Diff Bet Wcdma and Cdma 2000

8/8/2019 Diff Bet Wcdma and Cdma 2000

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3G CDMA - WCDMA and

cdma2000

Rodger E. Ziemer

IEEE Communications SocietyDistinguished Lecturer Program


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May 28-June1, 2001 R. Z. Ziemer, Colorado Springs, CO 2

Outlinev Multiple access/channel measurement guidelinesv Current 1G and 2G technology

v What is Third Generation?v WCDMA featuresv cdma2000 features

v WCDMA and cdma2000 contrastedv Summary


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Rules for Efficient Multiple Accessv Three immutable laws

v Know the channelv

Minimize interference to othersv Mitigate interference received from others

v Requirements of wireless multiple accessv Channel measurementv Channel control and modificationv Multiple user channel isolation


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Channel Measurement Guidelinesv Wider the bandwidth = better the measurementv Limitations on this rule

v Regulatory (indoor path isolation = 10 ns delay resolution)v Complexity (combining more paths = more hardware)v Physical limitations (splitting energy over more paths = increasingly

inaccurate parameter measurements)

v Measure at frequency > rate of change of channelv No other users: good receiver attempts to put together all

received multipath components coherentlyv Other users present: Optimum = multiuser detection;

suboptimum = power control; minimize near-far problem


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Current 1G and 2G Technology

Analog14%

cdmaOne12%

GSM58%

PDC8%

IS-1368%

System Jun-00Analog 78,339,980cdmaOne 67,964,980GSM 337,794,500

PDC 47,739,500IS-136 48,079,830

Asia Pacific32%

Europe:Eastern

3%

Europe:Western

36%

USA/Canada17%

Middle East

1%

Americas9%

Africa2%

Source: EMC World Cellular Database


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Why CDMA?v Higher capacityv Improved performance in multipath by diversityv Lower mobile transmit power = longer battery life

v Power controlv Variable transmission rate with voice activity detection

v Allows soft handoff v Sectorization gainv High peak data rates can be accommodatedv Combats other-user interference = lower reuse factors


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IS-95 Forward Link Xmtr Diagram [5]

pulseshaping

pulseshaping

cos ot

sin ot LPA

c I pilot ,

cQ pilot ,

R=1/2; k = 9convolutional

encoder

blockinterleaver

user mlong code

mux

reverselink powercontrol bit

wmuser m

Walsh code

cl m,

19200 sps

1.2288 Mcps

1.2288 Mcps

datascrambling


encoder

blockinterleaver

user nlong code

mux

reverselink powercontrol bit

user nWalsh code

19200 sps

1.2288 Mcps

datascrambling


encoder

blockinterleaver

pagingchannel

long codepaging channel

Walsh code

pagingchannel data9600/4800/ 2400 bps

19200 sps

1.2288 Mcps

datascrambling

w pcl page,

R=1/2; k = 9

convolutionalencoder

blockinterleaver

synch channelWalsh code

synchronization

channel data1200 bps

4800 sps

1.2288 Mcps

pilot channelWalsh code

pilot channeldata all 0's

1.2288 Mcps

w32

w0

S

cl n,

voiceencoder

172 bitsper 20 msec

error detectioncode (CRC)

& tail bits

12 bit CRC8 bit tail

8600 bps 9600 bps 19200 sps

384 symper 20 msec

voiceencoder

error detectioncode (CRC)

& tail bits

pagingchannelframing

syncchannelframing

user manalog voice

user nanalog voice

++

++

+ +

+

+

S


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What is Third Generation? [1]v Flexible support of multiple services

v Voicev Messaging email, fax, etc.v Medium-rate multimedia Internet access, educationalv High-rate multimedia file transfer, videov High-rate interactive multimedia video telecon-ferencing,

telemedicine, etc.

v Mobility: quasi-stationary to high-speed platformsv Global roaming: ubiquitous, seamless coveragev Evolution from second generation systems


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Evolution of Standards [1]GSM

IS-95A

PDC

IS-136

cdma2000

iDEN

1xEV-DVIS-95B

1xEV-DO

GPRS EDGE

W-CDMA HSPDA

2G 2.5G 3G

world

Japan

U.S.

U.S.

U.S./Asia


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Peak Data Rates [1]

171.0115.2

2072.0

614.2

473.0

0

500

1000

1500

2000

k b p s

GPRS IS-95B WCDMA cdma2000 EDGE


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3G Spectrum Availability [2]

ITU

Japan

China

USA

3G

3G

3G

3G

3G

3G

3G

1885

1885

1885

2025

2025

2025

2025

2110

2110

2110

2110

2110

2200

2200

2200

2200

2200

MSS

MSS

1850

DECT

1880 1900

1895 1918.1

PHS

1980 2010

1980 2010

BroadcastAuxiliary

1930

1910 1930 1990

PCSPCS Unl.PCS

Reserve

MSS MSS

All Frequencies in MHz

* Region 2

MSS MSS

3G

MSS

MSS*MSS*21702120

2170

1996 2010 2186

2150

MSS

DCS1800

DCS1800

1710 1785 1805

A D B E F C A D B E F C

Europe


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Main Differences between WCDMAand GSM Air Interfaces [3]

Not supportedSupportedDownlink diversity

Time slot basescheduling with GPRS

Load based packetscheduling

Packet data

Frequency hoppingWideband with RAKEFrequency diversity

Network planning(frequency planning)

Radio resourcemanagement algorithms

Quality control

2 Hz or lower1500 HzPower control freq

1-181Reuse factor

200 kHz5 MHzCarrier spacing

GSMWCDMA


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Main Differences between WCDMAand IS-95 Air Interfaces [3]

Not supportedSupportedDownlink transmit diversity

Packet data xmitted asshort circuit switched cells

Load-based packetscheduling

Packet dataNot needed (speech only)Yes, provides QoSRadio resource management

Possible; measurementmethod not specified

Yes, measurements withslotted mode

Inter-frequency handovers

Yes, typically via GPSNot neededBase station synchronization

800 Hz uplink; slow, DL1500 up- & downlink Power control freq1.2288 Mcps3.84 McpsChip rate

1.25 MHz5 MHzCarrier spacing

IS-95WCDMA


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WCDMA Transmission Parametersv Wideband direct-sequence spreadingv 3.84 Mcps chip ratev Spreading gains (ratios) from 4 to 512

v Complex QPSK spreadingv Both frequency- and time-division duplex modesv Both forward and reverse fast power control

v Coherent forward and reverse links using bothcode-division and time-division pilotsv Asynchronous cells


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New Features of cdma2000 vs. IS-95v Reverse Link [4]

v Coherent pilot channel assistedv Binary PSK data modulationv Complex PN spreadingv Enhanced access channel = decreased setup times for

traffic channeless connections (allows power controland slot reservations)

v Improvements to interfrequency hard handoff tosupport subframe searches


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W-CDMA Versus cdma2000 [2]W-CDMA IS-2000

Chip Rate 4.096 Mcps 3.6864 Mcps

Frame Duration 10 ms 20 ms

Base Stn Sync Asynchronous Synchronous

Base Stn Acq/Det 3 step paral code srch forbase stn det & slot/frameSync through time-shifted PN correlation

Forward Link Pilot TDM dedicated pilot CDM common pilot

Antenna Beam Form TDM dedicated pilot Auxiliary pilot


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Technologies Considered in Arrivingat Third Generationv Wideband Direct-Sequence Code Division

Multiple Access (CDMA)v Wideband Time Division Multiple Access

(TDMA)v Wideband C/TDMA

v Orthogonal Frequency Division Multiplexing(OFDM)v Opportunity Driven Multiple Access (ODMA)


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WCDMA Uplink Frame Structure [1]DPDCHI: data channel

Q: sync & control DPCCH

)6,,0( bits 2*10 k K== k N data

chips 2560 =slot T

bits pilot N Pilot: TFCI FBI TPC

TFCI = transmit format combination indicatorFBI = feedback informationTPC = transmit power control

DPDCH = dedicated physical data channelDPCCH = dedicated physical control channel

ms 667.0

slot 0 slot 1 slot i slot 14

radio frame = 10 ms


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WCDMA Uplink Modulator Structure [1]

pulse shapefilter (SRC)


d

d

d

c

1,d c

)cos( t c

)sin( t c

2,d c

3,d c

cc

DPDCH 1

DPDCH 2

DPDCH 3

DPCCH

I

Q

long,1c long,2c

+

+

+

-

+

+


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Orthogonal Variable Spreading Factor Codes

00

0

000000000000

01

0011

0101

0110

00001111

00110011

00111100

01010101

01011010

01100110

01101001

,c d i selected from this treeNotes:1) For fixed chip rate, desired information

rate determines length of spreadingsequence and therefore processing gain.

2) When a specific code is used, no othercode on the path from that code to the rootand or on the subtree beneath thatcode may be used.

3) All the codes at any depth into the treeare the set of Walsh Sequences.

4) Code phase is synchronous withinformation symbols.

5) FDD UL processing gain between 256 and 4

FDD DL processing gain between 512 and 4TDD UL/DL processing gain between 16 and 16) Multicode used only for SF = 4


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WCDMA Downlink Frame Structure [1]

DPDCH DPCCH

chips 2560 =slot T

TFCI PilotTPC

ms 667.0

slot 0 slot 1 slot i slot 14

radio frame = 10 ms

DPDCHDPCCH

1 data N 2 data N Data1 Data2

)7,,0(bits 2*10 22 K==+ k N N k

datadata


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WCDMA Downlink Modulator Structure [1]

long,2c

t je

long C

long C


PrimarySync Code

SecondarySync Code

1 G

nG

PG

SG

s u m

1,d c

nd c ,

PC

SC

dedicatedtraffic channels

primary &secondarycommon pilotchannels

primary &secondarycommoncontrolchannels

other channels

s/p

s/p


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WCDMA Forward Error Controlv Convolutional Codingv rate 1/2 & rate 1/3v 256 statev

puncture to higher ratesv interleave over 10, 20, 40 or 80 msv Turbo Coding

v parallel codingv rate 1/3v 8 state codesv block lengths 320 to 5114 bitsv interleaver designed within 3gpp


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WCDMA Convolutional Code

Output 0561 (octal)

Output 1753 (octal)

25.212 V3.5.0 (2000-12)

Rate Code

input


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WCDMA Convolutional Code

input

Output 1663 (octal)

Output 0557 (octal)

Output 2711 (octal)

Rate 1/3 Code

25.212 V3.5.0 (2000-12)


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WCDMA Turbo Coding+

+

+

+

+ +

+

+

interleaver

)(t X

)(t Y

)(t Y

)(t X


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Codng Performance Compared

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

2.50 3.00 3.50 4.00 4.50 5.00

average Ebi/N0

a v e r a g e

B E R

, F E R

PCTC,BER,N=5120,8st,4it,CDI int

PCTC,FER,N=5120,8st,4it,CDI int

conv+RS,BER,K=9,N=5120

conv+RS,FER,K=9,N=5120

PCTC,BER,N=640,8st,4it,CDI int

PCTC,FER,N=640,8st,4it,CDI int

conv+RS,BER,K=9,N=640

conv+RS,FER,K=9,N=640

1 dB


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Diversity Strategies for Downlink Transmit Diversity


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cdma2000 Transmission Parametersv Wideband direct-sequence CDMA

v uplink chip rates 1.2288 Mcps & 3.686 Mcpsv downlink chip rate 1.2288 Mcps

v single or 3X multicarrier downlink v spreading factors from TBD to TBD

v Complex QPSK spreadingv Frequency Division Duplexv Both forward and reverse fast power control ( 800 Hz )v Coherent forward and reverse links using code-division

pilotsv Synchronous cells


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cdma2000 Uplink Frame Structure

CRCencodertail bits

Convolutionalor Turbo Coder

symbolrepetition

symbolpuncture

blockinterleaver

modulationsymbol

Cchannel

bits

Bits/ Frame164080172350744151230486120

CRCbits668121616161616

tailbits

888888888

Data Ratekbps1.52.74.89.619.238.476.8153.6307.2

CodeRate1/41/41/41/41/41/41/41/41/2

Repeats1684211111

Delete1 of 51 of 9nonenonenonenonenonenonenone

Symbols15361536153615361536307261441228812288

Radio Configuration 3

C.S.0002-A-1 Fig 2.1.3.1.1.1-8


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cdma2000 Uplink Modulator

C

C

C

A

B

d

d

d

c

)cos( t c

)sin( t cIlong,c Qlong,c

+

+

+

+

+

_

s u m

s u m1 Dw

C w

2 Sw

1 Sw

PrimaryTraffic

SecondaryTraffic 1

SecondaryTraffic 2

Control

Pilot

pulseshape

pulseshape


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cdma2000 Long Code Generator

++++++++++ 17161076532 XXXXXXX1 X X

4235333127262522211918 XXXXXXXX X X X ++++++++++

M m,j identifies user

M m,1 M m,2 M m,3

42 X

I-channel PNQ-channel PN

walsh 2(0 1)

1-chip

delay

dec

by 2

1 X

+ + +

+


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Short PN Pilot Sequence: 1.2288 Mcps

C.S0002-A-1 paragraph 2.1.3.1.12.1

insertzero

insert

zero

+ + + + +

+ + + + + + +

inphase PN sequence

quadrature PN sequence

151211106543 XXXXXX1 X X ++++++++

15139875

XXXX1 X X ++++++


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cdma2000 UL Convolutional Codes

C.S.0002-A-1 Fig 2.1.3.1.4.1.1-1


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cdma2000 Turbo Code+ +

+ +

+

+ +

++

+

+

interleaver

s y m

b o l p

u n c t u r e

a n

d r e p e a

t

output

input

C.S.0002-A-1 Fig 2.1.3.1.4.2.1-1


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cdma2000 3X Code Generators

insertzero

+ + +

20953 XXX1 X ++++

Short Pilot CodeTruncate and use delay different segments for I and Q

1X longcode

s1.2288

1

s1.2288

1

+

+

MUX

C.S0002-A-1 Fig 2.1.3.1.12-1

Long CodeGenerator

Output(3.6864 Mcps)


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cdma2000 Uplink Data Rates


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cdma2000 1X Downlink CommonChannels

Pilot Channelall 0s

SyncChannel

PagingChannel

convencode

2Xrepeat interleave 4800 ksps

0 11 -1

0 11 -1

0 11 -1

channelgain

channelgain

channelgain

convencode repeat interleave

longcode decimate

+

Q X

I X

Q X

I X

Q X

I X

C.S0002-A-1 Fig 3.1.3.1.1.1-1


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cdma2000 1X DL ModulationProcessing+

longcode

longcodemask

0 11 -1

channelgain

fwd pwr

ctrl gain p o w e r c o n

t r o

l

s y m

b o

l p u n c t u r e

D E M U X

decimatepwr ctrlbit pos

I/Q scramblingbit extract

powercontrol

bits

puncturetiming800 Hz

W

YQ

YI

C.S.0002-A-1 Fig 3.1.3.1.1.1-18

modulationsymbol

rate


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cdma2000 Downlink Convolutional Codes


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cdma2000 3X Downlink CommonChannels

C.S.0002-A-1 Fig 3.1.3.1.1.2-1

Pilot Channelall 0s

SyncChannel

convencode


0 11 -1

0 11 -1

channelgain

channelgain

Q X

I X

Q X

I X


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cdma2000 1X Downlink Modulation

I channelpilot PN

Q channelpilot PN

Walsh code

QOF code

I Y

QY

pulseshape

pulse

shape

+

+

+

-

)cos( t c

)sin( t c

otherchannels

otherchannels

p h a s e r o

t a t e f o r

Q O F

Q X

I X


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cdma2000 Downlink Frame Structure

Other similar tables in specification.

Bits/ Frame16408017236074415123048

CRCbits6681216161616

tailbits

88888888

Data Ratekbps1.52.74.89.619.238.4

76.8153.6

CodeRate1/41/41/41/41/41/4

1/41/4

Repeats84211111

Delete1 of 51 of 9nonenonenonenonenonenone

Symbols76876876876815363072

614412288


CRCencodertail bits


symbolrepetition

symbolpuncture

blockinterleaver

modulationsymbolchannel

bits W


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cdma2000 3X DL Modulation Processing

+

longcode

longcodemask

0 11 -1

channelgain

fwd pwrctrl gain p o w e r c o n

t r o

l

s y m

b o

l p u n c t u r e

D E M U X

decimate pwr ctrlbit pos


power

controlbits


W Y1

modulationsymbol

rate Y0


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cdma2000 3X DownlinkCommon Channels

Pilot Channelall 0s

SyncChannel

convencode


0 11 -1

0 11 -1

channelgain

channelgain

Q X

I X

Q X

I X


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cdma2000 Downlink Frame Structure

Other similar tables in specification.

Bits/ Frame21551252675521128

22804584919220712

CRCbits6810121616

16161616

tailbits

888888

8888

Data Ratekbps1.83.67.214.428.857.6

115.2230.4460.81036.8

CodeRate1/21/21/21/21/21/2

1/21/21/21/2

Repeats842111

1111

Deletenonenonenonenonenonenone

nonenonenone2 of 18

Symbols57657657657611522304

460892161843236864


CRCencodertail bits


symbolrepetition

symbolpuncture

blockinterleaver

modulationsymbolchannel

bitsW


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cdma2000 3X DL ModulationProcessing+

longcode

longcodemask

0 11 -1

channelgain

fwd pwrctrl gain p

o w e r c o n

t r o

l

s y m

b o

l p u n c

t u r e

D E M U X

decimate pwr ctrlbit pos


powercontrol

bits


W YQ1YI1

modulationsymbol

rate

YQ2YI2

YQ3YI3


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cdma2000 3X Downlink Modulation

same as below

same as above

outputcarrier 1

outputcarrier 2

outputcarrier 3

YQ1

YI1

YQ2

YI2

YQ3

YI3


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cdma2000 Downlink Data Rates


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cdma2000 vs WCDMAv Chip ratev Coherent Pilot Channels

v Transmit Diversityv Underlying Network v Single Carrier versus Multicarrier Spreading

v Cell Site Synchronization


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References[1] R. L. Peterson, Third Generation Personal Communications: Physical LayerStatus, Presentation at Clemson University, Feb. 1, 2001

[2] Manjit Singh and Manoneet Singh, 3G Wireless with Respect to IMT-2000 andBeyond, Telecom 99

[3] Harri Holma and Antti Toskala, WCDMA for UMTS: Radio Access for Third Generation Mobile Communications , New York: Wiley, 2000

[4] CDMA Evolution from IS-95, IS-2000, to 1XTREME, Technology TransferTraining Class, Motorola, Inc., July 2000

[5] R. Ziemer and R. Peterson, Introduction to Digital Communications , UpperSaddle River, NJ: Prentice Hall, Chapter 10, 2001


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WCDMA: More Information?v http://www.3gpp.orgv 21.101 guide to all other documentsv 25.XXX series radio access network (RAN)

v 25.211 frame structure etc.v 25.212 channel coding etc.v 25.213 spreading and modulationv 25.214 physical layer procedures (tx diversity, etc.)v 25.321 medium access control (MAC)

v 25.322 radio link control (RLC)v 26.XXX series voice coding


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GSM/GPRS/EDGE: More Information?v http://www.3gpp.org

multiple access, logical channels, etc05.0245.002

general description05.0145.001

modulation05.0445.004

channel coding05.0345.003

RLC/MAC04.6044.060

link adaptation05.0945.009

radio link control05.0845.008

radio transmission and channelmodels05.0545.005

descriptionETSI3GPP


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cdma2000: More Information?v http://www.3gpp2.org

v Technical Specification Group C cdma2000v C.S0002-A-1 Physical Layer Standardv C.S0003-A-1 Medium Access Control (MAC)v C.S0004-A-1 Signaling Link Access Controlv C.S00024 1XEV-DO (high speed packet)

v C.S0005 Upper Layer Signaling (L3)


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3G Information Sourcesv Third Generation Partnership Projectsv http://www.3gpp.orgv http://www.3gpp2.org

v CDMA Development Group (CDG)v http://www.cdg.org

v International Mobile Telecommunications for the year 2000v http://www.tiaonline.org/standards/sfg/imt2k/

v Japan ARIB IMT-2000 proposalv http://www.arib.or.jp/IMT-2000/ARIB/Document/

Diff Bet Wcdma and Cdma 2000

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