Evolution From 2G to 3G Mobile Telecommunication Systems

7/30/2019 Evolution From 2G to 3G Mobile Telecommunication Systems

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Evolution from 2G To 4G

Mobile Telecommunicationsystems


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Wireless versus

wireline

Advantages :

Mobility

High efficiency in use of commonResources


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Wireless versus

wireline

Limitations :

Multipath channel

Doppler effect Complex technology

Reliability


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Mobile cellular generations


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First generation

freq. Band 400/800 MHzmod. FM

Ch. Bw. 30 k

Access FDMAservice voice

handoff yes

no. of Sub. > 40 mil

exm. TACS in EU, AMPS inUSA and

JTACS in Japan


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Second generation

Freq. Band 900/1800/1900mod. Digital( psk/msk)

Ch. Bw. 200(gsm),30(DAMPS)

Access T/FDMAService voice and data

No. of Sub. > 500 mil only for gsm

exm. gsm in EU, DAMPS inUSA and PDS in Japan


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second generation ( cordless sys.)

Freq. Band 1800mod. Digital

duplex TDD

Access T/FDMA

service voice and dataHandoff usu. no

Speech codec ADPCM(32k)

cell radius < 500 m

exm. CT2&DECT in EUPHS in Japan


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Second generation ( IS-95)

Freq. Band 900 M

Access CDMA

Ch. Bw. 1250 k

Mod BPSK/QPSK

chip rate 1.2288 M

Duplex FDD


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CDMA Technology

CDMA

CDMA


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CDMA History

Military

1940 : cdma is proposed for mobile comm.

due to more ability to enhance the

capacity and use high degree of freq.reuse

1991 : first field trials (IS-95)

1995 : first commercial cdma service inHong Kong


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CDMA characteristics

Near-far problem

cdma needs power control mechanism

Soft Handoff

No freq. Plan

Reduced burst power increase human health


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UTRAs modes

FDD mode ( using WCDMA)

data rates up to 384 kbps

TDD mode (using T/CDMA)

data rates up to 2 Mbps, asymmetric traffic


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Third generation requirement

- more capacity & flexibility

- global roaming

- unity standard IMT 2000

806-960MHZ,1710-1785MHZ,2110-2170MHZ

,1920-1980MHZ,2500-2690MHZ


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systems development

Speech

Circuit data

< 9.6 Kb/s

HSCSD


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200

400

600

800

2000 2001 2002 2003 2004

MillionSubscribers

Internet - Future

Year

PC

Access

MobileInternet


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Communication Technologies

TimeP

roductdeve

lopments

Analogue

Voice

1985 1994 2000 2002 2005

GPRS

UMTS(3G)Multimedia

GSM Voice

SMS

GSM

DataBluetooth

HSCSD

EDGE

802.11b

Today


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Increasing Data Rates

UMTS

GPRS

ISDN

PSTN

GSM

0 10 sec 1 min 10 min 1 hour

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Transmission Time


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Third Generation, How?

Revolution

use of the systems based on the 3rd Gen.

Standards.

Evolution

upgrading the existing systems to support

the new services.


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S


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Europa

(Asia,

Africa,

Australia)

Cellular 1GStarting

2G in 1992

GSM Global

CDMA IS-95

D-AMPS/TDMA

GSM PCS1900GSM PCS1900

NMT

TACS

C 450

. . . .

USA

(Amricas) AMPS 800

Europe

(Asia,

Africa,

Australia)

Today

71%

12%

10%

UMTS,

based on lessons from the past, ...

UMTS is reaching early


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88%

12%

100%

ofmar

ket

2G 2,5G 2,5G + 3G global

CDMA 1xRTT (1xEV) (3x)

UMTS

(WCDMA)

PDC

GSM

TDMA

(EDGE)

GPRS

Fontes: www.gsmworld.com / www.gprsmobile.com / www.cdg.org / www.cellular-news.com/3G

Existing frequencies Global frequencies

(1.9 - 2.2GHz)

... UMTS is reaching early

success

GSM R di St t 3 d


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GSM Radio Steps to 3rd

Generation

Evolution of GSM Platform

Introduction of 3rd generation radio

2001 - 2002

New multimedia services

Mass market cost of service (IMT-2000)

1999

Internet-like IP packet services (GPRS)

1998

Landline-like circuit services (HSCSD)

1997Basic GSM data at 9.6 kb/s


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GSM

(Global system for mobile communications)

Dual Band Network :


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Dual Band Network :GSM 900 & DCS 1800 Air

InterfaceGS M 900 DC S 1800Uplink Band 890-915 M Hz 1710-1785

M Hz

Dow nlink Band 935-960 M Hz 1805-1880

M HzChannel S acin 200 kHz 200 kHz

Total Number of

Channels

124 374

Duplex Spacing 45 M Hz 95 M Hz

Num ber of

Timeslots per

Channel

8 8

Wh t i GSM??


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What is GSM??(Global System for Mobile Communications)


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GSM Architecture

Three broad parts

Mobile Station (MS): carried by the subscriber

Base Station Subsystem: control radio link with MS

Network Subsystem: its main part is MSC

Interfaces:

Um Interface : known as air interface or radio link. Abis Interface: between BTS and BSC

A Interface: between BSC and MSC


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Mobile Station

ME(mobile equipment) the terminal

SIM (Subscriber identity Module)

Can insert the SIM card into another

GSM terminal and use


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Base Station Subsystem

BTS (Base Transceiver Station)

handle the radio link protocols

with the Mobile Station

BSC (Base Station Controller)

manages the radio resources for

one or more BTSs

handles such as: frequence

hopping and handovers.

connection between MS and

MSC


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Network Subsystem

MSC (Mobile Services Switching Center)

acts like a normal switching node of

the PSTN or ISDN

provides the connection to the fixed

networks (such as the PSTN or ISDN).

HLR (Home Location Register )

contains information of each

subscriber registered in thecorresponding GSM network, along

with the current location of the mobile.

logically one HLR per GSM network

N t k S b t ti


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Network Subsystem continue.

VLR (Visitor Location Register)

contains selected information from the

HLR, necessary for call control and

provision of the subscribed services,

each mobile currently located in the

geographical area controlled by the VLR.

EIR (The Equipment Identity Register)

a database that contains a list of all validmobile equipment on the network,

AuC (The Authentication Center)

is a protected database:secret key of SIM


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GSM System Architecture

PSTN

Data Terminal

HLR/

VLR

MSCBSC

OMC(Operation & Maintenance

Center)

Operation

Terminal

BTSHandset

A

X.25

A-bis SS7

Network sub-system PSTNRadiosub-system

Mobile

station

UM


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Air Interface Protocols

SS7 Between PSTN and PLMN ( Public Land Mobile

Network)

X.25 BSC and Operation centers

A Between BSC and MSC

A-bis Between BTS and BSC

Um Radio interface between BTS and Handset


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Air Interface Messages

RR: Radio Resource ManagementMessages

MM: Mobility Management Messages

CM: Call Management Messages


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Trafficchannels

Signalingchannel

Full-rate

TCH/Fhalf-rateTCH/H

Frequency correctionFCCH

SynchronizationSCH

Broadcast controlBCCH

PagingPCHAccess grantAGCH

Random accessRACH

Stand-alone dedicatedcontrol SDCCH

Slow associatedcontrol SACCH

Fast associatedcontrol FACCH

Two-way

Base-to-mobile

Two-way

Air Interface--Channels

Integrate GSM and DCS


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Integrate GSM and DCS

Networks

Integrating 900 and 1800 networks bylinking 900/1800 cells to same BSC: An

Integrated dual band network

Sharing BSC, MSC, and HLR Benefits

Reuse existing resources

Simplify the handoff between networks

Flexible and changeable infrastructure


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Integrated Dual Band Network

MSC

BSC

DCS

BTS

DCS

BTS

DCS

BTS

GSM

BTS

GSM

BTS

GSM

BTS

GPRS System


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GPRS System(General Packet Radio Service)

Wh i GPRS


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What is GPRS

GPRS is a new service in GSMnetworks which uses PS. technique andenhance data rate to 171 kbps.

charging is based on the volume of tr.data.

GPRS supports QoS ( in 4 level)

Ch allocation is dynamic

GPRS St d d


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GPRS Standards

GPRS standards are developed by ETSIin two phases :

1.phase: supports PtP connection and the

codes CS1 and 2 2.phase : supports PtMP connection and

the

codes CS3 and 4

GPRS - Applications


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l GPRS bearer service will

enable applications in thefollowing segment areas:

l Telemetry

l Messaging

l e-mail

l Access to the World

Wide Web

l Job Scheduling and

Despatch

l Vehicle Location

Servicesl Information services

l E-commerce

GPRS f d l


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GPRS reference model

GPRS MS


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classes

Class A : GPRS and GSM servicessimultaneosly

Class B : GPRS and GSM services but notsimultaneosly

Class C : only GPRS services are supported

GPRS l t


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GPRS elements

SGSNpacket routing and transfer to service

area,

ciphering, authentication, MM andcharging

GGSN

Interface to ext. IP nets, access & routingfunc.,Gateway func., Sub. address publish

and charging data collection

IP address allocation


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IP address allocation

Static Address

- the MS has a permanent address

Dynamic Address

- operator use and reuses IP address- reduces the total no. of required IPaddress

- it is a recommended technique ofallocation

EDGE


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EDGE(Enhanced Data Rates for GSM Evolution)

EDGE Features


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Introduce new methods at the physical layer

new form of modulation: 8PSK(phase Shift

Keying)

introduced as a complement to GMSK (Gaussian FilterMinimum Shift Keying)

8PSK: use 8 phases to carry signals

High radio interface data rates (up to 384kbps)

EDGE Features

EDGE Features cont


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EDGE Features cont.

Provides an evolutionary migration path from

GPRS to UMTS

Only one EDGE transceiver unit need to be

added to each cell.

Software upgrades to BSC and Base Stations

can be carried out remotely.

Higher layer protocols (GGSN, SGSN) stay thesame

Can be introduced smoothly in GPRS(doesnt

require any new elements)

What are 3G Technologies?


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What are 3G Technologies?

UMTS (Universal Mobile Telecommunications Service)

EDGE can co-exist with UMTS

Cdma 2000

based on the cdma One standard, two airmodes:

one based on the parallel use of 3 contiguous

cdmaOne carriers (multi-carrier approach),

the other one on the use of the corresponding 3

carriers width spreading (direct spread approach)

What does UMTS provide?


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What does UMTS provide?

Circuit- and Packet-Oriented Services Seamless Global Roaming

Capacity and Capability to serve more

than 50% population A Wide Range of Services

Voice, low-rate data and high-rate data

144kb/s, 384kb/s , 2Mb/s

UMTS coverage vs bit rate


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UMTS coverage vs. bit rate

Outdoors

Vehicle

Walk

Fixed

Indoors

155Mb/s2.00.5

GSM

UMTS

Broadband Radio

UTRAN-UMTS T t i l R di A N t k


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UTRAN-UMTS Terrestrial Radio Access Network

Core Network

RNC

Node B Node B

RNC

Node B Node B

RNC

Node B Node B

ME

lu lu lu

lur lur

Uu

lub


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Frequency Allocation


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Frequency Allocation

1920-1980 MHz paired with 2110-2170

MHz

1920 1980 2010 2025

C C A MSS B A

2110 2170 2200

MSS

WCDMA Radio Parameters


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WCDMA Radio Parameters

Group 200KHz bands into 4.2-5.0 MHz

carriers

Chip Rate is 3.84 Mchips/sec

Power Control In WCDMA


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Near-Far Problem in CDMA Different Performance for Subcriber Links

A Few Subscribers closest to the BTS may

contribute too much multiple Access

Interference.



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How to do power control Force all users to transmit the minimum

amount of power

Reduce the power transmitted by users

closest to the BTS increase the power

transmitted by users farest to the BTS



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Open Loop vs. Close Loop Open Loop Power Control

Subscriber measures the DL power and

adjusts its transmission power

Close Loop Power Control

BS measures the UL power. MS measures

the DL power and reports to the BS. BS

instructs the user to raise or lower ittransmission power

Future GSM


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Future GSM

SIM Card

GSM

mobile

GSM/UMTSmobile

UMTS

mobile

Internet(TCP/IP)

BSC(UMTS)

UMTS(IMT-2000)Base Station

BSC(GSM)

GSMBase Station

Co-sited GSM+UMTS Base

Station Subsystem

GGSNSGSN

GPRS+UMTS

Landline NW

(PSTN/ISDN)

Network Subsystem(GSM+UMTS)

MSC/HLR

(GSM+UMTS)

HLRMSC

IN servicecontrol point

SIM

Evolution From 2G to 3G Mobile Telecommunication Systems

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