1HSDPA: Speeding-Up Wireless Data in Practice

Andrea Garavaglia and Matthias SchulistQUALCOMM

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Outline

QUALCOMM Engineering Services

High Speed Downlink Packet Access (HSDPA)

HSDPA Performance Throughput Latency

Advanced HSDPA Performance

Outlook: HSUPA

Conclusions

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QUALCOMM Engineering Services

ESGLocations:San Diego | NrnbergIndia | Hong Kong | South Africa | Middle East

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Service AreasAssisting in network deployment, optimization & evolution

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Release 99 and HSDPA Data Channels

Low

Good

Not supported

None or slow (based on measurement

reports)

Common

FACH

HighMediumData Rate

Very GoodPoorSuitability for Bursty Data

Not supported(for HS channels)SupportedSoft Handover

(None)

Fast link adaptation

Closed inner loop at 1500 Hz slow

outer loopPower Control

SharedDedicatedChannel Type

HSDPADCHMode

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HSDPA UTRAN Functionalities

RELEASE 5 (HSDPA)RLC ARQ

RELEASE 5 (HSDPA)SchedulingLink AdaptationH-ARQResource Allocation

RELEASE 99SchedulingRLC ARQResource Allocation

RELEASE 5 (HSDPA)RLC ARQRELEASE 5 (HSDPA)RLC ARQ

RELEASE 5 (HSDPA)SchedulingLink AdaptationH-ARQResource Allocation

RELEASE 5 (HSDPA)SchedulingLink AdaptationH-ARQResource Allocation

RELEASE 99SchedulingRLC ARQResource Allocation

RELEASE 99SchedulingRLC ARQResource Allocation

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HSDPA Throughput Performance: Cat. 12

1410

1455

1600

1720

1815

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Throughput [kbps]

Max. L1 Data Rate (3GPP)

Max. L1 Data Rate (Vendor)

RLC Throughput without SBLER

RLC Throughput with SBLER

TCP/IP Throughput with SBLER

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HSDPA Latency Performance

208 ms240 msMininum RTT10*20ms=200ms10*20ms=200msUL delay64kbps RAB64kbps RABUL bearer4*2ms=8ms4*10ms=40msDL delay4 TBS 3440384kbps RABDL bearer1520 bytes62 ms120 msMininum RTT3*20ms=60ms3*20ms=60msUL delay64kbps RAB64kbps RABUL bearer1*2ms=2ms3*20ms=60msDL delay1 TBS 344064kbps RABDL bearer

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HSDPA and Advanced Performance

Higher Capability UE (16-QAM) 3.6 Mbps with 5 SF 16 HS-PDSCH codes Cat. 6 UE

Advanced Receiver Techniques Receive Diversity

Inter-cell interference dominated scenarios Low geometries (far-field, cell edge) Antenna and diversity gains

Equalizer Intra-cell, multi-path interference dominated scenarios High geometries (nearfield) Flattens received spectrum

Combined types

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Advanced HSDPA Throughput Performance: Basic Aspects

1410

1455

1600

1720

1815

2961

3055

3360

3584

3649

5921

6109

6720

7078

7206

0 1000 2000 3000 4000 5000 6000 7000 8000

Throughput [kbps]

7.0783.5841.720Max. Ph. Layer Thpt. [Mbps]

1415571683440Max. TBS used

QPSK &16-QAM

QPSK &16-QAM

QPSKModulation

1055# HS-PDSCH codes

Cat 8Cat 6Cat 12ParameterMax. L1 Data Rate (3GPP)

RLC Throughput with SBLER

TCP/IP Throughput with SBLER

Max. L1 Data Rate (Vendor)

RLC Throughput without SBLER

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Advanced HSDPA Throughput Performance: Throughput Gains

1.31

1.08

1.13

2.97

2.23

Cat 6 (Eq.)

57%0.690.59Multi-user

64%0.690.59Single User

45%2.051.50Multi-user

Mid/Far Cell

Mobility

Stationary

Scenario

FTP Throughput [Mbps]

Near Cell

Condition

Single User

Single User

User

0.80

1.39

Cat 12 (Rake)

0.90

1.78

Cat 6 (Rake)

46%

25%

GainEq. vs. Rake

Gains depend on structure of interference CQI gains do not directly transfer into throughput gains

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Advanced HSDPA Throughput Performance: CQI Gains

0 . 0 0

0 . 0 5

0 . 1 0

0 . 1 5

0 . 2 0

0 . 2 5

0 2 4 6 8 1 0 1 2 1 4 1 6 1 8 2 0 2 2 2 4 2 6 2 8 3 0C Q I

P

D

F

0

0 . 1

0 . 2

0 . 3

0 . 4

0 . 5

0 . 6

0 . 7

0 . 8

0 . 9

1

C

D

F

E q - P D F C a t 6 R a k e - P D F E q - C D F C a t 6 R a k e - C D F "

Median CQI improves to 20.3 with Eq. from 17.4 with Rake

0

500

1000

1500

2000

2500

3000

3500

4000

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30CQI [points]

L

1

T

h

r

o

u

g

h

p

u

t

[

K

b

p

s

]

QPSK 16-QAM

62%

41%

22%

72%0

500

1000

1500

2000

2500

3000

3500

4000

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30CQI [points]

L

1

T

h

r

o

u

g

h

p

u

t

[

K

b

p

s

]

QPSK 16-QAM

62%

41%

22%

72%

Gains limited for Cat.6 at high CQI

Same CQI gain leads to higher relative throughput gain towards lower CQI values (i.e. worse RF conditions)

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Advanced HSDPA Throughput Performance: 16-QAM Utilization

16-QAM utilization increased from 33.4% with Rake to 69.5% with Equalizer

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Outlook: HSUPA (Release 6)

Fast Node-B SchedulerMany-to-One

Rise-over-Thermal (RoT)

Fast Node-B SchedulerOne-to-Many

Shared Node-B Power and Code

Fast Power ControlSoft Handover

Rate/Modulation AdaptationSingle Serving Cell

HARQ with Fast Retransmission at Layer 1

Dedicated Channel with Enhanced Capabilities

New high-speedShared Channel

HSUPAHSDPA

UL data rate up to 5.76 Mbps (physical layer) TTI of 10 ms and 2 ms (later deployments) Uplink interference control most critical, sophisticated Grant concept

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Conclusions

HSDPA boosts the data experience in 3G

Advanced UE receivers required to fully exploit HSDPA capabilities HSUPA to further improve uplink and overall latencies (TTI=2 ms)

HSDPA is now and (almost) everywhere 3.6 Mbps rolled out First commercial deployment of 7.2 Mbps

First commercial deployments of HSUPA

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THANK YOU!!

Questions & Answers