Lecture

Iqra University IU
Cellular Wireless Communication:
Past Present and the Future
Past,
Presented
d bby: S
Syed
d Ismail
il Shah
Sh h
E-mail: [email protected]
[email protected]
@ g
g
1
Iqra University IU
Outline
1) Introduction to Mobile Communication and First
Generation Systems
2) Digital Communication and the 2G Systems
3) The 2.5G systems
4) Third Generation Systems
5) Wireless Local Loop
6) Other
O h Wi
Wireless
l Systems
S
7) IMT-Advanced (4G)
8) Wireless
Wi l Operators
O
t in
i Pakistan
P ki t
9) Some Recommendations
2
Iqra University IU
Why Mobile Communication?
Question: Why do we need a new technology when
we have
h
such
h a ddeveloped
l d public
bli telephone
l h
network.
k
Answer: Mobility.
Confinement Versus Freedom
3
Iqra University IU
Challenges of Mobility
Challenges of using a radio channel:
¾ The use of radio channels necessitates methods of sharingg them –
channel access. (FDMA, TDMA, CDMA)
¾ The wireless channel – poses a more challenging problem than
with wires.
¾Bandwidth: it is possible to add wires but not bandwidth. So it is
important to develop technologies that provide for spectrum reuse.
¾Privacy and security - a more difficult issue than with wired phone.
¾Others: low energy (battery), hand off, roaming, etc.
4
Iqra University IU
First Generation Systems
¾ Cellular concept emerges in early
1970s.
1970s
¾ Cellular technology allows
frequency-reuse.
q
y
With this we need to
have Handoff (handover)
¾ In 1G we had analog voice but
Control Link was digital
5
Iqra University IU
Examples of First Generation
Cellular Systems (FDMA based)
1) Advanced Mobile Phone System (AMPS)
2) Narrowband AMPS (NAMPS)
3) Nordic Mobile Telephone (NAMPS)
4) European Total Access System (ETACS)
5) Japanese TACS (JTACS)
6) Nippon Telephone and Telegram (NTT)
7) Cordless Telephone 2 (CT2)
6
First Generation – AMPS and
European Total Access Cellular
System (ETACS)
Parameter
AMPS
ETACS
Multiple Access
FDMA
FDMA
Duplexing
FDD
FDD
Channel Bandwidth
30kHz
25kHz
Traffic Channel per RF Channel
1
1
Reverse Channel Frequency
824 – 849 MHz
890 – 915 MHz
Forward Channel Frequency
869 – 894 MHz
935 – 960 MHz
Voice Modulation
FM
FM
Peak Deviation: Voice Channels
Control/Wideband Data
± 12 kHz
± 8 kHz
± 10 kHz
± 6.4 kHz
Channel Coding for Data
Transmission
BCH(40,28) on FC/BCH(48,36) on
RC
BCH(40,28) on FC/BCH(48,36) on
RC
Data Rate on Control channel
10kbps
8kbps
Spectral Efficiency
0.33 bps/Hz
0.33 bps/Hz
Number of Channels
832
1000
7
Iqra University IU
Digital Communication: Transmitter
From Other
Channels
10110
1010010
Analog
input
Analog to
Digital
Converter
Bits
Source
Encode
01101
Multiplex
p
Encrypt
Encoded
Bits
Encrypted
Data
01101
Multiplexed
Data
01010
10101
Digital Bandpass
waveform
Bandpass
modulate
Pulse
modulated
waveform
f
Bit to Sym.
& Pulse
Modulate
Channel
Encoded
D t
Data
1001101
Scrambled
data
Channel
Encode
Scrambler
10001
8
Iqra University IU
Digital Communication:
Receiver
Digital
Bandpass
waveform
De-modulate
Digital
Baseband
waveform
Bits
Equalizer,
Timing and
Sym. to Bits
Channel
Decode
Channel
Decoded
Data
De-scramble
01101
Descrambled
Bits
Source
Decoded
Bits
Analog
output
D/A
1010010
Demultiplexed
Bits
D
t d
Decrypted
Bits
Source
Decode
Decrypt
10110
To other
Channels
10001
DeMultiplex
9
Iqra University IU
Performance Metrics
• Analog Communication Systems
^ m(t)≈m(t)
– Metric is fidelity: want
– SNR typically used as performance metric
• Digital Communication Systems
^ are data rate (R bps) and probability of
– Metrics
bit error (Pb=p(b≠b))
– Symbols already known at the receiver
– Without noise/distortion/sync. problem, we will
never make bit errors
10
Iqra University IU
Second Generation Cellular
Systems (TDMA and CDMA
based)
1) GSM (Global System for Mobile)
2)) PDC ((Personal Digital
g
Cellular))
3) PHS (Personal Handy System)
4) DAMPS (Digital AMPS)
5) CDMAone (IS-95)
6) P
Personall C
Communication
i i S
System (PCS)
(PCS)-1900
1900
(IS-136)
11
Second Generation –
IS136/CDMA/GSM
Parameter
IS-136
IS-95
GSM
Multiple Access
TDMA/FDD
CDMA/FDD
TDMA/FDD
Modulation
π/4 DQPSK
BPSK
GMSK
Channel Bandwidth
30 kHz
1.25 MHz
200 kHz
Reverse Channel
Frequency Band
824 – 849 MHz
1.85 – 1.99 GHz
824 – 849 MHz
1.85 – 1.99 GHz
890 – 915 MHz
1.85 – 1.99 GHz
Forward Channel
Frequency Band
869 – 894 MHz
1.85 – 1.99 GHz
869 – 894 MHz
1.85 – 1.99 GHz
935 – 960 MHz
1.85 – 1.99 GHz
Channel Data Rate
48.6 kbps
1.2288 Mcps
270.83 kbps
Carrier Spacing
30 kHz
1.25 MHz
200 KHz
Speech Coding
VSELP(Vector Sum
excited linear prediction)
CELP
RPE-LTP
Users per carrier
3
variable
8
12
Iqra University IU
Second Generation –Benefits
ŠHigher Capacity, Mobility
ŠEasy frequency planning
-Dynamic Channel
Allocation (GSM)
-Single Frequency Band
(CDMA)
ŠBetter performance
ŠMAHO (Soft Handoff in
CDMA))
ŠError correction
-FEC
FEC
-Interleaving
ŠValue-added Services
-Low dropped call rate
-SMS
-Faster switching
-Limited data
13
transmission capabilities
Iqra University IU
Second Generation - Success
Four operational digital cellular technology: Dec’ 2000
Source: EMC Database
14
Iqra University IU
Evolution to 2.5G
2 5G Mobile Radio
Networks (data-centric)
1. High speed circuit switched data (HSCSD): GSM
2.
GPRS for 2.5G GSM and IS-136
3
3.
EDGE for 22.5G
5G GSM and IS
IS-136
136
4.
IS95B and CDMA2000 1x
15
Iqra University IU
General Packet Radio Service (GPRS)
16
Iqra University IU
Enhanced Data for Global Evolution (EDGE)
• EDGE uses 8PSK as opposed to GMSK as a modulation
scheme. Essentially squeezing in more data in the
available bandwidth.
• Data rates closer to 3G. Intended to be used by operators
who don
don’tt have a 3G license but wish to deliver higher
data rates.
• Requires all the radio cards in the existing GSM/GPRS
network to be replaced.
• Expensive solution to obtain similar data rates to the
lowest expected 3G performance.
• Raw data rate using one GSM carrier can go up to 547.2
kbps (practical 384 kbps)
17
Iqra University IU
IS 95 B and CDMA2000 1x
•
•
•
•
•
The 2.5 G Evolution of IS95 A.
Uses extra codes for increased data rates
Data Rates upto 115.2 kbps
Easy upgrade to CDMA2000
Intermediate steps to 3G:
– CDMA2000 1x, Release 0: Data rates of up to
153 6kbps
153.6kbps
– CDMA2000 1x, Release A: Data rates of up to
307.2 kbps
18
Iqra University IU
IMT-2000 (3G)
• The International Telecommunications Union (ITU)
defined the key requirements for International
Mobile Telecommunications 2000 (IMT-2000) services.
• These requirements were that the system should support
data rates of:
• 2 Mbps in fixed or in-building environments
• 384 kbps in pedestrian or urban environments
•144 kbps in wide area mobile environments
• IMT-2000 is more commonly known as… 3G.
19
Iqra University IU
Migration Path
2000
Japan
Europe
2001
2002
2003
PDC
W-CDMA
GSM
GPRS
EDGE
HSCSD
America
AMPS/D AMPS
AMPS/D-AMPS
IS-95A
2G System
3G System
D AMPS
D-AMPS
IS-95B
CDMA2000
Easy upgrade
Upgrade requiring new modulation
Upgrade requiring entire new radio system
20
Iqra University IU
Universal Frequency Reuse
Frequency
Reuse Factor = 7 for AMPS
CDMA Universal
F
Frequency
Reuse
R
CC
BB
C
B
AA
D
G
G
A
G
EE
FF
E
C
F
B
D
A
G
A
D
D
E
F
Frequency Reuse Factor = 4 for
TDMA systems
A
A
A
A
A
A
A
A
A
A
AA
A
A
A
A
A
A
A
A
A
21
Iqra University IU
CDMA2000
• E
Evolution
l ti off 1x
1 RTT conceptt
• High data rate service which is compatible to IS
95
• 1x EVDO: Evolution of the 1x system data
optimized
p
• As in 1x-RTT technology utilizes 1.25 MHz of
band
• System requires a separate carrier for the data
• 2.4 Mbps forward link, 153.3 kbps reverse link
• Rev. A: Support for VoIP: 3.1 Mbps FL, 1.8
Mbps RL
• New revisions: B and other enhancement
22
Iqra University IU
3G W-CDMA
W CDMA (UMTS)
• High-Speed
High Speed Downlink Packet Access (HSDPA)
• HSUPA and HSPA, HSPA+ Phase 1 and 2
23
Iqra University IU
TD-SCDMA
24
Iqra University IU
Timeline: For UMTS and CDMA2000
25
Iqra University IU
5) Wireless Local Loop
26
WIRELESS LOCAL LOOP
• Definition: A telephone system where subscribers are
connected to the p
public switched telephone
p
network
using radio signals rather than copper wire for part or all
of the communication between the subscriber and the
switch.
switch
• Countries with available elaborate telecommunication
infrastructure used it to increase competition
• C
Countries
t i without
ith t available
il bl elaborate
l b t telecommunication
t l
i ti
infrastructure use it for efficient and feasible method of
broadband delivery
27
Iqra University IU
Some Countries using CDMA for WLL
Algeria, Azerbaijan, Bermuda, Brazil,
Cambodia China,
Cambodia,
China Columbia,
Col mbia Dem.
Dem Rep.
Rep of
Congo,Dominican Republic, Egypt, Ethiopia,
Fiji Guatemala,
Fiji,
G atemala Haiti,
Haiti India,
India Indonesia
Kenya, Kuwait, Laos, Malaysia, Mauritius,
M i Moldova,
Mexico,
M ld
N
Nepal,
l Nigeria,
Ni i Pakistan
P ki t ,
Poland, Puerto Rico, Romania, Russia,
U d Uk
Uganda,
Ukraine,Vietnam,Yemen
i Vi t
Y
28
Iqra University IU
6) Other Systems
29
WIRELESS LOCAL AREA
NETWORKS (WLANs)
• Network- group of two or more computer
systems linked together. Local area networks
are usually confined to one building.
• Wireless Fidelity (Wi-Fi)
(Wi Fi)
– 802.11a (DS-SS) became standard (2Mpbs).
– 802.11b is common ((11Mbps)
p ) 2.4 GHz. Also has
the FH-SS extension.
– 802.11g also uses the 2.4 GHz band. Data Rate: 54
Mbps.
b Uses O
OFDM
– 802.11n: Uses OFDM and MIMO
30
Iqra University IU
Other Standards
• Long Term Evolution
– Initial Deployment in the 700 MHz Frequency Band
– Data Rate of tens of Mbps
– Uses OFDM and MIMO
• Worldwide Interoperability for Microwave Access
(WiMax)
– Operate in the 2.5,
2 5 3.5,
3 5 or 5.8
5 8 GHz bands.
bands
– Data Rates of tens of Mbps.
– Versions: IEEE 802.16d and e with amendments like:
802.16f, g, h, i, j and k
– Uses OFDM and MIMO
• Variants of both are candidates for IMT-Advanced (4G)
31
Iqra University IU
7) IMT-Advanced(4G)
32
Iqra University IU
IMT-Advanced (4G)
( )
• The min requirements for peak spectral efficiencies
– Downlink peak spectral efficiency is 15 bit/s/Hz
– Uplink peak spectral efficiency is 6.75 bit/s/Hz.
• Six Proposals are under review
• Some are based on WiMax 802.16m and some on LTE
• Both
B h uses OFDM and
d MIMO
• Final Decision by October 2010
33
Iqra University IU
IMT-Advanced ((4G):
) Time-Line
WP 5D
meetings
2008
No.1
(0)
No.2
2009
No.3
No.4
2010
No.5
No.6
No.7
No.8
2011
No.9
No.10
Step1 and 2
(20 months)
Step 3
(8 months)
(1)
Step 4
(16 months)
Steps 5,6 and 7
(20 months)
(2)
(3)
Steps 8
(12 months)
(4)
Steps in radio interface development process:
Step 1: Issuance of the circular letter
Step 2: Development of candidate RITs and SRITs
Step 3: Submission/Reception of the RIT and SRIT proposals
and acknowledgement of receipt
Step 4: Evaluation of candidate RITs and SRITs
by evaluation groups
Step 5: Review and coordination of outside evaluation activities
Step 6: Review to assess compliance with minimum requirements
Step 7: Consideration of evaluation results, consensus building
and decision
Step 8: Development of radio interface Recommendation(s)
Critical milestones in radio interface development process:
(0): Issue an invitation to propose RITs
(1): ITU proposed cut off for submission
of candidate RIT and SRIT proposals
March 2008
October 2009
(2): Cut off for evaluation report to ITU
June 2010
(3): WP 5D decides framework and key
October 2010
characteristics of IMT-Advanced RITs and SRITs
(4): WP 5D completes development of radio
February 2011
interface specification Recommendations
IMT-Advanced A2-01
Iqra University IU
Cellular Technology Roadmap
35
Iqra University IU
8) Wireless Operators in Pakistan
36
Iqra University IU
Cellular Operators in Pakistan
1) Mobilink
Technology: GSM,
GSM GPRS,
GPRS EDGE (WiMAx deployment:
Infinity)
2) Ufone
Technology: GSM, GPRS, EDGE
3) China Mobile Pakistan (CMPak, Paktel): Zong
Technology: EGSM
EGSM, GPRS
GPRS, EDGE
4) Warid
Technology: GSM, GPRS, EDGE (Associated company
Wateen: WiMax)
5) Telenor
Technology: GSM
GSM, GPRS,
GPRS EDGE
37
Iqra University IU
WLL Operators
1) V-PTCLWirless
Technology: CDMA2000,
CDMA2000 EVDO Rev
Rev. A
2) TeleCard
Technology: CDMA2000
3) WorldCall
ec o ogy: CDMA2000,
C
000, EVDO
V O Rev.
ev. A
Technology:
4) Diallog (negotiation going on with World Call)
gy CDMA2000 1x,, EVDO
Technology:
5) SCO
Technology: CDMA2000 1x, EVDO (?)
38
Iqra University IU
L t t News
Latest
N
(Pakistan)
(P ki t )
•
•
•
•
Auction of 3G spectrum????????
p
Only Mobile operators are eligible to bid ??
Three licenses to be issued??
Possible (UMTS FDD Band I):
– 1920 to 1980 MHz (Up link)
– 2110 to 2170 MHz (Down link)
• WiMax has been deployed
39
Iqra University IU
Issues with widespread usage of wireless data
‡
Why are new services/mobile content required?
‡ Tough competition
‡ Low ARPU
‡ No differentiation in Service Offerings
‡
Problem:
‡ What
Wh t services
i
will
ill differentiate
diff
ti t one operator
t from
f
the
th other?
th ?
‡ How would these services be delivered?
40
Iqra University IU
Technologies
‡
2G: Mainly Voice & SMS
‡
2.5G: Limited Data Capability
‡
3G and Beyond: High Speed Data coupled with data
centric applications and services
41
Iqra University IU
Ser ices E
Services
Evolution
ol tion With Enriched User Experiences
E periences
Mobile TV
Voice
Wallpaper
2D Gaming
Location Based
Services
Mobile
Commerce
3D Gaming
Services Evolution
Text
Messaging
Paul,
How
did the
meetin
g go?
Send
Options
Ringtones
MMS
Music & Video
on Demand
D
d
Blogging
Social Networking
RSS Feeds
& Tagging
42
Iqra University IU
Some Recommendations
•
•
•
•
•
•
•
Appoint a minister ????????????
Need to expand our knowledge base
Human resource development (HRD)
Industry-university collaboration: HRD can be a
starting point
p
Research: Both relevant like content development
and not so immediately relevant to the current
problems faced by the industry in Pakistan.
T h l
Technology
transfer
f through
h
h government policies
li i
Involvement of the private sector in policy
making
43
Iqra University IU
Thank You
44
Iqra University IU
Thank You
For qquestions/comments:
estions/comments:
E-mail: [email protected]
[email protected]
45