Module 2 - Basic UMTS Architecture

Training Slides

Module Objectives

Describe UMTS architecture Describe UMTS equipment Describe UMTS interfaces

General Principles of UMTS

The GSM operators offered an evolutionary way of upgrading their networks, including dual mode operation with GSM.

Greenfield operators should also be offered competitive solutions.

GPRS is seen as a stepping stone towards UMTS packet services.

Roaming and handover has to be supported between UMTS and GSM.

UMTS Network Management evolving from vendor current solutions for GSM Network Management.

Existing specifications (&software) to be used as much as possible, e.g. MAP signaling, existing supplementary services, etc.

UMTS Architecture

ATMBackbone

Node B(BTS)

UuRNC

Iu (CS & PS)

RNC

Iur

Iur

Iu (CS & PS)

Node B(BTS)

Uu

Packet Domain

Circuit DomainUE

UE

ATMBackbone

Iub (ATM)

Iub (ATM)

Iu CS

Iu PS

Core Network

UMTS Terrestrial Radio Access Network (UTRAN)

UMTS architecture New WCDMA air-interface => new Radio Access Network

(UTRAN = UMTS Terrestrial Radio Access Network) co-existing with GSM BSS

UTRAN consists of Base Stations and Radio Network Controllers (RNC)

New functionality needed to manage the radio resources New interface introduced between RNCs, Iur ATM is used - in UTRAN - between UTRAN and core network (IP over ATM) - however, base stations can be connected over existing

transmission lines Core network elements evolving from GSM Subscriber management based on SIM concept familiar from

GSM Security based on GSM security principles and mechanisms

and enhanced further

Node B or BTS

Node B(BTS)

Uu Iub (ATM)

UE RNC

Main Node B functions: Call Processing Radio access Performance Monitoring Network interface Random Access detection

Radio Network Controller

ATMBackbone

Node B(BTS)

RNCIu

ATMBackbone Core Network

Iub (ATM)

Iur

Main RNC functions: Radio Resource Management User Mobility Handling RNS Supervision Interfaces

UMTS Core NetworkCore Network

3G MSC

PSTN

3G-SGSN

3G-GGSN

Gn

Internet

Iu CS

Iu PS

HLR/AuC

IPBackbone

ATMBackbone

Packet Domain

64 K TDM

Circuit Domain

Intranet

VLR

TRAU

Gr

C

D

B

RadioAccessNetwork

Gn

TRAU TRAU (Transcoder and Rate Adaptation Unit)

3G MSC64 kb/sRNC AMR

Iu CSOver ATM

Iu CSOver PCM Links

12.2 kbit/s (GSM EFR)10.2 kbit/s7.95 kbit/s

7.40 kbit/s (IS-641)6.70 kbit/s (PDC EFR)

5.90 kbit/s5.15 kbit/s4.75 kbit/s

64 kbit/s

Main TRAU function: to change the speech coding Scheme

AMR ISDN VocoderAMR AMR

3G MSC

3G MSC

Main MSC functions: Switching Call Setup Call Ticketing Interfaces

TRAU

AccessNetwork

HLR VLR

PSTN

BC

Iu CS

D

HLR & AuC

Main HLR functions: Handling of permanent

subscriber data Handling of temporary

subscriber data Dialogue with AuC database

3G MSC

HLR/AuC

VLR

Gr

Main AuC functions: Storage of secret subscriber

keys and security algorithms Generation of security

information

3GSGSN

C

D

Gc

3GGGSN

VLR

3G MSC

VLR

HLR

B

D

Main VLR functions: Storing all subscriber information

required for call handling and other purposes for mobile subscribers within its area

C

3G SGSN

3G-SGSN

HLR/AuC

3G-GGSN

Gr

Gn

Iu PSRNC

Main SGSN functions: Packet Mobility Management Session Management Passing user traffic between

RNC and 3G-GGSN

3G GGSN

3G-GGSN

3G-SGSN

Internet

Intranets

Gn

Gi

HLR/AuC

Gc

Main GGSN functions: Accounting Tunneling towards SGSN Tunneling towards external networks

UMTS NetworkCore Network

ATMBackbone

UTRAN

Node B(BTS)

Uu

Iub (ATM)

RNCIu

(CS & PS)

RNC

Iur

Iur

Iu (CS & PS)

Node B(BTS)

Uu

ATMBackbone

Iub (ATM)

3G MSC

TRAUIu CS

PSTN

Circuit Domain

HLR/AuC

VLR

3GSGSN

PacketBackbone

Packet Domain

Iu PS

B C

D

3GGGSN

Gr

Internet

Intranets

UE

UE

Module Review

UMTS Terrestrial Radio Access Network (UTRAN)

New network element names: Node B, RNC

UMTS Core Networks elements: 3GMSC, 3GSGSN, 3GGGSN, VLR, HLR, AuC, TRAU

Interfaces: ATM (lub), lu, lur

Module 2 - Basic UMTS ArchitectureModule ObjectivesGeneral Principles of UMTSUMTS ArchitectureUMTS architectureNode B or BTSRadio Network ControllerUMTS Core NetworkTRAU3G MSCHLR & AuCVLR3G SGSN3G GGSNUMTS NetworkModule Review