Post on 02-Oct-2021
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
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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
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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
Electronic
Commerce
Web
Browsing
Chat
Positioning
Audio
File
Transfer
Still/Moving
Images
Electronic
Commerce
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