umts: universal mobile telecommunications system
TRANSCRIPT
UMTS: Universal Mobile UMTS: Universal Mobile Telecommunications SystemTelecommunications System
Aim of PresentationAim of Presentation
To attain a general understanding of UMTS systemsTo attain a general understanding of UMTS systems GSM Evolution Towards UMTSGSM Evolution Towards UMTS 2.5G Standards (Transition between 2G-3G)2.5G Standards (Transition between 2G-3G) Difference between GSM-UMTSDifference between GSM-UMTS UMTS: FDD/TDDUMTS: FDD/TDD UMTS Network Elements and ArchitectureUMTS Network Elements and Architecture
UE: User Equipments UE: User Equipments
UTRAN:UMTS Terrestrial Radio Accesses NetworkUTRAN:UMTS Terrestrial Radio Accesses Network
CN: Core NetworkCN: Core Network Major Interfaces in UMTSMajor Interfaces in UMTS Introduction to 3G Planning TechniquesIntroduction to 3G Planning Techniques
UMTS: A Brief Overview UMTS: A Brief Overview
UMTS is the recent telecomm Standard system UMTS is the recent telecomm Standard system (3G) developed from the existing GSM system,one (3G) developed from the existing GSM system,one can say that its a resultant of R&D done on various can say that its a resultant of R&D done on various levels of 1st and 2nd generation GSM systemlevels of 1st and 2nd generation GSM system
It is a universal Mobile telecom system designed It is a universal Mobile telecom system designed to provide seamless telecomm services with to provide seamless telecomm services with enhancement in quality,data, rate, enhancement in quality,data, rate, reliability,connectivity , system interfaces reliability,connectivity , system interfaces adaptability ,current and next generation adaptability ,current and next generation technologies …and so on technologies …and so on
UMTS is a 3G GSM successor standard i.e. UMTS is a 3G GSM successor standard i.e. downward-compatible with GSM,downward-compatible with GSM,
UMTS is the third generation solution developed UMTS is the third generation solution developed and adopted by ETSI (European Technical and adopted by ETSI (European Technical Standards Institute).Standards Institute).
It is therefore expected that the vast majority of It is therefore expected that the vast majority of current GSM operators will become involved in current GSM operators will become involved in deploying UMTS networks deploying UMTS networks
GSM Evolution Towards UMTSGSM Evolution Towards UMTSEvolution of GSM towards UMTS can be explained in terms of “generations”:
The entire cellular systems since intoduced has effectively
been replaced at times.These major changes are
referred to as a new “generation” of cellular
systems.
2.5G Standard A Transition 2G-3G 2.5G Standard A Transition 2G-3G
HSCSHSCS High Speed Circuit Switched DataHigh Speed Circuit Switched Data Enhancement to the GSM standardEnhancement to the GSM standard Utilises:Utilises:
Multiple channel coding schemes (4.8kbps, 9.6kbps, Multiple channel coding schemes (4.8kbps, 9.6kbps, 14.4kbps per timeslot)14.4kbps per timeslot)
Multiple timeslotsMultiple timeslots
Circuit Switched Data rates to 57.6kbpsCircuit Switched Data rates to 57.6kbps
4 slots with 14.4kbps channel coding per slot4 slots with 14.4kbps channel coding per slot
GPRSGPRS
General Packet Radio ServiceGeneral Packet Radio Service Enhancement to the GSM standardEnhancement to the GSM standard UtlilisesUtlilises
Multiple TimeslotsMultiple Timeslots Packet SwitchingPacket Switching
Packet Switched Data typically to rates of 56kbpsPacket Switched Data typically to rates of 56kbps Theoretically 171.2kbps for 8 timeslotsTheoretically 171.2kbps for 8 timeslots
UMTS Introduces serving GPRS support node - UMTS Introduces serving GPRS support node - SGSNSGSN
EDGEEDGE
Enhanced Data for GSM EvolutionEnhanced Data for GSM Evolution Sometimes called E-GPRS (Enhanced GPRS)Sometimes called E-GPRS (Enhanced GPRS)
Enhancement to the GSM and TDMA standardsEnhancement to the GSM and TDMA standards Utlilises:Utlilises:
8PSK Modulation8PSK Modulation Possible 1.6 MHz carrier under IS-136Possible 1.6 MHz carrier under IS-136 8 Channel Coding Schemes8 Channel Coding Schemes Multiple Timeslots (similar frame structure to GSM)Multiple Timeslots (similar frame structure to GSM) TDMATDMA
Data up to rates of 384kbps (typically less)Data up to rates of 384kbps (typically less)
Difference GSM and UMTSMajor difference is air interface– GSM: TDMA and FDMA
– UMTS: Wide-band code division multiple access (WCDMA)
UMTS Modes UMTS Modes
UMTS
UMTS-FDD UMTS-TDD
UMTS FDDUMTS FDD
• Universal Mobile Telecommunications System Frequency Division Duplexing Mode
• Built onto enhanced GSM core network
• Utilises:• QPSK modulation (Quadrature phase shift keying)• Multiple channel coding and bearer rates• Variable spreading factors and multi-code transmission• CDMA• FDD• Asynchronous operation
• Data up to rates of 2Mbps
UMTS TDDUMTS TDD
• Universal Mobile Telecommunications System Time Division Duplexing Mode• Built onto enhanced GSM core network • Utilises:
• QPSK modulation• Multiple channel coding and bearer rates• CDMA• TDD• Asynchronous operation
• Data up to rates of 2Mbps
• Will happen after UMTS FDD
UMTS Architecture Overview
User Equipment UEUser Equipment UE
The UMTS UE is based on the same principles as the GSM MS—
the separation between mobile equipment (ME) and the UMTS subscriber identity module (SIM)card
(USIM).
UE consists of :
Display and User Interface
Holds the Authentication Algorithms and keys
User End Termination of the Air Interface
Application Platform
Mobile EquipmentThe radio terminal is used for radio communication over the Uu interface
UMTS Subscriber Identity ModuleThe smartcard that holds the subscriber identity, authentication and encryption keysEtc
Terminal EquipmentThe terminal equipment connects to the UE. This carries the application specific userinterface
General Core Network ArchitectureGeneral Core Network Architecture
Home Location Register (HLR)The database storing the master copy of a users profile
Visitor Location Register (VLR)The database holding a copy of a visiting users profile
Mobile Switching Centre (MSC)Switch for Circuit Switched ServicesGateway MSC (GMSC)
Serving GPRS Support Node (SGSN)Router for Packet Switched ServicesGateway GPRS Support Node (GGSN)
UMTS Terrestrial Radio Access UMTS Terrestrial Radio Access Network UTRANNetwork UTRAN
Node BActs as the radio basestation (BTS in GSM)Converts the data flow between the Iub and Uu interfaces
RNC• Responsible for the use andintegrity of the radio resourceswithin the RNS• Responsible for the handoverdecisions that require signalling tothe UE• Provides a combining/splittingfunction to support macrodiversitybetween different Node Bs
Major Interfaces in UMTSMajor Interfaces in UMTS• There are four major new interfaces defined in UMTS
• Iu
The interface between UTRAN and the CN
• Iur
The Interface between different RNCs
• Iub
The interface between the Node B and the RNC
• Uu
The air interface
Radio Planning for UMTSRadio Planning for UMTS
Principle Design ConsiderationsPrinciple Design Considerations
There are two design considerations when planning a There are two design considerations when planning a 3G network.3G network.
3G is a multiservice network and 3g requires the 3G is a multiservice network and 3g requires the practical implementation of WCDMApractical implementation of WCDMA
Planning can be broken into 3 phasesPlanning can be broken into 3 phases
DimensioningDimensioning: To determine the approximate number of sites, cells and number of : To determine the approximate number of sites, cells and number of network elements.network elements.
· Radio Link Budget· Radio Link Budget· Coverage Analysis· Coverage Analysis· Capacity estimation· Capacity estimation· Required numbers of network elements eg RNC’s· Required numbers of network elements eg RNC’s
Detailed planningDetailed planning: Involves the use of a radio network planning tool.: Involves the use of a radio network planning tool. Ericcson - TEMS Cell plannerEriccson - TEMS Cell planner· ATDI - ICS Telecom System· ATDI - ICS Telecom System· Logica - Odyssey· Logica - Odyssey· Nokia – NetAct Planner· Nokia – NetAct Planner· CRIL - ELLIPSE M-NPT· CRIL - ELLIPSE M-NPT
OptimisationOptimisation:In WCDMA system optimisation starts right back at the planning :In WCDMA system optimisation starts right back at the planning phasephase
Interference is the biggest problem in WCDMA Interference is the biggest problem in WCDMA and need to control, this can be done throughand need to control, this can be done through
Optimisation of Optimisation of Site Location and configurationSite Location and configuration
Height, direction, beamwidth and tilt of antennasHeight, direction, beamwidth and tilt of antennas
Cable lossesCable losses
Mast head amplifiersMast head amplifiers