Ericsson ResearchWinlab 990222

Requirements for GPRS Evolution TowardsProviding Third Generation Services

Requirements for GPRS Evolution TowardsRequirements for GPRS Evolution TowardsProviding Third Generation ServicesProviding Third Generation Services

Håkan OlofssonEricsson Radio Systems AB

Ericsson ResearchWinlab 990222

OutlineOutlineOutline

lGPRS Background

lGPRS’ Role in Future Communications

lHigher bit rates: EGPRS

lImproved QoS Handling

lReal-time Support

lSummary: Standardization Activities

Ericsson ResearchWinlab 990222

General Packet Radio Service (GPRS)Network Architecture

General Packet Radio Service (GPRS)General Packet Radio Service (GPRS)Network ArchitectureNetwork Architecture

BackboneNetwork

X.25Network

IPNetwork

BTS

GGSNGGSNSGSNSGSN

BSC MSC

Radio AccessNetwork

BSC

Core Network

HLR

Ericsson ResearchWinlab 990222

GPRS as Basis for TDMA/136 3G EvolutionGPRS as Basis for TDMA/136 3G EvolutionGPRS as Basis for TDMA/136 3G Evolution

BackboneNetwork

X.25Network

IPNetwork

BTS

GGSNGGSNSGSNSGSN

ANSI41 MSC

136

RNC HLR

Ericsson ResearchWinlab 990222

Evolution Towards 3G in GSM EnvironmentsEvolution Towards 3G in GSM EnvironmentsEvolution Towards 3G in GSM Environments

Existing GSM spectrum

GSM Access

New UMTS spectrumor ‘modified’ spectrum

UMTS Access

PSTN/ISDN+

Internet/Intranet+

GSM/UMTSCore network

A, Gb

GSMRadio

Access

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GSM

lu

UMTSRadio

Access

Ch a n

n e l

4s

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GSM/UMTS UMTS

CSN PSN

Ericsson ResearchWinlab 990222

WCDMA

IMT-2000Capable Systems

IMT-2000Capable Systems

New or“Modified”Spectrum

ExistingSpectrum

PDC

GSM GSM+

TDMA/136+TDMA/136

Evolution to IMT-2000 Radio AccessEvolution to IMT-2000 Radio Access

EDGE/136HS

Ericsson ResearchWinlab 990222

GPRS Modifications for Full 3G SupportGPRS Modifications for Full 3G SupportGPRS Modifications for Full 3G Support

lEnhanced Radio Interface bit rates

lMore advanced QoS handling

lEnhanced support for real-time services

Ericsson ResearchWinlab 990222

Room for GPRS Bit Rate EnhancementsRoom for GPRS Bit Rate EnhancementsRoom for GPRS Bit Rate Enhancements

C/I [dB]0 5 10 15 20 25 30 35 40 45 50

0

100

200

300

400

500

600

700

800

900

1000

C/I [dB]0 5 10 15 20 25 30 35 40

0

100

200

300

400

500

600

EGPRS

GPRS

554

182

Bit rate [kbps]

Ericsson ResearchWinlab 990222

EDGE Radio Interface Key CharacteristicsEDGE Radio Interface Key CharacteristicsEDGE Radio Interface Key Characteristics

lNew modulation: 8-PSK data rate > 384 kbpslMany other parameters as in GSM

lPacket-switched access (EGPRS)lCircuit-switched access (ECSD)

lDynamic radio resource sharing with GSM speech and GPRS

lAdvanced Link Quality Control

(0,0,1)

(1,0,1)

(0,0,0)(0,1,0)

(0,1,1)

(1,1,1)

(1,1,0)

(1,0,0)

I

Q(d3i, d3i+1, d3i+2)=

Ericsson ResearchWinlab 990222

0 5 10 15 20 25 300

1

2

3

4

5

6x 10

4

C/I [dB]

Thr

ough

put [

bps]

EGPRS Link Quality ControlEGPRS Link Quality ControlEGPRS Link Quality Control

lLink Adaptation and Incremental RedundancyScheme Modulation Maximum

rate[kbps]

Code Rate Blocks per20 ms

Family

MCS-8 59.2 1.0 2 A

MCS-7 44.8 0.78 2 B

MCS-6 29.6 0.50 1 A

MCS-5

8PSK

22.4 0.38 1 B

MCS-4 16.8 1.0 1 C

MCS-3 14.8 0.89 1 A

MCS-2 11.2 0.69 1 B

MCS-1

GMSK

8.4 0.53 1 C

Ericsson ResearchWinlab 990222

EGPRS Link Quality ControlEGPRS Link Quality ControlEGPRS Link Quality Control

lSegmentation principle (coding scheme MCS-6)

612 bits32 bits3 bits

P1 P2

puncturing

1836 bits

USF RLC/MAC Data = 74 octets = 592 bits BCS

36 bits

Rate 1/3 convolutional coding

96 bits

1256 bits96 bits36 bitsSB = 4

1392 bits

TBFBI ECRC

1256 bits

RLC block

8-PSK bursts

Ericsson ResearchWinlab 990222

EGPRS Performance SimulationsEGPRS Performance SimulationsEGPRS Performance Simulations

Models and Assumptions:lMultiple Cells Simulator

lEqually sized 3-sector macro cells

l 3/9 frequency reuse

lPropagation model 35log(d) with lognormal fading 6 dB

l Frequency hopping

lDynamic simulations (20ms time step)

lARQ included

lMeasurement based WWW traffic model

lDownlink only 1 2 3

4 5 6

7 8 9

10 11 12

13 14 15

16 17 18

19 20 21

22 23 24

25 26 27

users base stations

Ericsson ResearchWinlab 990222

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.20

10

20

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C.D

.F.

[%]

normalized packet delay [s/kbit]

70

30 40

50

60

0 0.05 0.1 0.15 0.2 0.25 0.3 0.350

0.05

0.1

0.15

0.2

0.25

0.3

0.35

spectral efficiency [bps/Hz/site]

norm

aliz

ed d

elay

at 9

0th

perc

entil

e [s

/kbi

t]

standard GSM

EDGE

Simulation Result: CapacitySimulation Result: CapacitySimulation Result: Capacity

lSpectral efficiency more than doubled

Ericsson ResearchWinlab 990222

Simulation Result: FairnessSimulation Result: FairnessSimulation Result: Fairness

0 10(80) 20(160) 30(240) 40(320) 50(400) 60(480) 70(560)0

10

20

30

40

50

60

70

80

90

100C

.D.F

. [%

]

Average packet bitrate per user per timeslot (bitrate per 8 timeslots in brackets) [kbps]

standard GSM EDGE

l30% of users: >384 kbps, 97%: >144 kbps

Ericsson ResearchWinlab 990222

Simulation Result: CoverageSimulation Result: CoverageSimulation Result: Coverage

lAssume empty system with C/N as in standardGSM system

0 10(80) 20(160) 30(240) 40(320) 50(400) 60(480) 70(560)0

10

20

30

40

50

60

70

80

90

100

Average packet bitrate per user per timeslot (bitrate per 8 timeslots in brackets) [kbps]

C.D

.F. [

%]

EDGE

Standard GSM

Ericsson ResearchWinlab 990222

Why Quality of Service Handling in GPRS?Why Quality of Service Handling in GPRS?Why Quality of Service Handling in GPRS?

lMotivation: Spectral Efficiency!

End-to-End Service

BTS

GGSNSGSN

Radio Access Network

BSC

Core Network

ExternalNetwork

GPRS Bearer

Ericsson ResearchWinlab 990222

GGSN

Current GPRS QoS SupportCurrent GPRS Current GPRS QoS QoS SupportSupport

BTS

SGSN

Radio Access Network

BSC

Core Network

GPRS Bearer with certain QoS Profile

QoS ‘requested’

QoS Profile:l Precedencel Reliabilityl Delayl Max throughput

l Mean throughput

QoS ‘negotiated’

l Problem: BSC and BTS are not involved!

Ericsson ResearchWinlab 990222

UTRAN

QoS Comparison GPRS / UMTSQoSQoS Comparison GPRS / UMTS Comparison GPRS / UMTS

lGoal: Harmonization in GSM standards release ‘99

GGSNSGSN

Radio Access Network

BSS

Core Network

GPRS Bearer

‘SGSN’

UMTS Bearer

‘Traffic handling priority’ etc

Radio Access Bearer

Bearer Negotiation

GPRS

UMTS ‘GGSN’

Ericsson ResearchWinlab 990222

Real-time Services Support in GPRSReal-time Services Support in GPRSReal-time Services Support in GPRS

One Future Scenario: Multimedia over IP over GPRS

Key requirement areas:lData transfer delaylCell re-selection delaylQoS handling

Ericsson ResearchWinlab 990222

Bottle-necks for Real-time SupportBottle-necks for Real-time SupportBottle-necks for Real-time Support

SGSN SGSN

BSSBSSBSS

QoS

RLC/MAC

Inter-SGSN cell re-selection

Ericsson ResearchWinlab 990222

Standardization ActivitiesStandardization Standardization ActivitiesActivities

EGPRS

GPRS Quality of Service

1999 2000

LQC scheme stable(SMG2)

Total EGPRS concept stable(GSM release ‘99, SMG2, SMG3 etc)

Increased BSS role(GSM release ‘98, SMG12)

Harmonization GPRS/UMTS(GSM release ‘99, SMG12UMTS phase 1, 3GPP TSG SAWG2)