HSPA

1 HSPA course.PPT / 08-10-2007 / AT&HH

Harri Holma, Principal EngineerAntti Toskala, Senior Manager, Standardisation

Nokia Siemens Networks, Finland

High Speed Packet Access HSDPA/HSUPA

October 8th 2007Tampere


Agenda

• HSDPA in Release 5• HSUPA in Release 6• HSPA evolution in Release 7• HSPA evolution in Release 8


WCDMA High Speed Downlink PacketAccess (HSDPA) of Release 5


Outline• HSDPA Introduction• HSPDA Protocol Architecture• New Node B & UE functions• Modulation and coding• HSDPA & Soft Handover• HSDPA vs DCH/DSCH• HSDPA & Iub• Summary


High Speed Downlink Packet Access HSDPA

• Peak data rates increased to significantly higher than 2 Mbps; Theoretically exceeding 10 Mbps

• Packet data throughput increased 50-100% compared to 3GPP release 4

• Reduced delay from retransmissions.• Solutions

• Adaptive modulation and coding QPSK and 16-QAM• Layer 1 hybrid ARQ• Short frame 2 ms

• Schedule in 3GPP• Part of Release 5• First specifications version completed 03/02


HSPA Pushes Functionalities to Base Station• HSDPA = High Speed Downlink Packet Access • HSUPA = High Speed Uplink Packet Access• HSPA = HSDPA + HSUPA

HSDPA

HSUPA

Mobile Base station Radio network controller RNC

HSPA scheduling and retransmission control

in base station

HSPA scheduling and retransmission control

in base station

WCDMA R99 scheduling and retransmission

control in RNC

WCDMA R99 scheduling and retransmission

control in RNC

WCDMA R99 uplink/downlink


HSDPA – General Principle

Terminal 1 (UE)

Terminal 2

L1 Feedback

L1 Feedback

Data

Data

Downlink fast schedulingdone directly by Node B (BTS) based on knowledge of:

• UE's channel quality• UE's capability• QoS demands• Power and code resource availability• Node B buffer status

Users may be time and/or code multiplexed


Fast Link Adaptation in HSDPA

0 20 40 60 80 100 120 140 160-202468

10121416

Time [number of TTIs]

QPSK1/4

QPSK2/4

QPSK3/4

16QAM2/4

16QAM3/4

Inst

anta

neou

s Es

No

[dB]

C/I received by UE

Link adaptation

mode

C/I varies with fading

BTS adjusts link adaptation mode with a few ms delay based on channel quality

reports from the UE


Release’99 RRM Functional Split

• Admission control on interference and power level• Initial power and SIR setting• Radio resource reservation• Air interface scheduling for common channels• DL code allocation and code tree handling• Load and overload control

• Admission control on interference and power level• Initial power and SIR setting• Radio resource reservation• Air interface scheduling for common channels• DL code allocation and code tree handling• Load and overload control

• Mapping RAB QoS Parameters into air interface L1/L2 parameters (incl. transport channel selection)• Air interface scheduling (for dedicated channels)• Handover Control• Outer loop power control and power balancing

• Mapping RAB QoS Parameters into air interface L1/L2 parameters (incl. transport channel selection)• Air interface scheduling (for dedicated channels)• Handover Control• Outer loop power control and power balancing

Radio network topology hidden to the CN

Radio network topology hidden to the CN

Node BServing

RNC SGSN

MSCDrift RNC

Iur IuIub

RRC

• Fast power control• Overload control

• Fast power control• Overload control


HSDPA Protocol Architecture• New MAC entity, MAC-hs added to the Node B• Layers above, such as RLC, unchanged.

WCDMA L1

UE

Iub/Iur

SRNCNode B

Uu

MACRLC

NAS

HSDPA user plane

WCDMA L1

MAC-hs

TRANSPORT

FRAMEPROTOCOL

TRANSPORT

FRAMEPROTOCOL

MAC-dRLC

Iu


Release’99 vs HSDPA Retransmissions

Terminal

BTS

RNC

Rel’99 DCH/DSCH Rel’5 HS-DSCH

Packet Retransmission

RLC ACK/NACK

Retransmission

L1 ACK/NACK

Packet


HSDPA L1 Retransmissions• The L1 retransmission procedure (Hybrid ARQ, HARQ) achieves following

• L1 signaling to indicate need for retransmission -> fast round trip time facilitated between UE and BTS

• Decoder does not get rid off the received symbols when decoding fails but combines the new transmisssion with the old one in the buffer.

• There are two ways of operating:• A) Identical retransmission (soft/chase combining): where exactly same bits are

transmitted during each transmission for the packet• B) Non-identical retransmission (incremental redundancy): Channel encoder output is

used so that 1st transmission has systematic bits and less or not parity bits and in case retransmission needed then parity bits (or more of them) form the second transmission.


Rate Matching• Turbo encoder coding rate = 1/3.• Rate Matching is used to adapt to the

desired coding rate.• Either puncturing or repetition.• In the example, RM punctures into

rate 3/4.• Note: The systematic bits are more

important than parity bits!

SystematicParity 1Parity 2

Turbo Encoder

Rate Matching (Puncturing)


Data



Turbo Encoder



Chase Combining (at Receiver)


Original transmission Retransmission

Hybrid ARQ (HARQ): Chase Combining



Turbo Encoder



Incremental Redundancy Combining


Original transmission Retransmission

Hybrid ARQ (HARQ): Incremental Redundancy


HARQ Processes• Up to 8 processes can be configured per UE• HARQ principle used is stop-and-wait-ARQ• For continuous operation at least 6 processes is needed

HS-DSCH

1 2 3 4 5 6 1 2

…

CRC Check Result Fail Pass

NACKACK

RLC layer

1st TX 1st TX2nd TX

1st TX (new packet)

…

From scheduler buffer


New Functionality in RAN/Terminals

Terminal

BTS

RNC

HSDPA Radio Resource &Mobility Management

HSDPA Iub Traffic ManagementLarger Data Volume

Data BufferingARQ Handling

Feedback DecodingFlow Control Towards RNC

Downlink Scheduling16QAM Modulation

ARQ Handling withSoft Value Buffer

Feedback Generation & Transmission

16QAM Demodulation


Adaptive Modulation – QPSK and 16QAM• Release’99 uses QPSK • HSDPA uses both QPSK and 16-QAM• 16-QAM requires also amplitude estimation from CPICH for detection

QPSK 16QAM


HSDPA - UE Categories• Theoretical peak bit rate up to 14 Mbps• For the market 1.8 Mbps and 3.6 Mbps capability expected initially, then 7.2 Mbps

10

9

7/8

5/6

3/4

1/2

12

11

HSDPACategory

-

-

-

3.6 Mbps

1.8 Mbps

1.2 Mbps

1.8 Mbps

0.9 Mbps

5 Codes

--36302QPSK only

--36301QPSK only

QPSK/16QAM

QPSK/16QAM

QPSK/16QAM

QPSK/16QAM

QPSK/16QAM

QPSK/16QAM

Modulation

14.0 Mbps

10.1 Mbps

-

-

-

-

15 Codes

-279521

-202511

7.2 Mbps144111

-72981

-72982

-72983

10 CodesTransportBlock sizeInter-TTI


HSDPA DL Channel Structure• High speed downlink shared channel (HS-DSCH) carries the user data in the

downlink direction, with the peak rate up to 10 Mbps • High speed shared control channel (HS-SCCH) carries the necessary physical layer

control information to enable decoding of the data on HS-DSCH• Only one HS-SCCH needed if only time multiplexing is used• DCH always running in parallel

2 ms

HS-SCCHs

HS-DSCH

……

Demodulation information

User dataUser data

Control dataControl data


HSDPA DL Channel Structure: HS-DSCH• HS-DSCH does not carry any physical layer control or pilot info, only user data (+

MAC layer/RLC layer headers)• Only difference in the slot formats is the use of QPSK or 16QAM modululation

Slot format #i Channel Bit Rate (kbps)

Channel Symbol Rate (ksps)

SF Bits/ HS-DSCH subframe

Bits/ Slot Ndata

0(QPSK) 480 240 16 960 320 320

1(16QAM) 960 240 16 1920 640 640

Slot #0 Slot#1 Slot #2

Tslot = 2560 chips, M*10*2 k bits (k=4)

Data Ndata1 bits

1 subframe: Tf = 2 ms


HS-SCCH• The HS-SCCH is fixed data rate

channel with SF 128 (60 kbps)• First part carries

• code-set info• Modulation info

• Second Part• Transport-block size • Hybrid-ARQ process Redundancy and

constellation version• New data indicator

• Additionally UE identify informationis used target the information to correct user

• To separate which of the 4 HS-SCCHsUE needs to decode (UE specific masking)

• Decoder matrix to be observed…..

Channel coding & Rate Matching

Channel coding & Rate Matching

Channelisation codesModulation

Transport Block SizeHARQ ProcessRedundancy and Constellation VersionNew Data Indicator

UE Specific Masking

UE Specific CRC Attachment

Physical Channel Mapping

HS-SCCH


HS-DSCH TX Chain

CRC Attachment

Bit Scrambling

Code Block Segmentation

Channel Coding

HARQ Functionality

Physical Channel Segmentation

Interleaving

16QAM ConstellationRe-arrangement

Interleaving

Physical Channel Mapping

HS-PDSCHs

• The HS-DSCH uses 1 to 15 codes with fixed SF 16

• Specific parts in the channelcoding chain are related to HARQ and 16QAM modulation (and somesimplifications as there is no DTX, compressed mode etc…)

• Impacted by 16QAM• Interleaving (two identical

interleavers with 16QAM TTIs)

• Constellation re-arrangement (same bits notin same constellation pointbetween retransmissions


HSDPA UL Channel Structure• High Speed Dedicated Physical Control Channel (HS-DPCCH) carries the uplink

HSDPA related L1 control information to the BTS• This is parallel to the Uplink DCH• Timing from downlink packet to uplink feedback (ACK/NACK) is fixed thus

network knows for which packet the info is related to

2 ms

HS-SCCHs

HS-DSCH

7.5 slots (approx.)

HS-DPCCH

ACK/NACK Channel Quality Information

2 ms

CRC result


MAC-hs Round-Trip Loop Timing• Minimum retransmission delay 12 ms

HS-SCCH

HS-PDSCH2 slots 3 slots

A = HS-DPCCH L1, MAC-hs,HS-SCCH L1

B = HS-PDSCH L1

Retransmit

Retransmit

CQIA/N

A B

18 slots = 12 ms 2 slots

2 x Tprop + 15.5 slots


HS-DPCCH

message to be transmitted

w0

w1

w2

w3

w4

w5

w6

w7

w8

w9

ACK 1 1 1 1 1 1 1 1 1 1

NACK 0 0 0 0 0 0 0 0 0 0

PRE 0 0 1 0 0 1 0 0 1 0

POST 0 1 0 0 1 0 0 1 0 0

• The HS-DPCCH is fixed data rates channel with SF 256 • As this is BPSK channel, this gives 10 bits per slot• 1 slot used for ACK/NACK code word, 2 slots for the CQI info

• For CQI one of the 0 .. 30 values transmitted (one unused value)•(20,5) code used

i Mi,0 Mi,1 Mi,2 Mi,3 Mi,4 0 1 0 0 0 1 1 0 1 0 0 1 2 1 1 0 0 1 3 0 0 1 0 1 4 1 0 1 0 1 5 0 1 1 0 1 6 1 1 1 0 1 7 0 0 0 1 1 8 1 0 0 1 1 9 0 1 0 1 1

10 1 1 0 1 1 11 0 0 1 1 1 12 1 0 1 1 1

Party omitted …


HS-DPCCH Slot Format• The HS-DPCCH fields may have different power offsets• One may also repeat the ACK/NACK and/or CQI over more than one subframe

•This is needed for cell edge operation (subject to cell edge coverage level)

2560 Chips 5120 Chips

One HS-DPCCH subframe of 2 ms

ACK/NACKCQI

• HS-DPCCH is symbol aligned with the uplink DPCCH/DPDCH• BTS channel estimation done based on DPCCH (which carrier TPC, Pilot and TFCI)

Power offsetAs configured


PAR Increase due HS-DPCCH• Terminal TX power is allowed to be reduced with low DCH uplink data rates, due

to the added parallel channel -> increased peak to average ratio when channels haveclose to equal power

Ratio of DPCCH/DPDCH gain factors for all values of

HS-DPCCH gain factor

Power Class 3 Power Class 4

Power(dBm)

Tol(dB)

Power(dBm)

Tol(dB)

1/15 ≤ βc/βd ≤ 12/15 +24 +1/-3 +21 +2/-2

13/15 ≤ βc/βd ≤ 15/8 +23 +2/-3 +20 +3/-2

15/7 ≤ βc/βd ≤ 15/0 +22 +3/-3 +19 +4/-2


HSDPA Channel Quality Feedback

-14 -12 -10 -8 -6 -4 -2 0Tx Ec/Ior (dB)

Thr

ough

put (

kbps

)

Geometry=0dB Geometry=5dB Geometry=10dB

High Throughput

Low Throughput

• This will depend on the location in the cell, expected BTS TX power for HSDPA (parameter), channel condition & receiver etc. details

High CQI reported (close to BTS, high HSDPA power)

Low CQI reported (far from BTS, low HSDPA power)


Example CQI Mapping Table

• BTS can map the receivedCQI value for the data rateto be used in the linkadaptation

• Necessary conversion to bedone depending on BTS power availability

• Reference poweradjustment used whenquality would allow higherrate than UE capability

CQI value Transport Block Size

Number of HS-PDSCH Modulation

Reference power adjustment ∆

NIR XRV

0 N/A Out of range

1 137 1 QPSK 0

2 173 1 QPSK 0

3 233 1 QPSK 0

4 317 1 QPSK 0

5 377 1 QPSK 0

6 461 1 QPSK 0

7 650 2 QPSK 0

8 792 2 QPSK 0

9 931 2 QPSK 0

10 1262 3 QPSK 0

11 1483 3 QPSK 0

12 1742 3 QPSK 0

13 2279 4 QPSK 0

14 2583 4 QPSK 0

15 3319 5 QPSK 0

16 3565 5 16-QAM 0

17 4189 5 16-QAM 0

9600 0

(continues until 31…)


HSDPA & Soft Handover• In case of DCH all data is sent from all active set BTSs• In case of HSDPA, HS-DSCH sent from one BTS only, associated DCH (can be

low rate if only signaling) from all cells

Iub

Node B

RNC

Node BDCH

DCH

Iub

Node B

RNC

Node B

DCH +HS-DSCH

DCH


HSDPA & Soft Handover (cont.)• The intra-frequency measurement event ID is modified• Now a measurement report will be initiated when the best serving cell changed

(parameters to have some hysteresis)• This is needed to initiate the HS-DSCH serving cell change even when active set is

unchanged• In case serving cell change, RLC layer (in the RNC) will handle unfinished ARQ

processes when Node B memory is flushed.

Iub

Node B

RNC

Node B

DCH +HS-DSCH

DCH


HSPA Mobility ProcedureUE Node-B #1 Node-B #2 RNC

HS-DSCH from Node-B #2

Radio link reconfiguration and AAL2 setup to Node-B #2

“Measurement report”

“Radio bearer reconfiguration”

“RLC ACK”

“Radio bearer reconfiguration complete”

t1t2

t3

t4

HS-DSCH from Node-B #1

A

B

Radio link reconfiguration and AAL2 deletion to Node-B #1

Reroute data from Node-B #1 to Node-B #2

A = procedural delayB = gap in data flow


HSDPA & Compressed mode• The inter-frequency measurement is handled by scheduling• HS-SCCH/HS-PDSCH are always trasnsmitted fully or then not at all if there is

any overlapp during the 2 ms TTI• Alternatively one can switch back to DCH for inter-frequency measurements

2 ms

HS-SCCH

HS-DSCH

DL DCH for Terminal 1

…

…

Compressed frame

Not permitted HS-DSCH TTI for Terminal 1


HS-DSCH vs. DCH

Feature

Variable spreading factor

Fast power control

Adaptive modulation and coding

Fast L1 HARQ

DCH

No

Yes

No

No

HS-DSCH

No

No

Yes

Yes

BTS based scheduling No Yes

Multi-code operation Yes Yes, extended

• When compared to DCH, the key difference is the replacement of power controlwith link adaptation and L1 HARQ. Also the multicode operation has beenextended.


HSDPA & DCH Resource Sharing

Common channels

DCH RT

DCH NRT

HSDPA NRT

PtxTarget

Max power

Power control head-room

Non-controllable power

Controllable power

Total transmittedcarrier power

NEW non-HSDPApower measurements

Power measurementsfrom the Node-B to

the RNC

Node-B Tx power

In addition to power also code resource

shared!


HSDPA vs DCH Code Space Usage

PilotData

Slot 0.667 ms = 2/3 ms

TPC

• With Downlink DCH Time multiplexed DPCCH and DPDCH• Variable rate with DTX -> Code space not released due inactivity• Problematic for high bit rates -> Current highest DL rate 384 kbps

DPDCH DPDCH

Data

DPCCH DPCCH

TFCI

PilotData

Slot 0.667 ms = 2/3 ms

TPC

DPDCH DPDCH

Data

DPCCH DPCCH

TFCI

FULL RATE

HALF RATE

DTX


HSDPA vs DCH code space usage (cont.)• With HSDPA code resource (except what is needed for DCH) shared with 2 ms

resolution -> Optimum code resource use• Also no soft handover related extra code use

C0(0) = [ 1 ]

C1(0) = [ 1 1 ]

C1(1) = [ 1 0 ]

C2(0) = [ 1 1 1 1 ]

C2(1) = [ 1 1 0 0 ]

C2(2) = [ 1 0 1 0 ]

C2(3) = [ 1 0 0 1 ]

C3(0) = [ 1 1 1 1 1 1 1 1 ]

C3(1) = [ 1 1 1 1 0 0 0 0 ]

. . .

. . .

Spreading factor:

SF = 1 SF = 2 SF = 4 SF = 8

C3(2) = [ 1 1 0 0 1 1 0 0 ]

C3(3) = [ 1 1 0 0 0 0 1 1]

. . .

. . .

C3(4) = [ 1 0 1 0 1 0 1 0 ]

C3(5) = [ 1 0 1 0 0 1 0 1 ]

. . .

. . .

C3(6) = [ 1 0 0 1 1 0 0 1 ]

C3(7) = [ 1 0 0 1 0 1 1 0 ]

. . .

. . .

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

= Allocated code

= Code which canbe allocated at the sametime as C3(1)

= Code which cannotbe allocated at the sametime as C3(1)

These codes cannotbe used at the same

time as C3(1)


HSDPA Iub signaling• Parameters for Node B resource allocation , to indicate e.g. which HS-SCCH use

and which codes are available for HS-DSCH as well as how much power to use for HSDPA.

• Scheduler parameters, to control the scheduler behavior, such as scheduling priority indicator and guaranteed bit rate

• Terminal specific parameters, such a terminal capability and terminal specific HSDPA parameters (like the set of HS-SCCH codes the terminal is monitoring)

Node B RNC

Iub Iu-ps

PSCore

Data + QoSparameters (larger data rates than

Rel’99)

UE capabilityData + Scheduling

priority, discard timer, resources, CQI parameters…


HSDPA Data Rate on different interfaces

QoS Parameter: Maximum Bit Rate: 1 Mbps

Node B RNC

Iu-psIub

Terminal

Uu

Iub Bit Rate: 0 - 1 Mbps

SGSN

Data fromGGSN

HS-DSCH Peak Rate: 7.2 Mbps over 2 ms

QoS Parameter: Maximum Bit Rate: 384 kbps

Node B RNC

Iu-psIub

Terminal

Uu

Iub Bit Rate: 0 - 384 kbps

SGSN

Data fromGGSN

DCH Peak Rate: 384 kbps

Release’99 DCH

Release 5 HSDPA


Iub Flow Control

UE1 with high CQI

BTS

RNC

Scheduler buffer levelFor UE1

Scheduler buffer levelFor UE2

Increase Credits to UE1, Reduce

Credits to UE2

Data

UE2 with low CQI

Maximise Iubcapacity

utilisation in response to credits

Flow control is neededTo avoid buffer overflow In Node B

One unit responding to Flow control in RNC canmaximise the Iub usage


HSDPA - Summary• Multi-code operation combined with lower coding rates and fast HARQ

improves link performance at cell edge (low SIR) • Multi-code operation combined with increased coding rates (e.g. 3/4) fully

utilize favorable radio environments (high SIR) without running into code shortage.

• HSDPA is backwards compatible and can be introduced gradually in the network.

• Retransmission and scheduling into Node B• -> reduces (re-)transmission delays; Improves QoS control.

Freely configurable transmissionHSDPA is a natural capacity evolution to WCDMAand an enabler for higher speed data services


HSDPA Performance


HSDPA Peak Data Rates• Max Layer 1 and Layer 2 (RLC) throughput shown below• Max application layer throughput can be very close to RLC throughput

5 codes QPSK 1.8 Mbps 1.6 Mbps

# of codes Modulation Max L1 data rate

Max RLC data rate

5 codes 16-QAM 3.6 Mbps 3.36 Mbps




12

UE category

5/6

7/8

9

10

Phase 1

Phase 2


HSDPA Link Performance with Turbo Coding Approaches Shannon Limit

Higher bit rates can be obtained only with more antennas (MIMO) and/or wider bandwidth.

Sup

porte

d ef

fect

ive

data

rate

[Mbp

s]

0.1

1.0

10.0

-15 -10 -5 0 5 10 15 20

16QAM

0.01

Instantaneous HS-DSCH C/I before processing gain [dB]

QPSK

HSDPA linkadaptation curve

Shannon limit:3.84MHz*log (1+C/I)2

15 HS-PDSCH allocation(Rake, Pedestrian-A, 3km/h)


Link Simulations in Fading Channel – Including Link Adaptation, CQI Errors and Feedback Delay

-10 -5 0 5 10 15 20 25 30 35 400

2

4

6

8

10

12

SINR(dB)

Thro

ughp

ut (M

bits

/s)

5 codes, PedA5 codes VehA5 codes fit10 codes PedA10 codes VehA10 codes fit15 codes PedA15 codes VehA15 codes fit

10 Mbps requires very high SINR >30 dB

3 Mbps requires very high SINR >24 dB

15-code

10-code

5-code

With low SINR < 5 dB, 5-code HSDPA gives similar

throughput as 10/15-code HSDPA since the throughput is interference, not code limited


HSDPA SINR Definition• SF16 = HS-DSCH spreading factor = 16• PHS-DSCH = Received power of HS-DSCH channel• Pown = Own cell interference with orthogonal codes• Pother = Other cell interference• Pnoise = Receiver thermal noise• α = Own cell orthogonality

( ) noiseotherown

DSCHHS

PPPPSFSINR

++⋅−= −

α116

• SINR is increased with • Higher HS-DSCH power – network planning and dimensioning• Less own cell and other cell interference – network planning and dimensioning• Better orthogonality – multipath propagation or mobile equalizer


HSDPA Data Rate vs RSCP

RLC throughput shown, 5 codes, total BTS power 20 W, Release 99 power 0-10 W

-115 -110 -105 -100 -95 -90 -85 -800

500

1000

1500

2000

2500

3000

3500

4000

CPICH RSCP [dBm]

kbps

15 W HS-DSCH10 W HS-DSCH5 W HS-DSCH

More power increases data rate


HSDPA Scheduling and Cell Capacity


Fast Proportional Fair Scheduling

UE2

Channel quality(CQI, Ack/Nack, TPC)

Channel quality(CQI, Ack/Nack, TPC)

Data

Data

UE1

Multi-user selection diversity(give shared channel to “best” user)

TTI 1 TTI 2 TTI 3 TTI 4

USER 1 Es/N0USER 2 Es/N0

Scheduled user

Node-B scheduling can utilize information on the

instantaneous channel conditions for each user.


Proportional Fair Algorithm• Principle is to schedule the user who currently has the highest ratio of instantaneous

throughput to average throughput. The averaging time is typically a few 100 ms.• The user with the highest selection metric at a given time is selected for scheduling

in the following TTI• In practise, the gain in cell capacity is up to 30%

[ ][ ]nTnRM

k

kk ≡

Rk = instantaneous supported data rate for user k based on CQI report

Tk = average throughput for user k with 100-200 ms averaging period

Mk = selection metric where higher value gives higher probability of being scheduled


3GPP HSDPA Terminal PerformanceRequirements

Performance requirements

Baseline receiver

3GPP Release

Performance gain

Minimum requirement

1-antenna Rake

Release 5 Basic receiver

Enhanced type 1

2-antenna Rake

Release 6 Better performance also against other cell interference with 2 antennas. HSDPA reference receiver for relative LTE performance evaluation.

Enhanced type 2

1-antenna Equalizer

Release 6 Improved performance against intra-cell interference

Enhanced type 3

2-antenna Equalizer

Release 7 Combines the gain mechanisms of intra-cell interference mitigation and receiver diversity


0

500

1000

1500

2000

2500

3000

3500

4000

4500

Rake 1-ant Equalizer 1-ant Rake 2-ant Equalizer 2-ant

kbps

Round robin 5 codesRound robin 10 codesProportional fair 5 codesProportional fair 10 codesProportional fair 15 codes

1 Mbps

2.5 Mbps

4 Mbps

• 5-code BTS and single antenna UE Rake provides 1 Mbps• 10-code BTS and single antenna UE provides 2.5 Mbps• 15-code BTS and dual antenna UE provides 4 Mbps

HSDPA Capacity [kbps/Sector/5 MHz]


Maximum HSDPA Subscribers

Cell capacity 2.5 Mbps

Convert Mbps to GBytes

Busy hour averageloading 60%

Busy hour carries 20% of daily traffic

30 days per month

3 sectors per site

From simulations

/ 8192

x 60%

/ 20%

x 30

x 3x 3

3600 seconds per hour x 3600

Total 300 subs/site

1 GB traffic per user / 1 GB (300 GB/site/month)

Cell capacity 2.5 Mbps

Required user data rate

3 sectors per site

From simulations

0.5 Mbps

x 3

Overbooking factor 20

Total 300 subs/site

Traffic volume based dimensioning Data rate based dimensioning


HSDPA Measurements


Stabile approx 400 kB/s = 3.28 Mbps which is max application bit rate with

3.6 Mbps L1 capability terminal

Data Rate in Elisa Network, 3xE1 Site


HSDPA Round Trip Time

0

20

40

60

80

100

120

140

160

180

200

[ms]

WCDMA (128/384 kbps)HSDPA (384 kbps/1.8 Mbps)

WCDMA R99 130 ms on average (384/128 kbps)

HSDPA R5 <80 ms on average


HSDPA Multiuser Capacity Sharing

Impact of 3 Users on Throughput

0

200000

400000

600000

800000

1000000

1200000

1400000

1600000

Time (s)

App

licat

ion

Thro

ughp

ut (b

ps)

1 user 1 user2 users 2 users3 users

User throughput depends directly on the number of users while the cell throughput remains constant


Uplink Data Rate for HSDPA Feedback• TCP acknowledgements required approx 3% of

the downlink bandwidth in typical TCP case. • 64 kbps uplink is required to support 1.8 Mbps• 128 kbps uplink is required to support 3.6 Mbps• The uplink bandwidth may be smaller in case of

multiple TCP packets are acknowledged at once.

42 kbps application layer data rate in uplink when

1.6 Mbps in downlink


0,17:13:43:779,513,1,74,QPSK,16,3,0,0,62,0,4,5,2046,0,PASS0,17:13:43:781,513,2,-,-,-,-,-,-,-,-,-,-,-,-,-0,17:13:43:783,513,3,74,QPSK,16,2,0,1,63,0,4,5,2046,0,FAIL0,17:13:43:785,513,4,-,-,-,-,-,-,-,-,-,-,-,-,-0,17:13:43:787,514,0,74,QPSK,25,0,0,0,2,0,4,5,2404,0,FAIL0,17:13:43:789,514,1,-,-,-,-,-,-,-,-,-,-,-,-,-0,17:13:43:791,514,2,-,-,-,-,-,-,-,-,-,-,-,-,-0,17:13:43:793,514,3,-,-,-,-,-,-,-,-,-,-,-,-,-0,17:13:43:795,514,4,-,-,-,-,-,-,-,-,-,-,-,-,-1,17:13:43:797,1,17:13:43:799,1,17:13:43:801,1,17:13:43:803,1,17:13:43:805,0,17:13:43:807,920,0,10,QPSK,19,0,0,0,0,0,4,1,365,0,PASS0,17:13:43:809,920,1,-,-,-,-,-,-,-,-,-,-,-,-,-0,17:13:43:811,920,2,10,QPSK,19,1,0,0,1,0,4,1,365,0,PASS

HS-DSCH Cell Change Break• L1 break is 28 ms between correctly received blocks from Cell A and Cell B• The break is short enough even for seamless VoIP voice service. For reference: the break

in GSM handovers is typically >50 ms.

1

2

1 = Last correctly received transport block from Cell A

L1 log of received transport blocks

2 = First correctly received transport block from Cell B

L1 break = 43:807 – 43:779 = 28 ms

Connected to Cell A

Connected to Cell B


CQI Reports in Live Network

0.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%

14.00%

16.00%

18.00%

CQI_DIS

T_CL_

0 (Hsd

paw)

CQI_DIS

T_CL_

1 (Hsd

paw)

CQI_DIS

T_CL_

2 (Hsd

paw)

CQI_DIS

T_CL_

3 (Hsd

paw)

CQI_DIS

T_CL_

4 (Hsd

paw)

CQI_DIS

T_CL_

5 (Hsd

paw)

CQI_DIS

T_CL_

6 (Hsd

paw)

CQI_DIS

T_CL_

7 (Hsd

paw)

CQI_DIS

T_CL_

8 (Hsd

paw)

CQI_DIS

T_CL_

9 (Hsd

paw)

CQI_DIST_C

L_10

(Hsd

paw)

CQI_DIST_C

L_11

(Hsd

paw)

CQI_DIST_C

L_12

(Hsd

paw)

CQI_DIST_C

L_13

(Hsd

paw)

CQI_DIST_C

L_14

(Hsd

paw)

CQI_DIST_C

L_15

(Hsd

paw)

CQI_DIST_C

L_16

(Hsd

paw)

CQI_DIST_C

L_17

(Hsd

paw)

CQI_DIST_C

L_18

(Hsd

paw)

CQI_DIST_C

L_19

(Hsd

paw)

CQI_DIST_C

L_20

(Hsd

paw)

CQI_DIST_C

L_21

(Hsd

paw)

CQI_DIST_C

L_22

(Hsd

paw)

CQI_DIST_C

L_23

(Hsd

paw)

CQI_DIST_C

L_24

(Hsd

paw)

CQI_DIST_C

L_25

(Hsd

paw)

CQI_DIST_C

L_26

(Hsd

paw)

CQI_DIST_C

L_27

(Hsd

paw)

CQI_DIST_C

L_28

(Hsd

paw)

CQI_DIST_C

L_29

(Hsd

paw)

CQI_DIST_C

L_30

(Hsd

paw)

0.00%

20.00%

40.00%

60.00%

80.00%

100.00%

120.00%

%CDF

70% of time CQI>15 and 16QAM would be used

QPSK 16QAM

Most typical CQI = 18 corresponds to 2.1 Mbps

with BLER=10%

Max ratewith 16QAM


Example Traffic Figures• African customer

• 40 TB/week• 2130 sites ⇒ 20 GB/week/site on average• Peak cells carry >1 Mbps/cell during busy hour and up to 8 GB/day• Approx 400.000 subs ⇒ approx 0.5 GB/sub/month (not flat rate)• HSDPA carrier (two carriers)

• Asian customer• 10 TB/week• 1000 sites ⇒ 10 GB/week/site on average• Single frequency layer shared by R99 and HSDPA

• Middle East customer• 16 TB/week• 800 sites ⇒ 20 GB/week/site on average• Single frequency layer shared by R99 and HSDPA


HSDPA and Iub Capacity


HSDPA & Iub• HSDPA improves Iub efficiency compared to Release’99 packet data since HSDPA is a time

shared channel with a flow control in Iub• Release’99 requires dedicated resources from RNC to UE. Those resources are not fully utilized

during TCP slow start, during data rate variations or during inactivity timer• Additionally, HSDPA does not use soft handover ⇒ no need for soft handover overhead in Iub

= User 1= User 2= User 3

Iub link 1

Iub link 2

HSDPA Iubcapacity

1 2

1 = TCP slow start2 = Inactivity timer

Iub efficiently utilized by HSDPA

21


Achievable Throughputs with 1-3 x E1

Iub 1*E1

• HSDPA throughput is in most cases Iub limited – not radio limited

Approx 400 kB/s = 3.28 Mbps which is max application bit rate with 3.6

Mbps L1 capability terminal

Iub 2*E1

Iub 3*E1


Iub Capacity with Multiple E1s

0.01.02.03.04.05.06.07.08.09.0

10.0

1 x E1 2 x E1 3 x E1 4 x E1 5 x E1 6 x E1 7 x E1

Mbp

s

5-code QPSK UE (Cat 12)5-code 16QAM UE (Cat 6)10-code 16QAM UE (Cat 8)15-code 16QAM UE (Cat 9)Iub limit


Transport Solution Must Support High Data Rates

= Very high data rate solutions beyond 100 Mbps= High data rate solutions beyond 10 Mbps= Voice and low data rate solutions

Ethernet

E1

SHDSL.bis

ADSL2+

LTE

Ethernet

GPON

DSM L3

VDSL2 LTE

PeakData rate Downstream / Downlink Upstream / Uplink

WiMAX

HSPA WiMAX

HSPA

WCDMA

GPON

10 G

1 G

100 M

10 M

1 M

0,1 M

WCDMAEDGE

evolution

EDGE

DSM L3

VDSL2

ADSL2+

ADSL

SHDSL.bis

E1

ADSL

E1

EDGEEDGE

EDGEevolution


HSDPA Terminals


HSDPA Terminals Initially• Data rate 1.8/3.6 Mbps downlink • Data rate 384 kbps uplink• Power class 3 = 24 dBm

Sierra wirelessNovatel Option


Nokia Multimedia HSDPA Terminal N95• HSDPA 3.6 Mbps• 5-megapixel Camera• 2.6” display with 16 M colors• Integrated GPS• WLAN 802.11g• Standard 3.5 mm audio jack• Weight 120 g• Volume 90 cc

• Also E90 Communicator, 6110 Navigator, 6120, E51…


WCDMA High Speed Uplink Packet Access (HSUPA) of Release 6


Outline• HSUPA Introduction• HSUDA Protocol Architecture• HSUPA Retransmissions• HSUPA Peak Bit Rates• HSUPA UE Capabilites• HSUPA Channel Stuctures Uplink and Downlink• Summary


High Speed Uplink Packet Access HSUPA

• Peak data rates increased to significantly higher than 2 Mbps; Theoretically reaching 5.8 Mbps

• Packet data throughput increased, though not quite highnumbers expected as with HSDPA

• Reduced delay from retransmissions.• Solutions

• Layer 1 hybrid ARQ• Node B based scheduling for uplink• Frame sizes 2ms & 10 ms

• Schedule in 3GPP• Part of Release 6• First specifications version completed 12/04

• Not fully mature version (see later 3GPP slides)• In 3GPP specs with the name Enhanced uplink DCH (E-DCH)


RLC

HSUPA Protocol ArchitectureNew MAC entity, MAC-e added to the Node BIn RNC MAC-es handling packet in-sequence delivery & soft handover combiningLayers above, such as RLC, unchanged -> this required MAC-es to performreordering for packetsAdditions to physical layer (WCDMA L1)Additions to user plane Iub/Iur DCH data stream protocol (Frame Protocol)

WCDMA L1

UE

Iub/Iur

SRNCNode B

Uu

MAC

NAS

HSUPA user plane

WCDMA L1

MAC-e

TRANSPORT

FRAMEPROTOCOL

TRANSPORT

FRAMEPROTOCOL

MAC-esMAC-d

IuRLC

MAC-es/e

RLC


Node B Controlled HSUPA Scheduling

• Target is to shorten the packet scheduling period ⇒ packet scheduler is able to track burstiness of source application

Data packet

+ possible retransmissions

+ control for scheduling

ACK/NAK

+ control

Node B RNC

Mac-es

Iub

Mac-e

New Node B functions:Uplink packet data schedulingHARQ control: ACK/NAKs

New Iub signalling

New L1 signalling


0 1 2 3 4 5 6 7 8 9 100

0.1

0.2

0.3

0.4

0.5

0.6

0.7

NR [dB]

PDF of the NR per BTS

Mean: 4.1 (dB) StD: 1.2 (dB)

Mean: 5 (dB) StD: 0.72 (dB)

RNC sheduling Node B scheduling

Fast Scheduling Reduces Noise Variance

• Faster scheduling reduces noise rise variations

⇒ Less headroom needed⇒ Cell capacity and user data

rates are increased• With low loaded uplink, the

users may get significantly higher data rates as much more aggressive data rates can be granted to UEs

Operation point can be increased because variance is reduced.


DCH vs E-DCH Retransmissions

Terminal

BTS

RNC

DCH E-DCH

Packet Retransmission

RLC ACK/NACK

Retransmission

L1 ACK/NACK

Packet(1st TX)

Combining of packetand retransmission


Scheduling in soft handover• There is one serving cell• Serving cell sends either up or down command, also the absolute grant channel is

monitored from serving cell only• Other cells in the active set (assuming they also support HSUPA) send only relative

grant down commands• Those can be configured in such a way that multiple terminals listen to same

command -> overload handling

UEBTSRNC Part of activeset

Serving Cell

Hold/Down

Up/Down/Hold

E-DCH data

E-DCH data

Absolute Grant


Fast Hybrid-ARQ between UE and BTS• Fast ACK/NAK from BTS• N-process Stop-And-Wait (SAW) HARQ (similar to HSDPA)• short round trip delay => lower total delay• Chase combining or Incremental Redundancy, soft buffering in BTS• In SHO, each BTS sends ACK, retransmission if no ACKs

TerminalNode BRNC Correctlyreceived packet

HARQ control and soft combining

ACK/NAK

ACK/NAK

E-DCH data

E-DCH data

PacketReordering


Feedback from UE to BTSThe UE provides the BTS scheduler with (in MAC-e header)• UE buffer occupancy: how much data in RLC buffers • Information about the priority of the data in the buffer• Available transmission power resource

In physical layer (E-DPCCH) the UE provides to BTS the following• E-TFI indicating what is transmitted in the E-DPDCH• Information of the HARQ redundancy version for the packet

• Timing is known, thus BTS knows which ARQ channel to expect

• Happy bit: Is the current data rate satisfactory• UE would not be happy of the data rate if it could transmit with higher rate

due, • I.e. have enough data in its buffers and would have sufficient power resource

to transmit with a higher power than currently

E-DPCCH(L1)

MAC-e PDUon E-DPDCH

(L2)


Adaptive Modulation – Why not with HSUPA?• In the downlink direction, BTS has limited power control dynamics, in the order of

10-20 dB• However in the uplink received power level is kept constant with fast closed loop

power control with more than 70 dB dynamic range• Thus there are no times when there would be “free lunch” to use higher order

modulation

• Other reasons why higher order modulation sounds interesting*…• A) To get more bits per given bandwidth - > range problem• B) To reduce the terminal peak to average ratio as having multicodes in use later ->

This would have resulted to higher average power even if the PAR would have been smallel -> less capacity

* When searching from the web HSUPA info, often one sees adaptive modulationas part of the story. This is based on the outdated stuff from the study item phase


HSUPA Peak Bit Rates Initially 1.46-2 Mbps

• Theoretical peak bit rate up to 5.76 Mbps• Two SF2 and two SF4 codes in parallel• No channel coding, 0% initial transmission BLER

• Initial capability• Two SF2 codes reaches 2 Mbps (with 10 ms TTI)

• Only 10 ms TTI expected to be supported initially

2 x SF4 2 ms10 ms

# of codes TTI

2 x SF2 10 ms

2 x SF2 2 ms

2 x SF2 +2 x SF4 2 ms

1.46 Mbps

Maxdata rate

2.0 Mbps

2.9 Mbps

5.76 Mbps

Phase 1

* Devices not yet published, not 100% realiable…


HSUPA Peak Data Rates• Theoretical peak bit rate up to 5.76 Mbps

• Two SF2 and two SF4 codes in parallel• No channel coding, 0% initial transmission BLER

• Initial capability Category 5 with 2 x SF2 providing 2 Mbps with 10 ms TTI• Ericsson RAN initial support only Category 3 with 2 x SF4 providing 1.46 Mbps

1 x SF4 0.73 Mbps 0.67 Mbps

# of codes 10 ms 10 ms


1

UE category

2

3

4

5




6 2 x SF2 + 2 x SF4 2.0 Mbps 1.88 Mbps

-

2 ms

-

1.46 Mbps

2.9 Mbps

-

5.76 Mbps

-

2 ms

-

1.28 Mbps

2.72 Mbps

-

5.44 Mbps

Max L1 data rate Max RLC data rate


HSUPA structures in more detail


HSUPA building blocks - data path• A new uplink data path below the RLC layer parallel to DCH

• E-DCH - Uplink transport channel • E-DPDCH - Dedicated physical data channel for E-DCH• E-DPCCH - Dedicated physical control channel for E-DCH• Iub Frame protocol frame for E-DCH• E-DCH is parallel to and coexisting with the uplink DCH

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

E-DCH in E-DPDCH,Control in E-DPCCH

MAC-es PDUs

MAC-e PDUs

MAC-es PDUsin E-DCH FP


HSUPA building blocks - HARQ• Uplink HARQ functionality and control

• Synchronous N-process SAW HARQ• Timing of the uplink packet defines to which HARQ process it belongs to• Timing of the downlink ACK/NACK defines which packet is

• E-DPCCH carrying HARQ information to the Node B• E-HICH carrying HARQ ACK/NACK back to the UE• MAC-es in the RNC to reorder the packets arriving in disorder due to HARQ

10 ms

E-DPCCH

E-DPDCH

30 ms between end of 1st TX and start of retransmission (14 ms with 2 ms TTI)

E-HICH

Uplink

Downlink

10 msE-DCH TTI Potential retransmission

Node Bprocessing

Corresponding ACK or NACK

UEprocessing

8 ms


HSUPA UL/DL Timing• For the different TTIs, 2 ms and 10 ms, there is fixed number of ARQ subchannels

• For 2 ms TTI there are 8 ARQ sub-channels• For 10 ms TTI there are 4 ARQ sub-channels, see below

• Note the difference to HSDPA, where number of ARQ sub-channel may be configured (up to 8) + need to signal in downlink which process in used (as e.g. downlink scheduling needs to have timing freedom)

10 ms

E-DPCCH

30 ms (3 TTIs)

E-HICH

ACK/NACK

1st retransmission

E-DPCCH

E-DCHUL

DL

E-DCH

14 – 16 ms 5.5 – 7.5 ms

8 ms

Timing with 10 ms TTI


HSUPA building blocks - Scheduling• Uplink Node B scheduling

• E-RGCH and E-AGCH - DL physical channels for scheduling control• Happy-bit on UL E-DPCCH to indicate Node B of the instantaneous UE status• Scheduling Info in MAC-e header to give Node B more detailed information

BTS

UE

E-DPCCH (happy bit)

E-RGCH (Relative Grant)

E-AGCH (Absolute Grant)

E-DPDCH (SI in MAC-e header)

• RG and AG control the UE’s maximum allowed E-DPDCH to DPCCH power ratio• RG carries one bit only: UP/DOWN by one step relative to currently used max E-DPDCH/DPCCH power ratio• AG carries a command informing the UE of the E-DPDCH/DPCCH power ratio to be used at maximum

• Happy-bit and SI provide the Node B with information of the UE’s status• See a separate slide

• RNC is a master that provides the Node B scheduler with limits• RNC can allocate non-scheduled transmissions for specific data flows over which the Node B has no

control over• Control over specific HARQ processes and data flows


Physical channels with HSUPA, HSDPA and DCH

BTS

UE N x E-DPDCH (E-DCH)

DPCCH (Pilot, TPC, TFCI)*DPDCH (DCHs)

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

DPCCH (Pilot, TPC, TFCI)DPDCH (DCHs)

HS-DPCCH (CQI, ACK/NACK)

HS-SCCH (TFRI, HARQ info)

E-RGCH (RG)E-AGCH (AG)

E-HICH (ACK/NACK)

N x HS-PDSCH (HS-DSCH)

UPLINK• DPCCH is always present• DPDCH needed for DCH• HS-DPCCH used for HSDPA feedback• E-DPCCH needed if E-DCH transmitted• E-DPDCH needed if E-DCH transmitted

DOWNLINK• DPCCH is always present*• DPDCH used for DCH• HS-SCCH needed if HSDPA transmitted• HS-PDSCHs needed if HSDPA transmitted• E-RGCH needed if RG transmitted• E-AGCH needed if AG transmitted• E-HICH needed if E-DCH received

* Downlink DPCCH could be replaced with F-DPCH (TPC only) if no DL DCH configured


Uplink physical control channels with HSUPA• DPCCH is required for power control and uplink channel estimation

• Must be present even if the DPDCH is not used (and HS-DPCCH if HSDPA is used)

• E-DPCCH - (E-DCH Dedicated Physical Control Channel)• Delivers 10 information bits related to the E-DPDCH transmitted in parallel

• Retransmission Sequence Number for HARQ, 2 bits• Happy-bit for scheduling, 1 bit• E-TFCI 7 bits

• SF256 physical channel (10 channel bits per slot)• 30 channel bits result with 2 ms sub-frame

• With 10 ms E-DCH TTI the 2 ms sub-frame is repeated 5 times

Data: 10 info bits coded to 30 channel bits E-DPCCH

3 slots, 7680 chips

2 ms Sub-Frame

Slot#i Slot#14

10ms Radio Frame

Slot#0 Slot#1 Slot#2

Data: 10 info bits coded to 30 channel bits E-DPCCH

3 slots, 7680 chips

2 ms Sub-Frame

Slot#i Slot#14

10ms Radio Frame



E-DPCCH Coding

• Control information on E-DPCCH is multiplexed: •E-TFCI information (7 bits)•Retransmission sequence number (RSN, 2 bits)•‘Happy bit’ (Rate Request, 1 bit)

• Channel Coding: a sub-code of the second order Reed-Muller Code (similar to rel’99/4/5 TFCI coding)

• Physical Channel Mapping: similar to rel’99/4/5, channel coding output bits are mapped to the allocated E-DPCCH

E-DPCCH

Physical channel mapping

Multiplexing

xh,1 xrsn,1, xrsn,2

Channel Coding

xtfci,1, xtfci,2,..., xtfci,7

x1, x2,..., x10

z0, z1,..., z29

Coding chain for E-DPCCH


Uplink physical data channel with HSUPA• DPDCH is needed if uplink DCHs are configured (AMR speech etc.)• E-DPDCH (E-DCH Dedicated Physical Data Channel)

• Used to transmit the coded E-DCH transport channel• Turbo coding, 24 bit CRC, HARQ with incremental redundancy• SF 256/128/64/32/16/8/4/2 (SF 256/128 late additions!)• Two TTI lengths supported, 2 ms and 10 ms

• 10 ms TTI better from Range point of view

Data: 2560/SF bitsE-DPDCH

1 slot, 2560 chips, 2560/SF b its

2 ms Sub-Frame

Slot#i Slot#14

10ms Radio Frame


Data: 2560/SF bitsE-DPDCH

1 slot, 2560 chips, 2560/SF b its

2 ms Sub-Frame

Slot#i Slot#14

10ms Radio Frame



HSUPA Physical channels in the downlinkE-HICH & E-RGCH share the same structure and the same code channel

• E-HICH transmits one ACK/NACK per received uplink E-DCH TTI• E-RGCH transmits UP/DOWN (dtx for hold) scheduling commands• A 40-bit long orthogonal sequence is QPSK modulated and sent in one slot.

• Up to 40 sequences can be fitted in one SF128 code channel• E-HICH and E-RGCH meant to a UE must be in the same code channel

• 3-slot long (2 ms) sub-frame is formed by concatenating 3 sequences• E-HICH length

• 2 ms - From all cells in the E-DCH active set with 2 ms E-DCH TTI• 8 ms - (4 times repetition) from all cells in the E-DCH AS with 10 ms TTI

• E-RGCH length• 2 ms - Sent by the Serving HSUPA RLS with 2 ms E-DCH TTI• 8 ms - (4 times repetition) Sent by the Serving HSUPA RLS with 10 ms E-DCH TTI• 10 ms - (5 times repetition) Sent by cells not belonging to the Serving HSUPA RLS

Slot #14

Tslot = 2560 chip

bi,39bi,1 bi,0

Slot #0 Slot #1 Slot #2 Slot #i

1 radio frame, Tf = 10 ms

1 subframe = 2 ms E-HICH/E-RGCH(sub-)frame structure


HSUPA Physical channels in the downlinkE-AGCH• SF256 channel transmitting 6 information bits and a 16-bit

UE-specific CRC• 5 bits for E-DPDCH/DPCCH power ratio• 1 bit for process applicability• 16-bit CRC used to identify to which UE the AG is for

• 1/3 convolutional coding, resulting 72 bits• 2 ms sub-frame structure, 60 channel bits per sub-frame• 12 bits from the 72 punctured away to fit in the subframe• Sub-frame is repeated 5 times when 10 ms E-DCH TTI is used

Slot #1 Slot #14Slot #2 Slot #iSlot #0

Tslot = 2560 chips

1 subframe = 2 ms

1 radio frame, Tf = 10 ms

E-AGCH 20 bits

Channel coding

xag,1, xag,2,..., xag,w

Rate matching

ID specific CRC attachment

Physical channel mapping

y1, y2,..., yw+16

z1, z2,..., z3x(w+24)

E-AGCH

r1, r2,..., r60

Coding chain for E-AGCH

E-AGCH (sub-)frame structure


E-DCH (E-DPDCH) Coding• One transport block once per TTI• 24 bit CRC • Code block segmentation similar to DCH• 1/3 turbo coding (as rel’99)• Most of the blocks similar to Release’99• HARQ handling additional functionality

CRC attachment

Code block segmentation

Channel coding

Physical layerHARQ functionality/

rate matching

Physical channel segmentation

E-DPDCH#1 E-DPDCH#n

Transport block

E-DCH

Interleaving and physical channel mapping

CRC attachment

Code block segmentation

Channel coding

Physical layerHARQ functionality/

rate matching

Physical channel segmentation

E-DPDCH#1 E-DPDCH#n

Transport block

E-DCH

Interleaving and physical channel mapping


HSUPA and DCH co-existance• For an existing user, E-DCH users will only show as part

of the interference variations (at BTS receiver)• -> Thus mixing DCH & E-DCH users is not a problem• The load variation caused by DCH users are not under BTS

control (but under slower RNC based method)

• Depending on the allocation, there can be allocated both E-DCH and DCH for the same terminal

• E.g. with AMR speech call active while having packet data connection on-going

• This allows smooth introduction for the network as separate carrier is not needed until single carrier capacityfully utilised


HSDPA vs HSUPA Concepts

HSDPAHSDPA HSUPAHSUPA

ModulationModulation QPSK and 16-QAMQPSK and 16-QAM BPSK and Dual-BPSKBPSK and Dual-BPSK

Soft handoverSoft handover NoNo YesYes

HSUPA is like “reversed HSDPA”, except

Fast power control

Fast power control NoNo YesYes

SchedulingScheduling Point tomultipointPoint to

multipointMultipoint

to pointMultipoint

to point

Non-scheduled transmission

Non-scheduled transmission NoNo Yes, for minimum/

guaranteed bit rateYes, for minimum/guaranteed bit rate

Required for near-far avoidance

Efficient UE power amplifier

Scheduling cannot be as fast as in HSDPA

Similar to R99 DCH but with HARQ

HSUPA could be better described as Enhanced DCH in the uplink than “reversed HSDPA”


HSUPA vs UL DCH

Feature

Variable spreading factor

Fast power control

Adaptive modulation

BTS based scheduling

DCH

Yes

Yes

No

No

HSUPA

Yes

Yes

No

Yes

Fast L1 HARQ No Yes

HSDPA

No

No

Yes

Yes

Yes

Multicode transmission Yes(No in practice)

Yes Yes

HSUPA (E-DCH) is an uplink DCH with Node B based HARQ and scheduling and true multicode support

Soft handover Yes Yes No(associated DCH only)


HSUPA Iub signaling• Parameters for Node B resource allocation , to indicate e.g. which codes to use for

DL signaling channels, which signatures to use for which UE etc.• Scheduler parameters, to control the scheduler behavior, such as scheduling priority

and guaranteed bit rate• Terminal specific parameters, such a terminal capability and peak rate to be used

Node B RNC

Iub Iu-ps

PSCore

QoSparameters

UE capabilityScheduling

priority, resources, data

rates …

Data

Control


HSUPA - Summary• Node B based uplink scheduling and HARQ for improved performance• Adaptive modulation not part of HSUPA as power control maintained• HSUPA is backwards compatible and can be introduced gradually in the

network.• Fundamental differences to DCH not big as with HSDPA


HSUPA Performance


Benefit of Fast Retransmissions

10−2

10−1

100

0

1

2

3

4

5

6

BLEP at 1st transmission

Eff

ectiv

e E b/N

0 [dB

]

No HARQHARQ (IR)

0.8 dB gain providing 20% higher cell

throughput

• HSUPA allows to use higher BLER because of fast retransmissions

R99

HSUPA


Benefit of Node-B Based Fast Scheduling

1 2 3 4 5 6 7 80

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Noise Rise [dB]

Prob

abili

tyVA 3 km/h − 20 users/cell − 5% NR outage = 6 dB

RNC PS

Node B PS

5-10% cell throughput gain


HSUPA Capacity

Uplink cell throughput [kbps]

0

200

400

600

800

1000

1200

1400

1600

WCDMA R99 HSUPA

kbps

Release’99

HSUPA


-120 -115 -110 -105 -100 -95 -90 -85 -800

200

400

600

800

1000

1200

1400

1600

1800

2000

RLC

dat

a ra

te [k

bps]

RSCP [dBm]

HSUPA Coverage

High data rates if RSCP > -100 dBm

Uplink data rate limited by

UE tx power


Coverage of high data-rate

Coverage gain 0.5 – 1.0 dB

UE capabilitybeyond 384 kbps

Peak data rate1.4-5.8 Mbps

Capacity gain 20-

50%

Cell throughput

gain

Latency gain<50 ms

Quality of end user

experience

HSUPAHSUPA

Lower costs in transport

Iub capacity gain

Higher add-onPS Traffic

Savings in BB capacity costs

Saves BTS sites (~10%) and adds PS traffic

Savings in transport – in Dedicated VCCsolution max 25%

Higher add-onPS traffic

HSUPA Performance Gains


HSUPA Status in 3GPP


HSUPA Standardisation Timeline• 03/04 Study item for 3GPP Release 6 completed and work item initiated• 12/04 First versions of HSUPA specs published• 03/05 Official work item completion date for RAN1/RAN2/RAN3• 06/05 Specifications stabilising• 09/05 Remaining open issues closed• 09/05 Performance requirement work item completion (RAN4) • 03/06 ASN.1 of RRC, NBAP and RNSAP protocols freezing

• Backwards compatibility started

2003 2004 2005 2006

3GPP study item

Study item completed

1st version in 3GPP spec

Official work item completion date

2007

Issues closed, performance

WI closed

ASN.1 frozen


Key 3GPP specifications affected by HSUPA• TS25.309; FDD Enhanced Uplink; overall description; Stage 2

• 06/05 version (v. 6.3.0) is quite mature, no major open issues • TS25.211 - 25.215; Physical layer specifications

• 06/05 versions are mature and practically complete• TS25.306; UE radio access capabilities

• 06/05 version has the HSUPA UE categories,• TS25.321; MAC specification

• 06/05 version is still not fully stabile, user plane data flow is finalised, but the UE interaction with the scheduling commands requires further work

• TS25.331; RRC Protocol Specification• 06/05 version requires still further work to align with stage 2 and physical layer.

• TS25.423/25.433; RNSAP/NBAP signalling• 06/05 versions quite mature, some alignment to stage 2 and L1 still to be done

• TS25.427; Iur/Iub user plane protocols for DCH data streams• 06/05 version is mature and complete

• Performance requirement specifications TS25.101, 104, 133, 141• And others…


HSUPA measurements in Lahti 10.9.2007Elisa Network, Ericsson RAN


Tested card• Option GlobeTrotter GT MAX HSUPA PCMCIA modem

• Engineering sample• Drivers 5.1.0.1071• Firmware 2.7.0


HSUPA Latency in the Field

• HSUPA brings network latency below 70 ms• HSUPA improves latency by 20 ms compared to HSDPA + R99

uplink

90 ms 84 ms

69 ms 65 ms

HSDPA

HSDPA + HSUPA

Ericsson Lahti live Nokia VF trialChannel

21 ms 19 msImprovement with HSUPA


HSUPA Latency <45 msNSN – Nokia End-to-end Measurement

Nokia HSUPA terminal

prototypeNode-B RNC Packet core

ServerNokia Siemens networks

Minimum = 38ms, Maximum = 57ms, Average = 42msMinimum = 38ms, Maximum = 58ms, Average = 45msMinimum = 39ms, Maximum = 52ms, Average = 41msMinimum = 39ms, Maximum = 51ms, Average = 41ms

Lab measurements

05

101520253035404550

Latency

ms

RNC + coreBTS + IubAir interfaceUE


HSUPA Throughput with FTP• The bit rate steps are explained by the scheduling grant resolution

840 kbps

560 kbps

710 kbps


HSPA Evolution


UTRAN Evolution

• Best CS + PS combined radio• Spectrum shared with current 3G• Reduced latency• Lower mobile power consumption• Flat architecture option• Simple upgrade on top of HSPA

HSPA evolution in R7/R8

HSPA evolution in R7/R8

LTE new radio access in R8

LTE new radio access in R8

HSDPA/HSUPA3GPP R6

HSDPA/HSUPA3GPP R6

• Optimized for PS only• New architecture• New modulation• Spectrum and bandwidth flexibility• Further reduced latency

Similar technical solutions applied both in HSPA evolution and in LTE


3GPP Evolution in Release 5 – Release 8

HSPA R6HSPA R6 HSPA R7HSPA R7

• HSUPA 5.76 Mbps

• MBMS

• Continuous packet connectivity

• L2 optimization in downlink

• Enhanced FACH• Flat architecture• MIMO • 64QAM downlink• 16QAM uplink• MBMS evolution

HSPA R5HSPA R5

• HSDPA 14 Mbps

HSPA evolution

3GPP R83GPP R8

Long term evolution (LTE) +Further HSPA evolution

Basic HSDPA+HSUPA

• LTE: New PS only radio• L2 optimization in uplink• Enhanced RACH• Enhanced UE DRX • Flat architecture

enhancements• CS voice service over HSPA• 64QAM+MIMO • Downlink only broadcast • Synchronized E-DCH.


HSPA Deployment Schedule

2004 2005 2006 2007 2008 2009 2010

Commercial

3GPP schedule

3GPP R6 3GPP R83GPP R7

3GPP R5 3GPP R6 3GPP R7 3GPP R8

20032002

3GPP R5

• HSUPA commercial 2007• HSPA evolution commercial 2009• LTE commercial 2010 and beyond


MIMO and 64QAM


HSPA Peak Data Rate Evolution• HSPA downlink data rate increases with 2x2 MIMO and 64QAM up to 42 Mbps and

uplink data rate with 16QAM up to 11 Mbps• LTE further increases the data rate beyond 100 Mbps with larger bandwidth of 20 MHz

14 Mbps

0.4 Mbps

14 Mbps

5.7 Mbps

28 Mbps1

11 Mbps

LTE: 170 MbpsHSPA: 42 Mbps2

LTE: 50 Mbps

Downlink peak rate

Uplink peak rate

3GPP R5 3GPP R6 3GPP R71 3GPP R8

1With 2x2 MIMO and 16QAM2With 2x2 MIMO and 64QAM likely for R8


Category Codes Modulation MIMO Coding rate Peak bit rate 3GPP release 12 5 QPSK - ¾ 1.8 Mbps Release 5 5/6 5 16QAM - ¾ 3.6 Mbps Release 5 7/8 10 16QAM - ¾ 7.2 Mbps Release 5 9 15 16QAM - ¾ 10.1 Mbps Release 5 10 15 16QAM - Approx 1/1 14.0 Mbps Release 5 13 15 64QAM - 5/6 17.4 Mbps Release 7 14 15 64QAM - Approx 1/1 21.1 Mbps Release 7 15 15 16QAM 2x2 5/6 23.4 Mbps Release 7 16 15 16QAM 2x2 Approx 1/1 28.0 Mbps Release 7

Terminal Categories in Release 7

Category TTI Modulation Coding rate Peak bit rate 3GPP release 3 10 ms QPSK ¾ 1.4 Mbps Release 6 5 10 ms QPSK ¾ 2.0 Mbps Release 6 6 2 ms QPSK 1/1 5.7 Mbps Release 6 7 2 ms 16QAM 1/1 11.5 Mbps Release 7

HSDPA

HSUPA


MIMO in HSDPA in Release 7• MIMO for HSDPA is based on D-TxAA (Double Transmit Adaptive Array) with fast L1

feedback• 2x2 MIMO peak data rate 28 Mbps with 16QAM and up to 42 Mbps with 64QAM

+

+

Coding, spreading

Coding, spreading

Demux

Base stationFeedback weights from UE Terminal

2 antennas & MIMO decoding capability

Transmitter with 2 branches per sector


MIMO Modes

High CQI Multistreamtransmission

Low CQISingle stream

diversitytransmission

• Single stream transmission is similar to Release’99 closed loop transmit diversity, but with twodifferences

• The preferred antenna weights are delivered from UE to Node-B on HS-DPCCH, not on DPCCCH

• The used antenna weights in downlink are signaled on HS-SCCH while in Release 99 no explicit signaling was used. Therefore, Release 99 UE had to use antenna verification to identify the used antenna weights.

• Double data rate

• Interference resistance


MIMO Multistream Usage in Macro Cells

Percentage of MIMO Multistream Usage

0 %

10 %

20 %

30 %

40 %

50 %

60 %

70 %

80 %

90 %

100 %

Vehicular A,round robin

Pedestrian A,round robin

Vehicular A,proportional fair

Pedestrian A,proportional fair

Multistream usage15% with round

robin

Multistream usage70% with

proportional fair


64QAM Modulation in Release 7

QPSK 2 bits/symbol

16QAM 4 bits/symbol

64QAM 6 bits/symbol

• R5/R6 HSPA modulation• Dowlink QPSK and 16QAM• Uplink QPSK

• R7 HSPA modulation• Dowlink QPSK, 16QAM and 64QAM• Uplink QPSK and 16QAM


Percentage of 64QAM usage

0 %

10 %

20 %

30 %

40 %

50 %

60 %

70 %

80 %

90 %

100 %

Vehicular A,round robin

Pedestrian A,round robin

Vehicular A,proportional fair

Pedestrian A,proportional fair

1-rx2-rx

64QAM Usage in Macro Cells

64QAM usage 20% for 2-antenna

terminals64QAM usage 10%

for 1-antenna terminals

64QAM usage 35% in favorable case

• These simulations with full loading. 64QAM usage is higher in fractional load case. • If 2x2 MIMO is used, then 64QAM usage is <<10%.


Cell Capacity with Enhanced Terminals and R7 FeaturesCell throughput

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

HSPA 1-Equalizer(no 64QAM)

HSPA R7 2-Equalizer (no

MIMO, no 64QAM)

HSPA R7 withMIMO, no 64QAM

HSPA R7 withMIMO+64QAM

Mbp

s

+40%

+20%


Uplink 16QAM


Performance of Uplink 16QAM with Equalizer

• Up to 2x higher data rate in multipath channel with equalizer receiver compared to Rake receiver

Rake receiver BTS equalizer

Max 3.3 Mbps with Ec/N0=15 dB

Above 7 Mbps with Ec/N0=15 dB


Enhanced Cell FACH (High Speed FACH)


Enhanced Cell_FACH Concept

FACH HS-DSCH

S-CCPCH HS-PDSCH

HS-DSCH HS-DSCH in CELL_DCH state

HS-PDSCH

R99 solution R7 solution

• Benefits1. Seamless state transition since no physical channel reconfiguration2. Higher bit rate on CELL_FACH state (today 32 kbps for data)3. No changes to Release 5 physical channels (HS-DSCH and HS-SCCH)

32 kbps Up to 14 Mbps Up to 14 Mbps

Cell_FACH state Cell_FACH state


Fast State Transitions with Enhanced FACH

PCH

FACH

DCH/HSPA

No data flow during transition >500 ms

Cell update and C-RNTI allocation takes >300 ms

RB recon-figuration

RB recon-figuration

PCH

HS-FACH

HSPA

Data flows on HS-FACH also during transition

Immediate transmission w/o cell update. No PCH required.

Release 99 – Release 6 RRC States

Release 7 RRC States


Optimized Layer 2


RLC

MAC-hs

…

IP packet 1500 B

UE

Node-B

RNCPDCP

RLC packet 40 B

3GPP Release 6

…

RLC

MAC-hs

IP packet 1500 BPDCP

RLC packet size flexible between 10B -1500 B

3GPP Release 7

…

Transport block size depending on scheduling

Transport block size depending on scheduling

…

MAC + RLC + PDCP MAC + RLC + PDCP

Optimized Layer 2 Concept (Flexible RLC)

• Basic RLC functions are kept: Ciphering, polling, retransmission• Smaller RLC overhead• Less packet processing required in UE and in RNC • No RLC optimization required for each service


Optimized Layer 2 – RLC Header + Padding Overhead

0 %5 %

10 %15 %20 %25 %30 %35 %40 %45 %50 %

0 500 1000 1500IP packet size

Release 6 RLC (40-B RLC packet)Release 7 RLC (Flexible RLC)

Rel6: RLC PDU header 2 bytes; PDU size fixed to 336 bitRel7: RLC PDU header 2 bytes; PDU size flexible from 80 – 12000 bits


Continuous Packet Connectivity


Continuous Packet Connectivity in 3GPP R7

• Continuous packet connectivity includes 1. Uplink discontinuous transmission2. Downlink discontinuous reception3. HS-SCCH less HSDPA for VoIP

• Continuous packet connectivity gives• Low mobile power consumption for packet applications• Higher capacity due to less interference transmitted

DPCCHHS-DSCH

DPCCHHS-DSCH

Web page download

User reading web page

User moved to FACH/PCH

Connection goes immediately to gating mode to save mobile power when data transfer is

over

HSPA R6

HSPA R7


Continuous Packet Connectivity for VoIP

• Continuous packet connectivity improves also the capacity of low data rate services, like VoIP

• Data can be transmitted in short bursts and discontinuous operation can be utilized between the bursts

HSPA with continuous packet connectivity

DPCCHDPDCHWCDMA R99 CS voice

No transmission ⇒ lesspower consumption and less

interference

20 ms


UE Radio Modem Power Consumption

Power consumption relative to continuous rx/tx

0 %10 %20 %30 %40 %50 %60 %70 %80 %90 %

100 %

Tx/(Rx+Tx)=30% Tx/(Rx+Tx)=50% Tx/(Rx+Tx)=70%

VoIP call (2-ms TTI)Inactive user on Cell_DCH

VoIP assumptions - E-DCH activity 15%- DPCCH activity during E-DCH inactive 10%- DRX 60%

Inactive user- E-DCH activity 0%- DPCCH activity during E-DCH inactive 10%- DRX 80% 70% savings in

VoIP calls85% savings when inactive


Uplink Gating Gain for VoIP Capacity

• Reference case: Release 6 HSUPA

• Different configurations studied for signaling

• OFF=0 means CQI sent simultaneously with data

• OFF=3 means CQI sent after data

• From simulations it can be though concluded that for 50% improvement for uplink VoIP capacity could be achieved

Gating capacity gain 50%


0

20

40

60

80

100

120

140

160

WCDMA R99 CSvoice

HSPA R6 VoIP HSPA R7 VoIP

Use

rs

Downlink Uplink

VoIP Capacity• HSPA R7 VoIP can provide up to 2x higher voice capacity than CS

voice

2x

AMR12.2 kbps


VoIP Optimization Features in 3GPP Release 7

Packet bundling

Packet retransmissions

L1 control overhead

Packet scheduling

Packet bundling

Retransmissions possible due to fast L1 ARQ

Low overhead due to fractional DPCH and discontinuous uplink

Advanced HSDPA scheduling

HSPA VoIP of Release 7

Single packet transmission

Retransmissions not possibledue to excessive delay

Continuous L1 control channel

No scheduling

CS voice of Release 99

Advanced terminals HSDPA equalizer No equalize


0

10

20

30

40

50

60

GSMEFR

GSMAMR

GSMDFCA

WCDMACS voice

HSPA R7 LTE

Use

r per

MH

z

Voice Spectral Efficiency Evolution from GSM to LTE

• 20 x more users per MHz with 3GPP LTE than with GSM EFR!• VoIP is the way to go for future voice in mobile systems

CS voice VoIP


Round Trip Time Evolution


HSPA Round Trip Time

1 2 ms2 ms

1 12 ms

1.3 2 ms1

AlignHSUPA TTI

Node-B rxRNC+core

Node-B txAlign+SCCH+HSDPA TTI

Network RTT 13.3 ms

1 2 ms1.3 2 ms1

TTI align HSUPA TTI

Align+SCCH+HSDPA TTI

7.3 ms

x msUE tx

x msUE rx

Realistic RTT with HSPA evolution

3GPP limit for RTT (theory)

= UE processing time

= TTI alignment = 0..1 x TTI

= Air interface transmission time

= Network processing times

• End-to-end round trip time <30 ms expected with HSPA


MBMS Release 6

MBMS Release 7

Same scrambling code in all cellsDifferent cells = multipath propagation

Different scrambling codes Different cells = inter-cell interference

Single Frequency MBMS

Carrier can be shared with unicast

Dedicated MBMS carrier required


HSPA+ Architecture Evolution


Architecture EvolutionPacket Domain User Plane

HSPA (3GPP R6)

I-HSPA (3GPP R7)

LTE (3GPP R8) WiMAX

Node-B

RNC

SGSN

GGSN

Node-B with RNC functions

GGSN

eNode-B

SAE GW ASN GW

Base station

• Flat architecture = single network element in user plane in radio network and in core network

• Same architecture in I-HSPA, LTE and in WiMAX

Ciphering and header compression


I-HSPA Specified as Part of 3GPP Release 7

• 3GPP Release 7 has specified flat architecture for HSPA • A change to RANAP specification to extend the RNC-ID to allow it

to be longer than 4096 values• “Introduction of an Extended RNC-ID IE”• TS25.331, TS25.413, TS25.423, TS25.433, TS25.453, TS48.008, TS48.018

• A clarifying description how existing 3GPP functionalities can be used to allow UE mobile-originated and mobile-terminated CS call re-direction

• TR25.999, Section 7.1.4.4 CS Service in stand-alone scenario: “Evolved HSPA system focuses on PS services. Due to the PS optimized architecture in the stand-alone scenario, the HSPA UE should be served in the evolved HSPAwhen it requests a PS service only, and in the legacy architecture (WCDMA or GSM) when it requests a CS service…”

• Carrier sharing solution between RNC based architecture and flatarchitecture accepted using UE involved SRNS relocation procedure

• Soft handover optimization for Signalling Radio Bearers was included to Iur specifications


HSPA Evolution in Release 8


New Release 8 Items for HSPA Evolution Approved in 3GPP RAN September 2007

Work item Nokia/NSNWork item Nokia/NSN

Enhanced Uplink for CELL_FACH State in FDDEnhanced UE DRX

Work or study item RaporteurTitle

Work item Nokia/NSNSRNS Relocation Enhancement

05/0809/08

Target completion

03/08Work item Nokia/NSNEnhancement for HSPA Architecture 06/08Work item EricssonImproved L2 for uplink 03/08Work item Nokia/NSNCS voice service over HSPA 03/08Work item VodafoneHSDPA demodulation requirements for

16QAM and QPSK with 15-codes 06/08

Work item Ericsson64QAM+MIMO 03/08Work item EricssonDownlink only broadcast 06/08

Study item Nokia/NSNSynchronized E-DCH 03/08

Note: 6 out of 8 new items have Nokia/NSN as raporteur

New items in Release 8

Continuation from Release 7


3. UL data transmission4. MAC-e header with UE-id for

contention resolution

5. Collision resolution:UE id is returned on E-AGCH

#0 #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #12#13#14#11DPCCHE-DPCCHE-DPDCH

#0 #1 #2 #3 #4 #5 AICHE-AGCH

E-HICH E-HICH E-HICH

#0 #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #12#13#14#11 #0 #1 #2 #3 #4 #5DPCCH DPCCH DPCCHE-DPCCHE-DPDCH

1. PRACH preamble ramp-up phase with PRACH sub-channels and/or PRACH signaturesequences reserved for enhanced RACH

2. Acquisition indication and E-DCHresource allocation, extended AICH

6. E-DCH with a new data rate after reception of E-AGCH

F-DPCH

E-DPCCH

E-DPDCH

E-DPCCH

E-DPDCH

Enhanced RACH Item (One Proposal Below)• Fast access to high data rates also in uplink to complement R7 Enhanced FACH


Enhanced UE DRX Item• UE must decode all FACH frames in Release 7 ⇒ receiver is running continuously

eating batteries• The target in Release 8 is to enable Discontinuous reception (DRX) on FACH• Example keep alive transmission below, where FACH DRX can lead to

considerable battery savings• The work item also explores the state transition to PCH without any RRC signalling

RACH

FACH in R7

= Keep alive transmission

= No data coming to UE, but UE must still decode all FACH frames

FACH in R8 = UE uses discontinuous reception when no data coming


HS-DSCH

E-DCH

Cell_DCH Cell_FACH Cell_PCH

PCH

Direct mapping to HS-SCCH

DRX in Release 7 DRX in Release 8 Long DRX periods (>500 ms)

DTX in Release 7 Transmission only when needed

RRC States in 3GPP Release 7/8• The RRC states remain in Release 7/8 (DCH, FACH, PCH, idle), but the states will

have more similarities and the state transitions will be faster• Similar transport channels in DCH and FACH• DRX can be used in all states

• DRX period longer in PCH state than in DCH or FACH


Improved L2 in Uplink

• Follows the same principle that was applied in downlink in Release 7• The benefits

• Reduced L2 overhead MAC + RLC• Lower processing power requirements in UE and in RNC• No RLC optimization required per service


CS Voice over HSPA Concept• The target to use HSPA transport channels for carrying CS voice service to get end

user and operator performance benefits• No difference from service point of view compared to current CS voice : CS core is

not aware of radio mapping and roaming and charing remains the same• No changes to HSPA Layer 1 required

DCH

CS core

HS-DSCH + E-DCH

PS core

Transport channel

Layer 2 TM RLC UM RLC

PDCP1

1IP header compression2TM=transparent mode3UM=unacknowledged mode

Under discussion

Dejitter bufferApplication layer

Current CS voice VoIPCS voice

over HSPA


CS Voice over HSPA Benefits Compared to CS Voice over Release 99 Channels

• Improved talk-time• Uplink gating and downlink DRX can be used according to Release 7

Continuous packet connectivity (CPC)• Talk time improvement expected clearly more than 50%

• Faster call setup time• Core signalling runs fast on HSPA• HSPA allows asynchronous RAB Setup without slow DCH reconfiguration

procedures• UE-UE call setup time could ideally be below 1 s

• Higher capacity• Equaliser, L1 retransmissions, uplink gating, HS-SCCHless features.• No VoIP related overhead required : no IP, RTP headers


CS Voice over HSPA – Dejitter Buffer

• L1 retransmissions and downlink scheduling will cause delay fluctuations. The order of the packets may also change in L1 processes

• Dejitter buffer is required in RNC in uplink and internally in UE in downlink to hide the delay variations

• Dejitter buffers are not specified in 3GPP. The requirements for UE VoIPdejitter developed in 3GPP (memory, etc) can be reused for CS-HSPA

RNC12 3 4 1 2 3 4 CS core

Dejitter buffer in RNC


Synchronized E-DCH – Motivation • HSPA uplink cell throughput is low compared to traffic requirements and compared to

LTE• Expected traffic asymmetry DL:UL 2:1• HSPA downlink is 72% x LTE while uplink is 45% x LTE

• ⇒ Preferably 50% uplink cell throughput gain required in HSUPA

Cell throughput 5 MHz

0

1

2

3

4

5

6

7

8

9

10

Downlink Uplink

Mbp

s HSPALTE


Synchronized E-DCH Concept• Orthogonal uplink transmission by using the same scrambling code for all intra-cell

users with synchronous transmission. • Expected uplink capacity gain up to 70% in macro cells

• Simple upgrade to terminal transmission and BTS reception since existing channels are used

• Soft handover less important than in HSUPA R6 ⇒ well suited for I-HSPA • Required changes to 3GPP specifications and implementations

• new downlink scheduling channels• slow timing advance adjustment • updated scheduling algorithm

• Node-B based scheduling in HSUPA makes synchronous transmission more feasible compared to 3GPP USTS 2001


Synchronized E-DCH Code Allocation• Uplink code tree allocation given with HS-SCCH like channel (CRC for reliability) with 2 ms x

N duration (range for N to be defined) based in happy bit/HSUPA MAC header info

C1(0) = [ 1 1 ]

C1(1) = [ 1 0 ]

C2(0) = [ 1 1 1 1 ]

C2(1) = [ 1 1 0 0 ]

C2(2) = [ 1 0 1 0 ]

C2(3) = [ 1 0 0 1 ]

C3(0) = [ 1 1 1 1 1 1 1 1 ]

C3(1) = [ 1 1 1 1 0 0 0 0 ]

. . .

. . .

SF = 2 SF = 4 SF = 8

C3(2) = [ 1 1 0 0 1 1 0 0 ]

C3(3) = [ 1 1 0 0 0 0 1 1]

. . .

. . .

C3(4) = [ 1 0 1 0 1 0 1 0 ]

C3(5) = [ 1 0 1 0 0 1 0 1 ]

. . .

. . .

C3(6) = [ 1 0 0 1 1 0 0 1 ]

C3(7) = [ 1 0 0 1 0 1 1 0 ]

. . .

. . .

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

Code allocated with “HS-CACH”

These codes cannotbe used at the same

time as C3(1)

Codes at SF 256 allocated each users DPCCH and E-DPCCH


Synchronized E-DCH Timing Control and Soft Handover

• No soft handover intended for data (as other Node B would have to detect the code allocation blindly (not desirable to signal all the time, keeping E-DPCCH unchanged expect spreading/scrambling code different that usually)

• F-DPCH+ provides now both power control and uplink timing control (latter e.g. by puncturing some of the power control commands

• Timing adjustment resolution e.g. 1/6 to ¼ chips in order not to mandate a particular sampling rate

• Timing advance command rate max. 40 Hz (investigated in 2001 with USTS)

Node B

Node B

F-DPCH

F-DPCH+, O-HSUPA, HSDPA


Architecture Work Items• SRNS Relocation Enhancement

• Approved as the continuation of the HSPA Architecture Evolution work, aiming at optimizing the relocation procedures. The results may be applicable for both “legacy”and “flat” UTRAN architectures.

• Enhancement for HSPA Architecture• Continuing the HSPA architecture evolution work on the topics of e.g., optimizing the

RRM and introducing MBMS for a flat architecture.

Documents

HSPA