Hsdpa analysis

106
HSPA MAC-centric Technologies AUGUST 2007

Transcript of Hsdpa analysis

Page 1: Hsdpa analysis

HSPA MAC-centric Technologies

AUGUST 2007

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CONTENTS

3GPP UMTS Evolution

System Overview (HSPA and HSPA+)

HSDPA

HSUPA (E-DCH)

HSPA Common Issue

Annex

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3GPP UMTS Evolution

3GPP Rel.99/43GPP Rel.99/4 3GPP Rel.5/63GPP Rel.5/6 3GPP Rel.73GPP Rel.7 3GPP Rel.83GPP Rel.8

WCDMA384 kbps DL

128 kbps UL

RTT ~ 150 ms

HSDPA/HSUPA14 Mbps peak DL

5.7Mbps peak UL

RTT < 100ms

HSPA+28 Mbps peak DL

11 Mbps peak UL

RTT < 50ms

LTE100 Mbps peak DL

50 Mbps peak UL

RTT ~ 10ms

2003/4 2005/6 HSDPA

2007/8 HSUPA

2008/9 2009/10

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System Overview

HSPA Today168 HSDPA network deployments in 78 countries

115 commercial HSDPA launches (over 70% WCDMA networks)

More than 260 HSDPA devices launched

Fast upgrade to higher terminal categories

Introduction of receive diversity and advanced receivers

HSUPA launches expected in 2007

Clear evolution path for HSPA

HSPA+ ObjectivesEnhance performance of HSPA based radio networks in terms of spectrum efficiency, peak data rate and latency

Exploit full potential of WCDMA 5MHz operation

Provide a smooth path towards LTE and interworking between HSPA+ and LTE

Facilitate migration from existing HSPA infrastructure to HSPA+

Allow operation as a packet-only network for both voice and data

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System Overview

HSPA+ FeaturesHigher order modulation schemes

64 QAM for HSDPA

16 QAM for HSUPA

Multiple antenna systems for HSPAMultiple Input Multiple Output (MIMO)

Continuous connectivity for packet data usersIncrease number of packet data users by reducing uplink overhead

Fast restart of transmission after a period of temporary inactivity

Improved L1 support for high data rate

Enhanced CELL_FACH state

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System Overview

HSDPANew transport and physical channels

HS-DSCH : shared channel

Fast link adaptation

Fast schedulingPacket scheduling benefiting from the decorrelated UE fast fadings

Fast retransmission mechanism (HARQ)

HSUPANew transport and physical channels

E-DCH : enhanced dedicated channel

Fast schedulingPacket scheduling benefiting from UE activity vs. Max UL cell load

Fast retransmission mechanism (HARQ)

Supported but less reactiveSupported but less reactiveSupportedYesTurboBPSK and QPSK2 ms, 10 msSupportedHSUPA

SupportedSupportedSupportedNoTurboQPSK and 16QAM2 ms onlyNot supportedHSDPA

Fast link adaptationFast schedulingHARQPower controlChannel codingModulationTTIMacro Div

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System Overview

2795211516 (MIMO)

2337011515 (MIMO)

4219611514 (64 QAM)

3480011513 (64 QAM)

36301512 (QPSK only)

36302511 (QPSK only)

2795211510

202511159

144111108

144111107

7298156

7298155

7298254

7298253

7298352

7298351

Max TB sizeMinimum inter-TTI intervalHS-DSCH codesHS-DSCH Cat.

229962000010ms / 2msSF247 (16 QAM)

114842000010ms / 2msSF246

2000010msSF225

57722000010ms / 2msSF224

1448410msSF423

27981448410ms / 2msSF422

711010msSF411

TB size (2ms)TB size (10ms)TTIMin SFE-DCH codesE-DCH Cat.

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System Overview

Node B

DL 384 kbps

DL 64 kbps

Node B DL 384 kbps No coverage for PS 384 kbps

No service continuity

Service continuity for PS 64 kbps

Downgrade Upgrade

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System Overview

PowerPowerControlControl

Data Power

Unused Power Data

Unused

Same Throughput

RateRateAdaptationAdaptation 100% Power

100%

R99 : DL transmitted power controlled according to the radio conditions

HSDPA : Using all available power

Controlling DL user throughput according to the radio conditions

- user in good radio conditions : receives a higher bit rate

- user in bad radio conditions : receives a lower bit rate

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HSDPA

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HSDPA : MAC-hs Location

MAC-hsThe efficiency of rate adaptation

Near the PHYAllows a high reactivity in the resource allocation according to RF condition changes

HS-DSCHAssociated

UplinkSignaling

AssociatedDownlinkSignaling

DCCH DTCHDTCHMAC Control MAC ControlCCCH CTCHBCCHPCCHMAC Control

RRC (RNC)RRC (RNC)

RLC (RNC)RLC (RNC)

HS-PDSCH

FACH

S-CCPCH

FACH

S-CCPCH

RACH

PRACH

RACH

PRACH

DSCH

PDSCH

DSCH

PDSCH

DCH

DPCH

CPCH

PCPCH

CPCH

PCPCH

PCH

S-CCPCH

PCHPCH

S-CCPCHHS-DPCCHHS-SCCH

MAC-c/sh(C-RNC)

MAC-c/sh(C-RNC)

DCH

DPDCH/DPCCH

R99 L1: Channel Coding / Multiplexing (NodeB)R99 L1: Channel Coding / Multiplexing (NodeB)R5 L1: HSDPA (NodeB)R5 L1: HSDPA (NodeB)

MAC-d(S-RNC)

MAC-hs(NodeB)

MAC-hs(NodeB)

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HSDPA : MAC-hs Location

MAC-hs location at Node BTwo sub-layers

one for scheduling

one for HARQ operation

Permits fast, adaptive scheduling to leverage Adaptive modulation and Coding(AMC)

HARQ techniques

enabling higher peak data rates and capacity

HARQ round trip optimized keep soft memory requirements at UE to a minimum

Reduces delay for successful delivery of packet compared to RNC based architectureRLC (in RNC) remains the only repetition layer which guarantees no loss of data

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HSDPA : MAC-hs details – UTRAN side

MAC-hs

MAC – Control

HS-DSCH

TFRC selection

Priority Queuedistribution

Associated DownlinkSignalling

Associated UplinkSignalling

MAC-d flows

HARQ entity

Priority Queuedistribution

PriorityQueue

PriorityQueue

PriorityQueue

PriorityQueue

Scheduling/Priority handling

Logical channels

HS-DSCH

MAC-d MAC-d MUX

Logical channels

MAC-d MUX

Logical channels

MAC-d MUX

Iur MAC-d flow

MAC-c/sh (opt)

Iub MAC-d flow

MAC-hs MUX

MAC-hs

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HSDPA : MAC-hs details – UE side

MAC-hs

MAC – Control

Associated Uplink Signalling

To MAC-d

Associated Downlink Signalling

HS-DSCH

HARQ

Reordering Reordering

Re-ordering queue distribution

Disassembly Disassembly

C/T

MUX

Re-ordering Buffer

HARQ-Processes – Soft Memory

Re-ordering Buffer

Re-ordering Buffer

C/T

MUX

DCCH DTCHDTCH DTCH DTCH

MAC-d Flows

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HSDPA : Flow Control

ObjectiveKeep enough data to avoid data shortage when the scheduler selects a UE

Take into account the memory size to avoid overflow

Limit the number of messages sent to RNC on Iub

L2

L1

HS-DSCH

FP

RLC

L2

L1

HS-DSCH

FP

Iub/ Iur

PHY

MAC

PHY

RLC

Uu

MAC-hs

MAC-d

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HSDPA : Flow Control

HS-DSCH FP frame data structureOne MAC-d flow

MAC-d PDUs of same length and same priority level

CmCH-PI0~15

FlushDRNC should remove or not

Number of MAC-d PDUs is variableIndicated inband (NumOfPDUs)

NumOfPDUs per FP and FP emission interval : controlled by RNC

User Buffer SizeBytes

TNL Congestion ControlFrame Sequence Number (FP Frame)

Delay Reference Time (RFN)

Header CRC FT

CmCH-PI Frame Seq Nr

MAC-d PDU Length MAC-d PDU Length (cont) Spare 1-0

Num Of PDUs

User Buffer Size

User Buffer Size (cont)

Spare, bits 7-4 MAC-d PDU 1

MAC-d PDU 1 (cont) Pad

Header

Spare, bits 7-4 MAC-d PDU n

MAC-d PDU n (cont) PadPayload

New IE Flags7(E) 6 5 4 3 2 1 0

Spare Extension

Payload CRC (cont)

DRT

DRT (cont)

7 0

Payload CRC

Flush

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HSDPA : Flow Control

HS-DSCH Capacity RequestRNC indicates the amount of data in bytes pending in its buffer to Node B per QID

Used to warn Node BThere is nothing to transmit on this QID

There is new data after an IDLE period

HS-DSCH Capacity AllocationNode B indicates the amount of data to be sent per QID to RNC

Credits– 0 : stop

– 2047 : unlimited

Interval credits granted– 0~2550 (unit of 10ms)

Repetition period : subsequent interval granted– 0 : unlimited

– 255

DL transport network congestion– 0~3

1

User Buffer Size

User Buffer Size ( cont)

CmCH -PI Spare bits 7-4

Spare Extension

Payload

1

0-32

1

Number of Octets

7 0

HS-DSCH Interval

HS-DSCH Credits (cont)

Maximum MAC-d PDU Length

Maximum MAC-d PDU Length (cont)

HS-DSCH Credits

HS-DSCH Repetition Period

CmCH -PI Spare

bits 7-6

0 7

Spare Extension

HS-DSCH Credits

Congestion Status

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HSDPA : Transport Channels

NodeB

HSDPA UE

HS-PDSCH for data (I/B) trafficHS-PDSCH for data (I/B) traffic

HSDPA channelsHSDPA channels

HS-SCCH signaling part (UE id, …) associated to HS-PDSCHHS-SCCH signaling part (UE id, …) associated to HS-PDSCH

HS-DPCCH Feedback informationHS-DPCCH Feedback information

Associated DPCH for data, speech + SRB trafficAssociated DPCH for data, speech + SRB traffic

Maximum bit rate achievable in UL can be bottleneck for the maximum bit rate achievable in DL

excessive delay of RLC/TCP ACKs due to low BW in UL

limit DL throughput

Interactive or background / UL:384 DL: [max bit rate for UE categories 12 and 6] / PS RAB + UL:3.4 DL:3.4 kbps SRBsfor DCCH

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HSDPA : HS-SCCH

HS-SCCH reception : as many HS-SCCH transmitted during a TTI as the number of scheduled userChannelization code set information

Modulation scheme – QPSK/16QAM

TBS information

HARQ process information

Redundancy and constellation version

New data indicator

UE identity

HS-SCCH#2

ACK ACK ACK7,5 slots

HS-SCCH#1

HS-PDSCH

N_acknack_transmit = 2

2 ms

HS-DPCCH

2 slots

Time multiplexing : 1 HS-SCCH is enough

Code multiplexing : multiple HS-SCCHs are needed

UE may consider at most 4 HS-SCCHs

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HSDPA : HS-DPCCH

HS-DPCCHHARQ ACK/NACK

– Can be repeated in consecutive sub-frames : N_acknack_transmit

CQI– CQI feedback cycle : k

– Repetition factor of CQI : N_cqi_transmit

Power control– ΔACK offset to be used for ACK transmission

– ΔNACK offset to be used for NACK transmission

– ΔCQI offset to be used for CQI transmission

CQI

Subframe #0 Subframe #i Subframe #4

1 radio frame = 10ms

Tslot = 2560 chips = 10 bits

ACK/NACK

2.Tslot = 5120 chips = 20 bits

HS-DPCCH demodulationand CQI decoding

CQI adjustment based on BLER (to reach a BLER target)

and HS-DPCCH activity (in order to deactivatedeficient UE by artificially setting its CQI to 0)

CQIreported

CQIprocessed

HS-DPCCH demodulationand CQI decoding

CQI adjustment based on BLER (to reach a BLER target)

and HS-DPCCH activity (in order to deactivatedeficient UE by artificially setting its CQI to 0)

CQIreported

CQIprocessed

improve the detection quality

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HSDPA : HS-DPCCH

inter-TTI interval = 3 and N_acknack_transmit = 2

CQI Feedback Cycle = 8ms and N_cqi_transmit = 2

Repetition period is needed in some cases :

For cell edge operation, when the available power would not ensure sufficient quality for feedback information

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HSDPA : Rel.6 Enhancement – CQI Reporting

Enhanced CQI reportingActivity-based CQI feedback

NACK-based CQI feedback

CQI Feedback Cycle k

Regular CQIfeedback

Regular CQIfeedbackData Data

ACK NACK

CQICQI

Node-B

UE

CQI Feedback Cycle k

Regular CQIfeedback

Regular CQIfeedbackData Data

ACK NACK

CQI

Node-B

UE

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HSDPA : Rel.6 Enhancement – ACK/NACK Power Reduction

ACK/NACK transmit power reductionDetection threshold reduction helps Node B to distinguish between DTX and ACK without requiring a large ACK transmit power

Preamble/PostambleACK :1 1 1 1 1 1 1 1 1 1NACK:0 0 0 0 0 0 0 0 0 0PREAMBLE (”PRE”) : 0 0 1 0 0 1 0 0 1 0POSTAMBLE (”POST”): 0 1 0 0 1 0 0 1 0 0

N

HS-DPCCH

HS-DSCH

HS-SCCH

ACK or NACK

Data Packet

N N+1 N+2 N+3

N N+1 N+2N-1

PRE

PREAMBLE transmitted in sub-frame N-1 to indicate reception of relevant signalling information in sub-frame N on HS-SCCH

Normal ACK/NACK to indicate correct or incorrect decoding of packet

POSTAMBLE transmitted in sub-frame N+1 (unless a packet is correctly decoded from sub-frame N+1 on the HS-DSCH, or control information is detected in sub-frame N+2 on the HS-SCCH)

N+1 N+2 N+3

POST

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HSDPA : Rel.6 Enhancement – Fractional DPCH

Tf =10ms 1 radio frame

TPC PilotData1 TFCI Data2

Slot#0 Slot#1 …. …. Slot#14Slot#i

Tslot = 2560 chips

Tx OFF

TPC PilotTx OFFTx OFF

TPC PilotTx OFF

TPC PilotTx OFF

Tf =10ms 1 radio frame

Tx OFF

TPCTx OFF

Tx OFF TPC

Among HSDPA Data-Only users :

1) DCCH signaling is carried on HS-DSCH

2) UE specific TPC bits are present to maintain UL power control loop for each UE

3) Pilot bits are present to allow F-DPCH to be power controlled

and allow DL synchronization to be maintained by each UE

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HSDPA : Rel.6 Enhancement – Fractional DPCH

Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1P-CCPCH

Any CPICH

10 ms 10 ms

Subframe#0

0Subframe

#1Subframe

#2

2Subframe

#3Subframe

#46

Subframe#5

Subframe#6

Subframe#97

HS-PDSCHSubframes

UL 1 DPCCH

Ttx_diff

τDPCH1UE 1 DPCH

τDPCH2UE 2 DPCHUE 2 DPCH

τDPCH3UE 3 DPCH

T0

Shared PC channel

TPC + pilot bits for 1 slot (or less?)

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HSDPA : Fast Link Adaptation

Every TTIAdaptive Modulation and Coding UE radio conditions (CQI)

The number of codes

Code rate

Modulation type

QoS (10% BLER)

QPSK ¼QPSK ½QPSK ¾16QAM ½16QAM ¾

-20 -15 -10 -5 0 50

100

200

300

400

500

600

700

800

Ior/Ioc (dB)

Thro

ughp

ut (k

bps)

AMC Illustration

QPSK ¼QPSK ½QPSK ¾16QAM ½16QAM ¾

QPSK ¼QPSK ½QPSK ¾16QAM ½16QAM ¾

-20 -15 -10 -5 0 50

100

200

300

400

500

600

700

800

Ior/Ioc (dB)

Thro

ughp

ut (k

bps)

AMC Illustration

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HSDPA : HARQ Mechanism

DL asynchronous There is no fixed relationship between transport block set and timing over radio

flexibility for retransmission (no fixed timing between transmission and retransmission)

UL synchronous ACK/NACK is transmitted at time instants which have a known timing relationship to the related downlink transmission

Turbo encoder

Systematic

Parity 1

Parity 2

Systematic

Parity 1

Parity 2

Original transmission Retransmission

Chase Combining

Rate matching (puncturing) Retransmission

Incremental Redundancy combining

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HSDPA : HARQ Mechanism

Hybrid Automatic Repeat Query typesChase Combining

Same redundancy version than first transmission is appliedQPSK onlyRV=0

CC + Constellation Re-arrangementSame puncturing pattern is applied, but constellation rotation is performed16 QAM onlyRV ∈ [0; 4; 5; 6]

Partial Incremental RedundancySystematic bits are prioritizedRV ∈ [0; 2; 4; 6] in QPSKRV ∈ [0; 2; 4; 5; 6; 7] in 16QAM

Full Incremental RedundancyParity bits are prioritizedRV ∈ [1; 3; 5; 7] in QPSK RV ∈ [1; 3] in 16QAM

Consideration on soft bufferUE capabilityHARQ Type

Consideration on soft bufferUE capabilityHARQ Type

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HSDPA : HARQ Mechanism – Consideration on UE Capability

3630

3630

27952

20251

14411

14411

7298

7298

7298

7298

7298

7298

Max TB size

CC

CC

IR

CC

IR

CC

IR

CC

IR

CC

IR

CC

HARQ Type at max data rate

1.8

0.9

14.4

10.2

7.2

7.2

3.6

3.6

1.8

1.8

1.2

1.2

Achievable max data rate, Mbps

1512 (QPSK only)

2511 (QPSK only)

11510

1159

1108

1107

156

155

254

253

352

351

Minimum inter-TTI intervalHS-DSCH codesHS-DSCH Cat.

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HSDPA : HARQ Mechanism – Consideration on RLC Parameters

150 Kbytes89-10

100 Kbytes87-8

50 Kbytes61-6, 11 and 12

Minimum total RLC AM/MAC-hs memoryMaximum # AM RLC entitiesUE cat.

The size of RLC re-ordering buffer : determines the window length of the packets ensure in-sequence delivery

Buffer size should be no limitations to the data rate

assuming UTRAN end delays (including RLC retransmission handling) are reasonable

Page 31: Hsdpa analysis

HSDPA : HARQ Mechanism

HARQRetransmitting data blocks not received or received with errors

Combining the transmission and retransmissions Increase the probability to decode correctly the information

663366666666666633332222Number of HARQ Processes

121110987654321UE Category

ACK/NACK/DTX ?

HARQ process assignedby the scheduler

Y

Update of RV parametersData transmission

Wait for ACK/NACK reception

Insertion of DTX indication

Reset HARQ processRemove Mac-d PDUUpdate structures

Nret = Nret +1

Nret > Nret_max ?

Wait for retransmission

NACK

DTX

N

WACK state

NACK/DTX state

ACK

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HSDPA : HARQ Mechanism

RV parametersIR/Modulation parameters [r,s,b] channel coding/modulation

r,s : redundancy version 2nd rate matching state– s : indicate whether the systematic bits (s=1) or non-systematic bits (s=0) are prioritized in transmission

– r (0~rmax-1) : changes the initialization Rate Matching parameter value modify puncturing or repetition pattern

b : constellation re-arrangement step– b (0~3) : which operations are produced on the 4 bits of each symbol only in 16 QAM

Xrv value to UE : HS-SCCH

0117

3016

2015

1014

1103

1112

0001

0010

brsXrv (Value)

307

316

205

214

103

112

001

010

rsXrv (Value)

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HSDPA : Scheduling Principle

Cell-specific parameters :Allocated HS-SCCH codesAllocated HS-PDSCH codesAllocated HSDPA power

Cell-specific parameters :Allocated HS-SCCH codesAllocated HS-PDSCH codesAllocated HSDPA power

User-specific parameters :SPI : scheduling priority indicatorGuaranteed Bit RateDiscard TimerUE capability/categoryAmount of data buffered in Node B

User-specific parameters :SPI : scheduling priority indicatorGuaranteed Bit RateDiscard TimerUE capability/categoryAmount of data buffered in Node B

Packet Scheduler(metric calculation)Packet Scheduler

(metric calculation)

Scheduling principle

Operator service strategy

Scheduling decision

Basic : how to share the available resources to the pool of users eligible to receive data

Utility function (F. Kelly) : Un (rn)

n : a particular HSDPA user

rn : average throughput for the n-th user

measure of the “happiness or satisfaction” gained from being scheduled

The best scheduling function : the one that maximizes the sum of utility function for all the users at any given time !!!

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HSDPA : Fast Scheduling

MAC-hs schedulerGoal : optimize the radio resources occupancy between users

outputsSelect Queue ID

The amount of corresponding MAC-d PDUs to transmit

InputsNumber of codes available

Remaining power for HS-PDSCH/HS-SCCH

Received ACK/NACK and CQI

Previously scheduled data

UE capability

RNC configuration parameters

Main conceptsRetransmissions are of higher priority than new transmission (first scheduled)

QID is chosen according to the SPI/CmCH-PI and the radio conditions based on CQI

TBs should always be optimized according to the transmitted CQI when possible– If enough codes and power are available

– If there is no CPU limitation

No QID should be left starving (those with low priority and bad CQI)

Page 35: Hsdpa analysis

HSDPA : Fast Scheduling

Scheduling AlgorithmsRound Robin

UEs are scheduled one after the other one

MAX C/I UE with the best CQI is scheduler

Pure Fair SchedulerThroughput provided per UE must be equal

Users with the lowest throughput are then scheduled first

Classical Proportional FairUsers are chosen according to the instantaneous CQI/Averaged CQI criteria

UEs in their best instantaneous conditions with regard to their average are scheduled first

Page 36: Hsdpa analysis

HSDPA : MAC Processing

MAC-d multiplexing of logical channels into a single MAC-d flowMAC layer can multiplex different services together into a single transport channel

– Both services have similar QoS characteristics

Logical channels– DTCH

– DCCH : cannot mapped to MAC-d flow in Rel.5 (additional functionality in Rel.6)

Multiplexing (MAC-d in RNC)Multiplexing (MAC-d in RNC)

MAC-hs in Node BMAC-hs in Node B

PHY layer HS-DSCHPHY layer HS-DSCH

DTCHs

MAC-d flow

HS-DSCH

HS-PDSCH

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HSDPA : MAC PDU Format

MAC PDU : HS-DSCH

VF : 1 bit

Queue ID : 3 bitsIdentification of the reordering queue in the receiver

TSN : 6 bitsUsed for reordering process to support in-sequence delivery

SID : 3 bitsSize of a set of consecutive MAC-d PDUs

N : 7 bitsNumber of consecutive MAC-d PDUs with equal size

In FDD mode, the max number of PDUs transmitted in a single TTI = 70

F : 1 bitFlag indicating if more fields are present (0 additional SID/N/F, max number of extensions = 7)

Queue ID TSN SID1 N1 F1 SID2 N2 F2 SIDk Nk Fk

MAC-hs header MAC-hs SDU Padding (opt)MAC-hs SDU

Mac-hs payload

VF

Page 38: Hsdpa analysis

HSDPA : Fast Scheduling - MAC-d Flow and Priority Queue

CMCH_PI = 3CMCH_PI = 3CMCH_PI = 4

MAC_d Flow ID=0 MAC_d Flow ID=1

Queue ID# 0 # 1 # 2

Node B

RNC

MAC_d Flow ID = 0

Queue ID CMCH_PI 0

1

4

3

MAC_d Flow ID = 1

Queue ID CMCH_PI 2 3

UE #i 312

301

400

CmCH_PIMAC-d Flow IDQueue ID

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

UE # 0

UE # i

Priorities

• • •

UE # n• • •

1 / 2 0

Page 39: Hsdpa analysis

HSDPA : Fast Scheduling - Basic Concept of Scheduler

Flow Control

UE1 UE2

TTIs

NACK

Use all the codes for new packets …

New packets

New packetsPower Limitation

HARQ processes

…UE1 UE2 UEN

Q0Credit = x PDUs

…UE1 UE2 UEN

…UE1 UE2 UEN

Q15Credit = z PDUs

Q1Credit = y PDUs

…UE1 UE2 UEN

…UE1 UE2 UEN …

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HSDPA : Related Layer 1 and 2 Functionality

Page 41: Hsdpa analysis

HSDPA : Power Management

Traffic Power (SHO reserved)

Overhead Power

(Common Channels)

Traffic Power

P traffic

P traffic admission

Call Blocking Threshold

P traffic admission = P traffic * callAdmissionRatio

P traffic = maxTxPower-Overhead power

Call Blocking Threshold represents the level above which new calls are blocked, only new SHO legs are accepted.

maxTxPower

Page 42: Hsdpa analysis

HSDPA : Power Management

Flexible Power Management

Maximizes HS-DSCH throughput

DCH traffic is given priority over HSDPA traffic

Node B

Remaining power management : for HSDPA traffic, MAC-hs scheduler uses Node B PA power not used by DCH

RNC

Minimum power can be reserved for HS-DSCH and HS-SCCH

Admission for DCH traffic based on

Ptraffic = MaxTxPower – PminHsdpa – Pcch

Capability to reserve power for SHO still enabled

Power pool self-tuning based on new measurement “Transmitted carrier power of all codes not used for HS-PDSCH or HS-SCCH transmission”

Pcch(Common channels)

TrafficPower

Trafficpower (SHO

reserved)

P Tr

affic

P Tr

affic

adm

issi

on

Max

TxPo

wer

Min power for HS-DSCH and

HS-SCCH

RNCNodeB

Pmax for HSDPA cell operation

Ptotal on non-HSDPA channels

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HSDPA : Power Management

Yes

No

Compute HS-SCCH and HS-DSCH power for this UE

Update the remaining power UnusedHsdpaPower -= PHsScch+PHsDsch

Beginning of the TTI

A new UE is selected

Changing TTI

UnusedHsdpaPower = PHSDPA

Page 44: Hsdpa analysis

HSDPA : Power Management

CCCRNC

SHO margin

Ptraffic

RN

C

OCNS (opt.)

PminHsdpa

PMaxCell

PmaxHsdpa

CCCRNC

SHO margin

Ptraffic

RN

C

OCNS (opt.)

PminHsdpa

PMaxCell

PmaxHsdpa

PRemain

PTotNonHsdpaWithMargin

CCCNodeB

DCH margin

DCHNod

eB

OCNS (opt.)

PMaxCell

PTotNonHsdpa

PRemain

PTotNonHsdpaWithMargin

CCCNodeB

DCH margin

DCHNod

eB

OCNS (opt.)

PMaxCell

PTotNonHsdpa

PHSDPA = min( PRemain , PmaxHsdpa )

Common channel consumption at Node B is lower than at RNC level activity consideration

Flexible power management for HSDPA

Page 45: Hsdpa analysis

HSDPA : Power Management

Power consumed by

all codes

Nod

eBPMaxCell

PTotCell

Power consumed by non HSDPA

codes

Nod

eB

PMaxCell

PTotCell

HSDPA PTotHsdpa

Transmitted Carrier Power Averaged HSDPA Power

Power consumed by non HSDPA codes includes DL HSUPA channel power

COMMON MEASUREMENT message (100ms measurement) :

Total Non HSDPA Power RNC CAC for HSPA cells

Page 46: Hsdpa analysis

HSDPA : Power Management

HS-SCCH power

CQI

PHS-SCCH = PP-CPICH + hsScchPcOffset(CQIReported)

CQIReported hsScchPcOffset(CQIReported)CQ

I

PHS-SCCH = PP-CPICH + hsScchPcOffset(CQIReported)

CQIReported hsScchPcOffset(CQIReported)

CCC

DCH margin

PRemain

DCHNod

eB

OCNS (opt.)

HS-DSCH

HS-SCCH

PSEUDO closed loop power control for HS-SCCH :

1)Associated DPCCH power control commands

adjusted relative to the Tx power of the associated DL DPCCH

power offset between HS-SCCH and DPCCH can be set (QoS)

2)CQI reports

adjusted as a function of CQI report

power offset between each CQI index and the required HS-SCCH power

Page 47: Hsdpa analysis

HSDPA : Power Management

HS-DSCH powerHSDPA power not allocated to HS-SCCH(s)

PHS-DSCH [dBm] = PP-CPICH[dBm] + G[dB] + D(CQIprocessed)[dB]

PHS-PDSCH[dBm] = PHS-DSCH[dBm] - 10log(#codes)

– PP-CPICH is the power of the P-CPICH channel

– G : the measurement power offset (RRC)

– D : the reference power offset given by the tables of CQI

UE needs to have a power as reference in order to adapt the reported CQI to the radio link condition

– In the same radio condition, the reported CQI will be higher if more power is used to transmitted the HS-DSCH channel

CQI is chosen to insure a transmission with a given BLER (QoS)– Measurement power offset can be seen as HS-DSCH power required by the mobile

corresponding to the reported CQI

– The reference power offset is the one corresponding to the processed CQI, not the reported CQI

Page 48: Hsdpa analysis

HSDPA : Transmission Limitation

TFDetermined according to the processed CQI, not the reported one

CQI adjustmentPower limitation

Code limitation

Optimization of CQI according to MAC-d PDU size (336/656 bits)

Lack of MAC-d PDU in buffer or TB size limitation

320 1621 Padding

Mac-d PDU

Mac-hs transport block(CQI2)

320 16

320 1621 Padding

Mac-d PDU

Mac-hs transport block(CQI3)

320 16

Page 49: Hsdpa analysis

HSDPA : Iub Transport Bandwidth

15808 kbps12160 kbpsCat 10

10608 kbps8160 kbpsCat 9

8736 kbps6720 kbpsCat 7 – 8

4368 kbps3360 kbpsCat 1 – 6

1872 kbps1440 kbpsCat 11 – 12

Throughput. at ATM layer (+30% protocol headers)Throughput at RLC level (kbps)HS-DSCH category

15360134401152096007680576038401920 IuB bandwidth

8 E1(Kbps)

7 E1(Kbps)

6 E1(Kbps)

5 E1(Kbps)

4 E1(Kbps)

3 E1(Kbps)

2 E1(Kbps)

1 E1(Kbps)

# E1

+10% signalling&OaM

Iub Links(E1)

Eng margin

+31% Protocol headers

HSDPA trafficat RLC layer

R99 DL trafficat RLC layer

10% signalling&OaM+Macro Diversity (eg. 30%)

Protocol headers+RLC BLER for PS (eg. 10%)

R99+HSDPA average trafficat ATM layer

Bw = 5% (Aal5-Vcc)

+10% signalling&OaM

Iub Links(E1)

Eng margin

+31% Protocol headers

HSDPA trafficat RLC layer

R99 DL trafficat RLC layer

10% signalling&OaM+Macro Diversity (eg. 30%)

Protocol headers+RLC BLER for PS (eg. 10%)

R99+HSDPA average trafficat ATM layer

Bw = 5% (Aal5-Vcc)

+10% signalling&OaM

Iub Links(E1)

Eng margin

+31% Protocol headers

HSDPA trafficat RLC layer

R99 DL trafficat RLC layer

10% signalling&OaM+Macro Diversity (eg. 30%)

Protocol headers+RLC BLER for PS (eg. 10%)

R99+HSDPA average trafficat ATM layer

Bw = 5% (Aal5-Vcc)

Page 50: Hsdpa analysis

HSDPA : HS-DSCH Mobility

Lack of soft handover for HS-DSCHOnly 1 serving HS-DSCH cell

Associated DCH itself : soft handoverActive set up to 6 cells

Cell of DCH active set

ServingCell

Cell of DCH active set

Node-B Node-B Node-B

Associated DCHHS-SCCH

HS-PDSCH

HS-DPCCH

Comparison of relative CPICH levels inside the active set

trigger a change in the serving HS-DSCH cell

Rel.5 : serving cell change inside the active set

Rel.6 : active set update carries out serving cell change

Page 51: Hsdpa analysis

HSDPA : HS-DSCH Mobility

Received by one cellSofter handoverUL HS-DPCCH

NO

when RLC AM mode is usedNO

when RLC AM mode is used

when duplicate packets are sent on RLC UM mode

NO

Packet losses

RLC retransmissions used in SRNC

Not forwarded, RLC retransmissions used in SRNC

Forwarded from source MAC-hsto target MAC-hs

Packet retransmission

Serving RNCHO decision

Typically by UE, but possibly also by Node BHO measurement

HS-DSCH to DCHInter Node B

HS-DSCH to HS-DSCH

Intra Nod B

HS-DSCH to HS-DSCH

Page 52: Hsdpa analysis

HSDPA : HS-DSCH Mobility - Intra Node B Serving Cell Change

Uu IubUE SRNC

Serving HS-DSCH Node B DRNC

1. RNSAP: RL RECONFIGURATIONPREPARE

4. RNSAP: RL RECONFIGURATION READY

7. RRC: PHYSICAL CHANNEL RECONFIGURATION

5. RNSAP: RL RECONFIGURATION COMMIT6. NBAP: RL RECONFIGURATION COMMIT

2. NBAP: RL RECONFIGURATIONPREPARE

3. NBAP: RL RECONFIGURATION READY

8. RRC: PHYSICAL CHANNEL RECONFIGURATION COMPLETE

Iur

Page 53: Hsdpa analysis

HSDPA : HS-DSCH Mobility - Inter Node B Serving Cell Change

Uu IubUE SRNC

Source HS-DSCH Node B DRNC

1. RNSAP: RL RECONFIGURATIONPREPARE

6. RNSAP: RL RECONFIGURATION READY5. NBAP: RL RECONFIGURATION READY

4. NBAP: RL RECONFIGURATION PREPARE

9. RRC: PHYSICAL CHANNEL RECONFIGURATION

7. RNSAP: RL RECONFIGURATION COMMIT8. NBAP: RL RECONFIGURATION COMMIT

2. NBAP: RL RECONFIGURATIONPREPARE

3. NBAP: RL RECONFIGURATION READY

10. RRC: PHYSICAL CHANNEL RECONFIGURATION COMPLETE

Iur

ALCAP Iub Data Transport Bearer setup(HS-DSCH)

ALCAP Iur Data Transport Bearer setup(HS-DSCH)

ALCAP Iub Data TransportBearer release (HS-DSCH)

ALCAP Iur Data Transport Bearer release(HS-DSCH)

Target HS-DSCH Node B

Page 54: Hsdpa analysis

E-DCH (HSUPA)

Page 55: Hsdpa analysis

DCH vs. HSDPA vs. HSUPA

10, 2280, 40, 20, 10TTI [ms]

YESNOYESSoft handover

YESYESNOFast HARQ

YESYESNONode B based scheduling

NOYESNOAdaptive modulation

YESNOYESFast power control

YESNOYESVariable SF

HSUPA (E-DCH)HSDPA (HS-DSCH)DCHFEAUTRE

HSUPA HARQ : fully synchronous

with IR, even transmitted redundancy version can be predetermined

operates in soft handover

Page 56: Hsdpa analysis

DCH vs. HSUPA

SF256-SF4

2xSF4

-

2xSF2

-

2xSF4 + 2xSF2

SF256-SF4

2xSF4

3xSF4

4xSF4

5xSF4

6xSF4

15-960kbps

1.92Mbps

2.88Mbps

3.84Mbps

4.80Mbps

5.76Mbps

E-DPDCHDPDCHChannel bit rates

Physical channel bit rate

Multi-code not supported in practice with DPDCH (practical maximum for DPDCH is 1xSF4)

256

15kbps

2

1920kbps

YES

BPSK

10, 2

2xSF4 + 2xSF2

256

15kbps

4

960kbps

YES

BPSK

80, 40, 20, 10

6xSF4

Maximum SF

Minimum channel data rate

Minimum SF

Maximum channel data rate

Fast power control

Modulation

TTI

Maximum number of parallel codes

E-DPDCHDPDCHFeature

Page 57: Hsdpa analysis

HSUPA : Principle

Node-B

UE

E-HICHAbsolute Grant

E-DCH control and data

Associated DCH

Scheduler is much closer to the radio interface

has more instantaneous information about the UL interference situation

can control UL data rates in a rapid manner

UL load control tightly

Node B

Downgrade

2ms TTI feasible area

10ms TTI feasible area

Page 58: Hsdpa analysis

HSUPA : MAC Protocol Architecture - UTRAN side

PHY PHY

EDCH FP EDCH FP

IubUE NodeBUu

DCCH DTCH

TNL TNL

DTCH DCCH

MAC -e

SRNC

MAC -d

MAC -e

MAC -d

MAC -es /MAC -e

MAC -es

Iur

TNL TNL

DRNC

Page 59: Hsdpa analysis

HSUPA : MAC-es/e details – UTRAN side

MAC-es

MAC – Control

From MAC-e in NodeB #1

To MAC-d

Disassembly

Reordering Queue Distribution

Reordering Queue Distribution

Disassembly

Reordering/

Combining

Disassembly

Reordering/ Combining

Reordering/ Combining

From MAC-e in NodeB #k

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

MAC-e

MAC – Control

E-DCH Associated Downlink Signalling

Associated Uplink

Signalling

MAC-d Flows

De-multiplexing

HARQ entity

E-DCH

Control (FFS)

E-DCH Scheduling (FFS)

Page 60: Hsdpa analysis

HSUPA : MAC-es/e details – UTRAN side

MAC-d in RNCMAC-d in RNC

MAC-e in Node BMAC-e in Node B

PHY layer E-DCHPHY layer E-DCH

DCCH/DTCHs

MAC-d flows

E-DCH

E-DPDCHs

Reordering (MAC-es in RNC)Reordering (MAC-es in RNC)

MAC-d flows

Page 61: Hsdpa analysis

HSUPA : MAC-es/e details – UE side

MAC-es/e

MAC – Control

Associated Uplink Signalling E-TFC

(E-DPCCH)

To MAC-d

HARQ

Multiplexing and TSN setting E-TFC Selection

Associated Scheduling Downlink Signalling

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

Associated ACK/NACKsignaling (E-HICH)

Page 62: Hsdpa analysis

HSUPA : MAC PDU Processing – UE side

MAC-d Flows

MAC-es PDU MAC-e header

DCCH DTCH DTCH

HARQ processes

Multiplexing

DATA

MAC-d DATA

DATA

DDI N Padding (Opt)

RLC PDU:

MAC-e PDU:

L1

RLC

DDI N

Mapping info signaled over RRC PDU size, logical channel id, MAC-d flow id => DDI

DATA DATA

MAC-d PDU:

DDI

Header

MAC-es/e

Numbering MAC-es PDU: TSN DATA DATA Numbering Numbering

Page 63: Hsdpa analysis

HSUPA : MAC PDU Processing – UTRAN side

Mac-es PDU:

Reordering queue distribution

Reordering queue distribution

DCCH DTCH DTCH

MAC-d Flows

HARQ

Demultiplexing

DATA Header

MAC-d

MAC-e

DATA

DATA

DATA DATA

MAC-e PDU:

RLC PDU:

L1

RLC

Reordering

MAC-es

Reordering Reordering

Disassembly Disassembly Disassembly

MAC-d PDU:

Mapping info signaled to Node B DDI => MAC-d PDU size, MAC-d flow ID

TSN

MAC-e header

DDI N Padding (Opt)

DDI N DATA DATA DDI

Transport block:

DDI N Iub FP:

Page 64: Hsdpa analysis

HSUPA : MAC PDU Format

MAC-es PDU : E-DCH

TSN : 6 bits

MAC-d PDU MAC-d PDU MAC-d PDU

MAC-es SDUMAC-es SDUTSN1 N1DDI1 MAC-es SDU

MAC-d PDUs coming from one Logical Channel

N1 MAC-es SDUs of size and LCh indicated by DDI1

MAC-es PDU1

Page 65: Hsdpa analysis

HSUPA : MAC PDU Format

MAC-e PDU

DDI : 6 bitsIdentify the logical channel, MAC-d flow and size of the MAC-d PDUs concatenated into the associated MAC-es PDU

N : 6 bitsNumber of MAC-d PDUs corresponding to the same DDI value

DDI1 N1 DDI2 N2

DDI1 N1 DDI2 N2 DDIn Nn DDI0(Opt)

MAC-es PDU1 MAC-es PDU2 MAC-es PDUn

MAC-es PDU2MAC-es PDU1 DDIn Nn MAC-es PDUn

MAC-e PDU

SI (Opt)

Padding (Opt)

Page 66: Hsdpa analysis

HSUPA : MAC PDU Format

User Data BitsMAC-e headerSeveral MAC-es PDUs (336 bits each)

Scheduling InformationUPH (5 bits) : power headroomTEBS (5 bits) : buffer sizeHLID (4 bits) : ID of highest priority queueHLBS (4 bits) : occupancy of the highest priority queue

SI

0...19982 bits

Mac-e header

18 bits

Mac-es PDU Mac-es PDU padding

TBsize

...

Page 67: Hsdpa analysis

HSUPA : Signaling of Control Information

UL Scheduling InformationHappy Bit (in E-DPCCH)

Scheduling Information (in MAC-e PDU)Highest priority Logical channel ID (HLID)

Total E-DCH Buffer Status (TEBS)– The amount of data in number of bytes that is

available for transmission/ retransmission in the RLC layer

Highest priority Logical channel Buffer Status (HLBS)– The amount of data available from the logical

channel HLID, relative to (TEBS or 50000 bytes)

UE Power Headroom (UPH)

37642 < TEBS31

28339 < TEBS ≤ 3764230

10 < TEBS ≤ 142

0 < TEBS ≤ 101

TEBS = 00

TEBS Value (bytes)Index

82 < HLBS15

68 < HLBS ≤ 8214

55 < HLBS ≤ 6813

45 < HLBS ≤ 5512

12 < HLBS ≤ 145

4 < HLBS ≤ 61

0 < HLBS ≤ 40

HLBS values (%)Index

Page 68: Hsdpa analysis

HSUPA : Happy Bit Setting

Criteria for unhappyUE is transmitting as much scheduled data as allowed by Serving_Grant in E-TFC selection

UE has enough power available to transmit at higher data rateIdentify E-TFC : TBS > smallest RLC PDU + TBS of E-TFC selected

TEBS requires more than Happy_Bit_Delay_Condition with following patametersServing Grant

Ratio of active process to the total number of processes

Page 69: Hsdpa analysis

HSUPA : Scheduling Information Reporting

Triggering is indicated to E-TFC selection function at the first new transmission opportunity

May be delayed : HARQ processes are occupied with retransmissions

Not be transmitted if TEBS = 0

Take place on every HARQ process

SG=Zero_Grant or all processes are deactivatedTEBS > 0

Higher priority data arrives than that of already buffered

Periodic : RRC MACTEBS > 0

T_SING : Timer Scheduling Information – Zero_Grant

SG<>Zero_Grant and at least one process is activatedE-DCH serving cell change

New E-DCH serving cell is not part of the previous Serving E-DCH RLS

Periodic : RRC MACT_SIG : Timer Scheduling Information – different from Zero_Grant

Page 70: Hsdpa analysis

HSUPA : Related Transport/PHY Channels

E-DCH transport channelOnly for UL

Two possible TTI : 10ms and 2ms

Possibility of HARQ process with retransmission proceduresEach transmitted block is numbered

Possibility of smart redundancy management

Turbo coding with rate 1/3

CRC is 24 bits length

E-TFCIIndicates which format is currently used for UL transmission

E-DP

CCH

E-DP

DCH

E-HI

CHE-

HICH

E-AG

CH

E-AG

CHE-

RGCH

E-RG

CH

Page 71: Hsdpa analysis

HSUPA : PHY Channel- E-DPCCH

Happy bit (1 bit)1 : happy

0 : unhappy

RSN (2 bits)HARQ

0, 1, 2, 3, 3, ...

E-TFCi (7 bits)0-127 SF/E-DPDCHs

E-DPCCH powerRelative to DPCCH power

Index [0…8] is signaled by RNC

2

2

c

ecec β

β=Δ

HB RSN

10 bits

E-TFCi

⎟⎟⎠

⎞⎜⎜⎝

⎛=Δ 2

2

10log10c

ecdBec β

β

0 1 2 3 4 5 6 7 8-10

-8

-6

-4

-2

0

2

4

6

8

index

Δec

Page 72: Hsdpa analysis

HSUPA : PHY Channel- E-HICH and E-RGCH

+1

DTX

DTX

+1

-1

DTX

ACK

NACK

-

TTI received correctly

TTI received incorrectly

TTI not detected

Other cellsCells in the same RLS with serving HSUPA cell

Transmission on E-HICH

Logical responseE-DCH TTI reception

UE will continue retransmitting until at least one cell responds with an ACK

Save DL TX power : only ACKs actually consume DL capacity

All the cells in the same Node B in softer handover: assumed to receive UL E-DPDCH transmission in cooperation

Not allowed

-1

DTX

+1

-1

DTX

UP

DOWN

HOLD

Increase UE allocation

Decrease UE allocation

Keep the current one

Other cellsCells in the serving E-DCH RLS

Transmission on E-RGCHTransmitted

messageScheduler decision

Page 73: Hsdpa analysis

HSUPA : Signaling of Control Information

DL scheduling informationRelative Grants

Serving Relative Grant– Transmitted on downlink on the E-RGCH from all cells in the serving E-DCH RLS

– UP/DOWN/HOLD

Non-serving Relative Grant– Transmitted on downlink on the E-RGCH from a non-serving E-DCH RL

– DOWN/HOLD

Absolute GrantIdentity Type : E-RNTI

– Primary

– Secondary : group usage

Absolute Grant Value– Maximum E-DCH traffic to pilot ratio (E-DPDCH/DPCCH)

Absolute Grant Scope– Per HARQ process(2ms TTI only, reduction in the minimum data rate)

– 2ms : 320 bits PDU minimum RLC data rate of 160kbps (AVG 20kbps if 1 process)

– 10ms : 32kbps

– All HARQ process (10ms TTI, Identity Type=Secondary)

Page 74: Hsdpa analysis

HSUPA : Scheduling Principle

Scheduled transmissionNode B scheduling mode with L1/MAC control signaling

Advanced schedulingTurn off specific HARQ process (RRC or Node B EAGCH signaling)

Use 2 different UE-ids (Primary/Secondary E-RNTI) for flexible resource allocation

Non-scheduled transmissionRNC controlled mode

Allow RNC to configure a specific MAC-d flow (a specific service) to have a guaranteed data rate (GBR such as for VoIP : similar to DCH allocation)

Effectively disabling Node B scheduler control of this particular service

If 2ms TTI usedRestricted to specific HARQ process only

minimum data rate allocation can be reduced

Page 75: Hsdpa analysis

HSUPA : PHY Channel- E-DPDCH (TB size)

Signalled by RNC : 4 possible tablesTTI (2 / 10ms)

Type (0 / 1)

0 20 40 60 80 100 120 1400

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2x 104

E-TFCi

TBsi

ze

Table 10ms

type 0type 1

Page 76: Hsdpa analysis

HSUPA : PHY Channel- E-DPDCH (MAC PDU)

User Data BitsMAC-e header

Several MAC-es PDUs (336 bits each)

Scheduling InformationUPH (5 bits) : power headroom

TEBS (5 bits) : buffer size

HLID (4 bits) : ID of highest priority queue

HLBS (4 bits) : occupancy of the highest priority queue

SI

0...19982 bits

Mac-e header

18 bits

Mac-es PDU Mac-es PDU padding

TBsize

...

Page 77: Hsdpa analysis

HSUPA : Rel.6 Compliant Solution

RNCNode-BHSPA-

capable UE

HSUPA: L1, MAC-e Scheduler, HARQ

Uu Iub

MAC-d

EDCH FPMAC-e EDCH FP

PHY TNL TNL

MAC-e

PHY

MAC-es MAC-es

UE Node-B SRNC

3GPP E-DCH, an add-on to 3GPP UTRAN Rel’5 version

MAC-d

HS-SCCHHS-PDSCH(s)(No SHO)

HSDPA

HS-DPCCH

DPCCH+ DPDCH

(SHO)

DPCCH& DPDCH

DCH

E-HICH(SHO)

E-DPDCHE-DPCCH

HSUPATraffic

E-AGCHE-RGCHs

HSUPAScheduling

256 128128 256128 25664To2

nX16

256~4

512~4

eDCH FP

Page 78: Hsdpa analysis

HSUPA : Rel.6 Compliant Solution

HS-SCCHHS-PDSCH(s)

HSDPA

HS-DPCCH

shared

shared

per User

DPCCH+ DPDCH

DPCCH& DPDCH

DCH

per User

E-AGCHE-RGCHs

HSUPAScheduling

shared

shared

E-HICH

E-DPDCHE-DPCCH

HSUPATraffic

per User

per Usershared

Page 79: Hsdpa analysis

HSUPA : Rel.6 Compliant Solution

Rel.6 UEHSPA-capable

DPCCH

HS-DPCCH

HS-PDSCH(s)

HS-SCCH(s)

DPCCH

E-DPCCHE-DPDCH

E-HICH

E-AGCH

E-RGCH

DPCCH / DPDCH

DPCCH & DPDCH

Rel.5 HSDPA L1Rel.5 HSDPA L2 - MAC-hs scheduler

Rel.6 HSUPA L1Rel.6 HSUPA L2 - MAC-e scheduler

Rel.99 L1

: Dedicated PhCH(s) : Shared PhCH(s)

Page 80: Hsdpa analysis

HSUPA : Receiver Architecture

DPCCHreceiver

OKKO

channel estimation

E-DPCCHdetection

yesno

E-DPCCHdecoding

e-TFCi

E-DPDCHdecoding

CRCE-HICH

for re-transmission

MAC-e data frame

Page 81: Hsdpa analysis

HSUPA : Example of Multi-service Management

RNCNode-BHSPA-capable

Rel.6 UE

HS-SCCH Signaling part(UE id, …)

HS-PDSCH for Mono PS I/B traffic

HS-DPCCH Feedback information(CQI, ACK/NACK)

Associated DPDCH for CS/PS str/SRB traffic

E-AGCH Scheduling information(e-RNTI, Scheduling Grant)

E-DPDCH for Mono PS I/B traffic

E-HICH Feedback informationACK/NACK, signature)

E-DPCCH Feedback information(e-TFCI, RSN, Happy bit)

Once UL PS I/B + PS I/B

then UL DCH Fall back

Page 82: Hsdpa analysis

HSUPA : E-DCH Mobility

DCH active set

E-DCH active setIdentical or a subset of DCH active set (decided by SRNC)

E-HICH (cells belonging to the same RLS)Same RLS : same MAC-e entity (same Node B)

Same as the set of cells sending identical TPC bits– excluding the cells which are not in E-DCH active set

Have the same contentsCombined by UE

E-DCH Absolute GrantSingle Serving E-DCH cell

Serving E-DCH cell and HS-DSCH Serving cell shall be identical (RRC signaling is independent)

E-RGCHEach cell of E-DCH active setSame RLS RGCHs same contents : combinedNon-serving E-DCH RLS RGCHs cell specific : cannot be combined

L1 MACACK/NACKs after combiningAG from the servince cellRGs

One from the Serving E-DCH RLS after combingOne from each Non-serving RL

Page 83: Hsdpa analysis

HSUPA : Rel.6 Compliant Solution - Intra-frequency E-DCH Mobility

Non Serving Cell#3

ServingCell

Non ServingCell#2

Node-B Node-B Node-B

UE

DCH in Macro

diversity

Non Serving

Cell

Maximum Radio CombiningIn Serving Node-B

E-HICHAbsolute Grant

E-DCH control and data

Associated DCH (in SHO)

Page 84: Hsdpa analysis

HSUPA : Rel.6 Compliant Solution - Macro Diversity

Non Serving

Cell

ServingRL Cell

E-RGCH & E-HICHE-AGCH

E-DPCCH & E-DPDCH

Non Serving

Cell

Node-B

Node-BNode-B

Rel.6 UE

E-DCH in Macro

Diversity

Non Serving

Cell

Associated DCH

E-DCH Macro Div existence depending on available

processing resources !!!!!

e-DCH Macro diversity:One serving e-DCH cell (i.e. E-AGCH)Multiple Node-B E-DCH control

-E-DPCCH-E-DPDCH demodulation

E-HICH & E-RGCH from different cells -serving and non-serving cells

• Associated DCH still in classical Rel.99 Macro Diversity• Best Effort E-DCH Macro Diversity

• Macro Div link level gain on E-DPDCH traffic• Intra and Inter Node-B scheduling (i.e. E-RGCH mgt)

Page 85: Hsdpa analysis

HSUPA : Rel.6 Compliant Solution - Macro Diversity

Pros and ConsGain on link level performance

Pros– The higher number of SHO branches, the larger the e-DCH coverage

– The higher number of SHO branches, the higher the e-DCH throughput at cell edge

Cons– The higher the data rate on e-DCH in SHO, the higher the impact on neighboring Node

B processing capacity

– 3GPP best effort E-DCH SHO (no E-DCH SHO if neighboring Node B processing capacity is not enough)

Real seamless user connectivityPros

– Robust radio connection quite useful for RT services

Cons– As HSDPA, not requested for I/B (best-effort) traffic

Inter-cell managementPros

– Neighboring non-serving cells can regulate the load impact of surrounding serving E-DCH cell activity

Cons– Peak E-DCH user data rate could be limited by neighboring cell E-RGCH management

Page 86: Hsdpa analysis

HSUPA : Load Management in Node B

Received Total Wideband Power (RTWP, TS25.215)Cell

Measurement at the Rx antenna connector

UL load : =

N0 : corresponds to the thermal noise constant (-173dBm/Hz)

Nf : noise factor of the BTS (2dB)

W : bandwidth (3.84MHz)

RTWP : current total wideband received power in the cell

: thermal noise

Reference RTWP that corresponds to the amount of power received in the cell when the load is 0

N0 = kT ~ -174dBm/Hz– K is Boltzmann constant : 1.381 x 10-23 J/K

– T is the temperature expressed in Kelvin : T=290K (16.84oC)

Maximum Noise Rise allowed to E-DCH cell : RoTmax = RTWPmax - RTWPrefE-DCH scheduler must know the RoTmax

HSUPA max load = 1-10 - Noise_Rise_HSUPA (in dB) /10 (RoTmax=7dB 80% max UL load for R99/E-DCH)

RTWPWNN f

UL01−=η

RTWPRTWPref

UL −=1η

WNN f0 Thermal Noise

CS12.2

CS12.2

PS64

CS64

Max allowed UL load

Available UL load for E-DCH scheduling

RS

SI

Page 87: Hsdpa analysis

HSUPA : Load Management in Node B

UL load indicationUL PS384 RAB (SF4)

About 3 calls may generate a noise rise higher than 3dB, corresponding to 50% of UL load

What will be happened for EDCH SF4x2+SF2x2 service ?

Beyond 75% load system may be destabilizedSignificant neighboring cell interference

Cell coverage reduction

Call drop

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

2

4

6

8

10

12

14

16

18

20

UL load

Noi

se R

ise

(dB

)

Noise Rise vs. UL load

Page 88: Hsdpa analysis

HSUPA : E-DCH Power Allocation – 10ms TTI E-DCH Transport Block Size Table 1

1179681475840

1151480474039

199501201146079442238

198601191117878440437

192781181112477408636

191881171082476406835

186061161078875375034

185161151048874373233

179161141045273339632

178441131015272337831

12468855430443543

12186845412432042

12132835094421861

1185082507641180

TB Size (bits)E-TFCITB Size (bits)E-TFCITB Size (bits)E-TFCI

Page 89: Hsdpa analysis

1 2 3 4 5 6 7 8 90

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

SF256 SF128 SF64 SF32 SF16 SF8 SF4 2xSF4

Thro

ughp

ut (M

bps)

eDCH throughput vs physical channel configuration type table 1

PhCH Index (3GPP TS25212 definition)

70.8

37.2

5(1xSF16)

1448.4306154.835.41.8Max user MAC-ethroughput (kbps)

337.8169.885.818.61.8Min user MAC-ethroughput (kbps)

8(2xSF4)

7(1xSF4)

6(1xSF8)

4(1xSF32)

1(1xSF256)

PhCH Index(SF)

PhCH Index 1 for user Scheduling Information

data flow @ 1.8kbps on E-DPDCH (3GPP TS25.309)

RLC PDU size @ 336bits too big to match with PhCH

Index 2 & 3 TrBlock size

UE Rate Matching as function of UE Tx Pw availability, RF conditions, Node-B grants,…

HSUPA : E-DCH Power Allocation – MAC-e Throughput

Page 90: Hsdpa analysis

HSUPA : E-DCH Power Allocation

E-DPDCH powerRelative to DPCCH power

Signalled by RNConly 8 "References E-TFC" are signalled by RNC

ΔHARQ = an additionnal offset (in dB)

The 8 "References E-TFC" signalledETFC-iref : 0 - 127

Index of amplitude offset of a single channel : 0-31

Computed by the UE128 E-TFCi ⇔ 128 power offsets

-9.5dB ~ 28.7dB2

2,,

c

iedieded

nββ

2994

2889

2785

2679

2571

2462

2247

1711

PO indexETFC index

Example of reference E-TFC

Page 91: Hsdpa analysis

HSUPA : E-DCH Power Allocation – An Example of Reference Signaled E-TFCI

5/150

6/151

7/152

8/153

9/154

11/155

12/156

13/157

15/158

106/1525

119/1526

134/1527

150/1528

168/1529

Quantized amplitude ratiosAed =βed/βc

Signaled values for ∆E-DPDCH

29948

28897

27856

26795

25714

24623

22472

17111

referenceEtfciPowerOffsetreferenceEtfciReferenceEtfciList

Scheduling Grant Table (-9.5~28.7dB)

Page 92: Hsdpa analysis

HSUPA : E-DCH Power Allocation – An Example of TB size vs. E-DPDCH Power

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

x 104

0

5

10

15

20

25

30

TB size (bits)

E-D

PD

CH

pow

er re

lativ

to D

PC

CH

(dB

)

E-DPDCH power vs. transport block size

Reference signaled E-TFCI

Page 93: Hsdpa analysis

HSUPA : E-DCH Power Allocation

•E-DPCCH gain factor :

•E-DPDCH gain factor : takes a different value for each E-TFC and HARQ offset

•Gain factors for different E-TFCs and HARQ offsets are computed, based on reference gain factors of E-TFCs

•Gain factors of E-TFCs are signaled as reference E-TFCs (HARQ offset : 0~6dB)

•Reference gain factor (reference E-TFC) :

E-TFCIref,1 < E-TFCIref,2 < … < E-TFCIref,M

E-TFCIref,m <= E-TFCIj < E-TFCIref,m+1 (reference is m-th E-TFC)

eccec A⋅= ββ

edcrefed A⋅= ββ ,

20, ,, , ,

, ,

10harq

e ref e jed j harq ed ref

e j e ref

L KL K

β βΔ⎛ ⎞

⎜ ⎟⎜ ⎟⎝ ⎠= ⋅

Page 94: Hsdpa analysis

HSUPA : E-DCH Absolute Grant Value (25.212 Table 16B)

16(75/15)2

17(84/15)2

18(95/15)2

19(106/15)2

20(119/15)2

21(134/15)2

22(150/15)2

23(168/15)2

24(95/15)2x4

25(150/15)2x2

26(119/15)2x4

27(134/15)2x4

28(150/15)2x4

29(168/15)2x4

30(150/15)2x6

31(168/15)2x6

0INACTIVE*

1ZERO_GRANT*

2(7/15)2

3(11/15)2

4(15/15)2

5(19/15)2

6(24/15)2

7(27/15)2

8(30/15)2

9(34/15)2

10(38/15)2

11(42/15)2

12(47/15)2

13(53/15)2

14(60/15)2

15(67/15)2

2. edn β < signaled grant value

Page 95: Hsdpa analysis

HSUPA : HARQ Recombining for E-DPDCH

+ HARQ buffer

Received bits

Received soft bits

unpuncturing

Recombined soft bits

Decoding, CRC check

rsnE-DPCCHdefense

Page 96: Hsdpa analysis

HSUPA : HARQ

10338

11237

00136

01035

10334

11233

11222

10311

01000

rsRVRSNTransmission

11238

01037

11236

01035

11234

01033

01022

11211

01000

rsRVRSNTransmission

coding rate < 1/2 coding rate > 1/2

repetitions or low puncturing rate high puncturing rate

(s,r) punc./repet. bit selection

basedonTTI

Page 97: Hsdpa analysis

HSUPA : HARQ - E-DPCCH Defense

E-DPCCH error managementNon detection vs. False alarm

Bad decoding

E-DPCCHdefense

E-DPCCH : RSN, ETFCi

HARQ buffer managementretransmission

index

E-HICHACK / NACK / DTX

CRC

Page 98: Hsdpa analysis

HSPA Common Issue

Page 99: Hsdpa analysis

HSPA : Radio Resource Management

RRM (RNC/Node B - UE)Resource allocation

Packet scheduling

Power control / Load control

HARQ

Admission control

Mobility Management

Congestion controlNo congestion

Delay build-up

Lost packets

QoS parameterization

Page 100: Hsdpa analysis

HSPA : Transport Channel Type Selection

Some possible rulesCS RAB is established on a DCH channel

Streaming RAB is established on a DCH channel

For a R5 UE (HSDPA capable) DL PS I/B RB is preferred on HSDPA

For a R6 UE (HSDPA and HSUPA capable) DL PS I/B RB is preferred on HSDPA

UL PS I/B RB is preferred on HSUPA

Page 101: Hsdpa analysis

HSPA : QoS Differentiation

Service differentiationPS data services have different QoS requirements

Need to provide QoS differentiation among these different services

Streaming video, web browsing, …

Treat PS services differently when performing admission control

Subscribers differentiationPreferential treatment can be granted to premium users

Consuming a high volume of data

QoS attributes (by RNC)Traffic Class

Allocation/Retention Priority

Traffic Handling Priority (only defined for Interactive TC)

GBR

Differential prioritySubscriber priority

MAC logical channel priority

Scheduling priority indicator

Page 102: Hsdpa analysis

HSPA : CAC

RAB matchingAny PS RAB request with I/B traffic class HSDPA/HSUPA RB configuration

If HSDPA/HSUPA capable

If primary cell of the active set supports HSDPA/HSUPA

HSUPA not supported in the cell (but HSDPA present)Request is mapped on UL DCH/DL HSDPA

Neither HSUPA nor HSDPA supported in the cellRequest is mapped on UL/DL DCH

CACRNC CAC

Any I/B RAB request is admitted on HSDPA/HSUPA– Until the maximum number of simultaneous users allowed on HSDPA/HSUPA is reached

Not enough HSDPA/HSUPA resources– DCH fallback mechanism is triggered

Node B CAC : can be applied after RNC procedure

Page 103: Hsdpa analysis

HSPA : RLC Reconfiguration (by Bearer Transition)

RLC reconfiguration, if neededChanel type switching between DCH and HS-DSCH

Optional (PS I/B RAB – only RLC AM parameters)Tune RLC settings (like timers) to the characteristics of the transport channel

RB reconfiguration (due to mobility or Always-On)Done simultaneously with the transport channel reconfiguration

RB addition/delete (due to RAB assignment/release)Cannot be performed simultaneously with the RB addition/deletion

RLC PDU size/queue size cannot be changed

Page 104: Hsdpa analysis

Annex A : RLC Modes

RLC - SDU

RLC - PDU

RLC

RLC – SDU #1

RLC – Segment.

RLC – SDU #2

RLC – Segment.RLC Header

RLC Header

RLC PDU RLC PDU

Segmentation

Concatenation

RLC-PDU 1 RLC-PDU 2

RLC-SDU1

RLC-PDU not received

RLC-PDU 3 RLC-PDU 4 RLC-PDU 5 RLC-PDU 6

lost RLC-SDU RLC-SDU3

Transparent Mode (All CS, some kinds of PS)

UM/AM Mode (PS)

AM = UM + some properties

-ACK for RLC-PDU transmitted

-Flow control (suspend/resume)

-Error correction through retransmission

Sequence Number Check

Page 105: Hsdpa analysis

Annex B : MAC Functions (1/2)

Transport ChannelsCommon transport channels

RACH

FACH

HS-DSCH

BCH

PCH

Dedicated transport channelsDCH

E-DCH

Logical channels Broadcast Control Channel (BCCH)

Paging Control Channel (PCCH)

Dedicated Control Channel (DCCH)

Common Control Channel (CCCH)

Control Channel

Dedicated Traffic Channel (DTCH) Traffic Channel

Common Traffic Channel (CTCH)

Shared Channel Control Channel (SHCCH)

MBMS point-to-multipoint Control Channel (MCCH)

MBMS point-to-multipoint Traffic Channel (MTCH)

MBMS point-to-multipoint Scheduling Channel (MSCH)

Page 106: Hsdpa analysis

Annex B : MAC Functions (2/2)

MAC specific functionsControl of HS-DSCH transmission and reception

Network operation– Scheduler, HARQ

UE operation– HARQ, Reordering, Reassembly

Control of E-DCH transmission and receptionUE operation

– HARQ, Multiplexing and TSN setting, Serving Grant Update, E-TFC selection, Happy bit setting, Scheduling Information reporting

Node B operation– HARQ, De-multiplexing, Scheduler

RNC operation– Reordering