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8/2/2019 3rd Generation Wireless Network
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3rd Generation
Wireless Network
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Outline
IntroductiontoWCDMA
Why WCDMA ?
Evolution from 2G to 3G
WCDMA / UMTS Architecture Air Interface (WCDMA) Radio Access Network (UTRAN) Core Network
Radio Resources Management
Additional Briefs WCDMA V/s CDMA 2000
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Introduction to WCDMA
Wideband Code Division Multiple Access
(WCDMA) is a CDMA Channel that is four
times wider than the current channel that are
typically used in 2G Networks.
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Outline
Introduction to WCDMA
Why WCDMA ?
Evolution from 2G to 3G
WCDMA / UMTS Architecture Air Interface (WCDMA) Radio Access Network (UTRAN) Core Network
Radio Resources Management
Additional Briefs WCDMA V/s CDMA 2000
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Why WCDMA ?
The significant increase in subscribers and trafficrequires large BW. The answer to the capacity and BW
demand is the provision of new spectrum and the
development of a new technology
Wideband CDMA
(WCDMA)
WCDMA was developed in order to create a global
standard for real time multimedia services that
ensured international roaming.
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Outline
Introduction to WCDMA
Why WCDMA ?
Evolution from 2G to 3G
WCDMA / UMTS Architecture Air Interface (WCDMA) Radio Access Network (UTRAN) Core Network
Radio Resources Management
Additional Briefs WCDMA V/s CDMA 2000
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Evolution 2G to 3G Revolution
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GSM
CDMA2000
WCDMA
IS95A
IMT2000
IS95B
GPRS
EDGE
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Evolution : From 2G to 3G
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Evolution : From 2G to 3G
Fully specified and world-widely valid,Major interfaces should be standardized and open.
Supports multimedia and all of its components.
Wideband radio access.
Services must be independent from radio accesstechnology and is not limited by the network
infrastructure.
Primary Requirements of a 3G Network
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Standardization of WCDMA
Multiple Access Method DS-CDMADuplexing Method FDD/TDD
Base Station Synchronization Asychronous Operation
Channel Separation 5MHz
Chip Rate 3.84 Mbps
Frame Length 10 ms
Spreading modulation Balanced QPSK (downlink)Dual-channel QPSK(uplink)Complex spreading circuit
Data modulation QPSK (downlink), BPSK (uplink)Coherent detection User dedicated time multiplexed pilot
(downlink and uplink), common pilot inthe downlink
WCDMA Air Interface & Main Parameters
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Outline
Introduction to WCDMA
Why WCDMA ?
Evolution from 2G to 3G
WCDMA / UMTS Architecture Air Interface (WCDMA) Radio Access Network (UTRAN) Core Network
Radio Resources Management
Additional Briefs WCDMA V/s CDMA 2000
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WCDMA System Architecture
USIM
ME
Node B
Node B
RNC
Node B
Node B
RNC
MSC/VLR
GMSC
SGSN GGSN
HLR
UTRAN CNUE
ExternalNetw
orks
Cu
Uu Iu
IubIur
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WCDMA Air Interface
Wideband CDMA, Overview
DS-CDMA, 5 MHz Carrier Spacing,
CDMA Gives Frequency Reuse Factor = 1
5 MHz Bandwidth allows Multipath Diversity using Rake
Receiver
Variable Spreading Factor (VSF) to offer Bandwidth onDemand (BoD) up to 2MHz
Fast (1.5kHz) Power Control for Optimal InterferenceReduction
Services multiplexing with different QoS Real-time / Best-effort 10% Frame Error Rate to 10-6 Bit Error Rate
UE UTRAN CN
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WCDMA Air Interface UE UTRAN CN
Direct Sequence Spread Spectrum
User 1
User N
Spreading
SpreadingReceived
Dispreading
Narrowband
CodeGain
Frequency Reuse Factor = 1
Wideband
Wideband
f
f
ff
f
f
VSF Allows Bandwidthon Demand. LowerSpreading Factor requiresHigher SNR, causingHigher Interference inexchange.
Variable Spreading Factor (VSF)
User 1
Spreading : 256
Wideband
f f
User 2
Spreading : 16
Widebandf f
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WCDMA Air Interface UE UTRAN CN
Protocol Architecture
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UTRAN UE UTRAN CN
USIM
ME
Node B
Node B
RNC
Node B
Node B
RNC
MSC/VLR
GMSC
SGSN GGSN
HLR
UTRAN CNUE
ExternalNetw
orks
Cu
Uu Iu
IubIur
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UTRAN UE UTRAN CN
Node B
Node BRNC
Node B
Node B
RNC
IubIur
UTRAN
RNS
RNS
Two Distinct Elements :
Base Stations (Node B)Radio Network Controllers (RNC)
1 RNC and 1+ Node Bs are group togetherto form a Radio Network Sub-system (RNS)
Handles all Radio-Related Functionality
Soft Handover
Radio Resources Management Algorithms
UMTS Terrestrial Radio Access Network, Overview
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UTRAN UE UTRAN CN
Protocol Model for UTRAN Terrestrial Interfaces
Application
Protocol
Data
Stream(s)
ALCAP(s)
Transport
Network
Layer
Physical Layer
Signaling
Bearer(s)
Transport
User
Network
Plane
Control Plane User Plane
Transport
User
Network
PlaneTransport Network
Control Plane
RadioNetwork
Layer
Signaling
Bearer(s)
Data
Bearer(s)
Derivatives :
Iur1, Iur2, Iur3, Iur4
Iub
Iu CS
Iu PS
Iu BC
Functions of Node B (Base Station)
Air Interface L1 Processing (Channel Coding, Interleaving, Rate Adaptation,Spreading, etc.)
Basic RRM, e.g. Inner Loop Power Control
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UTRAN UE UTRAN CN
Node B
Node B
RNC
Logical Roles of the RNC
Controlling RNC (CRNC)
Responsible for the load andcongestion control of its own cells
CRNC
Node B
Node B
SRNCServing RNC (SRNC)
Terminates : Iu link of user data,Radio Resource Control Signaling
Performs : L2 processing of datato/from the radio interface, RRMoperations (Handover, Outer LoopPower Control)
Drift RNC (DRNC)
Performs : Macro-diversityCombining and splitting
Node B
Node B
DRNC
Node B
Node B
SRNC
Node B
Node B
DRNC
UE
UE
Iu
Iu
Iu
Iu
Iur
Iur
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Core Network UE UTRAN CN
USIM
ME
Node B
Node B
RNC
Node B
Node B
RNC
MSC/VLR
GMSC
SGSN GGSN
HLR
UTRAN CNUE
ExternalNetw
orks
Cu
Uu Iu
IubIur
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Summary
System Architecture, Bearer Services, QoS Classes
WCDMA Air Interface : Spread Spectrum, Transport Channels
UTRAN : Roles of RNCs and Node Bs
Core Network : Responsible for switching system
USIM
ME
Node B
Node B
RNC
Node B
Node B
RNC
MSC/VLR
GMSC
SGSN GGSN
HLR
UTRAN CNUE
ExternalNetworks
Cu
Uu Iu
IubIur
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Outline
Introduction to WCDMA
Why WCDMA ?
Evolution from 2G to 3G
WCDMA / UMTS Architecture Air Interface (WCDMA) Radio Access Network (UTRAN) Core Network
Radio Resources Management
Additional Briefs WCDMA V/s CDMA 2000
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Radio Resources Management
Network Based Functions
Admission Control (AC)
Load Control (LC)
Packet Scheduler (PS)
Connection Based Functions
Handover Control (HC)
Power Control (PC)
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Outline
Introduction to WCDMA
Why WCDMA ?
Evolution from 2G to 3G
WCDMA / UMTS Architecture Air Interface (WCDMA) Radio Access Network (UTRAN) Core Network
Radio Resources Management
Additional Briefs WCDMA V/s CDMA 2000
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WCDMA V/s cdma2000
Some of theMajor Differences
WCDMA cmda2000 Remarks
Spread SpectrumTechnique
5Mhz WidebandDS-SS
Multicarrier,
3x1.25MHzNarrowband DS-SS,250kHz Guard Band
Multicarrier does not requires acontiguous spectral band.
Both scheme can achieve similarperformance
Chip Rates 3.84Mcps 3.6864Mcps (1.2288
per carrier)
Chip Rate alone does not determine
system capacity
Frame Lengths 10ms 20ms for data, 5msfor control
Response and efficiency tradeoff
Power Control Rate 1.5kHz 800Hz Higher gives better link performance
Base StationSynchronization
Asynchronous Synchronized Asynchronous requires not timingreference which is usually hard toacquire.
Synchronized operation usually givesbetter performance
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Conclusion
The concept of a WCDMA adds flexibility in the 3Gdeployments, enhances system performance, andprotects network investments through reuse ofresources.
A WCDMA supports the growth of todays servicesas well as the creation and growth of mobileservices beyond voice, data, video.
In Short, WCDMA is the technology design toprovide service of voice, data and video with thesame handset that customer is using even oninternational roaming.
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Key References
Key References
WCDMA for UMTS Radio Access for Third Generation Mobile Communications, 2nd Ed., Edited by Harri Holma and Antti Toskala
Overview of UMTS Telecommunication Software and Multimedia Laboratory, Helsinki University of Technology
Course S-72.238 : Wideband CDMA systems, Communications Laboratory, Helsinki University of Technology
WCDMA Requirements and Practical Design Rudolf Tanner and Jason Woodard3
GPP, Technical Specification Group RAN, User Equipment (UE) Radio Transmission and Reception (FDD), 3GPP TS 25.101
version 6.11.0, March 2006, available at www.3gpp.org
GSM World www.gsmworld.com
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Thank You
Questions ???
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