EDGE

PLEASE MIND THIS The following document is strictly confidential and should not be copied or downloaded by any means. If any one is found in doing so will be dealt with immediate effect from the publisher. Publisher : DINENDRAN S

NORTEL NETWORKS CONFIDENTIAL

EDGE OVERVIEW

March 20, 2006 - 1RGMTTC

EDGE Technology Overview

Upon completion of this lesson, you will be able to know

- How EDGE is Introduced?

- What is EDGE?

- About EDGE modulation.

- About different Modulation and coding schemes(MCSs).

Objectives


Increasing GSM Data RatesTransmission Time

GPRS = General Packet Radio ServiceHSCSD = High Speed Circuit Switched DataEDGE = Enhanced Data rate for Gsm EvolutionUMTS = Universal Mobile Telecommunication System

10 sec 1 min 10 min 1 hour0

UMTS

E/GPRS

ISDN

PSTN

GSM

webe-mail photo

web photoe-mail

web photo

videoclipreportphoto

web photoe-mail

videoclipreport

videoclipreport

videoclipreport

videoclipreport


thro

ughp

ut k

bps

10 k

100 k64 k

1 M

2 M

1 k1998 1999 2000 2001 2002

Time frame

UMTSUMTS

GPRSGPRS

HSCSDHSCSD

9.69.614.414.4

packet

GPRS = General Packet Radio ServiceHSCSD = High Speed Circuit Switched DataEDGE = Enhanced Data rate for Gsm EvolutionUMTS = Universal Mobile Telecommunication System

EDGEcircuit

Wireless Data Technology Options


How is EDGE introduced? (1/2)How is EDGE introduced? (1/2)

• EDGE can be introduced in two ways 1. as a packet-switched enhancement for general packet radio service (GPRS), known as enhanced

GPRS or EGPRS, and

2. as a circuit-switched data enhancement called enhanced circuit-switched data (ECSD)

• ECSD: Enhanced Circuit Switched Data

• Circuit-switched Air interface

• Single radio-TS providing 38.4 Kbps

• Virtually Obsolete today

• EGPRS: Enhanced GPRS

• Packet-switched Air interface

• Encapsulates nearly all of

GPRS’s Service Levels and Protocols

• Additional features incorporated

providing even higher data throughput

However we shall discuss only

about EGPRS in this presentation.


How is EDGE introduced?(2/2)How is EDGE introduced?(2/2)

• The GPRS Coding Schemes are enhanced with 7 new EDGE Modulation and Coding Schemes (MCS2, MCS3 and MCS5 to MCS9). This set of Modulation and radio coding schemes increases the peak radio throughput of a carrier by a factor 3 compared to GPRS.

• In order to benefit from those new Coding Schemes, a specific hardware is needed on the BTS side (namely E-DRX & E-PA) and an extension of the backhaul is requested to take benefit of the full range of MCS.

E-DRX – Enhanced DRX

E-PA – Enhanced Power Amplifier


EGPRS: New Air Modulation TechniqueEGPRS: New Air Modulation Technique

•GSM/GPRS use a form of Digital Modulation called Gaussian Minimum Shift Keying (GMSK)

EGPRS uses an additional modulation technique called 8-Phase Shift Keying (8-PSK)•Digital info signal ‘modulates’ the analog

carrier frequency by varying its phase

•Carrier frequency can have up to

8 different phases (0º, 45º, 90º…… 315º)

•Each phase corresponds to a unique 3-bit

combination of the information signal

•Hence, each sinusoidal carrier cycle

transmits 3 information bits

•Contrast this with GMSK wherein only a

single bit is transmitted by a carrier cycle

•Hence, “potentially” 3 times the through

put !!!


What is EDGE ?

12 kbps14.4 kbps

20 kbps

8 kbps

GPRS

CS-1

CS-3

CS-2

CS-4

EDGE is an extension of GPRS. The 4 GPRS Coding Schemes are extended with 9 new EDGE Modulation and Coding Schemes

8.8 kbps

54.4 kbps44.8 kbps

29.6 kbps22.4 kbps

17.6 kbps14.8 kbps

11.2 kbps

EDGE

MCS-959.2 kbps

MCS-8

MCS-9

MCS-7MCS-6MCS-5MCS-4

MCS-3

MCS-2

MCS-1

Maximum Throughput is increased from 20 kbps

to 59.2 kbps per TS

EDGE = Enhanced Data rate for GSM Evolution

GPRS = General Packet Radio Service


EDGE Modulation & DemodulationSource decoding

Channel decoding

De-interleaving

Burst deformatting

Deciphering

Digitizing andsource coding

Channel coding

Ciphering

Burst formatting

Interleaving

Transmission Diversity

DemodulationequalizationModulation 8-PSK / GMSK

Modulation

Q

I

Q

I

(1,1,1)

(0,1,1)

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

(0,0,1)

(1,0,1)

(1,0,0)

(1,1,0)

1 bit per symbol

3 bits per symbol

GPRS: GMSK Modulation

EDGE: 8-PSK Modulation

+ 90 ° '0''1' - 90 °


8PSK Modulation: 3π/8 Shift

+ 3π/8

Q

I

Q

I

(0,1,0)

(0,1,0)

(0,1,0)

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

+ π/4

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

(0,0,1)

(1,0,1)

(1,0,0)

(1,1,0)


GPRS / EDGE Modulation Characteristics

473.6 kb/s160 kb/sUser data rate per TDMA

59.2 kb/s(MCS9)20 kb/s(CS4)User data rate per

PDCH

69.2 kb/s22.8 kb/sRadio data rate per PDCH

810 kb/s270 kb/sModulation bit rate270 ksym/s270 ksym/sSymbol Rate8-PSKGMSKModulation

EDGEGPRS


Modulation & Coding SchemesModulation & Coding SchemesMCS-1: 8.8 kbpsMCS-2: 11.2 kbpsMCS-3: 14.8 kbpsMCS-4: 17.6 kbps

MCS-5: 22.4 kbpsMCS-6: 29.6 kbpsMCS-7: 44.8 kbpsMCS-8: 54.4 kbpsMCS-9: 59.2 kbps

• MCS Families– Family-C: MCS – 1, 4– Family-B: MCS – 2, 5, 7– Family-A: MCS – 3, 6, 8, 9

GMSK

8-PSK

MCS: Nortel First EDGE MCS: Nortel First EDGE VersionVersion


EGPRS MCS:Layer 1 RF Radio Time Slot EGPRS MCS:Layer 1 RF Radio Time Slot OccupancyOccupancy


EDGE MCS: Family A, B and C

FAMILY A37 bytes 37 bytes 37 bytes 37 bytes

MCS-3

MCS-6MCS-9

FAMILY A’padding

34 + 3 bytes 34 + 3 bytes

MCS-3

MCS-634 bytes 34 bytes 34 bytes 34 bytes

MCS-8

FAMILY B28 bytes 28 bytes 28 bytes 28 bytes

MCS-2

MCS-5MCS-7

FAMILY C 22 bytes 22 bytes

MCS-1

MCS-4


Uplink MCS-1/2/3/4 Coding Scheme

178/226/298/35431

31 8 6

117

80 37

178/226/298/354 12 6 Parity Tail

Punctured

Parity Tail

372 216/360/576/744

Punctured

452 4 extra-stealing flag

209/257/329/385

DataHeader

588/732/948/1116

Rate 1/3 convolutional coding

Puncturing Puncturing



Downlink MCS-1/2/3/4 Coding Scheme

31

3 28 8 6

108

68 40

178/226/298/354 12 6 USF Parity Tail

Punctured

Parity Tail

372 216/360/576/744Punctured

12

452 4 extra-stealing flag

DataHeader178/226/298/354

209/257/329/385 bits

Block coding

588/732/948/1116

Rate 1/3convolutional coding

Puncturing Puncturing


NORTEL NETWORKS CONFIDENTIAL

Section 3

Nortel EDGE Hardware and Software solutions


TCUBSCe3

BTS

MSC

HLR/AUC

PSTN

SCP

A

GPRS

SGSN

GGSN

IntranetInternet

PCUSN

Backbone

GbEdge Radio

EDGE Leverages GSM/GPRS Capital InvestmentEDGE Leverages GSM/GPRS Capital Investment

SW Upgrade

eDRX & ePA

Nortel EDGE Hardware Solutions


DRX

TRX

PA

Non EDGE capable TRXCharacteristics of the ePA:• Available in GSM 850, 900, 1800 and 1900 MHz frequency bands.• RF Output power: 30 W

Characteristics of the HePA:• Only available in GSM 1900 MHz frequency band.• RF Output power:

60W for GMSK modulation. 45W for 8-PSK modulation.

eDRX: EDGE DRXePA: EDGE PAHePA: High Power ePA

eDRX

TRX

ePA orHePA

EDGE capable TRX

S8000/S12000 EDGE TRXFrom HW Point of View


Performance Enhancements

• 8-PSK modulation and 9 new Modulation Coding SchemesMaximum Throughput per TS is increased from 20 kbps to 59.2 kbps.

• Link Quality Measurements and Link Adaptation: Adapts the MCS based on those variable radio conditions

• Retransmission & Incremental Redundancy (ARQ type II)IR is the possibility to retransmit a data block, using a different

puncturing schemes.


Improving GPRS Performance with 8-PSK and New Modulation Coding Schemes

8

2014.4

12

GPRSGPRSCS-1

CS-3CS-2

CS-4Header + Protection User Payload

Header + Protection User Payload

8.8

54.444.8

29.622.4

17.614.8

11.2

EDGEEDGE

MCS-959.2MCS-8MCS-9

MCS-7MCS-6MCS-5

MCS-4MCS-3MCS-2MCS-1

GMSK

8-PSK

• GMSK Modulation– 1 bit per symbol– Robust but not spectrally efficient

• 8-PSK Modulation– 3 bits per symbol– Less robust but spectrally efficient

Maximum Throughput per TS is increased from 20 kbps to 59.2 kbps.


• Throughput highly depends on radio quality (distance from cell center and interferences).

Link Adaptationadapts the MCS based on those variable radio conditions.

0 5 10 15 20 25 30 350

10

20

30

40

50

60

MCS2MCS3MCS5MCS6MCS7MCS8MCS9

Throughput=f(C/I) URBAN IFH

C/I

Thro

ughp

ut (k

b/s)

Nortel EDGE Software SolutionsLink Adaptation


EDGE Link Adaptation EDGE Link Adaptation -- OverviewOverview• Higher the MCS scheme, lower the Interference tolerance• MS must dynamically vary MCS scheme used, based on radio conditions

MS BSS PCU

BER (UL Data/DL ACK)

MEAN_BEP, CV_BEP

New MCS Schema

New MCS Schema

PCU commands an MCS Schema change, based on…

• MEAN_BEP, CV_BEP• Backhaul Resource Availability• MS QoS

Data transfer via New MCS


Nortel EDGE Software SolutionsLink Adaptation Mechanism - Downlink

• MeasurementMS measures the signal quality of

each received block.

• ReportMS reports the signal measurement

to PCU.

• AdaptationPCU selects the accurate MCS

based on MS measurements.


• Joker DimensioningAbis Interface

– Main TS : • 16K TS use to manage circuit switch calls and a part of

the package data bandwidth which dedicated to one radio TS

– Joker TS : each TDMA is associated to a set of 64K TS• OMC-R parameter numberOfJokerDS0 – Max is 4 in

V15.0• Each 64k TS is divided in 16 k TS, which are then used

for only EDGE• Dynamically shared between all radio TS of the TDMA

every 20ms

– Each radio frame is managed with :• The main TS,• n joker TS, according to

the PDU size.• Each joker frame indicates

the associated main TS at each occurrence

radio frameAbisMain

Joker 1

Joker 2

Joker 3Abis Main and Joker TS relation

• Joker TS dimensioning: = Nb_of_Joker_per_EDGE_TS * Nb_of_EDGE_TS,

where Nb_of_Joker_per_EDGE_TS is calculated based on the MCS distribution.

• This formula provides the average required number of DS0 per joker.

Joker DS0:= round_up(Nb_of_16k_Joker/4)


THANK YOU!

EDGE

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