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Cellular Wireless Communication: Past Present and the FuturePast, Present and the Future
d b S d il Sh hPresented by: Syed Ismail Shah
E-mail: [email protected]@3gca.org@ g g
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Outline1) Introduction to Mobile Communication and First
Generation Systems2) Digital Communication and the 2G Systems3) The 2.5G systems4) Third Generation Systems5) Wireless Local Loop6) O h Wi l S6) Other Wireless Systems7) IMT-Advanced (4G)8) Wi l O t i P ki t8) Wireless Operators in Pakistan9) Some Recommendations
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Why Mobile Communication?Question: Why do we need a new technology when
h h d l d bli l h k
Why Mobile Communication?
we have such a developed public telephone network.
Answer: Mobility.
Confinement Versus Freedom
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Challenges of MobilityChallenges of using a radio channel:
The use of radio channels necessitates methods of sharing them –gchannel access. (FDMA, TDMA, CDMA)
The wireless channel – poses a more challenging problem than with wires.
Bandwidth: it is possible to add wires but not bandwidth. So it is important to develop technologies that provide for spectrum reuse.
Privacy and security - a more difficult issue than with wired phone.
Others: low energy (battery), hand off, roaming, etc.
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First Generation SystemsCellular concept emerges in early
1970s1970s.
Cellular technology allows frequency-reuse. With this we need to q yhave Handoff (handover)
In 1G we had analog voice but Control Link was digital
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Examples of First Generation Cellular Systems (FDMA based)
1) Advanced Mobile Phone System (AMPS)
2) Narrowband AMPS (NAMPS)
3) Nordic Mobile Telephone (NAMPS)3) Nordic Mobile Telephone (NAMPS)
4) European Total Access System (ETACS)
5) Japanese TACS (JTACS)5) Japanese TACS (JTACS)
6) Nippon Telephone and Telegram (NTT)
7) Cordless Telephone 2 (CT2)
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First Generation – AMPS and European Total Access CellularEuropean 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 MHzReverse 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 ± 12 kHz ± 10 kHzControl/Wideband Data ± 8 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
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Spectral Efficiency 0.33 bps/Hz 0.33 bps/Hz
Number of Channels 832 1000
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Digital Communication: TransmitterFrom Other
1 0 1 0 0 1 0Analog to
DigitalSource
1 0 1 1 0
Encrypt
0 1 1 0 1
Multiplex
From OtherChannels
Analog input
Digital Converter Bits Encoded
Bits
Encode EncryptEncrypted
Data
p
0 1 1 0 1
0 1 0 1 0Multiplexed
Pulse modulated
fDigital Bandpass
waveform
0 1 0 1 0
1 0 1 0 1Data
Channel Encoded
D t
Scrambled data
Bit to Sym. & Pulse
Modulate
waveformwaveformBandpass modulate
Channel Encode
Data
1 0 0 1 1 0 1
Scrambler
1 0 0 0 1
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1 0 0 0 1
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Digital Communication:Digital Communication: Receiver
Equalizer, Timing and
Bits
De-modulate
Digital Baseband waveform
Digital Bandpass waveform
Channel
Channel Decoded
DataDe-scrambleTiming and
Sym. to BitsDecode
0 1 1 0 1
Descrambled
D t dSource De-
Descrambled Bits 1 0 0 0 1
Decrypted Bits
1 0 1 1 0 DecryptAnalog
output
D/A
Decoded Bits
1 0 1 0 0 1 0
Source Decode De-
Multiplex
De-multiplexed
Bits
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output 1 0 1 0 0 1 0To other Channels
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Performance Metrics• Analog Communication SystemsAnalog Communication Systems
– Metric is fidelity: want m(t)≈m(t)– SNR typically used as performance metric
^
SNR typically used as performance metric
• Digital Communication Systems– Metrics are data rate (R bps) and probability of
bit error (Pb=p(b≠b))^
– Symbols already known at the receiver– Without noise/distortion/sync. problem, we will
10never make bit errors
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Second Generation Cellular Systems (TDMA and CDMA
based)1) GSM (Global System for Mobile)
2) PDC (Personal Digital Cellular)) ( g )
3) PHS (Personal Handy System)
4) DAMPS (Digital AMPS)4) DAMPS (Digital AMPS)
5) CDMAone (IS-95)
6) P l C i i S (PCS) 19006) Personal Communication System (PCS)-1900 (IS-136)
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Second Generation –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 MHz1.85 – 1.99 GHz
824 – 849 MHz1.85 – 1.99 GHz
890 – 915 MHz1.85 – 1.99 GHz
Forward Channel 869 894 MHz 869 894 MHz 935 960 MHzForward Channel Frequency Band
869 – 894 MHz1.85 – 1.99 GHz
869 – 894 MHz1.85 – 1.99 GHz
935 – 960 MHz1.85 – 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
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Second Generation –BenefitsHigher Capacity, Mobility
Easy frequency planning MAHO (Soft Handoff in CDMA)
-Dynamic Channel Allocation (GSM)
)
Error correction
FEC-Single Frequency Band (CDMA)
-FEC
-Interleaving
Better performance
-Low dropped call rate
Value-added Services
-SMS
13-Faster switching -Limited data
transmission capabilities
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Second Generation - Success
Four operational digital cellular technology: Dec’ 2000
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Four operational digital cellular technology: Dec’ 2000Source: EMC Database
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Evolution to 2 5G Mobile RadioEvolution to 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 EDGE for 2 5G GSM and IS 1363. EDGE for 2.5G GSM and IS-136
4. IS95B and CDMA2000 1x
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Enhanced Data for Global Evolution (EDGE)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’t have a 3G license but wish to deliver higherwho don t 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.lowest expected 3G performance.• Raw data rate using one GSM carrier can go up to 547.2 kbps (practical 384 kbps)
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IS 95 B and CDMA2000 1xIS 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:Intermediate steps to 3G:
– CDMA2000 1x, Release 0: Data rates of up to 153 6kbps153.6kbps
– CDMA2000 1x, Release A: Data rates of up to 307.2 kbps
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307.2 kbps
Iqra University IUIMT-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 supportdata rates of:
• 2 Mbps in fixed or in-building environments• 384 kbps in pedestrian or urban environments•144 kbps in wide area mobile environments•144 kbps in wide area mobile environments
• IMT-2000 is more commonly known as… 3G.
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2000 2001 2002 2003
Japan PDC W-CDMA
Europe
America
GSM
AMPS/D AMPS D AMPS
GPRS EDGE
HSCSD
America AMPS/D-AMPS
IS-95A IS-95B
D-AMPS
CDMA2000
2G System
3G System
Easy upgradeUpgrade requiring new modulationUpgrade requiring entire new radio system
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Universal Frequency ReuseUniversal Frequency ReuseUniversal Frequency ReuseUniversal Frequency ReuseFrequency
Reuse Factor = 7 for AMPSFrequency
Reuse Factor = 7 for AMPSCDMA UniversalF RCDMA UniversalF R
CC
B D AA
A A
Reuse Factor = 7 for AMPSReuse Factor = 7 for AMPS
CB D
Frequency ReuseFrequency Reuse
CB D
G EA
B D
FG E
A AA A
A
A A
A AA
B D
EA
FG
AF
G EC
B DA
FA
A AA
A A
AF A
FG E
A
AA A
A
21Frequency Reuse Factor = 4 for
TDMA systems
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CDMA2000 E l ti f 1 RTT t• Evolution of 1x RTT concept• High data rate service which is compatible to IS
9595• 1x EVDO: Evolution of the 1x system data
optimizedp• 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
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• New revisions: B and other enhancement
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3G W-CDMA (UMTS)3G W CDMA (UMTS)
• High Speed Downlink Packet Access (HSDPA)23
• High-Speed Downlink Packet Access (HSDPA)• HSUPA and HSPA, HSPA+ Phase 1 and 2
WIRELESS LOCAL LOOP• Definition: A telephone system where subscribers are
connected to the public switched telephone network p pusing radio signals rather than copper wire for part or all of the communication between the subscriber and the switchswitch.
• Countries with available elaborate telecommunication infrastructure used it to increase competition
C t i ith t il bl l b t t l i ti• Countries without available elaborate telecommunication infrastructure use it for efficient and feasible method of broadband delivery
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Some Countries using CDMA for WLLAlgeria, Azerbaijan, Bermuda, Brazil, Cambodia China Col mbia Dem Rep of
Some Countries using CDMA for WLL
Cambodia, China, Columbia, Dem. Rep. of Congo,Dominican Republic, Egypt, Ethiopia, Fiji G atemala Haiti India IndonesiaFiji, Guatemala, Haiti, India, IndonesiaKenya, Kuwait, Laos, Malaysia, Mauritius, M i M ld N l Ni i P ki tMexico, Moldova, Nepal, Nigeria, Pakistan, Poland, Puerto Rico, Romania, Russia, U d Uk i Vi t YUganda, Ukraine,Vietnam,Yemen
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WIRELESS LOCAL AREA NETWORKS (WLANs)NETWORKS (WLANs)
• Network- group of two or more computer systems linked together. Local area networkssystems linked together. Local area networks are usually confined to one building.
• Wireless Fidelity (Wi-Fi)Wireless Fidelity (Wi Fi)– 802.11a (DS-SS) became standard (2Mpbs).– 802.11b is common (11Mbps) 2.4 GHz. Also has ( p )
the FH-SS extension.– 802.11g also uses the 2.4 GHz band. Data Rate: 54
b OMbps. Uses OFDM– 802.11n: Uses OFDM and MIMO
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Other Standards • Long Term Evolution
– Initial Deployment in the 700 MHz Frequency Band– Data Rate of tens of MbpsData Rate of tens of Mbps– Uses OFDM and MIMO
• Worldwide Interoperability for Microwave Access (WiMax)
Operate in the 2 5 3 5 or 5 8 GHz bands– Operate in the 2.5, 3.5, or 5.8 GHz 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
31• Variants of both are candidates for IMT-Advanced (4G)
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IMT-Advanced (4G)( )• The min requirements for peak spectral efficiencies
Downlink peak spectral efficiency is 15 bit/s/Hz– 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
B h OFDM d MIMO• Both uses OFDM and MIMO
• Final Decision by October 201033
• Final Decision by October 2010
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IMT-Advanced (4G): Time-Line
Step1 and 2
No.1 No.2 No.3 No.4 No.5 No.6 No.7 No.8 No.9WP 5D meetings
2008 2009 2010No.10
2011
( )
Step1 and 2
Step 3(0)
(1)
(20 months)
Step 4(8 months)
(16 months) (2)Steps 5,6 and 7
(3)Steps 8
(20 months)
Steps in radio interface development process:(4)(12 months)
Step 1: Issuance of the circular letterStep 2: Development of candidate RITs and SRITsStep 3: Submission/Reception of the RIT and SRIT proposals
Step 5: Review and coordination of outside evaluation activitiesStep 6: Review to assess compliance with minimum requirementsStep 7: Consideration of evaluation results, consensus building
and acknowledgement of receiptStep 4: Evaluation of candidate RITs and SRITs
by evaluation groups
and decision Step 8: Development of radio interface Recommendation(s)
Critical milestones in radio interface development process:(0): Issue an invitation to propose RITs March 2008 (2): Cut off for evaluation report to ITU June 2010(1): ITU proposed cut off for submission October 2009
of candidate RIT and SRIT proposals(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
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Cellular Operators in PakistanCellular Operators in Pakistan1) Mobilink
Technology: GSM GPRS EDGE (WiMAx deployment:Technology: GSM, GPRS, EDGE (WiMAx deployment: Infinity)
2) UfoneTechnology: GSM, GPRS, EDGE
3) China Mobile Pakistan (CMPak, Paktel): ZongTechnology: EGSM GPRS EDGETechnology: EGSM, GPRS, EDGE
4) WaridTechnology: GSM, GPRS, EDGE (Associated company Wateen: WiMax)
5) TelenorTechnology: GSM GPRS EDGE
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Technology: GSM, GPRS, EDGE
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WLL OperatorsWLL Operators1) V-PTCLWirless
Technology: CDMA2000 EVDO Rev ATechnology: CDMA2000, EVDO Rev. A2) TeleCard
Technology: CDMA2000Technology: CDMA20003) WorldCall
Technology: CDMA2000, EVDO Rev. Aec o ogy: C 000, V O ev.4) Diallog (negotiation going on with World Call)
Technology: CDMA2000 1x, EVDO gy ,5) SCO
Technology: CDMA2000 1x, EVDO (?)
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L t t N (P ki t )Latest News (Pakistan)• Auction of 3G spectrum????????p• Only Mobile operators are eligible to bid ??• Three licenses to be issued??• 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
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Issues with widespread usage of wireless data
Why are new services/mobile content required?
Issues with widespread usage of wireless data
Tough competitionLow ARPUNo differentiation in Service OfferingsNo differentiation in Service Offerings
Problem:Wh t i ill diff ti t t f th th ?What services will differentiate one operator from the other?How would these services be delivered?
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Technologies
2G: Mainly Voice & SMS
2.5G: Limited Data Capability
3G and Beyond: High Speed Data coupled with data centric applications and services
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Ser ices E ol tion With Enriched User E periencesServices Evolution With Enriched User Experiences
Mobile TV
Wallpaper
Location BasedServices2D Gaming
Mobile TV
3D Gaming
Voice
Mobile Commerce
RingtonesMusic & Video
D d
Services Evolution
Paul,
Text Messaging MMS Blogging
on DemandPaul,How
did the meeting go?
Social Networking RSS Feeds & Tagging
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Send Options
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Some RecommendationsSome Recommendations• Appoint a minister ????????????• Need to expand our knowledge base• Need to expand our knowledge base• Human resource development (HRD)• Industry-university collaboration: HRD can be a• Industry-university collaboration: HRD can be a
starting point• Research: Both relevant like content development p
and not so immediately relevant to the current problems faced by the industry in Pakistan.T h l f h h li i• Technology transfer through government policies
• Involvement of the private sector in policy making
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making
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Thank You
For q estions/comments:For questions/comments:E-mail: [email protected]@3gca.org
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