04 UMTS Traffic Management Emad

7/30/2019 04 UMTS Traffic Management Emad

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1 2005 Nokia V1-Filename.ppt / yyyy-mm-dd/ Initials

UMTS Traffic ManagementUMTS Traffic Management


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For the trainer

This module is probably the one that overlaps the most with the (GSMSYSTRA), 2G SYSTRA, and GPRSSYS courses. The main new topics relate

to the URA and bearer concepts. The overlap is intentional, as it is

necessary to assure the participants after the Radio Path andTransmission module.

But, if you notice that the students are very familiar with the "old

stuff", then just conclude the main similarities and go on to the parts

with more "news value".

The module duration could be between 2 - 4 hours, if mainly focusing

on mobility and session management.


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Module topics

Subscriber information and databases

Network traffic and the radio connection Mobility management

Session management

Communication management


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Objectives

After this module the student will be able to:

List and identify the databases used within the UMTS network

Identify the subscriber addressing information

Name the characteristics of a bearer

Describe how the connection moves with the subscriber when a bearer is inuse

Explain what is meant by the term URA

List the procedures used to maintain mobility management in the network

List the procedures done when the mobile gains access to the network,also identify how the network selection is made

With the help of the material, describe how the session management ofreal-time and non-real-time bearers are handled through the networkwithout using any references.


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UMTS architecture

FiberFiber

AXC

ATM Access

Internet

RAN (UTRAN & GERAN) Core Network

Control Plane

Gateway Plane

PSTN2G

SGSN3G

SGSN GGSNRNC

BSC

Node B

Node B

Node B

HLR&AuC

3GMSC

SCEP

SMSC

BTS


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Management layers of a UMTS network

The network can be visualised from the point of view of theelements, or from how the user and control information is passed

through the architecture.

Mobility Management (MM)

Communication Management (CM)

Radio Resource Management (RRM)

UE RAN CN

CS (circuit switched): Call control (CC), supplementary services (SS) and short message service (SMS). PS (packet switched): Session management


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UMTS network databases

FiberFiber

AXC

ATM access

Internet

Mobility CoreRAN

Control Plane

Gateway Plane

PSTN2G

SGSN3G

SGSN GGSNRNC

BSC

TripleModeBTS

GSMBTS

WCDMABTS

HLR

AuCEIR

3GMSC

SMSC

Used as anintermediate store

for SMS

Contains subscriber IDs, serviceinformation and location

attributes. In AuC subscriber

security information and insome implementations EIR

Used to supportsubscriber services

Contains temporaryinformation on

subscriber

Contains temporaryinformation on the

subscriber

SCEP


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Other Servers

Packet core networkPacket core network

Domain Name Server (provides IP address to the correct GGSN)

Firewall servers (access to other networks)

Subscriber and network related information also in voice mail

system and other service platforms (such as MExE).


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FiberFiber

AXC

ATM Access

Internet


Control Plane

Gateway Plane

PSTN2G

SGSN3G

SGSN GGSNRNC

BSC

Node B

Node B

Node B

HLR&AuC

3GMSC

SCEP

SMSC

BTS

Unique subscriber identities

MSISDN = CC + NDC + SN

one or moreMSISDN is assignedto a subscriber fordifferent services

IMSI = MCC + MNC + MSIN

IMSI uniquely

identifies eachsubscriber.


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FiberFiber

AXC

ATM Access

Internet


Control Plane

Gateway Plane

PSTN2G

SGSN3G

SGSN GGSNRNC

BSC

Node B

Node B

Node B

HLR&AuC

3GMSC

SCEP

SMSC

BTS

Temporary subscriber identities

P-TMSI is allocatedfor packettransactions by the

SGSN.

The TMSI is

generated by the VLRand used for CS

transactions


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FiberFiber

AXC

ATM Access

Internet


Control Plane

Gateway Plane

PSTN2G

SGSN3G

SGSN GGSNRNC

BSC

Node B

Node B

Node B

HLR&AuCEIR

3GMSC

SCEP

SMSC

BTS

Mobile terminal security

RANThe IMEI is used to track

legal mobile equipment(optional)


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What is the bearer?

UE Node B RNC

Uu Iub/Iur Iu

Core Network

UE Node B RNC

Uu Iub/Iur Iu

Core Network

Data/Wireless Protocols are transparent to surrounding network

MGW

The MGW for 3G-MSC performs speech transcoding


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Bearer characteristics

Conversational class Voice and video

Streaming class Streaming video

Interactive class

Web browsing

Background class

Mail downloading


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Types of bearer

VoiceVoice Messages

MessagingTransactionalInfoservices

WWW browsingIntranet accessDownloading

Audio Streaming

0 8 16 32 48 64 80 96 112 128 144 160 kbit/s

Video StreamingVideotelephony

UE Node B RNC

Uu Iub/Iur Iu

Core Network

A bearer hasdifferent

parameters, such

as variable datarates, protection

and delay.

The bearer is

dependent onthe service

required.


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Transmission over the network

PSTN

3GSGSN

GGSN

RNC

HLR

AuCEIR 3G

MSC

Internet

Channels from the air-interfacealong the Iub Interface

Physical channels in the air-interface are separated by codes

ATM link to the MGW at theMSC

Packets are tunneled tothe SGSN

Packets tunneled from theSGSN to the GGSN

Packet Data

Dedicated circuit

Student Exercise:Why do you think the RNC makes the decision on the type of bearer that isallocated to a subscriber?


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Layers - Bearer services in UMTS

TE MT UTRAN CN IuEDGENODE

CNGateway

TE

End-to-End Service

TE/MT LocalBearer Service

UMTS Bearer Service External BearerService

UMTS Bearer Service

Radio Access

Bearer Service

CN BearerService

BackboneBearer Service

Iu BearerService

Radio BearerService

UTRAFDD/TDD

Service

PhysicalBearer Service


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Bearer management through the networkTE

ext.network3G-(G)MSC/GGSNMT UTRAN 3G-MSC/SGSN

UMTS BSManager

UMTS BSManager

UMTS BSManager

RABManager

CN BSMana-

ger

IuBSMana-

ger

Ext. BSMana-

ger

CN BSMana-

ger

IuBSMana-

ger

RadioBS

Mana-ger

RadioBS

Mana-ger

LocalBS

Mana-ger

BB NSMana-ger

IuNSMana-ger

BB NSMana-ger

IuNSMana-ger

UTRA

ph. BSMana-

ger

UTRA

ph. BSMana-

ger

Subscr

Control

Adm/

Cap.Control

Adm/

Cap.Control

Trans-

lation

Adm/

Cap.Control

Adm/

Cap.Control

Trans-

lation


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4

RAB (Radio Access Bearers) andRRC (Radio Resource Connection)

CNRAN

RANAP Connection

Radio Access Bearer

RANAP Connection

Radio

Acce

ssBe

arer

RRC Connection

UE

PacketNetwork

Circuit SwitchedNetwork

Packet Data Service

Speech Service

Video Service

Radio Access Bearer

Student Exercise:Can you think of an example where it may be necessary to modifythe radio resource connection?


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4

Example: RAB Establishment (simplified)

4 Uu Iub Iu

RAB Assignment Request

RAB Assignment Complete

SGSNRNC

Node B

Iub bearer set-up(AAL 5 virtual channel)

Iub bearer set-up(AAL 2 virtual channel)

Radio Bearer Set-up Complete

Radio Bearer Set-up

Radio Link Reconfiguration

Radio Link Reconfiguration Complete


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Management of the radio bearer

3GSGSN

RNC

3GMSC

RNC

RNC

Mobile has a single RRC


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3GSGSN

RNC

3GMSC

RNC

RNC

As the subscriber moves a secondconnection is made for a cell on the same

site (softer handover)


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3GSGSN

RNC

3GMSC

RNC

RNC

As the mobile continues then the firstlink is dropped, and a second cell is

added from another site (softhandover)

NOTE: Those BTS with anactive connection are known tobe part of the active set.


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3GSGSN

RNC

3G

MSC

RNC

RNC

As the mobile continues then the second link isdropped, and a second cell is added from another

RNC. A soft handover is possible as the Iurinterface exists.

The RNC is known as the serving

(S-RNC) and the new RNC is the drift(D-RNC). Note that the Iu connection is stillfrom the S-RNC.


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3GSGSN

RNC

3GMSC

RNC

RNC

As the mobile continues, the third connection isdropped. The S-RNC has no active connection's

itself, so the Iu-RRC connection is moved to the D-RNC. This is accomplished by S-RNC relocationfeature (R99)

No handover.


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3GSGSN

RNC

3GMSC

RNC

RNC

Finally, the mobile is now in area where the forthconnection is dropped and the new site selected is under

another RNC. The S-RNC does not have an Iur interfaceto the target RNC, so the core network is used to assistin the handover.

The type of handover is hard-handover.


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Mobility Management - the role of the HLR

The HLR is a centraliseddatabase, which contains

information about the subscriber,location and service information.

In the Nokia Solution

authentication information isalso stored in the HLR.

3GSGSN GGSN

RNC

3GMSC

3GSGSN

GGSN

RNC

3GMSC

3GMSC

Core Network

Foreign Network

Radio AccessHLRAuCEIR

Supplementary ServicesLocation Updating

Locating the Subscriber

Service Information


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Cellular architectureLA = Location Area (MSC)RA = Routing Area (SGSN)URA = UTRAN Registration Area (RNC)Cell = Cell (RNC)

CELL URACELL

URA

ROUTING

AREA (RA)

CELL

Position = PositioningService (UTRAN)

CELL

CELL

CELL

CELL

CELL

CELL

CELL

CELL

ROUTING

AREA (RA)

Location Area (LA)

CodeLAMNCMCCLAI ++= CILACodeMCCMNCCGI +++=

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UTRAN Registration Area - URA

3GSGSN

HLR&AuC

RNC RNC RNC

URA URA URAURAURAURA

3G

MSC

If the LA or RA changesRNC will ensure updatedinformation is sent to the

core network.

As the subscriber moves fromone URA to another, then aURA_update is performed.


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Location based information

Information about the actual position

of the subscriber (~40-70m) can be

stored and used by the emergencyservices.

This information can also be used to

provide mobility services.

BTS

BTS

BTS

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Location updating

3GSGSN

3GMSC

RNC

RNC

HLR

When switching on/off

IMSI Attach/Detach

When moving from area to area -

Update on cell/LA/RA/URA level

If the VLR is not informedabout the user then the

data is removed

VLR

The RNC keeps track of themobiles within the URAs. It alsoinforms the core network whenthe subscriber moves between

RAs and LAs.

The SGSN keeps track ofthe mobiles

Periodically over time if mobiledoes perform an update


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Routing area update

SGSN-1

RNC-1

RA-1

Old cell New cell


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Mobility Management of states in the SGSN

Detach DetachPacketAttach

PacketAttach

Packet Received Packet Received

Radio Link Release Iu Connection Release

MM States in UE: MM States in SGSN:


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Paging the subscriber

BTS BTS

Paging

BTS

Mobile responds

to paging

Routing Area

Paging

Paging


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Network roaming

3GSGSN

HLR

3GSGSN

3GMSC

RNC

HLR

3GMSC

RNC

BSC

BSC

Home Network

Visitor Network

International Network

3. Network Confirm access

1. User requests access (IMSI Attach)

2. If operators have a roaming agreement, informationis copied to visitor network (from VLR/HLR)


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Mobility Management procedures

Location Registration (Circuit and Packet Switched)

Location Update (Circuit Switched) IMSI Attach/Detach (Circuit Switched)

Routing Area Update (Packet Switched)

Cell Attach/Detach (Packet Switched)

Location Info Retrieval (Circuit and Packet Switched)

Paging (Circuit Switched)

Paging (Packet Switched)

Authentication Procedure (Circuit/Packet Switched)

Ciphering Procedure (Circuit/Packet Switched)

UE Identity Checking (Circuit/Packet Switched)

UE Hardware (IMEI) Checking (Circuit/Packet Switched)


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Session Management

Mobility Management (MM)

Session Management (SM)

Communication Management (CM)

Radio Resource Management (RRM)

UE RAN CN

FiberFiber

AXC

ATM Access

Internet


Control Plane

Gateway Plane

PSTN2G

SGSN

3G

SGSN GGSNRNC

BSC

Node B

Node B

Node B

HLR

&AuCEIR

3GMSC

SCEPSMSC

BTS


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Gaining initial access to the network

3GSGSN

3GMSC

RNC

HLR

Previous cell is tried and if not therethe terminal scans frequencies and

applies codes. If possible homenetwork is selected.

Networks transmitinformation about

themselves(MCC+MNC)

Operator A (frequency 1)

Operator B (frequency 2)

Operator C (frequency 3)


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IMSI Attach when a subscriber is registeredin another VLR

3GSGSN

RNC

HLRAC

EIR3G

MSC

3GMSC

RNC also keeps informationabout subscribers within

the URA.

1. Request Location Update (IMSI Attach)

1,

2. New VLR requests and receives authentication

information and IMSI from previous VLR.

2,

3. Authentication request and response

3,

4. New MSC/VLR updates HLR with new location.HLR sends acknowledgement and subscriberinformation. 4,

6. TMSI/TMUI allocation/acknowledgementand Location Update acknowledgement

6,

5. HLR cancels the old location,old VLR sends acknowledgement

5,


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Requesting a bearer

3GSGSN

3GMSC

RNC

HLR1. Mobile sends a request for a bearer(on RACH and listens for reply)

2. RNC will allocate a bearer for thesubscriber

Mobile in idle mode andcamping on a cell.


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Authentication

3GSGSN

3GMSC

RNC

HLR

The HLR contains information on thesubscriber, terminal, location and

services. Authentication codes andkeys are stored and generated in the

AuC

The SIM and terminalcontain authentication keys

The IMSI and IMEI are checked

(optional and at a changeable interval)

Information is checked from the HLR


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Authentication Data Request andAuthentication Data Response

VLR AuC

RAND K SQN

XRES AUTN CK IK

IMSI

RAND, AUTN, XRES, CK, IK

SGSN


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User Authentication

VLR

RAND, AUTN

RES

RAND K AUTN

RES SQN CK IK

UE SGSN

VLR/SGSN checkswhether RES = XRES

UE checks whether theSQN is big enough


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Ciphering on radio path

3GSGSN

3G

MSC

RNC

HLR

Authentication codes are used tocreate a signal which is

scrambled with the data. It isalmost impossible to decode thesignal without knowing the keys

Ciphering is performed inthe RNC and the mobile

In UMTS, multiple air-interfacechannels are used in theconnection to the mobile


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AuthenticationSummary

AKA Algorithms

K SQNAuC

Authentication Vectors

Encryption and IntegrityProtection Algorithms

Encryption and IntegrityProtection Algorithms

AKA Algorithms

K SQNUSIM

CK PS , IKPSCK CS , IKCS

CK PS , IKPSCK CS , IKCS

RAND, AUTNRES Securecommunication

VLR SGSN

AuC

RNC

ME

USIM


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UE BS BSCRNC BTS MSMSC/VLRMSC/VLR HLR

9. HLR Enquiry

10. Send Routing Information (MSRN)

11. Call Setup Continues

13. Paging Response

14. Setup

15. Call Confirmed/Alert16. Conversation

5. Call Setup

7. RAB Setup / Radio Link Modification

6. Bearer Assignment Request (Create) - Bearer Parameters and Binding ID

8. Bearer Assignment Complete

4. RRC Setup Complete

2. Radio Link Setup

3. Radio Resource Connection Setup

1. Radio Resource Connection Request

12. Paging

Simplified UMTS-GSM call setup


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Simplified steps - PDP Context Activation

UE BS RNC 3G-SGSN DNS GGSN-1

GTP PDU

12. Bearer Assignment Complete

1. Radio Resource Connection Request

2. Radio Link Setup

3. Radio Resource Connection Setup / Complete

4. PDP-Context Activation Request: Access Point Name (APN), QoS, IP Address

11. RAB Setup / Radio Link Modification

13. PDP Context Activation Accept: NSAPI, given dynamic IP-address, offered QoS

10. Bearer Assignment Request (Create): NSAPI, offered QoS

5. Authentication

8. Create PDP Context Request; APN, Dynamic IP Address

PDP PDU

6. GGSN address resolution Request (APN)

7. GGSN address resolution Response (192.10.45.1 = GGSN-1)

9. Create PDP Context Response; Dyn. IP-address, Charging Id

GGSN selects theAccess Point andassigns dynamic IPAddress

GTP PDU


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Packet states

- PDP Context Activation - PDP Context Deactivation(last)

- Packet Data Detach

- PDP Context Activation Rejected

- PDP Context Activation- PDP Context Modification- PDP Context Deactivation


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GTP - GPRS Tunnelling Protocol

User

packetUser

Packet

Userpacket

Userpacket

GGSN

The stream of containersformin a tunnel.

Userpacket

3G-

SGSN

RNC

The stream of containersform a 'tunnel'


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UE BS RNC 3G-SGSN

1. PDP Context Deactivation Request

2. PDP Context Deactivation Accept

3. Bearer Assignment Request(Release)

4. Radio Link Release

5. Bearer Assignment Complete(Release)

De-activation of PDP ContextReleasing of bearer


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Communication Management

Network ApplicationIntelligence

Connection

Service and customer

application control

Subscriber's service profile

- location information

- billing of service

- push control

- personalisation- etc...

Security

Mobility

Charging information collection

End user application Email

MO-MT SMS

etc...


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Call control

I II III

Fail:- Unsuccessful Setup- Restrictions- Unreasonable Numbers

Fail:- Wrong Dialling

- InterWorking FailureFail:- Circuits Not Available- Service Not Supported

Number Analysis Routing

Charging

A call coming in A call going out


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Collection of charging data

RNC

Billing Centre

Charging Gateway

HLR

3GSGSN

3G

MSC

GGSN

CDR (Charging DataRecords) are sent to the

Billing Centre


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Handling emergency calls

RNC

HLR

3GMSC

The MSC defines if calls areallowed and where they

should be routed to, basedupon location

3GSGSN

GGSN

To differentregional call

centres

No checking is done (alsoSIM does not need to be

active) to make emergencycall

Location Based Server

If location based services areused, then the emergencyservices can gain accurate

information on thesubscriber's location


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3G/UMTS Traffic Management

Review Questions


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Review

1. In which network elements is security related information located?

a. USIM

b. RNC

c. AuC

d. SGSN

e. Node B

f. non of all above


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Review

2. Which parameter identifies the subscriber?

a. IMSI

b. IMEI

c. MCC

d. P-TMSI

e. TMSI

f. PIN


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Review

3. Which location information is known in the UE?

a. LA

b. RA

c. URA

d. 3G-MSC supply area

e. 3G-SGSN supply area


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4. Which of the following is/are characteristic(s) of a UMTS bearer?

a. Variable data rateb. Transparent through the RAN

c. Different lengths of delay

d. Asymmetric connection

e. None of the above

Review


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Used by the CN CS Domain

______________________

Used by the CN PS Domain

______________________

Used in the RNC

______________________

What otherinformation is kept?

__________________

__________________

__________________

__________________

ReviewUTRAN Registration Areas

Routing Areas

Location Areas

Cell ID

Positioning Service


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Review

6. Which of the following sentences about location update is NOT true?

a. IMSI attach is always made when the terminal is switched on.

b. Location/routing Area update takes place when a subscriber moves

between LAs and/or RAs.

c. Periodic location updates are not used in UMTS.

d. None of the above.

7. TRUE or FALSE

The URA (UTRAN Registration Area) is used by the core network to keep track

of subscribers in the network.


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Review

7. Which of the following sentences about the RRC (Radio Resource

Connection) is true?a. It is only used in GPRS networks.

b. It is a collection of radio access bearers over the air interface.

c. It is a wireless protocol.

d. All of the above.

9. The operation of requesting a subscriber to contact the network iscalled:

a. IMSI attach

b. Location updatec. Paging

d. Bearer allocation

8


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10. Which of the following sentences best describes authentication:

a. Security of the user information on the air interface

b. IMSI and IMEI checkingc. Supplementary service status checking (by the subscriber)

d. A process used by the GGSN to determine firewall access

11. In UMTS a terminal has two states, idle and connected.In the following list, identify which state the mobile is in.

a. The mobile is in _______________mode when it is camping on a

cell.

b. The mobile is in _______________mode when it does not have

any connection state.c. If data is being transferred from the packet core to the mobile,

then the state is _______________.

Review

Idle

Idle

Connected


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Review

12. During a PDP context activation process, which

information is transmitted from the UE to the SGSN?

a. APN

b. PDPc. GGSN address

d. DNS address

e. TID


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13. When a subscriber triggers an event in the network (e.g. a call), aCDR is generated. What is a CDR?

a. Charging data record which is sent to a Billing/Charging Centreb. Caller digital reset to the MSCc. Customer data receipt, which is a bill that is sent to the customerd. All of the above

14. True or FalseSMS messages can be sent via the SGSN.

Review

04 UMTS Traffic Management Emad

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