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3G : An Overview

Ashish TayalDGM (Mobile-Core)

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Brief Outline

Wireless Generations.

Migration path

Mobile Soft Switch Architecture.

Spectrum for 3G

3G Deployment

LTE

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• 1946- 1960s 1980s 1990s 2000s

• Appeared 1G 2G 3G

• Analog Digital Digital

• Multi Multi Unified

Standard Standard Standard

Terrestrial Terrestrial Terr. & Sat

Wireless Generations

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• 1 G -analog (cellular revolution)

- only mobile voice services

• 2 G - digital (breaking digital barrier) - mostly for voice services & data delivery possible

• 3 G - Voice & data ( breaking data barrier)

- Mainly for data services where voice sevices will also be possible

• Beyond 3G -Wide band OFDM ?

- But surely higher data rates

Wireless Generations

1G FDMA (NMT, AMPS, TACS) 80’s- Voice (analog traffic, digital signaling)

2G TDMA (GSM, D-AMPS, PDC) and CDMA (IS-95) 90’s- Voice, SMS, CS data transfer ~ 9.6 kbit/s (50 kbit/s HSCSD)

2.5G TDMA (GPRS) 00’s- PS data transfer ~ 50 kbit/s

2.75G TDMA (GPRS+EDGE) 00’s- PS data ~ 150kbit/s

3-3.5G WCDMA (UMTS) and CDMA 2000 00’s- PS & CS data transfer ~ 14-42 Mbit/s (HSPA/HSPA+), Voice, SMS

3.9G OFDMA (LTE/SAE) 10’s- PS Data and Voice (VoIP) ~ 100Mbit/s

4G IMT Advanced

Wireless Generations

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- Enormous R & D investment by vendors like Ericsson, Nokia and Qualcomm, NTT Do Co Mo and Vodafone under 3GPP.

- Global momentum for HSDPA/HSUPA.

Beyond 3G – Promises and Pitfalls

- Emergence of alternative wireless technologies – WiMAX (Intel) and WiBro.

- Agreement on preferred modulation technology: OFDM- a de facto choice for next generation wireless technologies.

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Evolution Path for GSM

Newspectrum

Existingspectrum

2G evolved 2G 3G

14.4 kbps 64–115 kbps 0.384–2 mbps115–384 kbps

IMT-2000Capable Systems

GSM GPRS EDGE

3G

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GSM Evolution

GPRS200 KHz carrier115 Kbps peak data rates

EDGE200 KHz carrierData rates up to 384 Kbps8-PSK modulationHigher symbol rate

UMTS5 MHz carrier2 Mbps peak data ratesNew IMT-2000 2 GHz spectrum

GSM200 KHz carrier8 full-rate time slots16 half-rate time slots

GSM GPRS EDGE UMTS

3G2.5G2G

HSCSD

HSCSDCircuit-switched data64 Kbps peak data rates

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• Data Rates up-to 2 Mbps – for fixed or Indoor Environments.

• High speed Packet data services.

• Multimedia support.

• Backward compatibility with second generation ( 2G ) systems.

• Improved system capacity.

Key Requirements of 3G Services

• Data Rates up-to 384 kbps – for pedestrian or urban Environments.

• Data Rates up-to 144 kbps – for wide area mobile Environments.

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Third Generation System

Third generation systems are designed for multimedia communications;

With them person to person communication can be enhanced with high quality images

and video,

And access to information and services on public and private networks will be enhanced by higher data rates.

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WCDMA

UMTS (3G GSM)

CDMA 2000 1 x EVDO Rev 0

TDD – S C D M A

3G

UMTS

IMT – 2000

UTRAN

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3 GPP

Monolithic MSC

Layered Architecture

IMS

IMS

IMS NGN or VoIP network developed by Mobile industry.

R6

R5

R4

R99 (R3)

R98

R97

3GPP Releases The 3GPP produces a complete set of globally applicable

Technical Specifications and Reports for the UMTS standard. These are published in releases…

R4 MSS, IP

Core

R6HSDPA P2,

EUL P1, MBMS…

R5HSDPA P1,

IMS…

R991st 3G

networks

R7MIMO,

ALL - IP

R8A-bis

Over IP

R9LTE

Envolved

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Mobile Soft Switch Architecture

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Mobile Soft switch Solution

Layered Architecture

Connectivity Layer

Control Layer

Application Layer

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Application Layer:-Provide Services & contents

Control Layer:-Provide Session & call control function

Connectivity Layer:-Physical transport & access tech.

Layered Architecture

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Mobile soft switch enable a layered architecture

design for the mobile circuit core , where the

network functions responsible for service

management & control and for transport of service

data are physically & logically separated

Mobile Soft switch Solution

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Mobile Soft switch Solution

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Advantages of Mobile Soft switch Solution

1. Access independent (GSM/WCDMA) core network

2. Packet backbone technology (IP or ATM) enables more efficient transmission of voice traffic over the backbone by retaining the same voice coding in the backbone as is used in the air interface

3. Simplification of network planning through common core for WCDMA & GSM

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UMTS network structure

UE = User Equipment RAN = Radio Access NetworkCN = Core Network NMS = Network Management System

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Radio Access Method is Wideband Code Division Multiple Access

(WCDMA).

In GSM, we use TDM (Time Division Multiplexing) as the transmission method between the different network elements. For UMTS, ATM (Asynchronous Transfer Mode) has been chosen as the transmission method in the radio access network.

The basic difference between TDM and ATM is that in TDM, we use timeslots for conveying information between network elements. In ATM, on the other hand, the data is transmitted in cells (packets) of fixed size across the network. (An ATM cell has 48 octets of payload, 5 octets of headers.)

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1. MSC Server

2. MGW

3. HLR/AUC

4. SGSN

5. GGSN

6. Mobile Packet Backbone Network (MPBN)

7. OSS

8. Lawful Intercept System

UMTS network elements

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MSC

BSC

BTS

Jaipur

Alwar

Alwar City

Monolithic MSC Architecture

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Layered Architecture

Call Control

Switching

M S C Server

Media Gateway

BSC

BTS

MGW MGW

BSC

BTS

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M S C Server

MGW

RNC

Node - B

BSC

BTS

SGSN GGSN

Internet

3G Mobile N/W would look like

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Spectrum for 3G

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Spectrum for 3G Systems

The IMT 2000 band has been identified in most of the countries for the launch of 3G services-

Uplink -1920-1980 MHz,

Downlink-2110-2170 MHz.

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CRITICAL ISSUES IN 3G DEPLOYMENT

1. SEAMLESS MIGRATION OF EXISTING NETWORK.

2. NATURE AND QUANTUM OF LICENSE FEE.

3. INTER OPERATABILITY OF EQUIPMENTS.

4. ALLOCATION OF SPECTRUM.

5. PRICING OF SPECTRUM.

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ISSUES FOR 3G DEPLOVMENT

1. A HIGH RISK BUSINESS, HUGE INVESTMENTS.

2. IT IS UNLIKE 2G WHERE MARKET FORECASTS WERE CERTAIN.

3. NO ROAD-MAP TO 3G EXISTS.

4. NO PROVEN BUISNESS MODEL EXISTS FOR 3G.

5. IS 2.5 G NOT ENOUGH.

3g Spectrum Auction in India

In India Spectrum allocation is done by Department of Allocation (DoT).

DoT invited the application for spectrum allocation on ………. for total 4 WCDMA# operators per circle.

Auction finishes on 19th May 2010.

Total no. of rounds 183 till the end of 34 days.

# (In 5 Circles the no. of operators are 5)

22 Circles in India.

Total no. of Private WCDMA PLMN’s = (22 x 4) + 5* = 71

Nos.

* Punjab

WBHPBiharJ&K

OperatorNo. of

circles

Bharti 13

Aircel 13

Reliance 13

Idea 11

Vodafone 9

Tata 9

STel 3

Total 71

3g Spectrum Auction in India

3g Spectrum Allocation in India

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LTE : Long Term Evolution

AccessFlat Overall Architecture • 2-node architecture

• IP routable transport architecture

Improved Radio Principles• peak data rates [Mbps ] 173 DL , 58 UL

• Scalable BW: 1.4, 3, 5, 10, 15, 20 MHz

• Short latency: 10 – 20 ms

New Core Architecture• Simplified Protocol Stack

• Simple, more efficient QoS

• UMTS backward compatible security

LTE / SAE introduces the mechanism to fulfill the requirements of a next generation mobile network

Access Core Control

LTE BTS (eNodeB)

MMESAE-GW

IMS HLR/

HSS

RF Modulation:• OFDMA in DL• SC-FDMA in UL

LTE : Basic Concepts / Architecture

MME

S-GW and P-GW

TDMA FDMA CDMA OFDMA

f f

f

t

f

tcode

s

f

f

t

f

t

f

• Time Division • Frequency Division • Code Division • Frequency Division• Orthogonal subcarriers

Multiple Access Methods

User 1 User 2 User 3 User ..

Results of Multipath Fading

Reflections and multipath-fadingresult in large variationsof frequency response

Downlink - OFDMSubchannels / Tones (each 15 kHz)

time

1 TTI = 1ms

1 PRB (Physical Resource Block) = 12 Subcarriers = 180 kHz

1 PRB = 2 Slots = 2 * 0.5 ms

1.4 MHz = 72 Tones 20 MHz = 1200 TonesUser 1

User 2

User 3

User ..

dow

nlin

k

OFMD Downlink & SC-FDMA Uplink – TDD

SC-FDMA: PRB‘s are grouped to bring down Peak to Average Power Ratio (PAPR)> better power efficiency at the terminal

1.4 MHz = 72 Tones 20 MHz = 1200 Tones

Subchannels / Tones (each 15 kHz)tim

e

1 TTI = 1ms

1 PRB (Physical Resource Block) = 12 Subcarriers = 180 kHz

1 PRB = 2 Slots = 2 * 0.5 ms

User 1

User 2

User 3

User ..

uplin

k

dow

nlin

k

Special subframe containing guard period (switching from DL -> UL)

The Beauties of LTE

Channel only changes amplitude and phase of subcarriers

Fast Link Adaptationdue to channel behaviour

Short TTI = 1 msTransmission time interval

Advanced Scheduling Time & Freq. (Frequency Selective Scheduling)

TX RX

Tx RxMIMOChannel

DL: OFDMA

UL: SC-FDMA

scalable

HARQ: Hybrid Automatic Repeat Request

64QAMModulation

1

2

21NACK ACK

Rx Buffer

Combined decoding

LTE Radio Principles

• Power efficient uplink increasing battery lifetime

• Improved cell edge performance by low peak to average ratio

• Reduced Terminal complexity

Uplink:

SC-FDMA

• Enabling peak cell data rates of 173 Mbps DL and 58 Mbps in UL *

• Scalable bandwidth: 1.4 / 3 / 5 / 10 /15 / 20 MHz also allows deployment in lower frequency bands (rural coverage, refarming)

• Short latency: 10 – 20 ms **

• Improved spectral efficiency

• Reduced interference

• Very well suited for MIMO

* At 20 MHz bandwidth, FDD, 2 Tx, 2 Rx, DL MIMO, PHY layer gross bit rate ** roundtrip ping delay (server near RAN)

Downlink:

OFDMA

Subchannels / Tones (each 15 kHz)

time

1 TTI

= 1ms

1 PRB (Physical Resource Block)= 12 Subcarriers = 180 kHz

1 PRB = 2 Slots= 2 * 0.5 ms

User 1

User 2

User 3

User ..

Subchannels / Tones (each 15 kHz)

time

1 TTI

= 1ms

1 PRB (Physical Resource Block)= 12 Subcarriers = 180 kHz

1 PRB = 2 Slots= 2 * 0.5 ms

User 1

User 2

User 3

User ..

Access Aggregation

LTE Network ElementsAll protocols over IP

Inter-BTS connectivity

X2-u/c

O&M

S1-u

S1-c(S1_MME)

BTS

BTS

S-GW

MME

Ethernet will be the predominant equipment interface technology.

Inter-BTS connectivity (X2) for handover comes along with Ethernet Transport architecture.

Transport network

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AN

PRESENTATION