Mita Seminar Wcdma
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Transcript of Mita Seminar Wcdma
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MITA seminarMITA seminarWCDMA technology on UTRANWCDMA technology on UTRAN
Mobile Internet Technical ArchitectureMobile Internet Technical Architecture --Vol. 1. Technologies and Standardization (pp. 155Vol. 1. Technologies and Standardization (pp. 155 -- 167)167)
October 29, 2003October 29, 2003
[email protected]@lut.fi
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ContentContent
Scenery
UTRAN architecture
WCDMA basics
Features
Services
Specifications
References
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SceneryScenery
UTRAN/WCDMA and MITA (1/2)UTRAN/WCDMA and MITA (1/2) UMTS (Universal Mobile Telecommunications System) is a 3rd
generation cellular system UTRAN (UMTS Terrestrial Radio Access Network) is radio access part
of UMTS
UTRAN is categorized as a Network Environment on MITAterminology, [2]
WCDMA based radio access technology
UTRAN/WCDMA provides services to which MITA interactionmodes can be mapped (or vice versa), [2]
Messaging (e.g. SMS and MMS) Browsing (e.g. asymmetric uplink/downlink bit rates)
Rich call (e.g. audio/video calls with different QoS requirements)
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SceneryScenery
UTRAN/WCDMA and MITA (2/2)UTRAN/WCDMA and MITA (2/2)
User Interface
Browsing Messaging Rich Call
ApplicationFramework Internet
Protocols
OS and PlatformSupport
MITA access technologies 2.5G GSM/EDGE uses
TDMA/FDMA technology
UTRAN uses WCDMA technology Etc.
UTRAN provides WCDMA basedAir interface access technology
Based on Wideband Code DivisionMultiple Access (WCDMA)
Each vendor provide ownplatform for UTRAN equipment
UTRAN
AccessTechnologies
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SceneryScenery
IMTIMT--2000 technologies and spectrum2000 technologies and spectrum IMT-2000 is the umbrella specification of all 3G systems, [1]
In addition to 2nd generation modulation schemes (e.g. EDGE)
several CDMA spread spectrum modulations co-exist Direct sequence (DS), Frequency Hopping (FH), Time Hopping (TH),Hybrid Modulation (HM), and MultiCarrier (MC)
Direct Sequence modulation is used by UTRAN CDMA2000 applies MultiCarrier modulation
AmericasIMT-2000:WCDMA, MC-CDMA (1.8 2 GHz)GSM/GERAN:EDGE (existing bands)
EuropeIMT-2000:WCDMA (1.9 & 2.1 GHz)GSM/GERAN:EDGE (1.8 GHz)
Japan
IMT-2000:WCDMA (1.9 & 2.1 GHz)
AsiaIMT-2000:WCDMA (1.9 & 2.1 GHz)GSM/GERAN:
EDGE (900 MHz & 1.8 GHz)
KoreaIMT-2000:WCDMA (1.9 & 2.1 GHz)
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UTRAN
UTRAN architectureUTRAN architecture
ElementsElements UTRAN consists of
Base stations (Node B) Controller (RNC)
Iur interface between twoRNCs Iub interface between RNC
and Node B
UTRAN is connected to Circuit switched CN (i.e. 3G
MSC) via Iu-CS interface Packet switched CN (3G
SGSN) via Iu-PS interface User equipment via Air
interface (Uu)
RNC
Node B
3G SGSN
MSCRNC
Iu-PS
Iub
IurIurIurIur
Iu-CS
Uu
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25.4x0
Transport
NetworkLayer
UTRAN architectureUTRAN architecture
Layered structureLayered structure UTRAN protocol architecture is based on layered structure, [1,
3] Protocols categorized to access and non-access strata Access stratum consists of transport network layer protocols Non-access stratum consists of radio network layer protocols
Transport NetworkControl plane
Transport NetworkUser plane
25.4x4 + 25.426
RadioNetworkLayer
25.4x5 + 25.42725.419
Transport NetworkUser plane
25.4x2
25.4x3
25.4x1Legend:x = 1, Iu interfacex = 2, Iur interfacex = 3, Iub interface
Control Plane User Plane
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Code 1
WCDMAWCDMA
Basics (1/2)Basics (1/2) WCDMA users share same radio resources whereas TDMA or
FDMA users have their own radio resources allocated, [1, 4]
User signals are differentiated based on codes, [1, 4] CDMA modulation types, [1, 4]
Direct Sequence (DS,) Frequency Hopping (FH), Time Hopping (TH),Hybrid Modulation (HM), and MultiCarrier (MC)
Time
Frequency
Time
Frequency
Frequency 1
Frequency 2
Frequency n-1
Frequency n
Time
Frequency
Timeslot1
Timeslot2
Timeslotn-1
Timeslotn
Code 2
Code n-1Code n
FDMA TDMA CDMA
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WCDMAWCDMA
Basics (2/2)Basics (2/2)
Information is spread over frequencyband, [1, 4]
In UTRAN bandwidth is constant (effective
band is 3.84 MHz, 5 MHz with guardbands)
The better the spreading the lower thepower => interference decreases
The smaller the spreading the higher the
power => interference increases
UTRAN uses 10 ms frames, [1, 4] During single frame data rate is constant Data rates on consecutive frames may
vary 4.4 5.0 MHz
Frequency
Time
Power
10 ms
Energy
Frequency
Original signal
Spread signal
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WCDMAWCDMA
FeaturesFeatures
Macro diversity enables mechanisms tocope with system interference, [1, 3, 4]
Multiple simultaneous Node B connections (SoftHandover scenario)
Power control, [1, 3, 4] Objective is to minimise transmission power Aims to decrease interference => improves
overall performance Fast power control (1500 Hz cycles) Power control for downlink (decreases overall
interference) and uplink (near-far effect)
Partial security (spread code mechanism) User signals differentiated with different
spreading codes
Signal-to-interference ratio (SIR, a.k.a.Carrier-to-interference ratio, C/I), [4]
Signal can be recovered as long as despreadsignal is above interfering power
Power
Frequency
Widebandnoise level
Spread signal
De-spreadsignal
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WCDMAWCDMA
Services [1, 3, 4]Services [1, 3, 4]
Bit rates Circuit Switched connections up to 384 kbps Packet Switched connections up to on downlink 2Mbps (14.4 Mbps with
HSDPA), [1] Variable bit rates
Service multiplexing on single connectionDifferent QoS (e.g.speech, video and packet data)
Varying delays
QoS (from 10% FER to 106 bit error rate)
Co-existence of 2G and 3G systems (incl. Intersystem HOs)
Asymmetric uplink and downlink traffic
High spectrum efficiency (e.g. good frequency reuse)
Co-existence of FDD and TDD modes
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SpecificationsSpecifications
3GPP specifications (listed at the end of [1])
Encryption algorithms, etc.35-series
Test specifications.34-series
Security aspects.33-series
Operation and maintenance aspects.32-seriesUIM and interfaces between UIM and other entities.31-series
3GPP program management.30-series
Protocols within CN.29-series
Signaling protocols between radio subsystem and periphery of CN.28-series
Data application support functions.27-seriesCodecs.26-series
UTRA aspects.25-series
Non-access Stratum protocols (MS/UE CN).24-series
Technical realisation specifications describing interworking overseveral interfaces.
23-series
Services, service features, or platforms for services.22-series
Requirement specifications.21-series
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ReferencesReferences
1. Introduction to 3G Mobile Communications, 2nd Edition, J. Korhonen; ISBN1-58053-507-0
2. MITA, Mobile Internet Technical Architecture, Vol. 1 Technologies and
Standardization; Nokia; ISBN 951-826-668-93. UMTS Networks - Architecture, Mobility and Services; H. Kaaranen, A.
Ahtiainen, L. Laitinen, S. Naghian, V. Niemi; ISBN 0471-48654-X
4. WCDMA for UMTS Radio Access For Third Generation Mobile
Communications; Harri Holma, Antti Toskala; ISBN 0-471-72051-8
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Questions based on presentationQuestions based on presentation
1. What is the role of UTRAN/WCDMA in MITA concept?
2. Why macro diversity and power control are important features ofWCDMA?
3. How WCDMA services could be mapped to MITA interaction modes?
To be consideredTo be considered
1. GSM/EDGE and UMTS evolution?
2. How All-IP affects to radio access networks?
3. Trends on radio technology in future? What changes 4th generation willbring?
4. What kind of user equipments there will be in future (e.g. on a ten yeartime scale)?