UMTS Basic Principles

Introduction to UMTS ISSUE 1.0

Huawei Confidential. All Rights Reserved

object

Upon completion of this course, you will be able to:

2



Understand the communications

history

of

3G

mobile



Understand the UMTS network architecture and 3GPP different releases



Understand the UMTS network services



Understand the basic principles of UTRAN

Internal Use

References

  

3

TS 21.102 3rd Generation Mobile System Release 4 Specifications TS 21.103 3rd Generation Mobile System Release 5 Specifications Huawei’s UMTS RAN protocols and signaling analysis document

Internal Use

Part 1 Introduction to UMTS Part 2 UTRAN basic principles Part 3 ATM basic principles

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Internal Use

Part 1 Introduction to UMTS Section 1 History of 3G Section 2 UMTS network structure Section 3 UMTS network services

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Internal Use

Development of Mobile communication

1st Generation 1980s (analog)

GSM

AMPS TACS NMT OTHERS

2nd Generation 1990s (digital)

Analog to Digital

CDMA IS95 DAMPS PDC

AMPS = Advanced Mobile phone service TACS=Total Access Communications Systems NMT=Nordic Mobile Telephone

6

3rd Generation current (digital)

WCDMA FDD

Voice to Broadband

CDMA 2000 WCDMA TDD

GSM=Global system for Mobile Communications D-AMPS=Digital-AMPS PDC=personal digital cellular

Internal Use

History of 3G 



At 1985 : ITU started the process of defining the standard for third generation systems, referred to as International Mobile Telecommunications 2000 (IMT2000) Some of the features that IMT-2000 3G network must include 1-Circuit and packet oriented services 2-Simultaneous multiple services 3-Symmetrical and Asymmetrical services 4-Migration path from 2G systems 5-Supporting Multimedia services  Car speed environment: 144kbps  Walk speed environment: 384kbps  Indoor environment: 2048kbps



7

1992: 230MHz spectrum was allocated in 2GHz band (WARC92)

Internal Use

History of 3G 







8

Based on the IMT-200 performance objectives and frequency allocation the ITU-R formally requested a submission of RTT proposals with a closing date at the end of July 1998 . By the closing date , there were a total of 10 RTT proposals were submitted from Europe , United states , Japan , Korea and, China. All these proposal where accepted . Five RTT for IMT2000 • WCDMA FDD • CDMA2000 (1X-EV-DO and 3X modes) • WCDMA-TDD • UWC-136 (based on D-AMPS) • DECT Only three 3G network implemented and currently deployed 1-CDMA 2000 (1X-EV-DO) 2-WCDMA FDD (UMTS FDD) 3-WCDMA TDD (UMTS TDD)

Internal Use

3G standardization organizations 

Standardization organizations such as 3GPP, 3GPP2 were established

WCDMA 3GPP

CDMA2000

3G system

3GPP2

FDD/TDD mode

9

Internal Use

Frequency allocation for IMT2000 WARC in 1992 230MHz in 2GHZ Band was allocated to IMT2000 IMT-2000 1800

1900

2000

1885

ITU

1980

IMT-2000 1895 1918

Japan

2100

2010 2025

MSS MSS (Reg.2)

1980

2010 2025

PHS IMT-2000 MSS IMT-2000

Europe/ Australia USA

IMT-2000

1880 1900 1920

DECT 185 0

1980 2010 2025

UMTS

MSS UMTS

PCS

Unlicensed

2110

1990

2155 2170

MSS MSS IMT-2000 (Reg.2) 2110

2170

IMT-2000 MSS 2110

2170

UMTS 2110

1910 193 0

2200MHz

2150 2165

2025

MSS

MSS

Reserve

MSS

MSS: Mobile Satellite Service 10

Internal Use

Frequency allocation for IMT2000 

Additional (2nd of June, 2000)

WRC2000 Conference has decided to allocate additional bands for IMT-2000, 800MHz, 1.8GHz, and 2.5GHz Band. 2010

800

IMT-2000 GSM (Current) PDC (Current)

1000 960

806

2000 2025

1500 1710

1885 1980

810

960

958

1710

1429

MHz 2690

211 0 880

2500

2170

1990

1513

: Additionally assigned for IMT-2000 11

Internal Use

UMTS FDD and TDD

FDD (Frequency Division Duplex) pL U r o f : f1

ink

Link n w o D f 2: for Mobile Terminal

Base station

TDD (Time Division Duplex) f 1: for

U

Link n w o p&D

TS TS Up Down

Mobile Terminal

Base station

TS: Time slot 12

Internal Use

Summary  

 

13

IMT-2000 is the ITU standard for 3G mobile communications three 3G networks are implemented and currently deployed 1-CDMA 2000 (1X-EV-DO) 2-WCDMA FDD (UMTS FDD) 3-WCDMA TDD (UMTS TDD) 3GPP is responsible for producing UMTS network standard specifications 3GPP2 is responsible for producing CDMA2000 network standard specifications

Internal Use

Part 1 Introduction to UMTS Section 1 History of 3G Section 2 UMTS network structure Section 3 UMTS network services

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Internal Use

3GPP R99 network Architecture

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Internal Use

3GPP R99 network Architecture    

16

Interoperability with GSM CS domain elements are able to handle 2G and 3G subscribers. Changes (upgrades) in MSC/VLR and HLR/AC/EIR. For example SGSN  2G responsible for mobility management (MM) for packet connections  3G MM divided between RNC and SGSN

Internal Use

3GPP R4 network Architecture

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Internal Use

3GPP R4 network Architecture    

18

The 3GPP R4 introduces separation of the connection, its control, and services for CS domain of CN. Media Gateway (MGW): an element for maintaining the connection and performing switching function when required. MSC server: an element controlling MGW and responsible for signaling Packet switched voice  The CS call is changed to the packet switched call in MGW.

Internal Use

Difference between R99 and R4 CS domain evolution SCP

HLR

SCP

HLR

MAP Over TDM

MSC

TUP/ISUP TDM

MAP Over TDM/IP

MSC

MSC Server

ATM/IP/TDM

MSC Server

ATM/IP

MGW

RAN

RAN

RAN

RAN

R99

ATM/IP

RAN

MGW

RAN

R4

Notes: PS domain structure remain unchanged

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Internal Use

3GPP R5 network architecture

20

Internal Use

3GPP R5 network architecture     

21

3GPP R5 introduces the High Speed Downlink Packet Access (HSDPA) The HSDPA scheme proposes to add an additional wideband downlink shared channel that is optimized for very high-speed data transfer In HSDPA the coding and modulation scheme used are changed according to air interface conditions Release 5 employs two modulation schemes, QPSK and 16QAM. Later releases may introduce other schemes, such as 64QAM 3GPP R5 introduces a IP Multimedia subsystem (IMS)

Internal Use

Summary   

22

3GPP R99 is the first 3GPP specification for UMTS based on GSM NSS as a CN R4 softswitch based CS Core network was introduced in 3GPP R4 HSDPA and IMS are introduced in 3GPP R5

Internal Use

Part 1 Introduction to UMTS Section 1 History of 3G Section 2 UMTS network structure Section 3 UMTS network services

23

Internal Use

QoS of Different Services Quality (BER)

conversational

streaming

interactive

background

Time delay

24

Internal Use

UMTS services 

Conversational Services  Speech service:  Real time conversational service require the low time delay from end to end , and the uplink and the downlink service bandwidth is symmetrical .  Adopt AMR ( adaptive multi rate ) technique (WCDMA).

– 12.2, 10.2, 7.95, 7.40, 6.70, 5.90, 5.15 and 4.75kbps. – The bit rate of AMR voice can be controlled by the RAN according to the payload of air interface and the quality of voice service . 

25

Video phone (WCDMA)  The requirement of time delay is similar to the voice service  The CS connection :adopt ITU-T Rec.H.324M (AMR-H.263)  The PS connection :adopt IETF SIP or H.323

Internal Use

UMTS services 

Streaming Services  (eg. Telemetry (monitoring) , Audio and Video streaming )



Interactive Services  (eg. Web browsing , and online games ) Background Services  (eg. Email , Fax , and SMS )



26

Internal Use

Summary

27

Internal Use

Part 1 Introduction to UMTS Part 2 UTRAN basic principles Part 3 ATM basic principles

28

Internal Use

Multiple Access Techniques CDMA Power Tim

e

e Fr

cy en u q

Traffic channels: different users are assigned unique code and transmitted over the same frequency band, for example, WCDMA and CDMA2000

TDMA Power Tim e

FDMA Power

29

Us e U Us ser r Us e r Us e r er

Us er Tim

Fre

e

n ue q e Fr

cy

cy en u q

Traffic channels: different time slots are allocated to different users, for example, DAMPS and GSM

Traffic channels: different frequency bands are allocated to different users,for example, AMPS and TACS Internal Use

Multiple Access Techniques

Advantage FDMA

1. Simple Implementation

AMPS, TACS

Defect Defect 1. Frequency Reuse 2. privacy

1.Privacy

1. Need synchronized of frame

CDMA

1. Reduction the interference

IS95, W-CDMA

2. Diversity Hand-over

1. Sophisticated power control for mobile

TDMA GSM, PDC

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3. Privacy

Internal Use

Multiple Access Techniques

FDMA/TDMA

ｆ １ ｆ 7

ｆ 5 7 ｆ 6 ｆ 2

ｆ 6 7 ｆ 3 ｆ 4 ｆ 5

ｆ １ 6 ｆ 2 ｆ １ ｆ 7 ｆ 3

ｆ 4 ｆ 5 ｆ 6 ｆ 2

ｆ 7 ｆ 3 ｆ 4

CDMA

ｆ 2 ｆ １

ｆ 1 ｆ ｆ 51 ｆ ｆ 6 1 ｆ 1

ｆ 1 ｆ 1 ｆ 1

ｆ 1 ｆ 1

Frequency is different in each sector.

Frequency is same.

Need for

No need for frequency plan

frequency plan (Frequency Reuse) Reuse 31

ｆ 1 ｆ 1

ｆ ｆ １ ｆ ｆ ｆ 1 ｆ ｆ 2 １ 71 ｆ 1 ｆ ｆ 1 1 ｆ ｆ ｆ 41 ｆ 1 ｆ 71 1 ｆ 1

Internal Use

DS-CDMA

Narrow Band Spreading Signal Code 1 A

(Multiple Signal)

Despreading

(Receiver A)

Code 2 B

A

User-A (Receiver B)

Code 2 B

De-spreading Code

User-B Code 3

Narrow Band Signal

Code 1

C B A

User-A

32

Wide Band Signal

User-B (Receiver C)

Code 3

C

C

User-C

User-C Internal Use

Rake Receiver

C B

A

B

A

Rake 33

A

B

C

C

Internal Use

Rake receiver RAKE Receiver Finger Circuit RX

Combiner

Finger Circuit

Combined Signal

Finger Circuit Calculation Calculation

Searcher Electric Power

Electric Power

Output Power

Multiple Signal 1 Multiple Signal 2 Multiple Signal 3 Delay Time

Delay Time

Delay Profile 34

Internal Use

WCDMA handover types 

Soft Handover



UE is connected simultaneously to more than one base station (up to 3 sectors) using the same frequency The UE receives the downlink transmissions of two or more base stations. For this purpose it has to employ one of its RAKE receiver fingers for each received signal. in the uplink direction , the code channel of the mobile station is received from both base stations, but the received data is then routed to the RNC for combining The RNC selects the better frame between the two possible candidates based on frame reliability indicator







35

Internal Use

WCDMA handover types 

Softer Handover



UE is connected simultaneously to two sectors of one base station using the same frequency The UE receives the downlink transmissions the two sectors. For this purpose it has to employ one of its RAKE receiver fingers for each received signal. in the uplink direction , the code channel of the mobile station is received in each sector, then routed to the same baseband Rake receiver and the maximal ratio combined there in the usual way.





36

Internal Use

WCDMA handover types 

Hard Handover



The UE stops transmission on one frequency before it moves to another frequency and starts transmitting again During Hard Handover the used radio frequency (RF) of the UE changes



37

Internal Use

WCDMA handover types 

38

Inter-system Handover  Handover between two different radio access technologies  Handover between UMTS FDD and GSM  Handover between UMTS FDD and UMTS TDD

Internal Use

Spreading process in WCDMA

Coding & Interleaving

3,840 Kcps Channelization Code





39

Σ

Scrambling Code

1st Step: Channelization  Variable Rate Spreading ( According to user data rate) 2nd Step: Scrambling Code  Fixed Rate Spreading (3,840 Kchips)

Internal Use

Spreading process in WCDMA   

Downlink (NodeB to UE ) Scrambling Code: Identifies cell (sector). Channelization Code: Identifies user channels in cell (Sector).

Scrambling Code A Scrambling Code B Channelization Channelization Code 2 Channelization Code 3 Code 1 Channelization Code 1 Channelization Code 1 Channelization Code 2 40

Channelization Code 2

Scrambling Code C Internal Use

Spreading process in WCDMA 

Up Link (UE to NodeB ) Scrambling Code: Identifies user terminal. Channelization Code: Identifies channels in user terminal.

Channelization Code 2 Channelization Code 1

Scrambling Code A Channelization Code 1

Scrambling Code B

Channelization Code 1

Scrambling Code C

41

Internal Use

Spreading process in WCDMA 

42

Orthogonal Variable Spreading Factor [OVSF] codes are the channelization codes used for signal spreading in the uplink and downlink

Internal Use

Spreading process in WCDMA 

 

43

The code used for scrambling of the uplink Channels may be of either long or short type, There are 224 long and 224 short uplink scrambling codes. Uplink scrambling codes are assigned by higher layers. For downlink physical channels, a total of 218 -1 = 262,143 scrambling codes can be generated. Only scrambling codes k = 0, 1, …, 8191 are used. In the downlink direction 512 of scrambling codes are used to identify the cells in the downlink so downlink planning is required

Internal Use

W-CDMA (IMT-DS) Specification

44

Multiple access method

DS-CDMA (DS: Direct Spread)

Duplexing method

FDD/TDD (Frequency Division Duplex/Time Division Duplex)

Inter-cell synchronization

Asynchronous

Bandwidth

5 MHZ

Chip rate

3.84 Mcps

Carrier spacing

Flexible with 100/200kHz carrier raster

Frame length Unit

10 ms

Data modulation

Downlink: QPSK, Uplink: BPSK

Multi-rate concept

Variable spreading factor and/or multi-code

Maximum data rate

2 Mbps (indoor)/384 kbps (mobile)

Channel coding

Convolutional coding (R=1/3 or 1/2, K=9) Turbo code for High data rate

BPSK: Binary phase shift keying

QPSK: Quadrature phase shift keying

Internal Use

UMTS FDD frequency allocations

45

Operating Band

UL Frequencies UE transmit, Node B receive

DL frequencies UE receive, Node B transmit

I

1920 – 1980 MHz

2110 –2170 MHz

II

1850 –1910 MHz

1930 –1990 MHz

III

1710-1785 MHz

1805-1880 MHz

IV

1710-1755 MHz

2110-2155 MHz

V

824 – 849 MHz

869-894 MHz

VI

830-840 MHz

875-885 MHz

Operating Band

TX-RX frequency separation

I

190 MHz

II

80 MHz.

III

95 MHz.

IV

400 MHz

V

45 MHz

VI

45 MHz

Internal Use

Summary    



46

UMTS is based on DS-CDMA as a multiple access technique Rack receiver is used to combine signals and get benefits from Multipath fading . Also it is used to combine signals in soft and softer handover cases Two types of Power control are used in UMTS , open and closed loop power control Types of handover in UMTS  Soft handover  Softer handover  Hard handover  Inter-system handover Spreading process in WCDMA consists of two stages  Channelization  Scrambling

Internal Use

Part 1 Introduction to UMTS Part 2 UTRAN basic principles Part 3 ATM basic principles

47

Internal Use

Why do we need a new technology?

To provide a high-speed, low

delay

multiplexing and switching network to any

type of

user traffic, such as voice support, data,or video applications.

48

Internal Use

Traditional Switch Model’s Characteristic

Circuit Switching  Data is sent from the same route, so time delay is fixed



49

 High-speed switching  Fixed rate Packet Switching  Support multi-rate switching  Take full advantage of bandwidth/waste of bandwidth  Time delay is not fixed

Internal Use

What is ATM?  ATM

for Telecommunications is Asynchronous Transfer Mode, (not Automatic Teller Machine!).  In general, ATM means that traffic is carried in small, fixed-length packets called cells.  A technology that integrates advantages of circuit switch and packet switch.  ATM can support any type of user services, such as voice, data, or video service.

50

Internal Use

ATM can provides both CBR and VBR transport

51

Internal Use

ATM Overview

5-Bytes Header

48-Bytes Payload

53byte fixed length cell= 5Bytes cell header+48Bytes payload. ATM must set up virtual connection before communication.

Contract

52

ATM network will confer with terminal on parameter of QoS before the connection is set up.

Internal Use

ATM Network Model UNI

NNI

NNI

UNI

NNI

NNI NNI

ATM Switch

UNI

ATM End terminal

UNI = User to Network Interface NNI = Network to Network Interface

53

Internal Use

ATM Cell

54

Internal Use

ATM Cell   

  

55

GFC ( Generic Flow Control): It is intended for control of a possible bus system at the user interface and is not used at the moment. VPI ( Virtual Path Identifier): The VPI contains the second part of the addressing instructions and is of higher priority than the VCI. VCI ( Virtual Channel Identifier): VCI in each case indicates a path section between switching centers or between the switching center and the subscriber. PTI ( Payload Type Identifier): Indicates the type of data in the information field. CLP ( Cell Loss Priority): Determines whether a cell can be preferentially deleted or not in the case of a transmission bottleneck. HEC ( Header Error Control): Provided in order to control and, to some extent, correct errors in the header data that may occur. The HEC is used to synchronize the receiver to the start of the cell.

Internal Use

VP and VC

think VPI as a bundle of virtual channels. (256 VPI on one link)  the individual virtual channels have unique VCIs. The VCI values may be reused in each virtual path. 

56

Internal Use

ATM Connections

57

Internal Use

ATM Virtual Connection

UNI cell VPI =1 VCI =1

A

1

Port

VPI

VCI

1

1

1

2

26

44 1

3 2

NNI cell VPI =26 VCI =44 3 1

Port

VPI

VCI

1

26

44

2

2

44

UNI cell VPI =20 VCI =30 3

2

NNI cell VPI =2 VCI =44

NNI cell VPI =6 VCI =44 3

B

2

Port

VPI

VCI

2

6

44

3

20

30

2

1

ATM Virtual Connection

Port

VPI

VCI

1

2

44

2

6

44

In order to exchange cells between A and B, several tables must be set up in network node where the cells passed. After these tables have been set up, all the cells will be transferred along this route. This route is called Virtual Connection. 58

Internal Use

ATM Protocol Structure Model

59

Internal Use

ATM traffic classes

60

Internal Use

ATM traffic parameters

61

Internal Use

ATM applications in UMTS network 

UTRAN

Uu

NodeB

Iub

Iu

Iu-CS

RNC

UE

MSC

NodeB

Iur NodeB

RNC UE

62

NodeB

SGSN

Iu-PS

Internal Use

ATM applications in UMTS network

63

Internal Use

64

Internal Use