Siemens The UMTS Network

TM2201EU04TM_0002

2002 Siemens AG

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3

1 Release `99: Network Overview

Enhanced GSM Phase 2+

Core Network

BSSGSM Base Station

Subsystem

UTRANUMTS Terrestrial

Radio Access Network

PSTN /

ISDNIntra- /

Internet

Co-existence of

GSM & UMTS

network elements

Release `99

Network Overview

UMTS

Network

GSM UMTS Evolution saves investment costs

reduces implementation risks

A IuGb

Um Uu

GSM GSM / UMTS UMTS

Fig. 1


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Release `99: Network Overview

UMTS networks are based on GSM Phase 2+ Core Networks. This approach safeguards the investments made by today's GSM network operators and reduces the 3G implementation risks. The UMTS Terrestrial Radio Access Network UTRAN is connected to the enhanced Phase 2+ CN via Iu interface. The GSM Base Station Subsystem BSS and UTRAN can be connected to the same CN. The GSM Mobile Station MS is connected to the GSM BSS via GSM radio interface Um, the UMTS User Equipment UE to UTRAN via UMTS radio interface Uu.

An overview of the UMTS network architecture is given in TS 23.002.

The UMTS CN

The enhanced GSM Phase 2+ Core Network consists of a Circuit Switched CS Domain for speech, video telephony and real-time data transfer and a Packet Switched PS Domain for Non real-time data transfer. Furthermore, several network elements are necessary respectively optional for both domains, here determined as "Entities common to the CS & PS Domain".

An overview of the PS Domain is given in TS 23.060.



5

External

Networks

Network OverviewTS 23.002:

Network Architecture

CS Domain

PS Domain

Entities common

to the CS & PS Domain

GSM BSS

UTRANUE

RANRadio Access Network

CNCore Network

TS 23.060:GPRS

Fig. 2


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The UMTS Network

CS Domain

The CS Domain of the UMTS CN consists of the following functions:

MSC: Mobile Services switching Center

GMSC: Gateway MSC

SMS-GMSC: Short Message Services Gateway MSC

SMS-IWMSC: Short Message Services Interworking MSC

VLR: Visitor Location Register

TC/IWF: Transcoding & Interworking function

PS Domain

The PS Domain of the UMTS CN consists of the following functions:

GGSN: Gateway GPRS Support Node

SGSN: Serving GPRS Support Node

CGF: Charging Gateway Function

Entities common to the CS & PS Domain:

HLR: Home Location Register

AuC: Authentication Center

EIR: Equipment Identity Register

CSE: CAMEL Service Environment

UMTS Terrestrial Radio Access Network UTRAN & UE

The UTRAN consists of the following functions:

RNC: Radio Network Controller

Node B

UE: User Equipment

Remark: This list of UMTS functions is not complete (see TS23.002). Only the "most important" functions are shown. The listed functions are described in the following.



7

PSTN

X.25

ISDN

IP

TC: Transcoding

IWF: Interworking Functions

SM-SC: Short Message Service Centre

IWF/

TC

GMSC

GGSN

MSC /VLR

SGSN

HLR AuCEIRCSE

TRAU

B

S

C

BTS

R

N

C

BTS

Node B(n x BTS)

R

N

C

Node B(n x BTS)

Node B(n x BTS)

UE



SMS-GMSCSMS-IWMSC

SM-SC

CGFBilling

System

CS Domain

PSDomain

GSM BSS

UMTS

Network

TS 23.002

UTRAN

Fig. 3


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9

2 Release `99 CN: CS Domain

PSTN

X.25

ISDN

IP

IWF/

TC

GMSC

GGSN

MSC /VLR

SGSN

HLR AuCEIRCSEUTRAN

TRAU

B

S

C

BTS

R

N

C

BTS

Node B(n x BTS)

R

N

C

Node B(n x BTS)

Node B(n x BTS)

UE

SMS-GMSCSMS-IWMSC

SM-SC

CGFBilling

System

CS Domain

PSDomain

GSM BSS

Release `99 CN:

CS Domain

UMTS

Network

Fig. 4


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3G MSC

The Mobile-services Switching Center MSC constitutes the interface between the radio system and the external fixed networks (ISDN / PSTN). The MSC performs all necessary functions in order to handle the circuit switched services to and from the Mobile Stations MS / User Equipment UE.

The MSC is an exchange which performs all the switching and signaling functions for MSs / UEs located in a geographical area designated as the MSC area. The MSC area is sub-divided into so-called Location Areas LA. The main difference between a MSC and an exchange in a fixed network is that the MSC has to take into account the impact of the subscribers mobility.

Several MSCs may be required to cover a country.

The MSC is connected to other network elements via the following interfaces (Examples):

A-Interface: to the GSM Base Station Controller BSC

B-Interface: to the VLR. The MSC is always associated with a Visitor Location Register. Therefore, the B-Interface is proprietary.

C-Interface: to the HLR

E-Interface: to other MSCs

F-Interface: to the EIR

Gs-Interface: to the SGSN (for common Mobility Management)

Iu(CS)-Interface: to the RNC

Gateway MSC (GMSC): If a network delivering a call to the PLMN cannot interrogate the HLR, the call is routed to an MSC. This MSC will interrogate the appropriate HLR and then route the call to the MSC where the mobile station is located. The MSC which performs the routing function to the actual location of the MS / UE is called the Gateway MSC. The choice of which MSCs can act as Gateway MSCs is for the operator to decide (i.e. all MSCs or some designated MSCs).

Visited MSC (VMSC): For all the MSs / UEs in the MSCs area the serving MSC is regarded as Visited MSC.



11

ISDNMSC

VLR VLR

HLR

3G MSCMobile services

Switching Center

SGSN

IWF/

TC

TRAU

B

S

C

R

N

C

Iu(CS)

A

E

E

GsC

B

EIR

F MainMSCtasks:

Switching Handling CS Services Call Setup / Release Charging Interfaces:

A, B, C, E, F,Gs, Iu(CS)

SMS-GMSCSMS-IWMSC

SM-SC

PSTN

GMSC: PSTN/ISDN Interface Interrogating HLR routing to actual

UE location

GMSC: PSTN/ISDN Interface Interrogating HLR routing to actual

UE location

GMSC

B

MSC: always associated with VLR control of geographical area:

MSC Area = 1 / severalLocation Area LA

V(isited)-MSC for all UEsin MSC Area

MSC: always associated with VLR control of geographical area:

MSC Area = 1 / severalLocation Area LA

V(isited)-MSC for all UEsin MSC Area

LA1 LA2

LA3 LA4

MSC Area

Fig. 5


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Short Message Service SMS Gateway MSC (SMS-GMSC)

The SMS-GMSC acts as an interface between an external Short Message Service Center SMS-SC and the PLMN, to allow short messages to be delivered to MS / UE from the Service Center.

The choice of which MSCs can act as SMS Gateway MSCs is a network operator matter (e.g. all MSCs or some designated MSCs).

SMS Interworking MSC (SMS-IWMSC)

The SMS Interworking MSC acts as an interface between the PLMN and a SMS-SC to allow short messages to be submitted from MS / UE to the SMS-SC.

The choice of which MSCs can act as SMS Interworking MSCs is a network operator matter (e.g. all MSCs or some designated MSCs).

SMS-GMSC and SMS-IWMSC description can be found in TS 23.002.



13

SMS-GMSC

SMS-IWMSC

MSC /

VLR

SGSN

CS

Domain

PS

Domain

E

Gd

SM-SCShort MessageService Center

SMS-GMSCSMS Gateway MSC

SMS-IWMSCSMS Interworking MSC

all or some designatedMSCs can act as

SMS-GMSC/IWMSC(Network operator

dependent)

TS 23.002

External

Networks

Fig. 6


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Visitor Location Register VLR

The Visitor Location Register VLR is responsible to aid the MSC with information on the subscriber, which are temporarily in the MSC service area. Therefore, in praxis it is always associated with an MSC.

The VLR request the subscriber profiles of subscriber with activated MS / UE in the MSC service area from the Home Location Register HLR and stores them temporarily. Temporarily means as long as the subscriber is not registered in a new MSC/VLR, even if he deactivated the MS / UE.

Additional to the semi-permanent subscriber data received from the HLR the VLR stores temporary data, e.g. information on the subscribers current location (the Location Area), the state of activation (Attached / Detached),...

Furthermore, the VLR is responsible for the initiation of security functions, e.g. the Authentication procedure, the start of ciphering and the TMSI re-allocation.

Examples of subscriber data in the VLR:

MSISDN: Mobile Subscriber ISDN No.

IMSI: International Mobile Subscriber Identity

TMSI: Temporary Mobile Subscriber Identity

LMSI: Local Mobile Subscriber Identity

MSRN: Mobile Station Roaming Number

LAI: Location Area Identity

Authentication Parameter

the identity of the SGSN where the MS has been registered

The organization of the subscriber data is outlined in TS 23.008.



15

* e.g. Authentication, Authorization,

Cipher & Integrity Start

MainVLRtasks:

storing Subscriber profiles Mobility Management storing Location Information controlling

Security Features*

for all UEs in MSC AreaVLR as MSCs Data Base:

Subscriber Profile,e.g. IMSI, MSISDN,

Services (TS, BS, SS),..

Temporary Subscriber Datae.g. LMSI, TMSI, MSRN,

Security Parameter, Location Information, IMSI attach/detach,..

VLRVisitor Location

Register

VLRMSC

B

HLR

D Location Updates Subscriber Profiles VLR Security Parameter

(via HLR VLR)

Interrogation (MSRN via HLR to GMSC)

Location Updates Subscriber Profiles VLR Security Parameter

(via HLR VLR)

Interrogation (MSRN via HLR to GMSC)

AuC

TS: Tele ServicesBS: Bearer ServicesSS: Supplementary ServicesMSRN: Mobile Station Roaming Number

IMSI: International Mobile Subscriber IdentityLMSI: Local Mobile Subscriber IdentityTMSI: Temporary Mobile Subscriber Identity

Fig. 7


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Transcoding TC function

The Transcoding TC function is used to perform conversion between standard ISDN 64 kbit/s speech transmission and the UMTS Adaptive Multi-Rate AMR speech codec (Specs: 26-series).

The AMR speech coder is a single integrated speech codec with eight source rates from 4.75 kbit/s to 12.2 kbit/s, and a low rate background noise encoding mode. The speech coder is capable of switching its bit-rate every 20 ms speech frame upon command (TS 26.071).

Different to GSM, in UMTS the Transcoding function is not part of the Radio Access Network RAN. It has been defined as part of the UMTS Core Network CN.

Some optimization procedures allow it to be passed through, without transcoding, in the case of UE to UE communication for example, when double-transcoding would be performed for nothing.

Interworking Function IWF

The "classical" Core Network CN interfaces (e.g. A G) are all Time Division Multiplexed TDM based (E1/T1). Different to this, The Iu interface between UTRAN and the UMTS CN is ATM-based. An Interworking Function IWF is necessary for conversion between TDM-based and ATM-based interfaces.

Remark: IWF and TC function can be stand-alone network elements or be integrated into the UMTS MSC, depending on the manufacturers / network operators decision / demands.



17

TCTranscoding

&

IWFInterWorking Function

VLR

IWF/

TC

TRAU

B

S

C

R

N

C

MSC

Iu(CS)

A

B

TCTranscoding

BlaBla

Bla

BlaBlaBla

RANRadio Access

Network

CNCore Network

CN function in UMTS:part of MSC or standalone N.E.

Conversion of Speech Data (CN RAN):using AMR speech codec

CN: 64 kbit/s (ISDN) RAN: 4.75 12.2 kbit/s (AMR)

AMR: Adaptive MultiRate

FGs

E

C

Interworking: TDM ATM all classical CN-Interfaces (A-G):

TDM based (E1/T1 PCM30/PCM24)

Iu(CS): ATM based

IWF

4.75 12.2 kbit/s 64 kbit/s (ISDN)

UTRAN

CN

Fig. 8


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19

3 Release `99 CN: Entities common to CS &

PS Domain

PSTN

X.25

ISDN

IP

IWF/

TC

GMSC

GGSN

MSC /VLR

SGSN

HLR AuCEIRCSEUTRAN

TRAU

B

S

C

BTS

R

N

C

BTS

Node B(n x BTS)

R

N

C

Node B(n x BTS)

Node B(n x BTS)

UE

SMS-GMSCSMS-IWMSC

SM-SC

CGFBilling

System

CS Domain

PSDomain

GSM BSS

Release `99 CN:

Entities common

to CS & PS Domain

UMTS

Network

Fig. 9


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Home Location Register HLR

The HLR is a database in charge of the management of mobile subscribers There may be one or more HLRs in a GSM PLMN.

The HLR is always associated with an Authentication Center AC (proprietary interface). It participates in different procedures, for e.g.:

It sends all necessary data to the VLR.

It supports the call setup in case of Mobile Terminating Calls MTC by sending routing information to the Gateway MSC (Interrogation).

It transmits the security parameters from AuC to VLR on request

An HLR contains different semi-permanent mobile subscriber data, e.g.:

IMSI: International Mobile Subscriber Identity

MSISDN: Mobile Station International ISDN number

Packet Data Protocol (PDP) address(es), e.g. IP address

Services: Bearer Services BS, Tele Services TS, Supplementary Services SS

a list of all the group IDs a service subscriber is entitled to use to establish voice group or broadcast calls

CAMEL Subscription Information(s)

Service Restrictions (e.g. roaming limitations)

Additionally, the HLR contains different temporary information of the mobile subscriber, e.g.:

VLR and SGSN addresses

Mobile Station Roaming Number MSRN

SMS flags

The organization of the subscriber data is outlined in GSM 23.008.

Authentication Center AuC

The AuC is responsible to store the secret Keys of the subscribers and the security algorithm, which are necessary for the generation of the GSM and UMTS security parameters. On request of the VLR respectively the SGSN the AuC generates the security parameters. They are delivered via HLR to VLR / SGSN to enable Authentication, Ciphering and Integrity Check.

The AuC is always associated with an HLR (communication via a proprietary interface).



21

HLRHome Location Register

GMSC

GGSN

MSC /VLR

SGSN

HLR AuC

CS Domain

PS Domain

AuCAuthentication Center

C

Gr Gc

Subscriber data (Examples): Semi-permanent Data: MSISDN, IMSI, Services

(BS, TS, SS), QoS Profile, CSI, Service Restrictions,..

Temporary Data: VLR / SGSN address,

MS Non-Reachable flag, MSRN, SMS flags,..

Subscriber Registration Storing/Management

subscriber profiles Deliver profiles to VLR/SGSN Storing Location Information (VLR / SGSN) MTC: Deliver Routing

information to GMSC / GGSN Associated with AuC

Storing secret Keys(counterpart: USIM) &Security Algorithm

Generating Security Parameter(GSM: Triples; UMTS: Quintets)

Deliver Parameter to VLR / SGSN (via HLR)

Associated with HLR

BS: Bearer ServiceTS: Tele ServiceSS: Supplementary ServiceCSI: CAMEL Subscription InformationQoS: Quality of ServiceIMSI: International Mobile Subscriber IdentityMSISDN: Mobile Station ISDN NumberMSRN: Mobile Station Roaming Number

D

Fig. 10


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Equipment Identity Register EIR

The EIR is an optional feature in GSM and UMTS. It has been defined to enable theft prophylaxis. Stolen or non-valid Mobile Equipment ME can be blocked from further usage.

The Equipment Identity Register EIR is the logical entity, which is responsible for storing in the network the International Mobile Equipment Identities IMEIs (TS 23.002). An IMEI clearly identifies a unique Mobile Equipment ME and contains information about the place of manufacture, device type and the serial number of the equipment.

The Mobile Equipment ME is classified as "white listed", "grey listed", "black listed" or it may be unknown as specified in TS 22.016 and TS 29.002.

The EIR performs IMEI Checks on VLR respectively SGSN request to check whether the ME is stolen or non-valid.

The EIR is connected to:

the SGSN via Gf interface

the VLR via F interface



23

Storing IMEIs(counterpart: ME)

on White / Gray / Black List

Performing IMEI Checkon VLR / SGSN request

optional network function

EIREquipment Identity Register

MSC /VLR

SGSN

EIR

CS Domain

PS Domain

F

Gf

IMEIInternational

Mobile stationEquipment

Identity

Fig. 11


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CAMEL Service Environment CSE

For the introduction of CAMEL services, some network elements have to be enhanced and new functional entities have to be introduced (TS 23.078):

GSM Service Control Function gsmSCF: functional entity that contains the CAMEL service logic to implement Operator-Specific Services OSS. It interfaces e.g. with the gsmSSF, the gprsSSF and the HLR.

GSM Service Switching Function gsmSSF: functional entity that interfaces the MSC/GMSC to the gsmSCF. The concept of the gsmSSF is derived from the IN SSF, but uses different triggering mechanisms because of the nature of the mobile network

GPRS Service Switching Function gprsSSF: functional entity that interfaces the SGSN to the gsmSCF.

Home Location Register HLR: for subscribers requiring CAMEL support, the HLR stores different types of CAMEL Subscriber Information CSI (e.g. O-CSI for Mobile Originating Calls MOCs, T-CSI for Mobile Terminating Calls MTCs). The O-CSI is sent to the VLR at Location Update, on data restoration or if the O-CSI is updated by administrative action. The O/T-CSI is sent to the GMSC when the HLR responds to a request for routing information.

MSC/VLR or SGSN: VLR or SGSN store the different CSI information as part of the subscriber data for subscribers roaming in the MSC/VLR or SGSN area. MSC or SGSN monitor the call states and communicate (internally) with the gsmSSF for further proceeding.



25

GMSC

GGSN

MSC /VLR

SGSN

HLR AuCgsm

SCF

Gn

E

gsmSSF

gsmSSF

gprsSSF

GSM Service Switching Function interfaces MSC/VLR to gsmSCF derived from IN SSF

stores CAMEL Subscription Information CSI

GPRS Service Switching Function interfaces SGSN to gsmSCF

GSM Service Control Function:

contains CAMELservice logic for

Operator-SpecificServices

MSC/VLR & SGSN:store CSI as part ofsubscriber profile

MSC/VLR & SGSN:

store CSI as part ofsubscriber profile

CSECAMEL Service

Environment

CS

Domain

PSDomain

Fig. 12


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CAMEL Protocols & Interfaces

The Mobile Application Part MAP and the CAMEL Application Part CAP (TS 29.078) are used on the different interfaces (TS 23.078) applicable to CAMEL:

HLR - VLR interface (D-Interface): On this interface the MAP is used to send the CAMEL related subscriber data to the VPLMN and for provision of Mobile Station Roaming Numbers MSRN. The interface is also used to retrieve subscriber status and location information of the mobile subscriber or to indicate suppression of announcement for a CAMEL service.

GMSC - HLR interface (C-Interface): This interface is used at terminating calls to exchange routing information, subscriber status, location information, subscription information and suppression of announcements. The O/T-CSI that is passed to the IPLMN is sent over this interface using the MAP.

SGSN / MSC or GMSC gprsSSF / gsmSSF interface: These are internal interfaces. These interfaces are described in the specification to make it easier to understand the handling of Detection Points DPs.

gprsSSF / gsmSSF - gsmSCF interface (CAP Interfaces): On these interfaces the CAP is used by the gsmSCF to control a call in a certain gprsSSF / gsmSSF.

gsmSCF - HLR interface (CAP Interface): On this interface the MAP is used by the gsmSCF to request information from the HLR. As a network operator option the HLR may refuse to provide the information requested by the gsmSCF.

GMSC - MSC interface (E-Interface): On this interface the MAP is used to transfer control of a call from a VMSC back to a GMSC for optimal routing.



27

MAP

HPLMN

VPLMN

CAMELProtocols &

Interfaces

MSC/VLR

HLR

UE

gsmSSF

MSC/VLR

gsmSSF

CSE

gsmSCF


gsmSSF: GSM Service Switching Function

gsmSCF: GSM Service Control Function

CAP: CAMEL Application Part

MAP: Mobile Application Part

O-CSI: CAMEL Subscription Information (MOC)

T-CSI: CAMEL Subscription Information (MTC)

Signalling

Data transfer

SGSN

gprsSSF

MAPCAP

Interfaces

O-CSIT-CSI

TS 23.078,29.078

Fig. 13


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29

4 Release `99: PS Domain

PSTN

X.25

ISDN

IP

IWF/

TC

GMSC

GGSN

MSC /VLR

SGSN

HLR AuCEIRCSEUTRAN

TRAU

B

S

C

BTS

R

N

C

BTS

Node B(n x BTS)

R

N

C

Node B(n x BTS)

Node B(n x BTS)

UE

SMS-GMSCSMS-IWMSC

SM-SC

CGFBilling

System

CS Domain

PSDomain

GSM BSS

Release `99 CN:

PS Domain

UMTS

Network

Fig. 14


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PS Domain - Main Concept

The PS domain uses a packet-mode technique to transfer high-speed and low-speed data and signaling in an efficient manner. The PS domain optimizes the use of network and radio resources. Strict separation between the radio subsystem and network subsystem is maintained, allowing the network subsystem to be reused with other radio access technologies. (TS 23.060)

Gateway GPRS Support Node GGSN

The GGSN is the first point of Packet Data Network PDN interconnection with a GSM / UMTS PLMN (i.e. it supports the Gi interface). GGSN functionality is common for GSM and UMTS.

The Gateway GPRS Support Node GGSN provides interworking with external Packet-switched Data Networks PDNs and it is connected with SGSNs via an IP-based backbone network (Gn interface). When the SGSN and the GGSN are in different PLMNs, they are interconnected via the Gp interface. The Gp interface uses the same protocols as the Gn interface. Additional security features are necessary.

The GGSN is the node that is accessed by the PDN due to evaluation of the Packet Data Protocol PDP address. It contains routing information for PS-attached users. The routing information is used to tunnel packet data to the MS / UE's current point of attachment, i.e., the Serving GPRS Support Node SGSN. The GGSN may request location information from the HLR via the optional Gc interface.

Furthermore, the GGSN is responsible for message screening and it is collecting charging data. The GGSN forwards the charging data via Charging Gateway Functionality CGF (Ga interface) to the Billing Center.

The SGSN and GGSN functionalities may be combined in the same physical node, or they may reside in different physical nodes.



31

GGSNGateway GPRS

Support Node

X.25

IPGGSNSGSN

HLR AuC

CGFBilling

System

PSDomain

SGSN

GnIP-based

Backbone

Network

SGSNotherPLMN

Gc

GaGp

Gi

Interworking PLMN PDN (Gi) Screening / Filtering Storing Routing Information (current SGSN) Requesting Location Information from HLR

(Gc optional; for MTC) Routing Packets SGSN (Gn) Collecting Charging Data & forwarding

to CGF (Ga)

TS 23.060

ExternalNetworks

Fig. 15


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Serving GPRS Support Node SGSN

The Serving GPRS Support Node SGSN is responsible to provide service for all activated MS / UE in a certain geographical area, the so-called SGSN service area. The SGSN service area is subdivided into different Routing Area RA (a sub-set of the Location Area LA). A Routing Area consists of one or several cells.

The SGSN keeps track of the location of an individual MS / UE and stores it location (the Routing Area). It is responsible for the MS / UE Mobility Management (Location Updates, Attach, Paging,..). Furthermore, the SGSN performs security functions and access control.

The SGSN pulls the subscriber profiles via Gr interface from the HLR and stores it as long as the subscriber has not been registered in another SGSN.

It is signaling with MS / UE and GGSN to set up PDP Contexts to transmit packet data from MS / UE via RNC, SGSN and GGSN to external PDNs.

It is transmitting SMS via SMS IWF-/G-MSC (Gd interface) to the SM-SC.

It is controlling the QoS to be guaranteed for the subscribers service.

The SGSN also interfaces via the GPRS Service Switching Function gprsSSF with the GSM Service Control Function gsmSCF for optional CAMEL session and cost control service support.

The SGSN is connected to the GSM Base Station Subsystem BSS through the Gb interface and/or to the UMTS Terrestrial Radio Access Network UTRAN through the Iu interface.

It is interfaced with the MSC/VLR via Gs interface (optional) for Common Mobility Management. E.g. the SGSN may receive paging requests from the MSC/VLR via the Gs interface.

To provide Roaming it is connected via Gn / Gp (into other PLMNs) interface to other SGSNs. The Gp interface provides the functionality of the Gn interface, plus security functionality required for inter-PLMN communication. The security functionality is based on mutual agreements between operators.

The SGSN is collecting charging data and transmitting them via Ga interface to the Charging Gateway Function CGF.

The SGSN and GGSN functionalities may be combined in the same physical node, or they may reside in different physical nodes.



33

RA

1

RA

2

RA

3

RA

4

SGSN area

RA

5

RA

6

RA

7

GGSNSGSN

CGF

PSDomain

SGSN

GnIP-based

BackboneNetwork

SGSNother

PLMN

GaGp

EIRCSE

MSC /VLR

RNC

BSC

Iu(PS)

Gb

Serving all UEs in SGSN area =1 / several Routing Area(s) RA

Storing subscriber profiles(requested from HLR)

Mobility Management, e.gUpdate Location, Attach, Paging,..

Security & Access Control:Authentication, Cipher start, IMEI Check...

Routing / Traffic-Management Collecting charging data

UTRAN

GSM BSS

Gs

Gs Gr GdCAP

AuCHLRSMS-GMSCSMS-IWMSC

TS 23.060

SGSNServing GPRS

Support NodeLA

Fig. 16


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Charging Gateway Functionality CGF

Charging in GSM / UMTS should be flexible and allow to bill according to the amount of data transferred, the QoS supported, and the duration of the connection. The GGSNs and SGSNs are collecting the charging data.

The Charging Gateway Functionality CGF provides a mechanism to transfer charging information from the SGSN and GGSN nodes to the network operator's chosen Billing Systems BS.

The Charging Gateway concept enables an operator to have just one logical interface between the CGF and the BS. The CGF may be supported in one of the following ways:

-as a centralized separate Network Element, i.e. the Charging Gateway CG

-as a distributed functionality resident in the SGSNs and GGSNs.

Support of the centralized or distributed CGF in a network is implementation dependent, and subject to vendor/manufacturer agreement. Regardless of the way in which the CGF is supported in the network, the functionality of the CGF is similar.

The main functions of the CGF are:

-the collection of GPRS Charging Data Records CDRs from the GPRS nodes generating CDRs;

-intermediate CDR storage buffering;

-the transfer of the CDR data to the Billing Systems BS

The CGF acts as storage buffer for real-time CDR collection. It provides the CDR data to the BS.

Details of the Charging Gateway Functionality, the principles and transmission of CDRs and the protocol architecture of the Ga interface are given in TS 32.015.



35

GGSNSGSN

CGF

BillingSystem BS

PSDomain

CGFCharging Gateway

Functionality

TS 23.060& 32.015

ExternalNetworks

GaGa

Gn

GSNs

ChargingGateway

CG

GSN CGF BS

BS

collect CDRs from SGSNs & GGSNs

intermediate CDR storage buffering CDR data transfer to the BS

The CGF can:

reside in a separate N.E.:Charging Gateway CG

be integrated in the GSNs

CDR: Charging Data Record

N.E.: Network Element

TS32.015:

Charging & Billing

for the PS Domain

TS32.015:

Charging & Billing

for the PS Domain

Fig. 17


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37

5 Release `99: UTRAN & UE

PSTN

X.25

ISDN

IP

IWF/

TC

GMSC

GGSN

MSC /VLR

SGSN

HLR AuCEIRCSEUTRAN

TRAU

B

S

C

BTS

R

N

C

BTS

Node B(n x BTS)

R

N

C

Node B(n x BTS)

Node B(n x BTS)

UE

SMS-GMSCSMS-IWMSC

SM-SC

CGFBilling

System

CS Domain

PSDomain

GSM BSS

Release `99:

UTRAN & UE

UMTS

Network

Fig. 18


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Radio Network Controller RNC

The UMTS Terrestrial Radio Access Network UTRAN is sub-divided into Radio Network Subsystems RNS. The Radio Network Controller RNC is the central controlling unit of a RNS. It is controlling itself and all the Node Bs of the RNS.

The RNC is connected via the following ATM based interfaces:

Iub interface: to the connected Node Bs

Iur interface: to neighboring RNCs

Iu interface: to the Core Network CN

Due to different protocol stacks, the Iu interface can be sub-divided into an Iu(ps) interface and an Iu(cs) interface.

The Iu(ps) interface is used for data and signaling transmission to the PS Domain of the CN, the Iu(cs) interface is used for data exchange with the CS Domain.

The main task of the RNC is to perform Radio Resource Management RRM for all UEs in its service area. Therefore, it can be compared to the GSM BSC. Different to the GSM BSC, it is 100% autonomously responsible for all RRM decisions.

RRM means to be that the RNC is responsible for signaling with the UEs via Radio Resource Control RRC protocol, it is deciding about the allocation of resources, Handover to other cells and release of resources,...

The RNC is holding the RRC connection to the UEs as long as data have to be transmitted.

It is storing the UEs location information to transmit the data to the right location. The location information can be requested by the CN for Location Based Services.

It is responsible for reliable transmission over the radio interface, performing Backward Error Correction in acknowledged mode.

It is responsible for Ciphering / De-Ciphering and Integrity Check.

And it is responsible for many more WCDMA specific aspects shown in the following chapters and TS 25.3xx and 25.4xx series.



39

RNCRadio Network

Controller

RNCRadio Network

Controller

Node

B

RNSRadio

NetworkSub

system

UTRANIu(CS)

Iub

IurRNC

Node

B

Node

B

Iub

Node

B

SGSN

UE

IWF/ TC

MSC /VLR

Iu(PS)

Uu

PSDomain

CSDomain

100% autonomously RRM(e.g. Radio Resource Control, Access Control,

Admission Control, Handover Control,)

(De-)Ciphering & BEC (Layer 2 tasks)

storing UEs location information

RNS-Control (RNC & Node Bs)

ATM Switching(Iu, Iur & Iub: ATM Interfaces)

WCDMA specific tasks

Fig. 19


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Node B

One or more Node B's are controlled and addressed by an RNC. A Node B is a physical unit for implementation of the UMTS radio interface. It is converting the physical transmission of the data from fixed network transmission (ATM based) to WCDMA transmission.

As a central transmission and reception site, it serves one or more UMTS cells. It is serving one UMTS cell in case of an omni cell with 360 service or, for example, 2, 3 or 6 sector cells with 180, 120 and 60 service respectively.

The Node B is connected:

via Iub interface to its controlling RNC

via Uu interface to the UEs

To prepare the data for reliable transmission over the air interface Uu, the Node B performs many WCDMA specific aspects, which are shown in the following chapters and in the TS 25.3xx and 25.4xx series.



41

RNCRadio Network

Controller

Node

B

RNSRadio

NetworkSub

system

UTRAN

Iub

RNC

Node

B

Node

B

Node

B

UEUu

Support of 1or several cells

WCDMA Transmission

ATM Termination

Forward Error Correction FEC

Radio Interface Measurements(Quality & Strength)

Node B

Node

BOmni-Cell

Sector-Cell

Node

BSector-CellSector-Cell

Fig. 20


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User Equipment UE

The User Equipment UE is responsible for similar functions as the GSM Mobiles Station MS, i.e. it is a device allowing a user access to network services.

It consists of the:

Mobile Equipment ME, which means to be the Hardware and Software for WCDMA air interface transmission. The ME is identified by an International Mobile Equipment Identity IMEI.

UMTS Subscriber Identity Module USIM, which contains data and procedures, which unambiguously and securely identify itself. These functions are typically embedded in a stand-alone smart card. This device is associated to a given user (subscriber license), and as such allows to identify this user regardless of the ME he uses. The USIM stores the personal identities (e.g. IMSI, MSISDN, PIN), security algorithm (for e.g. Ciphering, Authentication), the personal phone book, the USIM Application Toolkit USAT (TS 22.038, 31.111) and many more information.

The basic functions of the UE are given in the TS TS 23.101. More detailed descriptions are given in the TS 31 series.



43

UEUser Equipment

Node

B

Uu

RNC

MEMobile Equipment

USIMUMTS Subscriber Identity Module

HW & SW for WCDMARadio Transmission

Man-Maschine-Interface MMI

Subscriber license

Personal Identities(e.g.MSISDN, IMSI, TMSI, PIN,...)

Security Algorithm & Keys(for Authentication, Ciphering,..)

Personal phone book

USIM Application Toolkit USAT

UE = ME + USIM

MSC/VLR

SGSN

TS 31.1xxseries

TS 23.101 &31series

Fig. 21


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UMTS Network Summary (Release `99)

The UMTS PLMN consists of an UMTS Terrestrial Radio Access Network UTRAN, The User Equipments UE and an enhanced GSM Phase 2+ Core Network CN.

The Core Network consists of a Circuit Switched CS Domain for speech, video telephony and real-time data transfer, a Packet Switched PS Domain for Non real-time data transfer and Entities common to the CS & PS Domain.

The CS Domain of the UMTS CN consists of the following functions:

MSC: Mobile Services switching Center

GMSC: Gateway MSC

SMS-IW-/G-MSC: Short Message Services Interworking-/Gateway-MSC

VLR: Visitor Location Register

TC/IWF: Transcoding & Interworking function

The PS Domain of the UMTS CN consists of the following functions:

GGSN: Gateway GPRS Support Node

SGSN: Serving GPRS Support Node


Entities common to the CS & PS Domain:

HLR: Home Location Register

AuC: Authentication Center

EIR: Equipment Identity Register


The UTRAN consists of the following functions:

RNC: Radio Network Controller

Node B

The UE consists of the following functions

ME: Mobile Equipment

USIM: UMTS Subscriber Identity Module

Remark: This list of UMTS functions is not complete. Only the "most important" functions are shown. A detailed overview is given in TS 23.002.



45

PSTN

X.25

ISDN

IP

IWF/

TC

GMSC

GGSN

MSC /

VLR

SGSN

HLR AuCEIRCSEUTRAN

T

R

A

U

B

S

C

BTS

R

N

C

BTS

Node B(n x BTS)

R

N

C

Node B(n x BTS)

Node B(n x BTS)

UE

SMS-GMSC

SMS-IWMSCSM-SC

CGFBilling

System

CS Domain

PS

Domain

GSM BSS

UMTS Network

Summary(Rel. `99)

Iu(CS)

Iu(PS)Iub

Iur Ga

Gd

Gn

GcGr

GfCAP

CAP

E

FC/D

Gi

Uu

A

Abis

Gb

Um

Fig. 22


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47

6 Further Evolution: Release 4 & 5

UMTS CN

GERAN UTRAN

PSTN /

ISDNIntra- /

Internet

Co-existence of

GSM & UMTS

network elements

Further Evolution

Release 4 & 5

UMTS

Network

GERAN: GSM/EDGE Radio Access Network

Fig. 23


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3G modularity and further options

In 3G networks, the functions of the Core Network CN and the Radio Access Network RAN will be strictly separated. This separation will allow modularity in the composition of networks. The objective is to be able to combine any 3G CN with any 3G RAN. In addition, technical enhancements and upgrades of individual modules will be able to be introduced more easily, quicker and at less expensively due to the separation of functions.

Core Network CN options

In the initial phase of 3G, the different RANs are based on two different CN platforms: These are the GSM CN platform and the IS-41 platform. The different protocol architecture has been harmonized to enable the demanded modularity.

The IS-41 CN has been used recently as platform for AMPS, D-AMPS and IS-95.

The GSM CN has been used for the GSM BSS only.

Pure IP CN solutions have been developed by the 3G.IP Forum / IETF. These ideas are incorporated now in UMTS Release 4 and 5 as additional CN options for enhanced 3G networks.

Radio Access Network RAN options

Different options for 3G RAN's have been developed and will be developed in 3G respectively for enhanced 3.5G networks.

EDGE Classic / Compact is the 3G enhancements for GSM and D-AMPS

UMTS includes the UTRA FDD and TDD mode, respectively from Release 4 on, two TDD modes (one with a High Chip Rate HCR and one with a Low Chip Rate LCR).

MC-CMDA is used as IS-95 successor

Different 3G proposals for MSS's

3.5G enhancements of 3G systems toward higher data rates might be Wireless Local Loop WLL or Mobile Broadband Systems MBS



49

3G modularity

& future options

3G

Core

Network

e.g.

enhanced

GSM / IS-41,

or

R`4, R`5

UMTS CN

EDGE

MC- CDMA

Hiperlan-2,MBS,..strict separation

CN - RAN tasks

flexibility in 3G

3G RAN

UTRA TDD HCR

UTRA TDD LCR

UTRA FDD

3G-MSS

Iu

Fig. 24


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UMTS Release 4 CN

The UMTS CN CS domain is a central aspect of Release 4 modifications (TS 23.002). The intention of these modifications is a separation of the call control from the transport user the user data.

In UMTS Release 4, the (G)MSC/VLR functions split into two different entities:

MSC Server: The MSC Server is responsible for e.g. Call Control CC and Mobility Management MM. It stores temporarily the subscribers data and takes over the "VLR functionality". It is interfacing and translating the user-network signaling (TS 24.008) and the network-network signaling and it is controlling one/several MGW(s) via Mc interface. Furthermore, it is collecting charging data (Call Data Records CDRs). As Gateway MSC Server, it is responsible for HLR interrogation.

Media Gateway MGW: The MGW is responsible for bearer control and transmission resource management (e.g. QoS guarantee). It is responsible for the conversion of the data formats from CN internal, i.e. Nb interface (IP, ATM,) to either Iu interface (ATM based) or external CS ISDN/PSTN networks. Additionally, the TC function is allocated to the MGWs interfacing Iu.

New Interfaces

Nc: between MSC Server and (G)MSC Server for Bearer-Independent Call Control BICC.

Mc: between CS-MGW and (G)MSC Server to separate between call control and bearer control. The ITU standard H.248 respectively its IETF standard equivalent Media Gateway Control MEGACO is used on Mc.

Nb: between MGWs. Different options are possible on Nb for user data transfer and bearer control signaling (e.g. ATM, IP).



51

PSTN/ISDN

Bearer Level

Call Control

Level

MSCServer

HLR

GMSCServer

CS-MGW

CS-MGW

GERAN

UTRAN

Applications and Services

Mc (H.248/MEGACO)Mc

CAPCAP

Nb (e.g. ATM, IP)

Nc (e.g. BICC)

AIu

CD

Iu

A

UMTS CN R`4

CS Domain

MEGACO: IETF Media Gateway Control protocolH.248: ITU protocol for Media Gateway Control

PS Domain

unchanged

compared to R`99

PS Domain

unchanged

compared to R`99

R`4

TS 23.002

(G-)MSC Server: Call Control Mobility Management

MGW Control

VLR functionality

CDRs

(HLR-Interrogation)

MGW: Bearer Control Transmission Resource Management

Data Format Conversion

TranscodingCDR: Call Data RecordsBICC: Bearer Independent Call ControlMGW: Media Gateway

Fig. 25


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UMTS Release 5 CN

In Release 5, it should be possible to transmit all data only via one PS domain (the so-called "All IP CN"). This PS domain can be split up logically into the GPRS CN with its well known network elements and an IP Multimedia Subsystem IMS, which is added to the GPRS CN like an external PDN (i.e. via Gi interface). Currently (late 2001) not all Release 5 network elements and functions are defined precisely.

For downward-compatibility reasons to GSM and UMTS Rel. `99 and Rel. `4 it might be necessary, to support additionally a CS domain.

Here some central Release 5 aspects / functions:

Home Subscriber Server HSS: The HSS is used for mobility related aspects, very similar to the "classical" HLR (storing subscription and routing information).

Media Gateway MGW: The MGW ensures interoperability and interworking between an All IP CN and the external fixed CS networks PSTN or ISDN. The MGW enables conversion from CS data transmission, e.g. voice transmission, to PS data transmission, e.g. Voice over IP VoIP. Echo cancellation and Transcoding functionality will take place in the MGW. The MGWs are connected via Gi interface towards the GGSNs.

Media Gateway Control Function MGCF: The MGCF are used e.g. for MGW control, Call Control and Signaling Protocol Conversion from external SS7 to internal Session Initiation Protocol SIP.

Call State Control Function CSCF: The CSCF are responsible e.g. for Session Flow Handling and Application Coordination. They are interfacing the IN / Application Server/ IN and they are responsible to collect charging data (Charging Data Records CDRs).

This description of Release 5 is regarded as a very first overview, giving an idea on the future UMTS options. It is not complete and needs to be extended in additional courses.



53

PSTN

UMTS CN R`5

IMS & PS Domain

HSS: Home Subscriber Server

MGW: Media Gateway

MGCF: Media Gateway Control Function

SIP: Session Initiation Protocol

Gi

UTRAN

R

N

C

NodeB

R

N

C

Iur

Iub

Iub

UE(USIM)

Uu

NodeB

NodeB

ISDN

SGSN GGSN

MGW

MGCF

X.25

IPR

R

R

R

R

R

CSCF

Iu

Intelligent & Application Servers

IMS: IP Multimedia Subsystem

CSCF: Call State Control Function

R: IP Router/Switch

CSE WAP

IP

Backbone

HSS

other

PLMN

R`5

TS 23.002

CSCF: Session Flow Handling

Application Coordination

interfaces IN/Application

Servers

CDR`s

HSS: similar HLR

MGCF: MGW control Call Control

Signalling Protocol

Conversion (SS7 to SIP)

Fig. 26


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55

7 Exercise


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57

Exercise

Title: UMTS Network

Objectives: The participant will learn the most important UMTS network elements and interfaces.

Pre-requisite: none

Task

Please answer the following questions!

Query

1. Which of the following elements are not part of the UMTS network:

HLR/AC

TRAU

MSC

EIR

BSC

OMC

SMS-SC

GGSN

2. What are the main tasks of a 3G MSC:

Switching of CS traffic

Call Setup & Release

Storing the User Equipments location

Charging

Generating Security Parameter

Serving all User Equipments of one Location Area


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3. Speech compression/decompression in UMTS:

is performed in the User Equipment and Radio Access Network

is performed in the User Equipment and Core Network

uses Full Rate, Half Rate and Enhanced Full Rate Speech codec

uses Adaptive Multirate AMR speech codec

is used in every speech connection

is only used in case of overload at the air interface

4. Which of the following information is wrong?

the VLR and SGSN are storing location information

the HLR and AuC are always associated

the security parameter generated by the AuC are the same as in GSM

there is always one HLR in a PLMN to store all subscribers profiles

the EIR can be used to check the identity of the subscriber

5. To implement CAMEL services the following network functions are used:

the GSM Service Control Function

the GPRS Service Control Function

the CAMEL Central Memory Function

the GSM Service Switching Function

the GPRS Service Switching Functions

the CAMEL Subscription Information data Unit



59

6. CAMEL

is helpful for the Virtual Home Environment VHE concept

will be used also for PS services in UMTS

uses the protocol CAP

is interacting with the UMTS Mobility Management to provide Location Based Services

information are stored in HLR, gsmSCF and EIR

7. Which of the following properties are GPRS (Packet Switched) advantages?

volume dependent charging

Video telephony support

support of extended length SMS

non-proprietary IN-services

direct access towards Packet Data Networks

resource efficient data transport

8. Central 3G SGSN tasks are:

Mobility Management for PS data user

Radio Resource Management for PS data user

Session Management

temporary storage of PS subscriber profiles

storing the users current location, i.e. his cell

controlling the connected RNC's, i.e. O&M support

initiating of Authentication and Authorization

collecting charging data


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9. The following network functions are necessary for PS data transmission:

SGSN

GGSN

HLR

EIR

gprsSSF

RNC

Node B

UE

10. The RNC is responsible for:

Session Management SM

Radio Resource Management RRM

RNS control

Handover Decision

Transcoding and Rate Adaptation

11. Which of the following network elements is not part of UTRAN?

RNC

Node B

TRAU

IWF



61

12. Please introduce the name of the interfaces into the following PLMN Summary:

PSTN

X.25

ISDN

IP

IWF/

TC

GMSC

GGSN

MSC /

VLR

SGSN

HLR AuCEIRCSEUTRAN

T

R

A

U

B

S

C

BTS

R

N

C

BTS

Node B(n x BTS)

R

N

C

Node B(n x BTS)

Node B(n x BTS)

UE

SMS-GMSC

SMS-IWMSCSM-SC

CGFBilling

System

CS Domain

PS

Domain

GSM BSS

UMTS Network

Summary(Rel. `99)

Iu(CS)

Iu(PS)Iub

Iur Ga

Gd

Gn

GcGr

GfCAP

CAP

E

FC/D

Gi

Uu

A

Abis

Gb

Um


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13. Which of the following interfaces is NOT defined as an open interface?

Uu interface

Iu interface

Iur interface

Abis interface

Asub interface

Iub interface

A interface

AuC-HLR interface

14. What is different between GSM Phase 2+ and UMTS CN?

Transcoding is part of the CN functions in UMTS

Real Time data transfer is possible in the UMTS PS domain

The UMTS CN does not participate in Radio Resource Management

The Mobility Management cycles differ in GSM and UMTS

The UMTS security mechanism is enhanced compared to GSM.

nothing has changed to prevent changes in the hardware / reduce costs for UMTS introduction


Release 4 CN are pure IP CN solutions

Release 4 defines bearer-independent call control

Release 4 CN allows to use IP or ATM for data transfer

Release 5 introduces the IP Multimedia Subsystem & Voice over IP

Release 5 introduces an "All IP Core Network" and All "IP Radio Access Network"

Release 5 enhances the data rates towards 4 Mbit/s defining a new modulation principle option



63

16. Which of the following network elements is new in Release 5:

Media Gateway MGW

Media Gateway Control Function MGCF

Call State Control Function CSCF

MSC Server

Home Subscriber Server HSS



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65

8 Solution


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67

Solution

Title: UMTS Network

Objectives: The participant will learn the most important UMTS network elements and interfaces

Pre-requisite: none

Task

In the following section, there are the answers to the exercises.

Query

1. Which of the following elements are not part of the UMTS network:

HLR/AC

TRAU

MSC

EIR

BSC

OMC

SMS-SC

GGSN

2. What are the main tasks of a 3G MSC:

Switching of CS traffic

Call Setup & Release

Storing the User Equipments location

Charging

Generating Security Parameter

Serving all User Equipments of one Location Area


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3. Speech compression/decompression in UMTS:

is performed in the User Equipment and Radio Access Network

is performed in the User Equipment and Core Network

uses Full Rate, Half Rate and Enhanced Full Rate Speech codec

uses Adaptive Multirate AMR speech codec

is used in every speech connection

is only used in case of overload at the air interface


the VLR and SGSN are storing location information

the HLR and AuC are always associated

the security parameter generated by the AuC are the same as in GSM

there is always one HLR in a PLMN to store all subscribers profiles

the EIR can be used to check the identity of the subscriber

5. To implement CAMEL services the following network functions are used:

the GSM Service Control Function

the GPRS Service Control Function

the CAMEL Central Memory Function

the GSM Service Switching Function

the GPRS Service Switching Functions

the CAMEL Subscription Information data Unit



69

6. CAMEL

is helpful for the Virtual Home Environment VHE concept

will be used also for PS services in UMTS

uses the protocol CAP

is interacting with the UMTS Mobility Management to provide Location Based Services

information are stored in HLR, gsmSCF and EIR

7. Which of the following properties are GPRS (Packet Switched) advantages?

volume dependent charging

Video telephony support

support of extended length SMS

non-proprietary IN-services

direct access towards Packet Data Networks

resource efficient data transport

8. Central 3G SGSN tasks are:

Mobility Management for PS data user

Radio Resource Management for PS data user

Session Management

temporary storage of PS subscriber profiles

storing the users current location, i.e. his cell

controlling the connected RNC's, i.e. O&M support

initiating of Authentication and Authorization

collecting charging data


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9. The following network functions are necessary for PS data transmission:

SGSN

GGSN

HLR

EIR

gprsSSF

RNC

Node B

UE

10. The RNC is responsible for:

Session Management SM

Radio Resource Management RRM

RNS control

Handover Decision

Transcoding and Rate Adaptation

11. Which of the following network elements is not part of UTRAN?

RNC

Node B

TRAU

IWF



71

12. Please introduce the name of the interfaces into the following PLMN Summary:

PSTN

X.25

ISDN

IP

IWF/

TC

GMSC

GGSN

MSC /VLR

SGSN

HLR AuCEIRCSEUTRAN

TRAU

B

S

C

BTS

R

N

C

BTS

Node B(n x BTS)

R

N

C

Node B(n x BTS)

Node B(n x BTS)

UE

SMS-GMSCSMS-IWMSC

SM-SC

CGFBilling

System

CS Domain

PSDomain

GSM BSS

UMTS Network

Summary(Rel. `99)

Iu(CS)

Iu(PS)Iub

Iur Ga

Gd

Gn

GcGr

GfCAP

CAP

E

FC/D

Gi

Uu

A

Abis

Gb

Um


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13. Which of the following interfaces is NOT defined as an open interface?

Uu interface

Iu interface

Iur interface

Abis interface

Asub interface

Iub interface

A interface

AuC-HLR interface

14. What is different between GSM Phase 2+ and UMTS CN?

Transcoding is part of the CN functions in UMTS

Real Time data transfer is possible in the UMTS PS domain

The UMTS CN does not participate in Radio Resource Management

The Mobility Management cycles differ in GSM and UMTS

The UMTS security mechanism is enhanced compared to GSM.

nothing has changed to prevent changes in the hardware / reduce costs for UMTS introduction


Release 4 CN are pure IP CN solutions

Release 4 defines bearer-independent call control

Release 4 CN allows to use IP or ATM for data transfer

Release 5 introduces the IP Multimedia Subsystem & Voice over IP

Release 5 introduces an "All IP Core Network" and All "IP Radio Access Network"

Release 5 enhances the data rates towards 4 Mbit/s defining a new modulation principle option



73

16. Which of the following network elements is new in Release 5:

Media Gateway MGW

Media Gateway Control Function MGCF

Call State Control Function CSCF

MSC Server

Home Subscriber Server HSS



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The UMTS NetworkRelease `99: Network OverviewRelease `99 CN: CS DomainRelease `99 CN: Entities common to CS & PS DomainRelease `99: PS DomainRelease `99: UTRAN & UEFurther Evolution: Release 4 & 5ExerciseSolution

umts network

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