Enhanced Uplink Dedicated ChannelEnhanced Uplink … · High Speed Uplink Packet Access (HSUPA) ... E-DCHisaRelDCH is a Rel-6featurewithfollowingtargets6 feature with following targets

Enhanced Uplink Dedicated Channel (EDCH)Enhanced Uplink Dedicated Channel (EDCH)

High Speed Uplink Packet Access (HSUPA)High Speed Uplink Packet Access (HSUPA)

EDCH Background & BasicsChannels/ UTRAN ArchitectureChannels/ UTRAN ArchitecturePrinciples: scheduling, handoverPerformance Results

Background

E DCH is a Rel 6 feature with following targetsE-DCH is a Rel-6 feature with following targetsImprove coverage and throughput, and reduce delay of the uplink dedicated transport channelsPriority given to services such as streaming, interactive and background services, conversational (e.g. VoIP) also to be consideredFull mobility support with optimizing for low/ medium speedSimple implementationSpecial focus on co-working with HSDPA

Standardization started in September 2002Study item completed in February 2004Stage II/ III started in September/ December 2004Release 6 frozen in December 2005/ March 2006Various improvements have been introduced in Rel-7 & Rel-8p

UMTS Networks 2Andreas Mitschele-Thiel, Jens Mückenheim Nov. 2009

E-DCH Basics

E DCH is a modification of DCH Not a shared channel such asE-DCH is a modification of DCH – Not a shared channel, such as HSDPA in the downlink !!

PHY taken from R99PHY taken from R99Turbo coding and BPSK modulationPower Control

/10 msec/ 2 msec TTISpreading on separate OVSF code, i.e. code mux with existing PHY channels

MAC similarities to HSDPAFast schedulingStop and Wait HARQ: but synchronous

New principlesp pIntra Node B “softer” and Inter Node B “soft” HO should be supported for the E-DCH with HARQScheduling distributed between UE and NodeB


E-DCH Scheduling

UE NodeB

Scheduling information

DATA

UE detects data in buffer

Scheduling informationScheduler takes UE for scheduling

Scheduling grant

UE sends scheduling information

MAC e signaling

Scheduling grant

Scheduling grantMAC-e signaling

On E-DPCCH: “happy bit”

NodeB allocates the resources

Ab l t / l ti h d li t

Scheduling information

Scheduling grant

Absolute/ relative scheduling grants

Algorithms left open from standards

Depending on the received grants, UE decides on transmission

ll d b f lMaintains allocated resources by means of internal serving grants

Selects at each TTI amount of E-DCH data to transmit

Algorithms fully specified by UMTS standard


E-DCH Scheduling Principle

E-DCH scheduler constraintUL Load UL Load Keep UL load within the limitScheduler controls:

E-DCH load portion from non-serving users of other cellsS i

UL Load target

UE #m

serving users of other cellsE-DCH resources from each serving user of own cell

Non E-DCH load portion

Serving E-DCH users

UE #1 Non E DCH load portionDCH, RACH, HS-DPCCHMay include non-scheduled E-DCHControlled by legacy load control,

Non-serving E-DCH users

y g y ,e.g. Admission/ Congestion control

Notes: E-DCH users transmit

h l

Non E-DCH

asynchronouslyEach UE owns whole code tree


UMTS Channels with E-DCH

C ll 1 C ll 2Cell 1

UEUE

Cell 2= Serving

E-DCH cell

R99 DCH (in SHO)UL/DL signalling (DCCH)UL/DL CS voice/ data

Rel-6 E-DCH (in SHO)UL PS service (DTCH) UL/DL CS voice/ data

Rel-5 HS-DSCH (not shown)DL PS service (DTCH)DL signalling (Rel 6 DCCH)

UL PS service (DTCH)UL Signalling (DCCH)


DL signalling (Rel-6, DCCH)

E-DCH Channels

E DPDCHE-DPDCHCarries the data trafficVariable SF = 256 … 2UE supports up to 4 E-DPDCH

E-DPCCHContains the configuration as used on E-DPDCHContains the configuration as used on E DPDCHFixed SF = 256

E RGCH/ E HICHE-RGCH/ E-HICHE-HICH carries the HARQ acknowledgementsE-RGCH carries the relative scheduling grantsg gFixed SF = 128Up to 40 users multiplexed onto the same channel by using specific signaturessignatures

E-AGCHCarries the absolute scheduling grants

d


Fixed SF = 256

Timing Relation (UL)

CFN+1 Downlink DPCH CFN

Uplink DPCCH CFN

15 × Tslot (10 msec)0.4 × Tslot (1024 chips) p

E-DPDCH/E DPCCH

10 msec

±148chips

10 msec TTI

Subframe #0 E-DPCCH

3 × Tslot (2 msec)

Subframe #1 Subframe #2 Subframe #3 Subframe #4 2msec TTI

E-DPDCH/ E-DPCCH time-aligned to UL DPCCH


HSUPA UE Categories

E-DCH Category

Max. num.Codes

Min SF EDCH TTI Maximum MAC-e TB size

Theoretical maximum PHY data rate (Mbit/s)

Category 1 1 SF4 10 msec 7110 0.71

Category 2 2 SF4 10 msec/2 msec

14484/2798

1.45/1.4


Category 4 2 SF2 10 msec/2 msec

20000/5772

2.0/2 892 msec 5772 2.89


Category 6 4 SF2 10 msec/ 20000/ 2 0/Category 6 4 SF2 10 msec/2 msec

20000/11484

2.0/5.74

Category 7(Rel 7)

4 SF2 10 msec/2 msec

20000/22996

2.0/11 5

When 4 codes are transmitted, 2 codes are transmitted with SF2 and 2 with SF4

(Rel.7) 2 msec 22996 11.5


,UE Category 7 supports 16QAM

E-DCH UTRAN Architecture

RRC PDCPSRNCEvolution from Rel-5

RLC

Logical Channels BCCHDCCHDTCH

• E-DCH functionality is intended for transport of dedicated logical channels (DTCH/ DCCH)

MAC-d

DCH

channels (DTCH/ DCCH)

MAC-d flows

MAC-es

MAC-d flows

E-DCH in Rel-6

• Additions in RRC to

MAC-c/sh

CRNC Upper phy

o M

AC

-c/s

hconfigure E-DCH

• RLC unchanged(UM & AM)

MAC-b

NodeBMAC-hs

w/o

MAC-e

• New MAC-es entity with link to MAC-d

• New MAC-e entity located

Transport Channels BCHDSCHFACHHS-DSCHEDCH

in the Node B

• MAC-e entities from multiple NodeB may serve

UE ( ft HO)


one UE (soft HO)

MAC-e/es in UE

MAC-e/es FunctionsPriority handling

Per logical channelMAC-es/e

MAC – Control To MAC-d

MultiplexingE-TFC Selection

MultiplexingMAC-d flow concept

HARQ

MultiplexingE-TFC Selection

Mux of data from multiple MAC-d flows into single MAC-e PDU

SchedulingMaintain scheduling grant

Associated Uplink Signalling:

Associated Scheduling Downlink Signalling

(E-AGCH / E-RGCH(s))

Associated ACK/NACK UL data

(E-DPDCH)

E-TFC selectionHARQ handling

E-TFCI, RSN, happy bit(E-DPCCH)

signaling (E-HICH)


Cf. 25.309

MAC-e in NodeB

MAC-e FunctionsPer user

HARQ handling:

MAC-d Flows

ACK/ NACK generationDe-multiplexingE DCH t lMAC Control

UE #2

UE #N

UE #1 E-DCH control:Rx/ Tx control signals

MAC – Control

De-multiplexing

E-DCH Control

E-DCH Scheduling

UE #1

E-DCH scheduling for all users

Assign resources

HARQ entity

Assign resources (scheduling grants)

Iub overload control

MAC-e

E-DCH


Cf. 25.309Associated Downlink Signalling

Associated Uplink

Signalling Common RG

MAC-es in SRNC

To MAC-d

MAC-es

MAC C t l

MAC-es Functions

Queue distribution

MAC – Control

Disassembly

Disassembly

Reordering/

Combining

Disassembly

Reordering/ Combining

Reordering/ Combining

Reordering

Per logical channel

Reordering Queue Distribution

Reordering Queue Distribution

Co b g Co b g Co b g

In-sequence delivery

Macro-diversity combining:

MAC-d flow #1 MAC-d flow #n

gframe selection

Disassembly

From From

Disassembly


MAC-e in NodeB #1

MAC-e in NodeB #k Cf. 25.309

Data Flow through Layer 2

RLCDATAHeader

DATA

RLC PDU:

MAC-d PDU:

RLC

MAC-d

DDI: Data Description Indicator (6bit)

MAC-d PDU sizeDATAMAC d PDU:

MAC-e/es TSN DATA DATA MAC-es PDU:

Log. Channel ID

Mac-d flow ID

N N b f MAC d PDU

DDI N Padding DDI N DATADDI DATA

N: Number of MAC-d PDUs (6bit)

TSN: Transmission Sequence

MAC-es PDU MAC-e header

(Opt)

MAC-e PDU:

Number (6bit)

DATAPHY


Hybrid ARQ Operation

N-channel parallel HARQ with stop-and-wait protocolNumber of HARQ processes N to allow uninterrupted E-DCH transmission

10 msec TTI: 42 msec TTI: 8

Synchronous retransmissionsyRetransmission of a MAC-e PDU follows its previous HARQ (re)transmission after N TTI = 1 RTTIncremental Redundancy via rate matching

Max. # HARQ retransmissions specified in HARQ profile

ACK

ACK

ACK

NACK

NACK

New Tx 2 New Tx 3 New Tx 4 Re-Tx 1 New Tx 2 Re-Tx 3 New Tx 4 Re-Tx 1 Re-Tx 2New Tx 1

NACK


NACKNACK

E-DCH UE Scheduling

UE maintains internal serving grant SGUE maintains internal serving grant SGSG are quantized Maximum E-DPDCH/ DPCCH power ratio (TPR), which are defined by 3GPPReception of absolute grant: SG = AG

No transmission: SG = “Zero_Grant”Reception of relative grants: increment/ decrement index of SG in the SG p g /tableAG and RG from serving RLS can be activated for specific HARQ processes for 2msec TTIsecUE selects E-TFC at each TTIAllocates the E-TFC according to the given restrictions

S i t SGServing grant SGUE transmit power

Provides priority between the different logical channels


Scheduling Grant Table

Index Scheduled Grant

37 (168/15)2*6

Scheduling grants are max. E-DPDCH/ DPCCH power ratio (TPR –t ffi t il t ti )37 (168/15)2*6

36 (150/15)2*6 35 (168/15)2*4 34 (150/15)2*4 33 (134/15)2*4 32 (119/15)2*4

traffic to pilot ratio)Power Ratio is related to UE data rate

32 (119/15)2*431 (150/15)2*2 30 (95/15)2*4 29 (168/15)2

•

Relative GrantsSG moves up/ down when RG = UP/ DOWN

• •

14 (30/15)2 13 (27/15)2 12 (24/15)2 11 (21/15)2

Absolute GrantsSG jumps to entry for AG

11 (21/15)10 (19/15)2 9 (17/15)2 8 (15/15)2 7 (13/15)2 6 (12/15)2

2 reserved values for ZERO_GRANT/ INACTIVE

6 (12/15)2

5 (11/15)2 4 (9/15)2 3 (8/15)2 2 (7/15)2

2


1 (6/15)2

0 (5/15)2

Rate Scheduling Time Scheduling

E-DCH Scheduling Options

Rate Scheduling Time Schedulingat

e

ate

ra ra

UE2

UE1UE2 UE3 UE1

UE1

UE3

time time

UEs are continuously activeData rate is incremental increased/ decreased by relative scheduling grantsN h b t UE i d

UEs are switched on/ off by absolute scheduling grantsUEs should be in synchL d i ti i ht b lNo synch between UEs required

Load variations can be kept lowFor low to medium data rates

Load variations might be largeFor (verry) high data rates


Timing Relation for Scheduling Grants

Scheduling

E-RGCHE-AGCH

HARQ process number

decision

Load estimation, etc

1 2 3 4 1 2 3 E-DCH

• AG applied to this HARQ process

• RG interpreted relative to the previous TTI in

AG and RG associated with specific uplink E-DCH TTI, i.e. specific HARQ processAssociation based on the timing of the E AGCH and E RGCH

this HARQ process.

Association based on the timing of the E-AGCH and E-RGCH.Timing is tight enough that this relationship is un-ambiguous.Example: 10msec TTI


Scheduling Information

Happy bit signalingHappy bit signalingOne bit status flag send on E-DPCCH at each TTICriterion for happy bitCriterion for happy bit

Set to “unhappy” if UE is able to send more data than given with existing serving grantO h i “h ”Otherwise set to “happy”

Scheduling Information ReportingContent of MAC-e reportContent of MAC e report

Provides more detailed information (log. channel, buffer status, UE power headroom)Will be sent less frequently (e.g. every 100 msec)

Parameters adjusted by RRC (e.g. reporting intervals, channels to report)report)


HSUPA Resource Allocation

Node B resources-decoding capability

Cell resources-Admissible uplink noise rise/load

Capabilities of the UEs-MAC-e PDU size limits

decoding capability-Iub bandwidth capacity

rise/load-CAC via RNC-Number AGCH/RGCH

QoS parameters-Throughput bounds

E-DCH Radio Resource Management “E-RRM”-Keep uplink load within the limit-Control E-DCH load portion from non-serving users of other cells

MAC e PDU size limits-SF limits

Throughput bounds

serving users of other cells-Control E-DCH resources from each serving user of own cell-Satisfy QoS/ GoS requirements (Ranking PF/SW)-Maximize HSUPA cell throughput-Maximize HSUPA cell throughput

Task: assigns Serving Grants (relative or absolute grants) in terms of a power offset to the current DPCCH power to the UEs in order to control the

maximum data ratemaximum data rate

Finally, the UE decides by itself on the used power ratio and the transport


block size taking into account the restrictions sent by Node B

NodeB Scheduling Principle

E-DCH scheduler constraintUL Load UL LoadKeep UL load within the limit

Scheduler controls:

E DCH load portion of non servingS i

UL Load target

UE #m

E-DCH load portion of non-serving users from other cells

E-DCH resources of each serving user of own cell

Serving E-DCH users

UE #1of own cell

Principles:

Rate vs. time scheduling


Dedicated control for serving users

Common control for non-serving users

Non E-DCH

Note: Scheduler cannot exploit fast fading !


Non-scheduled Mode

Configured by the SRNCConfigured by the SRNC

UE is allowed to send E-DCH data at any time

Signaling overhead and scheduling delay are minimizedSignaling overhead and scheduling delay are minimized

Support of QoS traffic on E-DCH, e.g. VoIP & SRB

Characteristics

Resource given by SRNC: Non-scheduled Grant = max. # of bits that can be included in a MAC-e PDU

UTRAN can reserve HARQ processes for non-scheduled transmissionUTRAN can reserve HARQ processes for non-scheduled transmission

Non-scheduled transmissions defined per MAC-d flowMultiple non-scheduled MAC-d flows may be configured in parallel

One specific non-scheduled MAC-d flow can only transmit up to the non-scheduled grant configured for that MAC-d flow

Scheduled grants will be considered on top of non-scheduled Sc edu ed g a ts be co s de ed o top o o sc edu edtransmissions

Scheduled logical channels cannot use non-scheduled grant

Non scheduled logical channels cannot transmit data using Scheduling Grant


Non-scheduled logical channels cannot transmit data using Scheduling Grant

E-DCH Operation in Soft Handover

scheduling grantscheduling grant

UEUE

scheduling grantHARQ ACK/ NACK

scheduling grantHARQ ACK/ NACK

Macro diversity operation on multiple NodeBs

NodeB 1NodeB 1 NodeB 2NodeB 2

Macro-diversity operation on multiple NodeBsSofter handover combining in the same NodeBSoft handover combining in RNC (part of MAC-es)

I d d MAC i i b h N d BIndependent MAC-e processing in both NodeBsHARQ handling rule: if at least one NodeB tells ACK, then ACKScheduling rule: relative grants “DOWN” from any NodeB have

d


precedence

Mobility Handling

The UE uses soft handover for associated DCH as well as for E DCHThe UE uses soft handover for associated DCH as well as for E-DCHUsing existing triggers and procedures for the active set update (events 1A, 1B, 1C)E-DCH active set is equal or smaller than DCH active set

New event 1J: non-active E-DCH link becomes better than active one

The UE receives AG on E-AGCH from only one cell out of the E-DCHThe UE receives AG on E AGCH from only one cell out of the E DCH active set (serving E-DCH cell)

E-DCH and HSDPA serving cell must be the sameH d H d i h f i E DCH llHard Handover, i.e. change of serving E-DCH cellUsing RRC procedures, which maybe triggered by event 1D

Could be also combined with Active Set Update


Mobility Procedures

SRNC SRNC

MAC-es MAC-es

MAC-e MAC-e MAC-e MAC-e

NodeB NodeB NodeB NodeB

S i

s t

Serving E-DCH radio link

Serving E-DCH radio link

Inter-Node B serving E-DCH cell change within E-DCH active setNote: MAC e still established in both NodeBs !


Note: MAC-e still established in both NodeBs !

Serving E-DCH Cell Change

SRNC =

DRNC Target servingE-DCH cell

UE Source servingE-DCH cell

RL Reconfiguration Prepare RL Reconfiguration Ready

Serving E-DCH cell change decision i.e. event 1D

If new NodeB

Synchronous Reconfiguration

RL Reconfiguration Prepare

RL Reconfiguration Ready

RL Reconfiguration CommitRadio Bearer Reconfiguration

Radio Bearer Reconfiguration Complete

with Tactivation RL Reconfiguration Commit RL Reconfiguration Commit

UE receives now AG & dedicated RG from target cell

Handover of E-DCH scheduler controlNo changes in UL transport bearerNo MAC es RESET

Handover of HS-DSCH serving cellDL transport bearer setupMAC hs RESET


No MAC-es RESET MAC-hs RESET

E-DCH RRM Principle

E-DCH resources controlled byUL load targetUL Load UL Load UL load targetE-DCH non-serving load portion

NodeB schedules E-DCH users S i

UL Load target

NodeB schedules E DCH users according to RNC settings

Priority for non E-DCH traffic

Serving E-DCH users

RNC still controls non E-DCH load portion

By means of e.g. admission/ ti t l


congestion controlBased on an estimate of non-EDCH loadNon E-DCH

Non E-DCH load portion


E-DCH Performance & Capacity

E DCH offers improved throughput due toE-DCH offers improved throughput due toHARQ gainFaster scheduling with tighter UL load controlFaster scheduling with tighter UL load control

The additional PHY channels consume resourcesUL load: DPCCH, E-DPCCHDL power/ codes: E-HICH/ E-RGCH, E-AGCH


User Throughput vs. Aggregate Cell Throughput

36 cells network

1000

1200

10ms TTI, unlimited CE dec. rate 2ms TTI, next release 36 cells network

UMTS composite channel model

FTP t ffi d l (2 Mb t

#UEs/cell1

2

800

1000

put [

kbps

]

FTP traffic model (2 Mbyte upload, 30 seconds thinking time)

M i ll th h t

3

4

400

600

Use

r Thr

ough Maximum cell throughput

reached for about 7…8 UEs per cell

Cell throughput drops if #UEs

5678

0

200

200 400 600 800 1000 1200 1400 1600

Cell throughput drops if #UEs increases further since the associated signaling channel consume UL resources too

89

10

200 400 600 800 1000 1200 1400 1600

Aggregated Cell Throughput [kbps]


Single User Performance

Average user throughput (RLC layer) for different 2ms, 1Tx 10ms, 1Tx ( C aye ) o d e echannel profiles

1 UE in the network

1 target HARQ transmission3000

3500

, ,

g Q

For AWGN channel conditions:

10ms TTI: up to 1.7 Mbps 2000

2500

ghpu

t [kb

ps]

p p(near theoretical limit of 1.88 Mbps)

2ms TTI: up to 3 Mbps (b l th ti l li it 5 44

1000

1500

age

User

Thr

ou

(below theoretical limit 5.44 Mbps)

E.g. due to restrictions from RLC layer (window 0

500

Aver

a

y (size, PDU size)

0AWGN PedA3 PedA30 VehA30 VehA120

Scenario


E-DCH Summary

New uplink transmission conceptNew uplink transmission conceptOptimized for interactive, background and streaming, support of conversationalFull support of mobility with optimizing for low/ medium speed

Improved PHY approachNew UL transport channel: E-DCHpAdditional signalling channels to support HARQ and E-DCH scheduling

MAC-e/es entity located in NodeB/ SRNCDistributed E DCH scheduling between UE and NodeBDistributed E-DCH scheduling between UE and NodeBE-DCH supports soft/ softer HO

Radio Resource Control procedures similar to HSDPAE-DCH Resource Management

Cumulated resources managed by Controlling-RNCRe-use of principles for DCH control (handover state transition)Re use of principles for DCH control (handover, state transition)

Significant improved performance


References

PapersPapers

A. Ghosh et al: “Overview of Enhanced Uplink for 3GPP W-CDMA,” Proc. IEEE VTC ’04/ Milan, vol. 4, pp. 2261–2265

H. Holma et al: “HSDPA/ HSUPA for UMTS,” Wiley 2006

Standards

TS 25 xxx series: RAN AspectsTS 25.xxx series: RAN Aspects

TR 25.896: “Feasibility Study for Enhanced Uplink for UTRA FDD”

TR 25.808: “FDD Enhanced Uplink; Physical Layer Aspects”p ; y y p

TR 25.309/ 25.319 (Rel.7 onwards): “(FDD) Enhanced Uplink: Overall Description (Stage 2)”


Abbreviations

ACK (positive) AcknowledgementAG Absolute GrantAM Acknowledged (RLC) ModeAMC Adaptive Modulation & Coding

Mux MultiplexingNACK Negative AcknowledgementNBAP NodeB Application PartOVSF Orthogonal Variable SF (code)AMC Adaptive Modulation & Coding

BO Buffer OccupancyCAC Call Admission ControlCDMA Code Division Multiple AccessDBC Dynamic Bearer Control

OVSF Orthogonal Variable SF (code)PDU Protocol Data UnitPHY Physical LayerPO Power OffsetQoS Quality of ServiceDBC Dynamic Bearer Control

DCH Dedicated ChannelDDI Data Description IndicatorDPCCH Dedicated Physical Control ChannelE-AGCH E-DCH Absolute Grant Channel

Qo Qua y oQPSK Quadrature Phase Shift KeyingRB Radio BearerRG Relative GrantRL Radio LinkE AGCH E DCH Absolute Grant Channel

E-DCH Enhanced (uplink) Dedicated ChannelE-HICH E-DCH HARQ Acknowledgement Indicator ChannelE-RGCH E-DCH Relative Grant Channel

RLC Radio Link ControlRLS Radio Link SetRRC Radio Resource ControlRRM Radio Resource Management

E-TFC E-DCH Transport Format CombinationFDD Frequency Division DuplexFEC Forward Error CorrectionFIFO First In First OutFP F i P t l

RV Redundancy VersionSDU Service Data UnitSF Spreading FactorSG Serving Grant

FP Framing ProtocolGoS Grade of ServiceHARQ Hybrid Automatic Repeat RequestIE Information ElementMAC d dedicated Medium Access Control

SI Scheduling InformationTNL Transport Network LayerTPR Traffic to Pilot RatioTTI Transmission Time IntervalUM U k l d d (RLC) M d


MAC-d dedicated Medium Access ControlMAC-e/es E-DCH Medium Access Control

UM Unacknowledged (RLC) Mode

Documents

Enhanced Uplink Dedicated ChannelEnhanced Uplink … · High Speed Uplink Packet Access (HSUPA) ... E-DCHisaRelDCH is a Rel-6featurewithfollowingtargets6 feature with following targets