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114.11.2001Antti Siitonen

UMTS

Antti Siitonen

Technologist, MSc (EE), Radiolinja

[email protected]

›T-110.300 Telecommunications architectures

›Lectures on 15.11.2001

›Introduction to UMTS


Contents1. Introduction to UMTS

1.1. Standards evolution

1.2. Radio interface in general

1.3. Network architecture

1.4. Mobile handset

2. Services in UMTS environment

2.1. Theoretical bitrates and Quality of Service

2.2. Service capabilities

2.3. Service concepts

3. UMTS protocols

3.1. Protocol architectures in UMTS overview

3.2. Signalling


Worldwide Telecommunications Growthmillions of customers

0200

400

600800

1000

12001400

16001800

1996 1998 2000 2002 2004 2006 2008 2010

Fixed Mobile Internet Mobile Internetsource ETSI GMM report


Picture: Nokia

UMTS› Universal Mobile Telecommunications System

› UMTS = European variation of the WCDMA technology

› FDD and TDD bands

› New licences

› ”GSM combatible”

› What is new?

› Wideband data access andmultimedia support

› Open service creation environment

› Videophone


3G StandardsVariant Radio access Switching 2G Basis3G (US) WCDMA,

EDGE,CDMA2000

IS-41 IS-95,GSM1900,

TDMA3G (Europe) WCDMA, GSM,

EDGEAdvanced GSMNSS andpacket core

GSM 900/1800

3G (Japan) WCDMA Advanced GSMNSS andpacket core

PDC

UMTS

• UMTS standardization is done in 3GPP = 3rd Generation Partnership Project• ETSI = European Telecommunication Standard Institute / Europe• ARIB = Association of Radio Industries and Business / Japan• CWTS = China Wireless Telecommunication Standard Group / China• T1 = Standardisation Committee T1 - Telecommunications /US• TTC = Telecommunications Technology Committee /Japan• TTA = Telecommunication Technology Association /Korea


3GPP Standards

2000 2003Q2

2001 2002Q2 Q1Q3 Q2 Q3Q4 Q4 Q1Q1 Q2 Q3 Q4Q4 Q3 Q1

3GPP Release 4 3GPP Release 5

3GPP Release 3(Release 1999)

Commercial servicesR3




UMTS releases› Release 3 (Officially named Release 1999)

› UMTS expansion + EDGE

› quick start = faster GPRS, faster Circuit Switched Data

› MultiMediaMessaging (For GPRS also), Adaptive Multirate …

› New radio network for UMTS

› Release 4

› New network architecture: MSC server

› Location based services (PS), VHE, Camel 3, MAP over IP

› Release 5 (and Release 6)

› OSA, MediaGateway, GSN server

› IPv6 mandatory, IPv4 optional

› SIP signalling and VoIP

› Interfaces to other networks (WLAN (HiperLan2)….)


What is new with UMTS radio?›In shot: everything

› Wideband CDMA - 2 Mbit/s channel bitrate» Soft handover» Cell breathing

› Both FDD and TDD modes» Frequency Division Duplex» Time Division Duplex

› New frequencies 2100 MHz = 2,1 GHz

› Later other frequency bands (900, 1800, 2600...)

› Cell planning is changed from frequency planning into capacityplanning


WCDMA - cell breathing 1

64 kbit/s64 kbit/s 64 kbit/s

64 kbit/s64 kbit/s64 kbit/s


WCDMA- cell breathing 2More load...

512 kbit/s64 kbit/s

64 kbit/s

64 kbit/s

64 kbit/s 64 kbit/s


WCDMA- cell breathing 3Serving 2 Mbit user

2 Mbit/s

64 kbit/s

64 kbit/s

64 kbit/s

64 kbit/s

64 kbit/s


WCDMA- cell breathing 4Several 2 Mbit users?

2 Mbit/s2 Mbit/s

2 Mbit/s

2 Mbit/s


WCDMA frequencies (ITU)

1850 1900 1950 2000 2050 2100 2150 2200 2250 MHz

1850 1900 1950 2000 2050 2100 2150 2200 2250 MHz

NorthAmerica

MSS Reserve

Europe UMTSGSM 1800 DECT MSS

1880

1980

JapanKorea

MSSIMT 2000 MSSIMT 2000

2160

1893 1919

ITU Allocations1885

IMT 20002010 2110 2170

China MSSIMT 2000IMT 2000

IMT 2000

MSSUMTS

MSS

1990

B BMSS

2025 22001900

MSS MSS

PCS

MSS =Mobile Satellite

Services

TDD

FDD


WCDMA Frequency use

› 2 times more effective than GSM

› 1 WCDMA channel = 28 GSMchannels

WCDMA 5MHz

.....

f

GSM 0,2 MHz


UMTS Network release 99- Based mainly on GSM+GPRS

BSC

SS7

HLR VAS

GSMInternet

LAN

GPRS

PSTN3G MSC

SGSN GGSN

RNC

UTRA

MS

UE

BTS

BS

Circuit Switched Domain

Packet Switched Domain

Camel, WAP, MExE, USAT

RNC

UTRA

BS


UMTS Network release 4

BSC

SS7

GSMInternet

LAN

GPRS

PSTN

MSC Server

SGSN GGSN

RNC

UTRA

MS

UE

BTS

BS



Media Gateway

Media Gateway

HSS

Switching

Control

HSS = Home Subscriber Server

VAS Camel, WAP, MExE, USAT


Core network release 5 (6)

BSC

SS7

GSM Internet

MGW

RNC

UMTS

MS

UE

BS

BTS

IP/ATM

IP/ATM

HSS

HSS = Home Subscriber ServerCPS = Call Processing Server

VAS Camel, WAP, MExE, USAT

Core Network Packet Switched Domain

SGSN GGSN

IP/ATM

IMS

IMS = IP MultimediaSubsystemMGW+HSS+CPSSIP-signalling

PSTN

IP RAN

CPS


Bearer architecture in UMTS

TE MT UTRAN CN Iu edge CN Gateway

End-to-end Service

TE = Terminal Equipment, MT = Mobile Termination, UTRAN = UMTS Radio Network, CN = Core Network

Local BearerService UMTS Bearer Service

ExternalBearerService

Radio Access Bearer Service CN BearerService

Radio BearerService IU Bearer Service Backbone

Bearer Service

Backbone Phys.Bearer Service

Physical BearerService

UTRA BearerService


UMTS Terminal, User Equipment (UE)› Mandatory functions:

› Interface to USIM = Universal Subscriber Identity Module

› Service provider and network registration and deregistration

› Location update

› Originating and receiving connection orinented and connectionlessservices

› An unalternable equipment identification (IMEI)

› Basic identification of the terminal capabilities

› Emergency calls without USIM

› Authentication and ciphering algorithm support

› Optional, but important

› API, Service related information download, Virtual HomeEnvironment maintenance interface, Secondary IC-card slot


Terminal ComplexityComparisonMIPS

0

10

20

30

40

50

60

70

80

90

Speech 8 kbit/s 144 kbit/s

GSM/EDGEWCDMA

Source: SMG2 evaluion documents by Nokia, Ericsson and Siemens


Services in UMTS Environment

Content Provider Content Provider Content Provider

Service Provider Service Provider Service Provider

Carrier Provider Carrier Provider

End User End User

CommunicationServices

InfoServices

Games

End User


Theoretical bitrates

› Theoretical bitrates seem to remain theory

› Specified rates are:

› In commercial deployments maximum bit rates are expected to be384 kbit/s and basic service bit rate 64 kbit/s

› Indoor coverage for UMTS?

› One issue is also the availability of high speed terminals

Circuit Switched bitrate (kbit/s)

Packet Switched bitrate (kbit/s)

Coverage Type

144 kbit/s 144 kbit/s peak rate Basic coverage,rural/suburban,fast moving vehicles, outdoor

384 kbit/s 384 kbit/s peak rate Extended Coverage, urban,moving vehicles, outdoor

2 Mbit/s 2 Mbit/s peak rate Hot Spot areas, urban, centre,walking speeds, indoor


Quality of Service

› Radio capacity optimisation

› Core Network and UTRAN independent from each other andsurrounding networks

› Transport Network optimisation

› QoS classes:

› Conversational class: minimum fixed delay, no buffering, symmetrictraffic, guaranteed bit rate = Real Time Traffic

› Streaming class: minimum variable delay, buffering allowed,asymmetric traffic, guaranteed bit rate = Near Real Time Traffic

› Interactive class: moderate variable delay, buffering allowed,asymmetric traffic, no guaranteed bit rate = Not Real Time Traffic

› Background class: big variable delay, buffering allowed, asymmetrictraffic, no guaranteed bit rate = Data synchronisation


Quality of Service (cont.)› QoS parameters in UMTS:

› Maximum bit rate (kbit/s)

› Guaranteed bit rate (Kbit/s)

› Allowed transfer delay (ms)

› Is QoS class negotiable?UE UTRAN CN

UMTS End-to-end Service

RAB = Radio Access Bearer, RRM = Radio Resource Management

UMTS Bearer Service: Request for UMTS QoS Class

RAB Assignment Request

RRM:- Admission Control

QoS NegotiationRadio Bearer and Radio Link establishment

RAB Assignment Response

UMTS Bearer Service with Negotiated QoS


Quality of Service (cont.)

› Challenges:

› First typical use cases will be in hybrid networks (UMTS/GPRS/GSM),How is this taken into account?

› How much can content compression and background synchronisationsolve user needs?

Conversational Streaming Interactive BackgroundMax. Bitrate (kbit/s)

< 2048 < 2048 < 2048 < 2048

GuaranteedBit rate(kbit/s)

< 2048 < 2048 N/A N/A

Symmetry Symmetric Asymmetric Asymmetric AsymmetricTransferdelay (ms)

100-250 > 250 N/A N/A


Service capabilities

› Principle: Connections are separated from service maintaining

› Network components called service capabilities = service platforms

› Initially identified service capabilities (Release 99)

› WAP Server / WAP Gateway - Mobile browser capabilities

› Positioning servers - UE position information, Location Based Services

› Mobile Station Application Execution Environment - Providesinformation to other services about UE information handlingcapabilities

› UMTS SIM Application Toolkit (USAT) - SIM card handling tools

› Customised Applications for Mobile network Enhanced Logic (CAMEL)- Service interconnection point (Service control, implementation andprovisioning)


Service capabilities (cont.)

› In Release 4 there are new possibilities for service creation

› OSA = Open Service Architecture

› Common centralized point for Service Creation

= Service Creation Environment (SCE)

› All capabilities implemented are accessible via APIs

› Practically CAMEL is required for effective service creation

› Possibility to make the services roam between networks

› Challenge:

› Will the operators open the networks for open service creation?


Location Communication Services› There are different methods to provide UE position information toservices or users

› Cell ID based positioning

› Round-Trip Time (RTT) based positioning

› Timing Advance, Received Signal Strength (TA/Rx)

› Time-of-Arrival (TOA) positioning

› Time Difference of Arrival (TDOA) positioning

› Enhanced Observed Time difference (E-OTD)

› Angle of Arrival (AOA) positioning

› Reference Node Based Positioning (RNBP)

› Assisted Global Positioning System (Assisted GPS)


Accuracy of different positioning systems

Accuracy

10m 100m 1 km 10 km

GPSTA/Rx

E-OTD Cell-ID

› Always an estimate

› Different methods for different usage

› Most accurate isn’t always the best choise


UMTS System architecture for LCS

BSC

SS7

HLR VAS

GSMInternet

LAN

GPRS

PSTN3G MSC

SGSN GGSN

RNC

UTRA

MS

UE

BTS

BS



Camel, WAP, MExE, USATLCSExt. Client

SRNC/SMLC

GMLC

SMLC = Serving Mobile Location CentreGMLC = Gateway Mobile Location CentreLCS

Internal Client


MExE› Terminals will have different capabilities - how to tell to theservice which are the current capabilities?

› Mobile Application Execution Environment (MExE) wasintroduced to handle terminal capabilities

› MExE Classmark 1: Numeric keypad, limited screensize, fixedcharacter amounts (WAP type Terminal)

› MExE Classmark 2: Colour screen, full keypad, wide applicationsupport (JAVA supporting terminal)

› MExE Service Environment: Set of supported services

› Personalisation database - interacts with USIM


USAT› USIM Application Toolkit

› Extension to GSM SIM Application Toolkit to support USIMproperties

› Applications executed in USIM

› Most likely to be “closed” environment - operators are in control ofUSAT applications


CAMEL SCECustomised Applications for Mobile network Enhanced Logic- Developed to provide automatic roaming with full service set- Mobility and Service Portability on top of IN

Subscriber Locationand State Retrieval

CAMEL - functioningenvironment

Subscription DataHandling

Mobility ManagementSMS - MMS

GPRS-interworking

Circuit SwitchedCall Control


Virtual Home Environment

› Idea: To have the same, personalised individual interface through theterminal regardless of the UMTS network the user is attached to

› Requirements for Release 99 based network are based on CAMEL

› Subscriber profiles are handled in MExE Service Environment

› Location Based Services information can be transferred through CAMEL

› Provisioned services and their usage information is transferred betweenNetworks through CAMEL

› Number portability can be handled through CAMEL

› Question:

› Would this be easier in All IP environment?


Service Concepts› GSM inherited Services supported in R99 are quite BASIC:

› Voice

› FAX

› Alternate FAX/Voice

› Circuit Switched Data Bearer services

› Supplementary Services

› USSD (Unstructured Supplementary Service Data)

› MMS

› Packet Switched Services are actually same as in GPRS, but

› Bigger bit rate

› Smaller delay


UMTS Security›There are three key principles behind 3G security:

› 3G security will build on the security of second generationsystems. Security elements within GSM and other second-generation systems that have proved to be needed and robust shallbe adopted for 3G security.

› 3G security will improve on the security of second generationsystems - 3G security will address and correct real and perceivedweaknesses in second generation systems.

› 3G security will offer new security features and will secure newservices offered by 3G.


UMTS Security (cont.)› High Level objectives of security:

› To ensure that information generated by or relating to a user is adequatelyprotected against misuse or misappropriation;

› Environments are adequately protected against misuse or misappropriation;

› To ensure that the security features standardised are compatible with world-wide availability. (There shall be at least one ciphering algorithm that can beexported on a worldwide basis (in accordance with the Wassenaaragreement));

› To ensure that the security features are adequately standardised to ensureworld-wide interoperability and roaming between different serving networks;

› To ensure that the level of protection afforded to users and providers ofservices is better than that provided in contemporary fixed and mobilenetworks (including GSM);

› To ensure that the implementation of 3GPP security features andmechanisms can be extended and enhanced as required by new threats andservices.


Protocol architectures in UMTS

UE BS RNC MSC/SGSN GMSC/GGSN

Transport Network Layer

Radio Network Layer

System Network Layer

User Plane Control Plane

User & Control planes are parallel


Transport Network Protocol Architecture›R99

WCDMA Physical Layer Physical Layer (PDH or SDH)

MAC

RLC

MAC

RLCATM orUDP/IP

AAL (n) orGTP-U

WCDMA Physical Layer Physical Layer (PDH or SDH)

MAC

RLC

MAC

RLC

ATM or IP

SCCP

ATM or IP

SCCP

MTP

SCCP

MTP

SCCP

User plane protocols in transport network

Control plane protocols in transport network

RLC = Radio Link Control, MAC = Medium Access Control, SCCP = Signalling Connection Control Part

Uu Iub/Iur Iu Gn

Uu Iub/Iur Iu D/Gr HLR

UE

UE

BS

BS RNC

RNC

MSC/SGSN

SGSNGGSN

ATM orUDP/IP

AAL (n) orGTP-U

ATM orUDP/IP

AAL (n) orGTP-U

ATM orUDP/IP

AAL (n) orGTP-U


Protocol layers› Physical layers

› WCDMA Physical Layer

› PDH or SDH Physical Layer

› MAC

› Set of logical channels

› RLC

› Radio Link Control» eg. Segmentation and reassembly, Error correction,..

› UMTS is primarly specified to use ATM as Layer3-protocol

› IP is defined for user data and there is an IP option for signallingtransport


System Network Protocols› Mobility Management -protocol (MM)

› Between UE and MSC

› Basic mechanisms for Mobility management and authentication functions

› GPRS Mobility Management -protocol (GMM)

› Mobility mangement for Packet Switched domain

› Call Control -protocol (CC)


› Basic Mechanisms for Call Control in Circuit Switched domain

› Session Management -protocol (SM)

› Between UE and SGSN

› Supplementary Services -protocol (SS)


› Additional services in Circuit Switched domain


Role of IP in UMTS evolution

Traffic Control

Traffic Transport

Traffic Control

User Traffic & Services

Traffic Transport


R99 R4

Traffic Transport

Traffic Control


R5/6Role of IP


All-IP

› In UMTS R5› IPv6-support mandatory

› IPv4-support optional

› Signalling› Interface to external networs via SIP

› Towards PSTN SIP over IP is translated to SS7 Call Control -signalling (eg. ISUP)

› IPSec is needed to ensure integrity of SIP-sessions» Still no decision of end-to-end multimedia session ciphering


SIP services› Session Initiation Protocol based signalling

› VoIP

› Instant messaging

› Presence information

› Browser sessions

› SIP based services (examples)› Rich Call

› Multimedia conference/Chat


IP Multicast Architecture – Multicast connections example: 5 users, 1 group.

IP Multicast Network

GGSN

GGSN

SGSN

SGSN

SGSN

SGSN

RNC

RNC

RNC

RNC

RNC

RNC

RNC

Radio Bearer (Broadcast)

Multicast_RAB

Multicast_GTP_Tunnel

IP Multicast


UMTS for mobile operator› New investments to the network

› New set of subscribers and services

› Several service networks - serveral service mechanisms

› New security challenges in IP: Everything cannot be blocked out,IP has more flexibility

› Number of IP connected devices will be greater than number ofindividuals in the network

IS THERE GOOD ALTERNATIVES? - For Mobile use, not yet.- For Wireless Connectivity, yes there is.

To be continued in the next lecture ..

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