General Introduction to CDMA Mobile Communications
CDMA Business Department
Shenzhen ZTE Corporation, China
Contents
Overview of Mobile Communications
Technical Features of CDMA
Dynamics of 3 G ( the 3rd Generation Communications System)
Basic Concepts of Cellular Mobile Communication
Cell/sector
Frequency Reuse
Handoff
Cell-splitting
Mobility: flexible and convenient, global personal
communication Poor environment and conditions :
Co-channel interference, multi-path(space and time)shadow effect and delay, power change and other noise,
Multiple MS and channels: Interference 、 near and far effect
Limit of frequency resources Reliability is a must
registration, handoff, switching, control
Characteristics of Mobile Communication
1946 First mobile phone system , 120 KHZ( AT&T): FM 60’s IMTS 25-30KHZ ( Bell System): FM 1 G Analog Cellular/FDMA
AMPS (US, 800 MHZ/30KHZ/10 kbps) TACS (British, 900 MHZ/25 KHZ/8 kbps)
2 G digital cellular/TDMA GSM, DAMPS, JDC IS-95 CDMA
3G IMT-2000 (International Mobile telecommunications) UTRA/W-CDMA (Japan, Europe) CDMA 2000 MC (US) UTRA TDD (Europe) and TD-SCDMA(China) UWC-136 (TDMA) DECT (TDMA)
Evolution of Mobile Communications System
Concepts: FDMA, TDMA & CDMA
FDMA TDMA CDMA
Channel: An individually-assigned, dedicated pathway through a transmission medium for one user information
Any of the dimensions of the transmitted signal can be segmented into private assigned channels for users. Here how the three most popular technologies establish channels:
FDMA: Frequency Division Multiple Access each user on a different frequency a channel is a frequency
TDMA: Time Division Multiple Access each user on a different window period
in time slot a channel is a specific time slot on a
specific frequency CDMA: Code Division Multiple Access
each user uses the same frequency all the time, but mixed with different distinguishing code patterns
a channel is a unique code pattern FrequencyTime
Power
FrequencyTime
Power
FrequencyTime
Power
FDMA
TDMA
CDMA
Channel Structure For FDMA/TDMA/CDMA
Frequency Reuse and Large Capacity
Comparison between CDMA & GSM System (1)
Cell Coverage CDMA: varies with traffic load
No load: 3 × GSM coverage
20 channels/sector: 2 × GSM coverage
GSM: coverage not affected by traffic load
Number of BTS CDMA=20% × GSM
1000 km2 coverage: CDMA 45 BTS, GSM 200 BTS
Capacity: CDMA=5 × GSM=10 × AMPS
Voice quality: vocoder CDMA 8K> GSM 13K, CDMA 13K approaches 64K PCM
Handoff CDMA : soft handoff, GSM: hard handoff, more dropp
ed calls Network Planning and Expansion
CDMA : simple ( N=1), GSM: more complicated (N=4/7)
Comparison between CDMA & GSM System (2)
13
2
4
3
2
4
24
4
1
2
3
14
2
31
4
GSM: N= 4 CDMA: N= 1
111
11 1
1
11
11
1
111
11
11
11
1
Contents
Overview of Mobile Communications
Technical Features of CDMA
Dynamics of 3 G ( the 3rd Generation Communications System)
Technical Features of CDMA Spread Spectrum
Ensures high transmission and voice quality, security Short PN, long PN and Wash codes are used for coding
Multiple Access Code Division:Improve frequency reuse and guarantee large capacity
Soft Handoff Seamless communication without call dropping High communication quality
Power Control Ensure optimum power level with least interference to other channels,
reducing Near and Far Effect and thus increasing capacity Low radiation and longer battery usage time
Diversity Receiver (Rake Receiver) Achieve signal gain and avoid Multi-path Effect
Voice Activation Lower transmitting power and low speed
Voice Coding
Spread Spectrum-Basis for CDMA Technology
Definition: Spread spectrum technique ,employ a transmission bandwidth that is
several orders of magnitude greater than the minimum required signal bandwidth.
Theoretic Basis: Shannon’s Law C=Blog2(1+S/N)
C: Channel Capacity B: bandwidth S/N: signal to noise ratio
Conclusion: When C is a fixed value, S/N is a reciprocal ratio of B
Another techniques for Spread Spectrum: DSSS: Direct Sequence Spread Spectrum FHSS: Frequency Hopping Spread Spectrum
Traditional radio communication systems transmit data using the minimum bandwidth required to carry it as a narrowband signal, e.g. FDMA and TDMA systems.
TRADITIONAL COMMUNICATIONS SYSTEM
SlowInformation
Sent
TX
SlowInformationRecovered
RX
NarrowbandSignal
Spread Spectrum Principles
SHANON Formula
C = Blog2(1+S/N)
Spread Spectrum Principles (Continued)
Where, C is capacity of channel, b/s B is signal bandwidth, Hz S is average power for signal, W N is average power for noise, W
It is the basic principle and theory for spread spectrum communications.
Direct-Sequence Spread spectrum systems mix their input data with a fast spreading sequence and transmit a wideband signal The spreading sequence is independently regenerated at the
receiver and mixed with the incoming wideband signal to recover the original data
SPREAD-SPECTRUM SYSTEM
FastSpreadingSequence
SlowInformation
Sent
TX
SlowInformationRecovered
RX
FastSpreadingSequence
WidebandSignal
Spread Spectrum Principles (Continued
The de-spreading gives substantial gain proportional to the bandwidth of the spread-spectrum signal
The gain can be used to increase system performance and range, or allow multiple coded users, or both
Processing Gain For SPREAD-SPECTRUM SYSTEM
Gp=10log (B/Bm) Where, Gp is processing gain, dB B is spreading signal bandwidth, Hz Bm is original signal bandwith, Hz E.g., it is 21 dB for IS-95A CDMA system.
Spread Spectrum Principles (Continued)
Basic Spreading & DeSpreading ExampleUser Data Spread, Sent, Recovered
XORExclusive-OR
Gate
1
1
Input A: Received Signal
Input B: Spreading Code
Output: User Original Data
Input A: User Data
Input B: Spreading Code
Spread Spectrum Signal
XORExclusive-OR
Gate
At Originating Site: Input A: User’s Data @ 19,200 b
its/second Input B: Walsh Code #23 @ 1.22
88 Mcps Output: Spread spectrum signal
At Destination Site: Input A: Received spread spectr
um signal Input B: Walsh Code #23 @ 1.22
88 Mcps Output: User’s Data @ 19,200 b
its/second just as originally sent
via air interface
Channel Coding( SS)
Carrier Modulation
DS-PN
Radio Channel
Source Coding
Channel Decoding
CarrierDemodulation
DS-PN
SourceDecoding
Transmit Receive
Antenna
Channel Decoding
Carrier Demodulation
DS-PN
Radio Channel
Source Decoding
ChannelCoding( SS)
CarrierModulation
DS-PN
SourceCoding
TransmitReceive
Antenna
A B
Spread Spectrum ( 1 )
f
S( f)
f0Signal Frequency Before Decoding
f
S( f)
f0Signal Frequency Before SS
Signal
Signal
Noise
f
S( f)
f0
Signal Frequency after SS
Signal
f
S( f)
f0
Signal Frequency After Decoding
Signal
Noise
Signal Pulse Noise Other Noise
Spread Spectrum (2)
Spread Spectrum (3)- Spreading Codes
Spreading Code Rate: 1.2288Mc/s Multi-path separation,(delay:1--100µs)
Delay<1 µs , rate>1 MHZ Multiples of base band rate 9.6 kbps
Spreading Codes Forward : Walsh code Reverse: Long PN Codes (242-1)
Spread Spectrum (4)
Advantages: Avoid interference arising from jamming
signal or multi-path effects SS and demodulation, noise is suppressed
and filtered Security: difficult to detect Privacy: Difficult to demodulate Multiple Access:
Improve Frequency Reuse Enlarge Capacity
CDMA Spreading Principle
Any data bitstream can be combined with a spreading sequence The resulting signal can be de-spreading and the data stream recovered if t
he original spreading sequence is available and properly timed After de-spreading, the original data stream is recovered intactNote - The spread sequences actually shown are icons, not accurate or to scal
e
ORIGINATING SITE DESTINATION
SpreadingSequence
SpreadingSequence
InputData
RecoveredData
Spread Data Stream
Single spreading sequence are reversible
CDMA Spreading Principle (Continued)
Multiple spreading sequences can be applied in succession and then reapplied in opposite order, to recover the original data stream the spreading sequences can have different desired properties
All spreading sequences originally used must be available in proper synchronization at the recovering destination
Note - The spread sequences actually shown are icons, not accurate or to scale
Multiple successive sequence are reversible
SpreadingSequence
A
SpreadingSequence
B
SpreadingSequence
C
SpreadingSequence
C
SpreadingSequence
B
SpreadingSequence
A
InputData
X
RecoveredData
X
X+A X+A+B X+A+B+C X+A+B X+ASpread-Spectrum Chip Streams
ORIGINATING SITE DESTINATION
Code Division Multiple Access (1)
Orthogonal Walsh function Forward link: Spreading and building of coded channels Reverse link: orthogonal modulation of MS signal
Long PN Code ( cycle length: 242 –1) Forward link: identification of MS Reverse link: Spreading and user MS identification
Short PN Code (cycle length: 215-1) Forward and Reverse link: both for orthogonal QPSK
modulation, with different phase for different BS and identical phase for different MS (0 offset)
Division of Channels Forward Link
Pilot: continuous transmission, for synchronization and handoff, no message
Synchronization : for the mobile to capture initial timing or synchronization when initializing
Paging Channel: for the transmission of system message and paging message, registration and traffic channel assignment
Forward Traffic Channel: transmission of voice, data and related signalling
Reverse Link Access : used for initiating communication with BS and responding to
paging message ( 1 Paging channel corresponds to up to32 access ) Reverse Traffic: for transmission of user and signalling information during
call establishment.
Code Division Multiple Access (2)
Code Division Multiple Access (3)
Traffic
User traffic MS power control Sub-channel
Forward CDMA Channels
Pilot Sync. Paging Paging Traffic Traffic
W0 W32 W1 W7 W8 W62 W63
Reverse CDMA Channels
Access Access Traffic Traffic Traffic
CDMA Spreading Code
64Sequences, each 64 chips long
Each Walsh Code is precisely Orthogonal with respect to all other Walsh Codes
Walsh Code
EXAMPLE:
Correlation of Walsh Code #23 with Walsh Code #59
#23 0110100101101001100101101001011001101001011010011001011010010110#59 0110011010011001100110010110011010011001011001100110011010011001Sum 0000111111110000000011111111000011110000000011111111000000001111
Correlation Results: 32 “1”, 32 “0”: Orthogonal!!
Unique Properties:Mutual Orthogonality
WALSH CODES # ---------------------------------- 64-Chip Sequence ------------------------------------------ 0 0000000000000000000000000000000000000000000000000000000000000000 1 0101010101010101010101010101010101010101010101010101010101010101 2 0011001100110011001100110011001100110011001100110011001100110011 3 0110011001100110011001100110011001100110011001100110011001100110 4 0000111100001111000011110000111100001111000011110000111100001111 5 0101101001011010010110100101101001011010010110100101101001011010 6 0011110000111100001111000011110000111100001111000011110000111100 7 0110100101101001011010010110100101101001011010010110100101101001 8 0000000011111111000000001111111100000000111111110000000011111111 9 010101011010101001010101101010100101010110101010010101011010101010 001100111100110000110011110011000011001111001100001100111100110011 011001101001100101100110100110010110011010011001011001101001100112 000011111111000000001111111100000000111111110000000011111111000013 010110101010010101011010101001010101101010100101010110101010010114 001111001100001100111100110000110011110011000011001111001100001115 011010011001011001101001100101100110100110010110011010011001011016 000000000000000011111111111111110000000000000000111111111111111117 010101010101010110101010101010100101010101010101101010101010101018 001100110011001111001100110011000011001100110011110011001100110019 011001100110011010011001100110010110011001100110100110011001100120 000011110000111111110000111100000000111100001111111100001111000021 010110100101101010100101101001010101101001011010101001011010010122 001111000011110011000011110000110011110000111100110000111100001123 011010010110100110010110100101100110100101101001100101101001011024 000000001111111111111111000000000000000011111111111111110000000025 010101011010101010101010010101010101010110101010101010100101010126 001100111100110011001100001100110011001111001100110011000011001127 011001101001100110011001011001100110011010011001100110010110011028 000011111111000011110000000011110000111111110000111100000000111129 010110101010010110100101010110100101101010100101101001010101101030 001111001100001111000011001111000011110011000011110000110011110031 011010011001011010010110011010010110100110010110100101100110100132 000000000000000000000000000000001111111111111111111111111111111133 010101010101010101010101010101011010101010101010101010101010101034 001100110011001100110011001100111100110011001100110011001100110035 011001100110011001100110011001101001100110011001100110011001100136 000011110000111100001111000011111111000011110000111100001111000037 010110100101101001011010010110101010010110100101101001011010010138 001111000011110000111100001111001100001111000011110000111100001139 011010010110100101101001011010011001011010010110100101101001011040 000000001111111100000000111111111111111100000000111111110000000041 010101011010101001010101101010101010101001010101101010100101010142 001100111100110000110011110011001100110000110011110011000011001143 011001101001100101100110100110011001100101100110100110010110011044 000011111111000000001111111100001111000000001111111100000000111145 010110101010010101011010101001011010010101011010101001010101101046 001111001100001100111100110000111100001100111100110000110011110047 011010011001011001101001100101101001011001101001100101100110100148 000000000000000011111111111111111111111111111111000000000000000049 010101010101010110101010101010101010101010101010010101010101010150 001100110011001111001100110011001100110011001100001100110011001151 011001100110011010011001100110011001100110011001011001100110011052 000011110000111111110000111100001111000011110000000011110000111153 010110100101101010100101101001011010010110100101010110100101101054 001111000011110011000011110000111100001111000011001111000011110055 011010010110100110010110100101101001011010010110011010010110100156 000000001111111111111111000000001111111100000000000000001111111157 010101011010101010101010010101011010101001010101010101011010101058 001100111100110011001100001100111100110000110011001100111100110059 011001101001100110011001011001101001100101100110011001101001100160 000011111111000011110000000011111111000000001111000011111111000061 010110101010010110100101010110101010010101011010010110101010010162 001111001100001111000011001111001100001100111100001111001100001163 0110100110010110100101100110100110010110011010010110100110010110
Hn Hn
H2n = ___
Hn Hn
0110
1100
1010
0000
10
000
CDMA Spreading Code(Continued)
Every User’s Long Code is 242 chips long Generated at 1.2288 Mcps, it requires 41.4 days to complete Each phone has a world-unique User Long Code generated using its 32-bit ESN, an Operato
r-Definable 10-bit User Mask, and the current long code state expressed as a 42-bit binary number
Users Long Codes are not exactly orthogonal but are sufficiently different to permit reliable decoding on the reverse link
Long Code( GENERATED I N TAP - SUMMED SH I F T TER )REG I S
1 1 0 0 0 1 1 0 0 0 PERMUTED ESN+=
0
Long CodeState
(@ 1.2288 MCPS)
Public Long CodeMask (STATIC)
User Long Code(@1.2288 MCPS)
one chip at a time
SUM
Modulo-2 Addition
CDMA Spreading Code(Continued)
Short Code The PN Sequence is 32,768(215)
chips long a two-dimensional binary
sector with distinct I and Q component sequences, each 32,768 chips long
The PN Sequence (and any sequence) correlates with itself perfectly if compared at a timing offset of 0 chips
The Short PN Sequence is special: Orthogonal compared with itself using any possible timing offset other than 0
IQ
IQIQ
Total Correlation: All bits = 0
Short PN Sequence vs. Itself @ 0 Offset
IQIQ
Orthogonal: 16,384 “1 “ + 16,384 “0”
Short PN Sequence vs. Itself @ Any Offset
Unique Properties:
32,768 chips long26.666 ms.
(75 repetitions in 2 sec.)
CDMA Spreading Code(Continued)Summary of Characteristics & Functions
Walsh Code
Short Code
Long Code
Type of Sequence
Mutually Orthogonal
Orthogonal with itself at any time shift value
near-orthogonal if shifted
Special Properties
64
1
1
HowMany
64 chips1/19,200 sec.
32,768 chips26-2/3 mS
75x in 2 sec.
242 chips~40 days
Length
Modulation
Quadrature Spreading (Zero offset)
Distinguish users, allow recovery
Reverse Link Function
User identitywithin logic
channel
Distinguish Cells & Sectors
Data Scrambling to distinguish
users
Forward Link Function
Each CDMA spreading sequence is used for a specific purpose on the forward link and a different purpose on the reverse link
The sequences are used to form code channels for users in both directions
Cell
Forward Link
Forward CDMA channel modulation process
User data fromBS in 9600bps4800bps 2400bps1200bps
ConvolutionalEncoder andRepetitioninterleaverr=1/2,K=9
19.2kbps
Datascrambling
MUX
Power contrl bit
Walsh code
Long code generator
Long codefor user
Decimator
1.2288Mcps
Decimator
4
800Hz
Base band Filter
Base band Filter
I Q
I-channel Pilot PN SequenceQ- channel Pilot PN Sequence
Reverse IS-95 channel modulation for a single user
InformationBit9600bps4800bps2400bps1200bps
Converlutional
Encoder andRepetitionr=1/3 K=9
BlockInter-leaver
CodeSymbol28.8kbps
64-aryOrtho-gonal
Modulator
Code Symbol
DataBurstRand-omizer
Walshchip307.2kcps
Long Code Generator
Long Code Maskfor user PN chip
1.2288Mcps
Base-bandFilter
I-channel
PN chip
DBasebandFilter
I(t)
Q(t) Q-channel
1/2 PN chip Delay=406.9ns
I、 Q :Zero-offset Pilot Sequence
41 33 32 28 27 25 24 9 8 0
110001111 ACN PCN BASE_ID PILOT_PN
ACN:number of access channel;PCN:number of paging chBASE_ID, PILOT_PN.
Access channel long code mask:
Public long code mask:
41 32 31 0
1100011000 Permuted ESN
What is mask ?
Different approaches to bandwidth problem
CDMA
TDMAFDMA
Coding Process on CDMA Forward Channels
Each user is assigned one of the 64 Walsh Codes and their traffic is mixed with the Walsh code to establish a dedicated code channel
Each Users Long code is applied incidentally for data scrambling All user code signals are then analog-summed to produce one composite waveform The composite waveform is the combined with the PN sequence using a specific offs
et to uniquely identify this cell sector
BTSPilot Walsh 0
Walsh 19
Paging Walsh 1
Walsh 6
Walsh 11
Walsh 20
Sync Walsh 32
Walsh 42
Walsh 37
Walsh 41
Walsh 55
Walsh 60
Walsh 55
PN OFFSET 372
PN OFFSET 116BTS
PN OFFSET 226BTS
PN OFFSET 511BTS
ANALOG
SUM
PN372
WALSH19
x
x
x
Functions of the CDMA Forward channels
Pilot Walsh 0
Walsh 19
Paging Walsh 1
Walsh 6
Walsh 11
Walsh 20
Sync Walsh 32
Walsh 42
Walsh 37
Walsh 41
Walsh 55
Walsh 60
Walsh 55
PILOT: WALSH CODE 0 The Pilot is a structural beacon which does
not contain a character stream. It is a timing source used in system acquisition and as a measurement device during handoffs
SYNC: WALSH CODE 32 This carries a data stream of system
identification and parameter information used by mobiles during system acquisition
PAGING: WALSH CODES 1 up to 7 There can be from one to seven paging
channels as determined by capacity needs. They carry pages, system parameters information, and call setup orders
TRAFFIC: any remaining WALSH codes The traffic channels are assigned to
individual users to carry call traffic. All remaining Walsh codes are available, subject to overall capacity limited by noise
Analog Summing for Multiple Access
This simplified demonstration shows analog summing using only four abbreviated Walsh codes, each 4 bits long. Four users are talking.
Each user signal is XORed with their assigned Walsh code, and the results are analog-summed and sent over a single medium, much like in CDMA.
At the other end, the Walsh codes are applied to recover each user data.
X
X
X
X
User A
User B
User C
User D
User A
User B
User C
User D
Walsh 0
Walsh 1
Walsh 2
Walsh 3
Walsh 0
Walsh 1
Walsh 2
Walsh 3
A + 0
B + 1
C + 2
D + 3
Analog Summing
Input Bits#1 #2
Spreading De-SpreadingPower
IntegrationOutput Bits
#1 #2
In CDMA, this is the air
interface
Coding Process on CDMA Reverse Channels
Each mobile is uniquely identified by an offset of the User Long Code, which it generates internally
All mobiles transmit simultaneously on the same 1.25-MHz wide frequency band Any nearby BTS can dedicate a channel element to the mobile and successfully
extract its signal Mobiles also use the other CDMA spreading sequences, but not for channel-
identifying purposes Short PN Sequence is used to achieve phase modulation Walsh Codes are used as symbols to give ultra-reliable communications recovery
at the BTS
User Long Code BTS BSC MSC
Functions of the CDMA Reverse channels
ACCESS: It is used by mobiles not yet in a call to transmit registration requests, call setup requests, page responses, order responses, and other signalling information
an access channel is defined by a special public long code mask
Access channels are paired with Paging Channels. There can be up to 32 access channels per paging channel
TRAFFIC:It is used by individual users during their actual calls to transmit traffic to the BTS
a traffic channel is defined by a specific User Long Code
there are as many reverse Traffic Channels as there are CDMA phones in the world
911
REG
BTS
Technical Advantages of CDMA Technology
For the Telecom Service Provider High Efficiency of Frequency Utilization Large Capacity Network Simple Frequency Planning Compatible with Analog Mobile Network Smooth migration to 3G
For the Subscriber Crystal-clear Voice Quality Good Anti-jamming Inter system soft handoff reduces call dropping Low radiation and Long Standby time (long battery duration) Reliable Security
Development of CDMA Technology
CDMA One : core technology IS95 : IS 95A: only 1 spreading code for 1 traffic channel, 14.4 Kbps
1980, First field test by Qualcomm 1990, first version of CDMA UM interface standard by Qualcomm 1995, N-CDMA standard IS-95A by TIA
IS 95B : max. 8 codes for 1 traffic channel (one user for high-speed packet data service
enhanced Air interface, hardware compatible with IS-95A 64 kbps dual way data service ,
CDMA 2000 :144K/384K/2M bps CDMA 2000-1X: 144 kbps CDMA 2000-3X: 2 Mbps (CDMA 2000-1X-EV)
Contents
Overview of Mobile Communications
Technical Features of CDMA
Dynamics of 3 G ( the 3rd Generation Communications System)
Dynamics of 3G Background
Higher demand of QoS Seamless internal roaming, wideband, flexible Large capacity, frequency resource usage
IMT-2000 Naming
commercial use expected in 2002 First phase frequency band around 2 G HZ.
Requirements QoS: voice/coverage, transmission/delay(BER<10 -3 for voice/video, BER<10 –6 for dat
a; delay is variable with multi-media data services) New services and capabilities: wideband service(mobile laptop, medical applications, r
eal-time map), flexible band allocation(low rate paging message—high rate video transmission, low delay requirement for voice while absolute integrity for document)
Development and evolution: step by step evolution, investment protection Flexibility: MS (multi-mode/frequency support international roaming), self-adaptive co
ntrol (adjustment of radio channel parameters for different environment) Mobility management: Personal communication, seamless roaming among different net
works.
Dynamics of 3G
UIM MT RAN CNOther CN of IMT-2000
family
UIM: user identity module
MT: mobile terminal
RAN: radio access network
CN: core network
RTT: Radio Transmission Technology Proposed standards: 10 (FDD: 8 , TDD 5)
Dynamics of 3G
No. RTT Proposed Duplex Proposer
1 J: W – CDMA FDD, TDD Japan: ARIB
2 ETSI – UTRA - UMTS FDD, TDD Europe: ETSI
3 WIMS W - CDMA FDD US: TIA
4 WCDMA/NA FDD US: TIPI
5 Global CDMA II FDD SK: TTA
6 TD - SCDMA TDD China: CATT
7 CDMA 2000 FDD, TDD US: TIA
8 Global CDMA I FDD SK: TTA
9 UWC - 136 FDD US: TIA
10 DP – DECT TDD Europe: ETSI
1. 1 – 5 : similar to WCDMA, harmonization forms 3GPP WCDMA
2. 7 – 8 similar to CDMA 2000, harmonization forms 3GPP2 CDMA 2000
3. 9 : UWC – 136, based on IS – 136 TDMA (D-AMPS)
Dynamics of 3G
Wireless Access Network Various standards:
W-CDMA FDD, W-CDMA TDD(TD-SCDMA), CDMA-2000 Multi-carrier, UWC-136 TDMA
Widely accepted standards: CDMA 2000 W-CDMA UWC-136
Core Network ANSI TIA/EIA-41 MAP GSM MAP
Comparison Between W-CDMA & CDMA 2000
Item W-CDMA CDMA-2000
Min. Band Width
SS technique Single Carrier DS Multi-carrier Or DS
Code chip rate 4.096Mcps , reduced to 3.84Mc
N1.2288Mcps
Sync. Between BS
Async, Sync. Can be selected Sync. (GPS)
Frame length 10ms 20ms
Voice Coding Fixed rate Variable rate
Power Control Rate
1600Hz 800Hz
Dynamics of 3 G
Wireless Access Standards Development from 2 G to 3 G GSMGSM-----GRPS and EDGE (up to 384 kbps)---W-CDMA (5 MHZ) CDMA
IS 95A/B(14.4-64 kbps) cdma2000-1X (144 kbps) cdma2000-3X
cdma2000-1X-EV TDMA (TIA-EIA-136)IS136 IS-136+(TIA/EIA 136-A/B) TDMA/EDGE/GRPS(384kbps) IS137
2.5 G 3 G
Consolidation of ITU IMT-2000 : Very complicated task Technical difference:
SS, code chip rate, Sync. Mode, Pilot, core network(GSM-MAP and IS-41)
Conflict of interest of various parties involved : current market status of mobile communications, IPR, interest of
service provider and manufacturers 3GPP ( 1998-12 )
Initiated by ETSI and joined by ARIB, TCC, TI, TTA CN: GSM-MAP, RAN: UTRA
3GPP2 ( 1999-1 ) Initiated by TIA/ANSI and joined by ARIB, TTC, TTA CN: ANSI/IS-41, RAN: cdma2000
Dynamics of 3 G
Typical IS95A Network Structure of ZTE
MSC/VLR
HLR/AUC
MS
Abis
Abis
Abis
PSTN/PLMN
BSC
BSC
Abis
BSC
A-ISO2 .x
Um IS41D/E
Evolution from 2G System to 3G System
HDR
IS-95Acdma2000-3x
1X-EV
IS-95B
cdma2000-1x
CDMA Network Evolution of ZTE
IS95A Cdma 2000 1X
Transition methods
Data service rate
Adopts IOS4.0 for A Interface
144K — 2M
Smooth evolution to 3G
MSS evolves from current Circuit Switching
mode to full IP mode
CDMA2000-1X Network Structure
MSC/VLR
HLR/AUC
2G BTS
3G BTS (1X) or 2G BTS+upgrade
2G/3G MS
Abis
Abis
Abis
PSTN/PLMN
2G BSC+upgrade or 3G BSC/ PCF (1X)
Internet
PDSN
HAAAA server
router router
Ethernet
ATM
2G BTS
2G BSC
Abis
BSM
E1Um
IS95
Um
IS2000 E1 STM-1
E1 STM-1
Ethernet
2G BSC+upgrade or 3G BSC/ PCF (1X)
3G BTS (1X) or 2G BTS+upgrade
The end !
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