the

upstream Common Signaling Channel isupstream Common Signaling Channel is

controlled by Base Station assignmentscontrolled by Base Station assignments

[IEEE 802.16mp-00/05]2000-01-13



Proposed Common SignalingProposed Common SignalingChannel Message FormatChannel Message Format

•• Goals:Goals:

–– to assure robust system operationto assure robust system operation(synchronization and error control)(synchronization and error control)

–– to minimize required control messagingto minimize required control messagingbandwidthbandwidth

–– to provide flexibility for meeting futureto provide flexibility for meeting futureneeds without major modificationneeds without major modification

[IEEE 802.16mp-00/05]2000-01-13



Possible Message FormatPossible Message Format

FC 3 2 b i t s

FC = Message Framing Control BitSet to 0 if following bits are start of messageSet to 1 if following bits are message continuation

Message Bits

Message Frame

0 1 0 B y t e 1 B y t e 2 B y t e 3 B y t e 4 B y t e 5 B y t e 6 B y t e 7 B y t e 8

2-Frame Message (5-8 bytes)

Type Start SSID Bandwidth

2 bits 14 bits 8 bits 8 bits

Basic Bandwidth Control Message

Type Field 00 – Bandwidth Control Message (downstream) 01 – Bandwidth Control Message (upstream) 10 – General Message (downstream) 11 – General Message (upstream)

SSID – Sublayer Service IDBandwidth – Number of increments for partition

identified by SSIDStart – Channel start Element Address (in partition

bandwidth increments) after partitionboundary

[IEEE 802.16mp-00/05]2000-01-13



Rationale for FormatRationale for Format

•• Most messages will be bandwidthMost messages will be bandwidthallocation messagesallocation messages

•• For CSC bandwidth = 3% total,For CSC bandwidth = 3% total,one bit per 33 bits = 0.09% of totalone bit per 33 bits = 0.09% of total–– Note: The amount of bandwidth devoted to CommonNote: The amount of bandwidth devoted to Common

Signaling Channel is an integer multiple of 33 bytes perSignaling Channel is an integer multiple of 33 bytes perframe. For example, for an 8 msec frame, it would be anframe. For example, for an 8 msec frame, it would be aninteger multiple of 33,000 bps.integer multiple of 33,000 bps.

[IEEE 802.16mp-00/05]2000-01-13



Suggested DownstreamSuggested DownstreamError Detection ApproachError Detection Approach

•• Send a 32-bit CRC at fixed periods (e.g.,Send a 32-bit CRC at fixed periods (e.g.,once each millisecond)once each millisecond)

•• Advantages:Advantages:–– More robust error control than 16-bit More robust error control than 16-bit CRCs CRCs perper

messagemessage–– More bandwidth efficient than 16-bit More bandwidth efficient than 16-bit CRCs CRCs perper

messagemessage–– For ~ 1 Mbps Common Signaling Channel, thisFor ~ 1 Mbps Common Signaling Channel, this

error control method uses only 32 Kbps. Forerror control method uses only 32 Kbps. Foran aggregate 50 Mbps payload bandwidth, thisan aggregate 50 Mbps payload bandwidth, thisamounts to only 0.06% of bandwidthamounts to only 0.06% of bandwidth

[IEEE 802.16mp-00/05]2000-01-13



MAC Sublayer /MAC Sublayer /PHY Interface SchematicPHY Interface Schematic

Channel ID – 15 bits 1

Send/Receive Clock/Channel ID

Bandwidth-On-Demand

MAC Sublayer

PHY Layer

Send Clock/ Frame

Receive Data Common

Signaling

Channel

API Request Receive

Clock/ Frame

Send Data

API Response

Upper MAC and Network Layers

Framing Bit

[IEEE 802.16mp-00/05]2000-01-13



Role of the PHY LayerRole of the PHY Layer

To transfer primitive data elements To transfer primitive data elements

sent across the MAC/PHY interfacesent across the MAC/PHY interface

from one end of a physicalfrom one end of a physical

connection to anotherconnection to another

[IEEE 802.16mp-00/05]2000-01-13



Primitive Data Elements:Primitive Data Elements:How big?How big?

•• The size of primitive data elementsThe size of primitive data elementsis a critical parameter affectingis a critical parameter affectingBWA system performanceBWA system performance

•• Few physical constraints existFew physical constraints existdownstream for PHYdownstream for PHY

•• Practical modem constraints existPractical modem constraints existupstream for PHYupstream for PHY

[IEEE 802.16mp-00/05]2000-01-13



Primitive Data Elements: How Big?

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1 10 100 1,000Payload Fragment Size (Bytes)

Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1.0

10.0

100.0

1,000.0

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512

12

48

Sum of Guard Time Plus Preamble

48 1,024

0.2

0.5

2

5

20

50

20

500.125

0.25

0.5

97%

(Bytes)

PHY Parameters

[IEEE 802.16mp-00/05]2000-01-13




0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1.0

10.0

100.0

1,000.0

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512

12

48


48 1,024

0.2

0.5

2

5

20

50

20

500.125

0.25

0.5

97%

64 Kbs

0.125

0.5 msec

1.0 msec

6.0 msec

(Bytes)

PHY Parameters

[IEEE 802.16mp-00/05]2000-01-13




0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1.0

10.0

100.0

1,000.0

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512

12

48


48 1,024

0.2

0.5

2

5

20

50

20

500.125

0.25

0.5

97%

64 Kbs

32 Kbs

0.25 msec

0.1 msec

2.0 msec

12.0 msec

(Bytes)

PHY Parameters

[IEEE 802.16mp-00/05]2000-01-13




0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1.0

10.0

100.0

1,000.0

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512

12

48


48 1,024

0.2

0.5

2

5

20

50

20

500.125

0.25

0.5

97%

64 Kbs

32 Kbs

0.5 msec

0.2 msec

4.0 msec

24.0 msec

16 Kbs

(Bytes)

PHY Parameters

[IEEE 802.16mp-00/05]2000-01-13




0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1.0

10.0

100.0

1,000.0

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512

12

48


48 1,024

0.2

0.5

2

5

20

50

20

500.125

0.25

0.5

97%

64 Kbs

32 Kbs1.0 msec

0.4 msec

8.0 msec

48.0 msec

16 Kbs

8 Kbs

(Bytes)

PHY Parameters

[IEEE 802.16mp-00/05]2000-01-13




0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1.0

10.0

100.0

1,000.0

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512

12

48


48 1,024

0.2

0.5

2

5

20

50

20

500.125

0.25

0.5

97%

64 Kbs

32 Kbs

16 Kbs

8 Kbs

48-byte Fragment(6 – 48 msec)

(Bytes)

PHY Parameters

[IEEE 802.16mp-00/05]2000-01-13




0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1.0

10.0

100.0

1,000.0

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512

12

48


48 1,024

0.2

0.5

2

5

20

50

20

500.125

0.25

0.5

97%

64 Kbs

32 Kbs

16 Kbs

8 Kbs



(Bytes)

PHY Parameters

[IEEE 802.16mp-00/05]2000-01-13




0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1.0

10.0

100.0

1,000.0

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512

12

48


48 1,024

0.2

0.5

2

5

20

50

20

500.125

0.25

0.5

97%

64 Kbs

32 Kbs

16 Kbs

8 Kbs



4-byte Fragment(0.5 – 4 msec)

(Bytes)

PHY Parameters

[IEEE 802.16mp-00/05]2000-01-13




0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1.0

10.0

100.0

1,000.0

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512

12

48


48 1,024

0.2

0.5

2

5

20

50

20

500.125

0.25

0.5

97%

64 Kbs

32 Kbs

16 Kbs

8 Kbs





(Bytes)

PHY Parameters

[IEEE 802.16mp-00/05]2000-01-13




0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

1.0

10.0

100.0

1,000.0

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512

12

48


48 1,024

2

5

20

50

200

5000.125

0.25

0.5

97%

78.5 msec48.0 msec

12.1 msec8.0 msec

6.0 msec4.0 msec

1.5 msec1.0 msec

8.0 Kbs

5.3 Kbs

(Bytes)

PHY Parameters

[IEEE 802.16mp-00/05]2000-01-13



PHY Layer Primitive DataPHY Layer Primitive DataElement Size ConstraintsElement Size Constraints

•• Small primitive data element size isSmall primitive data element size isnecessary fornecessary for

–– low latency voice supportlow latency voice support

–– minimizing bandwidth required forminimizing bandwidth required formaintaining Subscriber Stationmaintaining Subscriber Stationsynchronization and transmitter powersynchronization and transmitter powercontrolcontrol

[IEEE 802.16mp-00/05]2000-01-13



PHY Layer Primitive DataPHY Layer Primitive DataElement Size ConstraintsElement Size Constraints

•• No substantial primitive data elementNo substantial primitive data elementsize constraints downstream — sizesize constraints downstream — sizecan be one bytecan be one byte

•• Upstream primitive data element sizeUpstream primitive data element sizeconstrained by a tradeoff betweenconstrained by a tradeoff betweenminimum burst size and requiredminimum burst size and requiredguard time plus burst preambleguard time plus burst preamble

[IEEE 802.16mp-00/05]2000-01-13



Role of the MACRole of the MAC

To multiplex data flows To multiplex data flows

to and fromto and from

a diverse set ofa diverse set of

sources and sinkssources and sinks

and connect them to the PHY Layerand connect them to the PHY Layer

[IEEE 802.16mp-00/05]2000-01-13



Primitive Data Elements:Primitive Data Elements:How big?How big?

•• The size of primitive data elementsThe size of primitive data elementsis a critical parameter affectingis a critical parameter affectingBroadband Wireless Access systemBroadband Wireless Access systemperformanceperformance

•• MAC multiplexing methodology is keyMAC multiplexing methodology is key

•• Current Packet/Cell based multiplexingCurrent Packet/Cell based multiplexingdoes not efficiently support low speeddoes not efficiently support low speedvoice channels or power monitoring andvoice channels or power monitoring andcontrolcontrol

[IEEE 802.16mp-00/05]2000-01-13



Bandwidth Efficiency versus Payload Fragment Size forMAC Header Sizes of 1, 2, 4 & 8 Bytes

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1

10

100

1000

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512

Headerless Bandwidth-On-Demand Efficiency

12

48

MAC Header Sizes

48 1024

0.2

0.5

2

5

20

50

200

50096 %

MAC Parameters

[IEEE 802.16mp-00/05]2000-01-13



0.2

0.5

2

5

20

50

Bandwidth Efficiency and Buffer Delay for 64 Kbps Channel

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1

10

100

1000

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512482 41 8 16 32 64 128 256 51248 1024

0.2

0.5

2

5

20

50

200

500

2 41 8 16 32 64 128 256 512


12

48

MAC Header Sizes

48

64 Kbps

1024

0.2

0.5

2

5

20

50

6 msec

1 msec

0.5 msec

0.125 msec

200

50096 %

MAC Parameters

[IEEE 802.16mp-00/05]2000-01-13



0.2

0.5

2

5

20

50

200

Bandwidth Efficiency and Buffer Delay for32 & 64 Kbps Channels

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1

10

100

1000

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 51248 1024

0.2

0.5

2

5

20

50

200

500

2 41 8 16 32 64 128 256 512


12

48

MAC Header Sizes

48

64 Kbps

1024

0.2

0.5

2

5

20

50

12 msec

2 msec

1 msec

0.25 msec

32 Kbps

200

500

96 %

MAC Parameters

[IEEE 802.16mp-00/05]2000-01-13



0.2

0.5

2

5

20

50

200

500

Bandwidth Efficiency and Buffer Delay for16, 32 & 64 Kbps Channels

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1

10

100

1000

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512


12

48

MAC Header Sizes

48

64 Kbps

1024

0.2

0.5

2

5

20

50

24 msec

4 msec

2 msec

.5 msec

32 Kbps

16 Kbps

200

500

96 %

MAC Parameters

[IEEE 802.16mp-00/05]2000-01-13



Bandwidth Efficiency and Buffer Delay for8, 16, 32 & 64 Kbps Channels

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1

10

100

1000

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512


12

48

MAC Header Sizes

48

64 Kbps

1024

0.2

0.5

2

5

20

5048 msec

8 msec

4 msec

1 msec

32 Kbps

16 Kbps

200

500

8 Kbps

96 %

MAC Parameters

[IEEE 802.16mp-00/05]2000-01-13



0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1

10

100

1000

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512


12

48

MAC Header Sizes

48

64 Kbps

1024

0.2

0.5

2

5

20

50

32 Kbps

16 Kbps

200

500

8 Kbps

96 %



MAC Parameters

[IEEE 802.16mp-00/05]2000-01-13



0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1

10

100

1000

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512


12

48

MAC Header Sizes

48

64 Kbps

1024

0.2

0.5

2

5

20

50

32 Kbps

16 Kbps

200

500

8 Kbps

96 %




MAC Parameters

[IEEE 802.16mp-00/05]2000-01-13



0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1

10

100

1000

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512


12

48

MAC Header Sizes

48

64 Kbps

1024

0.2

0.5

2

5

20

50

32 Kbps

16 Kbps

200

500

8 Kbps

96 %





MAC Parameters

[IEEE 802.16mp-00/05]2000-01-13



0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

0.1

1

10

100

1000

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512


12

48

MAC Header Sizes

48

64 Kbps

1024

0.2

0.5

2

5

20

50

32 Kbps

16 Kbps

200

500

8 Kbps

96 %






MAC Parameters

[IEEE 802.16mp-00/05]2000-01-13



0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Per

cen

t B

and

wid

th E

ffic

ien

cy

1

10

100

1000

Serial B

uffer D

elay (msec)

2 41 8 16 32 64 128 256 512


12

48

MAC Header Sizes

48

6 msec

8 Kbps

48 msec

5.3 Kbps

72.5 msec8 Kbps

8 msec12.1 msec

4 msec6.0 msec

1 msec1.5 msec

1024

2

5

20

50

200

500

Bandwidth Efficiency and Buffer Delay for5.3, 6.3 & 8 Kbps Channels

MAC Parameters

[IEEE 802.16mp-00/05]2000-01-13



MAC Layer Size ConstraintsMAC Layer Size Constraints

•• A major constraint on data elementA major constraint on data elementsize is a tradeoff between MACsize is a tradeoff between MACheader size and payload sizeheader size and payload size

•• Efficiency is adversely affected byEfficiency is adversely affected bythe need for control packets thatthe need for control packets thatdelineate bandwidth-control mapsdelineate bandwidth-control maps

[IEEE 802.16mp-00/05]2000-01-13



Factors AffectingFactors AffectingBandwidth EfficiencyBandwidth Efficiency

•• PHY guard time and preamblePHY guard time and preambleoverheadoverhead

•• MAC header and control packetMAC header and control packetoverheadoverhead

•• Efficiency of asynchronous queuesEfficiency of asynchronous queues

[IEEE 802.16mp-00/05]2000-01-13



Asynchronous QueuingAsynchronous Queuing•• Random queues without effective flowRandom queues without effective flow

control produce unacceptable delays orcontrol produce unacceptable delays orpacket/cell discardpacket/cell discard

•• Source flow control (bandwidthSource flow control (bandwidthmanagement) is the most effective way ofmanagement) is the most effective way ofassuring QoS and efficient use ofassuring QoS and efficient use ofbandwidthbandwidth

•• A Bandwidth-On-Demand MAC Sublayer isA Bandwidth-On-Demand MAC Sublayer isa simple, efficient, generic flow controla simple, efficient, generic flow controlmechanismmechanism

[IEEE 802.16mp-00/05]2000-01-13



Best-of-Breed ApproachBest-of-Breed Approach

•• Use Use shortshort fixed length “cell slots” fixed length “cell slots”that are assigned to channels usingthat are assigned to channels usingElement Address to Ordinal PositionElement Address to Ordinal PositionNumber domain transformationNumber domain transformation

•• Use Common Signaling Channel toUse Common Signaling Channel tocontrol bandwidth assignments andcontrol bandwidth assignments andfor system managementfor system management

[IEEE 802.16mp-00/05]2000-01-13



What’s the ProblemWhat’s the Problem

•• The approach works great forThe approach works great fordownstream traffic — cell slots candownstream traffic — cell slots canbe one byte longbe one byte long

•• BUT … there is no short burstBUT … there is no short burstmodem that exists with small guardmodem that exists with small guardtime and preamble requirementstime and preamble requirements

•• Also …Also …

[IEEE 802.16mp-00/05]2000-01-13



The DilemmaThe Dilemma

•• Current Broadband Wireless AccessCurrent Broadband Wireless Accesscustomers are not clamoring for lowcustomers are not clamoring for lowspeed channel supportspeed channel support

•• However, Broadband WirelessHowever, Broadband WirelessAccess customer needs will likelyAccess customer needs will likelychange in the near future (probablychange in the near future (probablyat Internet speed)at Internet speed)

[IEEE 802.16mp-00/05]2000-01-13



Proposed Next GenerationProposed Next GenerationBroadband Wireless AccessBroadband Wireless Access

System ApproachSystem ApproachStandard based on aStandard based on a

Bandwidth-on-DemandBandwidth-on-DemandMAC SublayerMAC Sublayer

[IEEE 802.16mp-00/05]2000-01-13



Proposed First ApproachProposed First Approach

•• Use current burst size modems toUse current burst size modems toaggregate upstream traffic usingaggregate upstream traffic usingfixed length microframes (that are offixed length microframes (that are ofthe order of 1 msec long or less)the order of 1 msec long or less)

•• The multiplexing functionality for aThe multiplexing functionality for aSubscriber Station is the same as forSubscriber Station is the same as forthe Base Station (except for control)the Base Station (except for control)

[IEEE 802.16mp-00/05]2000-01-13



Proposed First ApproachProposed First Approach

•• Within each microframe period,Within each microframe period,aggregate traffic from eachaggregate traffic from eachSubscriber Station into variableSubscriber Station into variablelength packetslength packets

•• Since there are a fixed number of cellSince there are a fixed number of cellslots in a frame, the variable lengthslots in a frame, the variable lengthpackets always fit within the timepackets always fit within the timeallottedallotted

[IEEE 802.16mp-00/05]2000-01-13



Single UpstreamSingle UpstreamAggregated Traffic ExampleAggregated Traffic Example

CBR:2

CBR:4

Voice:1

Voice:3

Voice:5

IP:4

IP:6

IP:7

VBR:2

Composite

Compressed Variable-Length

Packets

Uncompressed Output at Base

Station

Previous Microframe -1

Previous Microframe -1

Previous Microframe - 2

[IEEE 802.16mp-00/05]2000-01-13



BenefitsBenefits

•• Provides efficient use of bandwidthProvides efficient use of bandwidthfor (multiple) low speed channels asfor (multiple) low speed channels aswell as high speed channelswell as high speed channels

•• Provides an infrastructure that canProvides an infrastructure that canquickly move to voice-centric low-quickly move to voice-centric low-aggregate bandwidth markets whenaggregate bandwidth markets whennext generation modems arenext generation modems areavailableavailable

[IEEE 802.16mp-00/05]2000-01-13



Proposed Reference ModelProposed Reference Model

Bandwidth-On-Demand MAC Sublayer

STM Convergence

ATM Convergence

IP 802 Convergence

802.16 MAC Convergence

Frame Relay Convergence

PHY Layer

MPEG Video Convergence

Proposed First Applications Future Applications Examples

[IEEE 802.16mp-00/05]2000-01-13



The Unmet Market NeedThe Unmet Market Need

Support for low speed channelsSupport for low speed channels

[IEEE 802.16mp-00/05]2000-01-13



Market FactsMarket Facts

•• Wireless telephones are becoming theWireless telephones are becoming theaccess method of choice for all voiceaccess method of choice for all voicecommunicationcommunication

•• Internet access is being integrated intoInternet access is being integrated intowireless telephoneswireless telephones

•• Estimated wireless telephones in useEstimated wireless telephones in use•• (estimates provided by UMTS)(estimates provided by UMTS)

–– 1 billion by 2005 (77 million data)1 billion by 2005 (77 million data)–– 1.8 billion by 2010 (?? data)1.8 billion by 2010 (?? data)

[IEEE 802.16mp-00/05]2000-01-13



What Are MajorWhat Are MajorCell-phone Vendors Doing?Cell-phone Vendors Doing?

•• Adding LAN wireless capabilityAdding LAN wireless capabilitywithin Cellular Telephones forwithin Cellular Telephones forpremises Voice/Internet accesspremises Voice/Internet access

•• Voice traffic will be supported byVoice traffic will be supported by–– Cellular wireless sites for mobile users,Cellular wireless sites for mobile users,

BUT …BUT …–– LAN wireless (802.11 / Bluetooth) forLAN wireless (802.11 / Bluetooth) for

premises accesspremises access

[IEEE 802.16mp-00/05]2000-01-13



The Emerging Voice MarketThe Emerging Voice Market

•• Cellular telephones (includingCellular telephones (includingwireless LAN capability) will drive thewireless LAN capability) will drive themarketmarket

•• The largest growth markets areThe largest growth markets areprojected to be Asia and Southprojected to be Asia and SouthAmerica … BUT …America … BUT …

[IEEE 802.16mp-00/05]2000-01-13



The Emerging Voice MarketThe Emerging Voice Market

•• In these markets wireline to premisesIn these markets wireline to premisesconnections are insufficient to supportconnections are insufficient to supportprojected growth and are costly to installprojected growth and are costly to install

•• Cellular telephone base stations areCellular telephone base stations areexpensive and provide limited dataexpensive and provide limited databandwidthbandwidth

Fixed wireless has a singular opportunityFixed wireless has a singular opportunityto fill the void for both business &to fill the void for both business &

residenceresidence

[IEEE 802.16mp-00/05]2000-01-13



A Potential Logic TrapA Potential Logic Trap

•• Premise:Premise:

Since data traffic will predominate Since data traffic will predominate

within communication networks,within communication networks,

it is not important to worry aboutit is not important to worry about

network efficiency for voice trafficnetwork efficiency for voice traffic

[IEEE 802.16mp-00/05]2000-01-13



Backbone vs. Fixed WirelessBackbone vs. Fixed WirelessDistribution NetworksDistribution Networks

•• The premise is probably OK forThe premise is probably OK forbackbone networks that aggregatebackbone networks that aggregatetraffic from many sourcestraffic from many sources

•• The premise The premise maymay be true for some be true for somedistribution network marketsdistribution network markets

•• It is clearly It is clearly notnot true for many others true for many otherswhere voice will predominate for thewhere voice will predominate for theforeseeable future.foreseeable future.

[IEEE 802.16mp-00/05]2000-01-13



To assure its long-term success,To assure its long-term success,the 802.16 standardthe 802.16 standardmust address both:must address both:

Broadband-dominated marketsBroadband-dominated marketsVoice-dominated marketsVoice-dominated markets

[IEEE 802.16mp-00/05]2000-01-13



Broadband DominatedBroadband DominatedMarketMarket

Base Station

[IEEE 802.16mp-00/05]2000-01-13



Voice Dominated MarketVoice Dominated Market

[IEEE 802.16mp-00/05]2000-01-13



Local Subscriber StationLocal Subscriber StationAccessAccess

Subscriber Station

802.11 /

BluetoothEthernet DSL

Voice Data Remote

[IEEE 802.16mp-00/05]2000-01-13



The Good NewsThe Good News Only Fixed Wireless can satisfyOnly Fixed Wireless can satisfy

fast-growing voice dominated marketsfast-growing voice dominated markets

•• Cellular telephone base stations are notCellular telephone base stations are notenoughenough

•• Wireline infrastructure to supportWireline infrastructure to supportprojected growth does not existprojected growth does not exist

•• Wireline infrastructure will be expensiveWireline infrastructure will be expensive(or impractical) to install(or impractical) to install

[IEEE 802.16mp-00/05]2000-01-13



SummarySummary

•• A Bandwidth-on-Demand Sublayer isA Bandwidth-on-Demand Sublayer isimportant to the future of Broadbandimportant to the future of BroadbandWireless SystemsWireless Systems

•• An untapped market exists that canAn untapped market exists that canbecome a major application forbecome a major application forBroadband WirelessBroadband Wireless

[IEEE 802.16mp-00/05]2000-01-13



Proposed ProgramProposed Program

•• Form an (ad hoc) task group to formulateForm an (ad hoc) task group to formulateplan to develop an efficient short-burstplan to develop an efficient short-burstmodemmodem

•• Develop draft PHY standard based onDevelop draft PHY standard based onBandwidth-On-Demand MAC Sublayer forBandwidth-On-Demand MAC Sublayer for–– Aggregated upstream traffic with variable-Aggregated upstream traffic with variable-

length burst modemslength burst modems–– Non-aggregated traffic with short-burstNon-aggregated traffic with short-burst

modemsmodems

[IEEE 802.16mp-00/05]2000-01-13



Additional InformationAdditional Information

Two other (annotated) PowerPoint presentations are available that Two other (annotated) PowerPoint presentations are available thatfurther describe the proposed approach. To receive thesefurther describe the proposed approach. To receive these

presentations or other descriptive material, please contact:presentations or other descriptive material, please contact:

Ray Sanders at Ray Sanders at [email protected]@CircuitPath.com

2000-01-13 working group on broadband wireless access · 2000. 11. 21. · 2000-01-13 [ieee...

Documents