- 1 - POSITIONING EDGE IN THE MOBILE NETWORK EVOLUTION TIK-109.551 Research Seminar on Telecommunications Business II 12.3.2003 [email protected]

- 1 -

POSITIONING EDGE IN THE MOBILE NETWORK EVOLUTION

TIK-109.551 Research Seminar on Telecommunications Business II

12.3.2003

[email protected]

[email protected]

- 2 -

• GSM evolution towards 3G

• Introduction to GSM EDGE (Rel’99)

• EDGE performance in theory

• GERAN Rel’5

• EDGE services

• EDGE investments for an operator

• EDGE network planning

• EDGE performance in real life networks

• What is the future of GSM EDGE?

• Conclusions

Positioning EDGE in the mobile network evolution

- 3 -

GSM Evolution paths towards 3G

GSM9.6kbps

UMTS<2Mbps

HSCSD57.6kbps

GPRS115kbps

1999 2000 2001 2002 2003

EDGE384kbps

- 4 -

What is GSM EDGE ?

• EDGE = Enhanced Datarates for GSM Evolution– GSM2+ specification accepted 3G standard by 3GPP and ITU– GSM/EDGE RAN = GERAN– GERAN Rel’5: In the future common 3G core with same Iu-

interfaces for multiradio GSM/EDGE/WCDMA RAN

• Improved GSM air-interface performance– 8-PSK modulation method– New modulation & coding schemes (1-9)– Incremental Redundancy (IR)– Link Adaptation (LA) Enhancements– In the near future: AMR

(0,0,1)

(1,0,1)

(d(3k),d(3k+1),d(3k+2))=

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

(0,1,1)

(1,1,1)

(1,1,0)

(1,0,0)

- 5 -

Assuming • CS1&2 • Average C/I from tested networks (-> 11,5 kbps/TS)• BCCH re-use 12• TCH re-use 3

EDGE performance in theory (1)Spectral efficiencyKbps /

MHz

100

50

150

200

250

300

350

GPRS

Assuming • MCS5-8 • Average C/I from tested networks (-> 34,2 kbps/TS)• BCCH re-use 12• TCH re-use 3

EDGE

Assuming • Max load of 75%• Orthgonality of 0,6• 15% of DL power to CCCHs• Frequency re-use efficiency of 60%

WCDMA

- 6 -

EDGE performance in theory (2)

Modulation Method

1 TS (kbps)

4 TS’s (kbps)

8 TS’s (kbps)

MCS-1 GMSK 8,8 35,2 70,4 MCS-2 GMSK 11,2 44,8 89,6 MCS-3 GMSK 14,8 59,2 118,4 MCS-4 GMSK 17,6 70,4 140,8 MCS-5 8-PSK 22,4 89,6 179,2 MCS-6 8-PSK 29,6 118,4 236,8 MCS-7 8-PSK 44,8 179,2 358,4 MCS-8 8-PSK 54,4 217,6 435,2 MCS-9 8-PSK 59,2 236,8 473,6

In theory EDGE offers

• 3-4 x higher data bit rates for end-users than GPRS

• Improved voice capacity via

enhanced data capabilities (+ later

AMR)

Average3-4 x

0

10

20

30

40

50

60

8 10 12 14 16 18 20 22 24 26 28 30

C/I

Kbps/

TS

E-GPRSGPRS CS 1-4GPRS CS 1-2

- 7 -

Incremental redundancy

– Incremental Redundancy gives additional 2-3 dB to radio link– IR adjusts the code rate of the transmission to true channel conditions with incremental transmissions of the redundant information until

the decoding is successful– Utilises ARQ protocol

Link Adaptation

– Link Adaptation is used to select the best MCS for the radio link conditions– LA algorithms compare the estimated channel quality to threshold values -> optimised throughput– In EDGE LA works more effectively than in GPRS, because of IR gives better re-transmission performance

EDGE performance in theory (3)

- 8 -

GERAN Rel’5 GoalsPerformance enhancements for existing services.

Adoption of the UMTS Iu interface and UMTS quality of service (QoS) architecture – Enable GERAN to the same 3G CN (core network) as UTRAN– Enable GERAN to provide the same set of services as UTRAN– Support for conversational and streaming service classes as defined for

WCDMA First steps towards efficient resource optimizations in multi-radio networks Making the radio technology invisible to the end-user, while allowing

operators to efficiently manage the available spectrum.

Significant modifications to the existing GERAN radio protocols – increases the complexity of radio interface protocols.

- 9 -

GERAN Rel’5 Features

Enhancements for speech and data services:

– Iu interface (GERAN can be directly connected to IMS)– Header adaptation mechanism (RTP/UDP/IP)– Wideband AMR (quality)– Half-rate 8-PSK (capacity)– Fast power control for speech– Location service enhancements for Gb and Iu– Network assisted cell change (NACC)

Rel´5 supports

– A true multi-vendor environment– Backward compatibility (support of services for Release 99 terminals)

- 10 -

GERAN Rel’5 Architecture

BSS

RNC

Um

GERAN

UTRAN

BSC

BTS

BTS

GSM/WCDMA Core Network

MS

MS

Iur-g

A

GbIu

Iur-g

(Halonen et al 2002)

- 11 -

Network elements of combined UMTS

and GSM EDGE networks

IP Network

HLR

MSC/VLR

SGSN

RNC

RNCBTS

PSTN

GGSN

UTRAN

Network Subsystem

GPRS-backbone

BTS

EDGE BS

BSCBTS

GPRS/EDGE Radio Network

Core Network UMTS Radio Network

- 12 -

EDGE Services (1)

Traffic class Example of application Fundamental characteristics

Conversational Voice and video Preserve time relation between class telephony information elements, low delay

Streaming Real time Preserve time relation between, class streaming video low level retransmission

Interactive Web browsing and real Preservation of content, class time control channels retransmission, "request response"

Background Downloading of files Delay insensitive, preservation of class and email content, retransmission

QoS classes for UMTS and EDGE Rel´5

No significant changes in achievable services before GERAN Rel’5 -> Iu interface and UMTS QoS classes

- 13 -

EDGE Services (2)

Service QoS Requirements for Bearers, Data rates and Services 2003 [Auramo 2002]

Datarate

Con

vers

atio

nal

Bac

kgro

und

0 8 16 48 128 473 2048

Con

vers

atio

nal

Inte

ract

ive

Con

vers

atio

nal

Strea

min

gCon

vers

atio

nal Voice

Corporatesolutions

InfotainmentVoice

FAXCollaborative working

Communication

Transactionservices

Advertising

Audio clip downl.

Video clip downl.Short

Messaging

Corporate Data Access

WEB Browsing

WAP Applications

E-mail

Video streaming

Multimedia Messaging

Video telephony

Audio streaming

Gaming

WCDMAWCDMA

EGPRSEGPRS

GPRSGPRS

- 14 -

Latin America:

Will eventually follow US.

US+Canada: EDGE roll-outs on the way and

EDGE will be deployed

during 2003APAC:

Market follows global trends. “Ongoing

technology standard war”. Also public commitments to

EDGE

China: Political

commitments to every technology. No rush to

3G. No public EDGE

commitments yet

Europe: WCDMA

technology commitment.

Strong need for delaying UMTS roll-

outs

Growing interest towards

EDGE, but no public

commitments yet.

Global EDGE Status

- 15 -

EDGE from network investments point of view

(1)

• European 3G -market could be divided as follows:

• In the current market situation Operators have to decide how to divide their network investments between WCDMA and EDGE

2H2002 1H2003 2H2003 1H2004 2H2004 2005 “Early

WCDMA” m

arkets

“Early

EDGE” markets

“WCDMA fo

llower”

markets

“Complim

entary WCDMA &

EDGE” markets Heavily influenced by

the UMTS delays and availability of

EDGE/UMTS terminals

- 16 -


(2)What’s required to go for EDGE?

GSM BS

Depending on the age and manufacturer of the GSM BS:

• EDGE TRX:s must be introduced

• EDGE BSS/NSS software acquired

• Possible baseband units obtained

• In worst case new EDGE compatible BS:s introduced

• Transmission

What’s required to go for WCDMA?

A complete Radio Access Network… and possible updates to

GPRS core+ transmission

- 17 -


(3) Compared to WCDMA the investments in EDGE are

smaller for an operator with moderate traffic growth

The feasibility of EDGE depends on the amount

of traffic :

• With moderate traffic, EDGE is clearly

more cost efficient

• With higher traffic WCDMA becomes

more feasiblenetwork CAPEX

Traffic ~1 Mbps* per base station

Traffic ~2 Mbps**per base station

EDGE

EDGE

WCDMA

WCDMA

* Equals approx.

4+4+4 GPRS thrput

** Equals approx.1+1+1 WCDMA

thrput (2,4Mbps)

- 18 -

250 500 750 1000 1250 1500 2000 2500 3000

• Total CAPEX, EDGE vs WCDMA


(4)

Traffic (kbps/ site)

WCDMA

EDGE

Point of equal CAPEX for both technologies to support

the required traffic

- 19 -

• The cheapest way to implement EDGE is to replace or add one (or several) GSM TRXs with EDGE TRXs in most feasible site locations.


(5)

EDGE TRX CAPEX

per site (k€)

Traffic (kbps/ site)500 750 1000 1250 1500 2000 2500 3000 250

20

80

100

40

60

Only one EDGE TRX needed per site to support

the required traffic

The needed amount of EDGE TRXs increase as the required

traffic grows

Feasibility of replace strategy dependson the amount of

EDGEcapable BSs

Replacing more than one

TRX is more complex

- 20 -

• When compared to investments needed for WCDMA to support the same amount of traffic per site…


(6)

CAPEX per site (k€)

Traffic (kbps/ site)500 750 1000 1250 1500 250

20

80

100

40

60

WCDMA

EDGE

Assumed only EDGE TRX costs and total WCDMA

site CAPEX

Assumed total EDGE site CAPEX after more than one

EDGE TRX must be implemented

Significantly higher investments

needed for WCDMA

- 21 -

• Provide more cost-effective coverage in wide area

• WCDMA focus on urban areas and license requirements

• Minimal service differentitation between GSM and UMTS network -> services easier to plan

EDGE as astepping stone

to UMTS

EDGE and WCDMA co-exist but for

different user segments

EDGE as acomplementary

solution to WCDMA: Different Coverage

areas

• EDGE to provide ”3G like” data services prior to large scale WCDMA deployment

• ”US style” mobile evolution

• Both WCDMA and EDGE deployed in cities and EDGE also elsewhere

• EDGE positioned clearly to different market segment than WCDMA: “GPRS enhancer”

EDGE from network investments point of view (7) – investment

strategies

- 22 -

• As GPRS, EDGE performance is dependent on the achievable C/I (and RXlev) in the network

EDGE from network planning perspective (1)

• The most effective means to gain this is to come up with a optimised frequency plan

Propagationestimations

CoverageAnalysis

Interference

matrix• co-

channel• adjacent

channel

Frequency plan

Separationconstraints

TRX requirements

Help from automation in large networks required

- 23 -

• Example case from a live network, EDGE throughput measured based on network C/I and Rxlev:


• Frequency plan optimisation can make a significant difference for the achievable throughput

29,9 kbps 34,7 kbps

Average throughputper TS over the network

with “old” frequency plan

Average throughputper TS over the network

with optimised frequency plan

- 24 -

• EDGE deployment doesn’t bring dramatical changes to radio network planning with GPRS

• Main concerns the allocation of capacity and steering of traffic to wanted layer/cell/TRX


• Features such as LA should be utilised optimally

• Upcoming 2G/2,5G/3G parameterisation challenges

• Changes to transmission capacity will be needed, if

larger scale EDGE deployment per cell/area is done

- 25 -

• The easiest way to implement EDGE from network planning point of view is the TRX replacing strategy

new frequency plan not mandatory

• The replacing can be done for every 1-3rd site


E.g. hotspots or rural can be selected for EDGE, but

limited amount of data throughput

- 26 -


Higher data amounts with EDGE can be offered if it is implemented by

• Bringing an additional EDGE TRX dedicated to data usage to (some of)

the cells in the network

• Reserving more timeslots for the use of EDGE data users from the

TRXs (-> decrease in the GoS experienced by the speech users )• In real life these actions are not always possible to perform and they will require significant amount more implementation and planning work

• In order to utilise EDGE performance in full, a totally new frequency plan

and possibly new GSM cell structure are required

- 27 -

EDGE performance in live networks (2)

Achievable EDGE throughput per TS versus GPRS (DL in kbit/s)

Approx. 2,5 times higher

throughput to end users

European small/medium and larger size GSM networks

0

5

10

15

20

25

30

35

GPRS EDGE GPRS EDGE

Th

rou

gh

pu

t p

er T

S (

kbit

/s)

- 28 -

The future of EDGE

• Traffic growth

• UMTS timetable

• EDGE terminals

• Operator business cases

• EDGE capable infrastructure

• How has the GPRS traffic evolved in the

network ?

• How does the GSM capacity respond to

this ?

• Do we believe in short term mobile data

take off ?

- 29 -

The future of EDGE

• Traffic growth

• UMTS timetable

• EDGE terminals



• What is the operators strategic/ financial

UMTS commitment ?

• Launch dates are postponed in Europe

• How ready is the UMTS infrastructure ?

• Would EDGE offer competitive advantage before UMTS is widely

deployed ?

• When to start utilising the enormous capacity

of WCDMA ?

- 30 -

The future of EDGE

• Traffic growth

• UMTS timetable

• EDGE terminals



• E2002 in US, but when in Europe ?

• Classical chicken-and-egg problem again

• Asian EDGE commitment will guarantee EDGE

terminals to 900/1800 bands ?

• What is the vendors’ commitment and ability

to take risks ?

• Multimode UMTS/EDGE terminals

the best bet ?

- 31 -

The future of EDGE

• Traffic growth

• UMTS timetable

• EDGE terminals



• When will the saturation point of current network technology be

reached ?

• How should the network investments be planned for next 5

years ?

• Roll-out strategy for EDGE and UMTS

• Service strategy for EDGE and UMTS

- 32 -

The future of EDGE

• Traffic growth

• UMTS timetable

• EDGE terminals



• What is the EDGE capability of current

network infrastructure ?

• How is that capability spread over the

network ?

• Capacity extensions done with EDGE HW ?

• Geographical swap ?

- 33 -

Conclusions• EDGE would be the best network evolution for GSM operators on the

road to UMTS (as in US)

• The needed investments are a lot smaller than in WCDMA

• Planning/deployment complexity is a fraction of that of WCDMA

• EDGE provides ~2,5 times the performance of GPRS and enables similar services than UMTS

• EDGE is been specified by the 3GPP to fully meet UMTS QoS in the future with Iu-interface + common 3G core network

• The feasibility of EDGE is network specific

EDGE will live alongside of WCDMA, but who is ready to drive the market and set the role of EDGE in 3G field for the future?The scale of EDGE deployment is highly dependant on early UMTS success

- 34 -

Thank you!

[email protected]@omnitele.fi

mailto:[email protected]%[email protected]

Documents

- 1 - POSITIONING EDGE IN THE MOBILE NETWORK EVOLUTION TIK-109.551 Research Seminar on Telecommunications Business II 12.3.2003 [email protected]