04 umts traffic managementnew

1 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss

UMTS Traffic ManagementUMTS Traffic Management


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


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 an intermediate store for SMS

Contains subscriber IDs, service information and location attributes. In

AuC subscriber security information and in some

implementations EIR

Used to support

subscriber services

Contains temporary

information on subscriber

Contains temporary

information on the subscriber

SCEP


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 more MSISDN is

assigned to a subscriber for

different services

IMSI = MCC + MNC + MSIN

IMSI uniquely identifies each

subscriber.


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 allocated for

packet transactions by

the SGSN.

The TMSI/TMUI is generated by

the VLR and used for CS transactions


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)


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


Bearer characteristicsD O C U M E N T T Y P E 1 ( 1 )

M o b i l e P h o n e sT y p e Y o u r N a m e H e r e T y p e D a t e H e r e

C o n v e r s a t i o n a l c l a s s V o i c e a n d v i d e o

S t r e a m i n g c l a s s S t r e a m i n g v i d e o

I n t e r a c t i v e c l a s s W e b b r o w s i n g

B a c k g r o u n d c l a s s M a i l d o w n l o a d i n g


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 has different parameters, such as variable data rates, protection and delay.

• The bearer is dependent on the service required.


Transmission over the network

PSTN

3GSGSN

GGSN

RNC

HLR AuCEIR 3G

MSC

Internet

Channels from the air-interface along the Iub Interface

Physical channels in the air-interface are separated by codes

ATM link to the MGW at the MSC

Packets are tunneled to the SGSN

Packets tunneled from the SGSN to the GGSN

Packet Data

Dedicated circuit

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


Layers - Bearer services in UMTSTE MT UTRAN CN Iu

EDGENODE

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


4

RAB (Radio Access Bearers) and RRC (Radio Resource Connection)

CNRAN

RANAP Connection

Radio Access Bearer

RANAP Connection

Radio Access Bearer

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 modify the radio resource connection?


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


Management of the radio bearer

3GSGSN

RNC

3GMSC

RNC

RNC

Mobile has a single RRC



3GSGSN

RNC

3GMSC

RNC

RNC

As the subscriber moves a second connection is made for a cell on the same

site (softer handover)



3GSGSN

RNC

3GMSC

RNC

RNC

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

added from another site (soft handover)

NOTE: Those BTS with an active connection are known to be part of the active set.



3GSGSN

RNC

3GMSC

RNC

RNC

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

another RNC. A soft handover is possible as the Iur interface 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 still from the S-RNC.



3GSGSN

RNC

3GMSC

RNC

RNC

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

itself, so the Iu-RRC connection is moved to the D-RNC.



3GSGSN

RNC

3GMSC

RNC

RNC

Finally, the mobile is now in area where the forth connection is dropped and the new site selected is under another RNC. The S-RNC does not have an Iur interface to the target RNC, so the core network is used to assist

in the handover.


Mobility Management - the role of the HLR

The HLR is a centralised database, which contains

information about the subscriber, location and service information. In

the Nokia Solution authentication

information is also stored in the HLR.

3GSGSN GGSN

RNC

3GMSC

3GSGSN

GGSN

RNC

3GMSC

3GMSC

Core Network

Foreign Network

Radio AccessHLR AuCEIR

Supplementary Services Location Updating

Locating the Subscriber

Service Information


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

CELL

URACEL

L

URA

ROUTING

AREA (RA)

CELL

Position = Positioning Service (UTRAN)

CELL

CELL

CELL

CELL

CELL

CELL

CELL

CELL

ROUTING

AREA (RA)

Location Area (LA)

CodeLAMNCMCCLAI CILACodeMCCMNCCGI

Page 29


UTRAN Registration Area - URA3G

SGSNHLR &AuC

RNC RNC RNC

URA URA URAURAURAURA

3GMSCIf the LA or RA changes

RNC will ensure updated information is sent to the

core network.

As the subscriber moves from one URA to another, then a URA_update is performed.


Location based information

• Information about the actual position of the subscriber (~40-70m) can be stored and used by the emergency services.

• This information can also be used to provide mobility services.

BTS

BTS

BTS

Page 32


Location updating

3GSGSN

3GMSC

RNC

RNC

HLRWhen switching on/off

IMSI Attach/Detach

When moving from area to area - Update on cell/LA/RA/URA level

If the VLR is not informed about the user then the data

is removed

VLR

The RNC keeps track of the mobiles within the

URAs. It also informs the core network when the

subscriber moves between RAs and LAs.

The SGSN keeps track of the mobiles

Periodically over time if mobile does perform an update


Routing area update

SGSN-1

RNC-1

RA-1

Old cell New cell


Mobility Management of states in the SGSN

D etach D etachP acke tA ttach

P acke tA ttach

P acke t R eceived P acke t R eceived

R ad io L ink R e lease Iu C onnection R e lease

MM States in UE: MM States in SGSN:


Paging the subscriber

BTS BTS

Paging

BTS

Mobile responds to paging

Routing Area

Paging

Paging


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, information is copied to visitor network (from VLR/HLR)


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)


Session Management

Mobility Management (MM)

Session Management (SM)

Communication Management (CM)

Radio Resource Management (RRM)

UE RAN CN

Fiber Fiber

AXC

ATM Access

Internet


Control Plane

Gateway Plane

PSTN2G

SGSN3G

SGSN GGSNRNC

BSC

Node B

Node B

Node B

HLR &AuCEIR

3GMSC

SCEPSMSC

BTS


Gaining initial access to the network

3GSGSN

3GMSC

RNC

HLR

Previous cell is tried and if not there the terminal scans

frequencies and applies codes. If possible home

network is selected.

Networks transmit information about

themselves (MCC+MNC)

Operator A (frequency 1)

Operator B (frequency 2)

Operator C (frequency 3)


IMSI Attach when a subscriber is registered

in another VLR

3GSGSN

RNC

HLRACEIR

3GMSC

3GMSC

RNC also keeps information about 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 subscriber information. 4,

6. TMSI/TMUI allocation/acknowledgement and Location Update acknowledgement

6,

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

5,


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 the subscriber

Mobile in idle mode and camping on a

cell.


Authentication

3GSGSN

3GMSC

RNC

HLR

The HLR contains information on the subscriber, terminal,

location and services. Authentication codes and

keys are stored and generated in the AuC

The SIM and terminal contain

authentication keys

The IMSI and IMEI are checked (optional and at a changeable interval)

Information is checked from the HLR


Authentication Data Request andAuthentication Data Response

VLR AuC

RAND K SQN

XRES AUTN CK IK

IM SI

RAND, AUTN, XRES, CK, IK

SG SN


User Authentication

VLR

RAND, AUTN

RES

RAND K AUTN

RES SQN CK IK

U E SG SN

VLR/S GS N checkswhether RES = XRE S

UE checks whether theSQ N is b ig enough


Ciphering on radio path

3GSGSN

3GMSC

RNC

HLR

Authentication codes are used to create a signal which is scrambled with

the data. It is almost impossible to decode the signal without knowing

the keys

Ciphering is performed in the

RNC and the mobile

In UMTS, multiple air-interface channels are

used in the connection to the mobile


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


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 the Access Point and assigns dynamic IP Address

GTP PDU


Packet states

- P D P C o n te x t A ctiva tio n - P D P C o n te x t D e a ctiva tion (las t)- P a cke t D a ta D e ta ch

- P D P C o n te x t A ctiva tio n R e je c te d

- P D P C o n te x t A ctiva tio n- P D P C o n te x t M od if ica tio n- P D P C o n te x t D e a ctiva tion


GTP - GPRS Tunnelling Protocol

DOCUMENTTYPETypeUnitOrDepartmentHereTypeYourNameHere TypeDateHere

User

packetUserPacket

Userpacket

Userpacket

GGSN

The stream of containersforming a tunnel.

Userpacket

3G-

SGSN

RNC

The stream of containers

form a 'tunnel'


UE BS RNC 3G-SGSN1. 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


Communication Management

Network Application Intelligence

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...


Collection of charging data

RNC

Billing Centre

Charging Gateway

HLR

3GSGSN

3GMSC

GGSN

CDR (Charging Data Records) are sent to

the Billing Centre


Handling emergency calls

RNC

HLR

3GMSC

The MSC defines if calls are allowed and where they should be routed to, based upon

location

3GSGSN GGSN

To different regional call

centres

No checking is done (also SIM does not

need to be active) to make emergency call

Location Based Server

If location based services are used,

then the emergency services can gain

accurate information on the subscriber's

location


3G/UMTS Traffic Management

Review Questions


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


Review

2. Which parameter identifies the subscriber?

a. IMSI

b. IMEI

c. MCC

d. P-TMSI

e. TMSI

f. PIN


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


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

a. Variable data rate

b. Transparent through the RAN

c. Different lengths of delay

d. Asymmetric connection

e. None of the above

Review


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


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 FALSEThe URA (UTRAN Registration Area) is used by the core network to keep track of subscribers in the network.

Review


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.

8. The operation of requesting a subscriber to contact the network is called:a. IMSI attachb. Location updatec. Pagingd. Bearer allocation9

8


9. Which of the following sentences best describes authentication:a. Security of the user information on the air interfaceb. IMSI and IMEI checkingc. Supplementary service status checking (by the subscriber)d. A process used by the GGSN to determine firewall access

10. 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

10

11


Review

12. During a PDP context activation process, which information is transmitted from the UE to the SGSN?a. APNb. PDPc. GGSN addressd. DNS addresse. TID


12. When a subscriber triggers an event in the network (e.g. a call), a CDR 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 customer d. All of the above

13. True or False SMS messages can be sent via the SGSN.

Review

Software

04 umts traffic managementnew