1

Wireless Generations:Transitions & Multimedia Suitability

Prof. Abdulmotaleb El Saddik

ELG 5121: Multimedia CommunicationsThanks to:Ahmad Abdo & Salim Said

Outline

�Introduction

�2.5 G�GPRS

�EDGE

�CDMA�Benefits

�Simulation

�Third Generation

�Expectations of 4G

�Conclusion

Wireless Technology: A Gentle Definition

“The wireless telegraph is not difficult to

understand. The ordinary telegraph is like

a very long cat. You pull the tail in New

York, and it meows in Los Angeles. The

wireless is the same, only without the cat”

Einstein

2

� 1920s

� 1978

� 1980s

Pre-cellular trunked radio system� Successful services such as emergency dispatch

Field trials in Chicago of Bell Systems

AMPS (Advanced Mobile Phone System)� Deployed in North America

TACS :Total Access Cellular System� Deployed in Europe

� 900 MHz derivative of AMPS

NMT: Nordic Mobile Telephones� 450 & 900 MHz versions

Analog Cellular Radio

Second Generation (2G)

�Digital radio technology

�Added services such as data

�Improved in capacity, voice quality, and spectral

efficiency over 1G

�Data rates between 10 & 20 Kbps

�Enhanced telephony features such as caller ID

�Text based messaging “The famous SMS”

�Not suitable for web browsing and multimedia

applications

2G Technologies

�TDMA: Time Division Multiple Access

�30 KHz channels

�used in North and South America

�CDMA: Code Division Multiple Access

�1.25 MHz bad

�used allover the globe (started in USA)

�PCD: Personal Digital Cellular

�Used only in Japan

3

�GSM: Global System for Mobiles �Combination of FDMA and TDMA

�Started in Europe

�Uses 900, 1800, 1900 MHz bands

�Bands divided into 200 KHz carrier frequencies

�Each carrier frequency is divided into 8 time slots or channels

�1995 5.5 million users in 60 countries

�2000 270 million users in Europe alone!

2G Technologies (contd.)

Distribution of Subscribers in 2000

58%

12%

8%

8%

14%

0% 10% 20% 30% 40% 50% 60%

GSM

CDMA one

PDC

IS-136

Analog

Source: EMC World Cellular Database

Wireless Communications Evolution

EDGE

MC1X

WCDMA

CDMA 2000

2G 2.5G 3G

CDMA One

TDMA

PDC

GSMGPRS ?

4G

4

GPRSGeneral Packet Radio Service

GPRS

�An extension of GSM & TDMA toward 3G

�Packet-based data service�Supplement to circuit switched network

�More spectrum efficient

�Improved quality of data service�Faster (max of 171.2 Kbps � real 56Kbps)

�Robust

�Security support

�Immediacy�Always-on connection

�Allow IP-based architecture

GPRS Network

IrDA Link

Bluetooth Connection

PCMCIA

as GPRS modem

Serial Link

Built-in GPRS modems

or

5

Serving GPRS

Support Node

(SGSN)

Gateway GPRS

Support Node

(GGSN)

Home Location Register (HLR)

X.25 Network

X.25 Network

Business Network

Base Station Subsystem (BSS)

IP Network/ Internet

IP Network/ Internet

GPRS Network (contd.)

GPRS Applications

�Communications� Email

� Fax

� Internet Access

� Unified messaging

�Advertising

�E-commerce� Retail

� Packet purchasing

� Banking

� Financial trading

�Location-based Applications� Location finder

� Airline/rail schedules

�Value Added

Services (VAS)� Information services

�Games

�Vertical Applications� Fleet management

� Sales-force automation

Limitations of GPRS

�Cell capacity

�Limited radio resources

�Speed

�Not all time slots are used!

�Sub-optimal modulation

�Based on GMSK (Gaussian Min. Shift Keying)

�1-bit per symbol

�Transit delays

6

EDGEEnhanced Data Rates for GSM Evolution

What is Edge?

�It is an add-on to GPRS

�Method to increase data rates on GSM

radio links (384 Kbps)

�Increase spectrum efficiency

�Facilitate new applications

�New modulation and channel coding

techniques (8PSK)

Modulation Techniques

8 PSK ModulationEDGE

GMSK ModulationGPRS

000

010

011

Real

Imaginary Imaginary

Real

110

111

100

101

001

0

1

7

Coding Schemes

0

10

20

30

40

50

60

70

CS1

CS2

CS3

CS4

MCS1

MCS2

MCS3

MCS4

MCS5

MCS6

MCS7

MCS8

MCS9

GMSK Modulation 8PSK Modulation

8

1214.4

20

8.411.2

14.8

59.2

17.622.4

29.6

44.8

54.4

Advantages of EDGE

�Packet handling i.e. re-segmentation

�Can adapt to the radio environment (C/I ratios)

�Better throughput

�Addressing Window

�GPRS: 128, window size 64

�EDGE: 2048, window size 1024

�Measurement Accuracy

�Interleaving

�Link adaptation

Added Benefits with EDGE

�Improved Quality of Service

�Potentially lower price per bit

�Personal multimedia applications�Online email

�Web

�Enhanced short messages

�Wireless imaging with instant pictures

�Video services

�Document and information sharing

�Voice over internet (IP)

�broadcasting

8

CDMACode Division Multiple Access

Why CDMA?

�It allows frequency reuse

�Security

�Soft Handoff

�Multiple Access Capability

�Efficient power control

Channel

Noise

De-Spreading

using Walsh

Code

MUD

&

BER Vs. SNR

Simulation of CDMA System

Source

bits

Spreading

using Walsh

code

9

Walsh Codes of length 32 bits

w1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

w2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1

function Walsh_Code=Generate_Walsh(k)

% Hadamard Matrix

L=hadamard(k);

% Generating the Walsh code from the

Hadamard Matrix

for i=1:k

counter=1;

for j=1:k-1

if L(i,j)~=L(i,j+1)counter=counter+1;

end

end

Walsh_Code(counter,:)=L(i,:);

end

disp('Walsh_Code=');

disp(Walsh_Code);

w30 1 -1 1 -1 1 -1 1 -1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 1 -1 1 -1 1 -1 1 -1

w32 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1

w31 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1

.

.

.

.

.

3GThird Generation

Wireless Communications Networks

Motivation

� The need to shift wireless technology

from voice-centric services to multimedia-

oriented services [5].

� Be connected anywhere, anytime, any-device.

� Allows multicasting services.

� Better usage of the available spectrum.

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Streaming over 3G

VIVO 3G channel

Off line

Storage

Content

Creation

Subsystem

Multimedia

Distribution

Subsystem

Multimedia

Terminal

Subsystem

Multimedia Protocols over 3G

Video

Audio

Still Images (Bitmap,..)

Text

Vector graphics

Presentation

description

RTP Hypertext RTSP

UDP TCP

IP

3G packet

3G Capabilities

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Pico Cell

Indoor

Up to 2.048Mb/s

Micro Cell

Up to 384 Kb/s

Macro Cell

Up to 144 Kb/s

Global

Include Satellite

Systems

Up to 9.6 Kb/s

Cells and Data Rate in 3G

Handset Characteristics

� some of 3G handsets uses intelligent OS and Hardware

based on the concept “reconfigurable computing”.

� Many way for connectivity

� IrDA

� Bluetooth

� Extend battery life

Still/Moving

Images

Email

Electronic

Commerce

Web

Browsing

Chat

Positioning

Audio

File

Transfer

Still/Moving

Images

Electronic

Commerce

Email

Chat

Web

BrowsingPositioning

File

Transfer

+many others

Applications

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Applications Along Evolution

2G 2.5G 3G

� Simple text

�SMS

�M-mail

� Multimedia Messaging

�MMS

. * ” ” * . * ” ” * .

* I LOVE YOU! *

“. .”

* . . *

*

•Love

U!!

� Richer messaging

�Enhanced SMS

4GFourth Generation

Wireless Communications Networks

What is 4G?

Is a VISION or CONCEPT to be discussed by governments, research organizations and wireless venders

No official definition…

4G means different things to different people

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Technological Drivers

�Processor performance

�Moor’s law

�Air interference

�Shannon’s capacity

�Battery performance

�Power consumption of handset display

Graphical Interpretation

Mobility &Reach

Bandwidth Larger investments in physical

infrastructure (more base-stations)

Higher transmitter power (causing higher radiation)

In the Hot-spots Cities Suburbs Country- Developing Entire

office (airports, hotels, bus. distr.) central towns side countries planet

$

$

Some Suggestions

�WLANs + 2.5G/3G?�Mobile on the move

�Applications: Voice, SMS/E-mail, stock quotes, weather, time-tables, driving directions, bank accounts, yellow pages, delayed flights ...

�High mobility, lower bandwidths

�Semi-Mobile i.e. WLAN�Laptop or PDA download of e-mail and files

�Low mobility, high bandwidths

�Some new radio interface (e.g. UWB) ?

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4G Characteristics

� Use smaller cell size than 3G

�Will be far cheaper than 3G

� Convergence of cellular with IPv6,

cable TV, PC, ATM, DWDM, etc.

� Smooth transition from 3G

� Coexist with 3G and 2G

Potential 4G Tools [1/2]

�Advanced antenna technologies

�MIMO techniques

Potential 4G Tools [2/2]

�Access technologies

� MC-CDMA

� OFDMA

� UWB

Serial

To

Parallel

X

X

X

cos(2πf0t)

cos(2πf1t)

cos(2πfN-1t)

Σ

Modulator

BPF

BPF

BPF

s(t)

bit

stream

x

x

x

cos(2πf0t)

cos(2πf1t)

cos(2πfN-1t)

LPF

LPF

LPF

P/Sr(t)

Detector

Detector

Detector

S/P IDFT P/S

Real

Img

BPF

x

x

Σ

Mapping

OFDM Modulator

Bit

Streams(t)

cos(2πfct)

sin(2πfct)

OFDM Demodulator

x

x

cos(2πfct)

π/2

LPF

LPF

A/D S/P DFT P/S

Demapping

Received

Bit

Stream

r(t) PN Sequence

Generator Timing

Delay

Pulse

Generatorx BPF

Data

Oscillator

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Conclusion

References

[1] www.3gtoday.com

[2] www.ALTERA.com

[3] “Delivering Streaming Media to the Mobile

Masses”, Wireless Multimedia Forum, 2001

[4] “Wireless Network Evolution, 2G to 3G”,

Vijay K. Garg, 2002

[5] “Third Generation (3G) Wireless”, WhitePaper, Trillium Digital Systems Inc., March 2000

[6] http://www.commsdesign.com/story/OEG20010626S0065#equation1

[7] “Yes 2GPRS”, Mobile Streams. www.mobileGPRS.com

[8] “EDGE Introduction of high-speed data in GSM/GPRS networks. Ericsson”

[9] “GPRS. Cisco Systems, 2000”

[10] Upkar Varshney and Radhika Jain, “Issues in Emerging 4G Wireless Networks”. IEEE Communications Magazine

[11] www.gsmworld.com