Ch4-GPRS Traffic Management

8/7/2019 Ch4-GPRS Traffic Management

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GPRS Traffic Management


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This module enables the participant to:

Explain the mobility management functions in GPRS:Paging CoordinationGPRS attach/detachcell updaterouting area update

Explain the session management functions in GPRS:PDP context activation

Explain the difference between idle, ready and standby MS states andtheir relation to the different MM functions.

Explain addressing in GPRS. Describe charging in GPRS.

Explain the concept of security in GPRS. Describe the data flows for a roaming GPRS MS.

.

Module objectives


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We have had a look at

GPRS ConceptsGPRS Functions

GPRS Protocols

GPRS Components

GPRS Interfaces

Next we will look at Operation of the GPRS Network (GPRSProcedures):

That is, how is a GPRS function implemented by the sending ofmessages with some parameters between GPRS componentson one or more interfaces using a protocol.

For example: Charging functionality is implemented by the

sending of Charging Data Records between GSNs and CG usingthe GTP protocol on the Ga interface.

So far ...


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MS switches on for the first time.

MS indicates that it is switched on and ready. (GPRS Attach)

MS indicates that it is switched off. (GPRS Detach)

MS indicates that it wants to transmit data. (PDP Context Activation)

MS indicates to stop data transmission. (PDP Context Deactivation)

MS moves from one part to another of a service area. (Cell Update andRA Update procedure)

MS may roam into another networks service area. (Roaming)

etc.

What sort of procedures are needed?


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Traffic Management Procedure is subdivided into 2 areas:1. What is Mobility Management?

Procedures that take care of the mobility of the user, such asthe GPRS attach, are called GPRS Mobility Management(GMM).

The GMM procedures are similar to the mobilitymanagement for circuit switched users.

Examples: GPRS Attach, GPRS Detach, Cell Update,Intra-SGSN Routing Area Update

2. What is Session Management?

Procedures that handle the GPRS MS connection managementto the external data networks are called SessionManagement (SM).

Examples: PDP Context Activation

What is Traffic Management?


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Subscriber Identity

How do we uniquely identify a subscriber? IMSI, TMSI, IP Address

Where will this information be maintained?

Subscriber Location

How do we know the location of the subscriber?

Location Area (LA) and Routing Area (RA)Where will this information be maintained?

Subscriber Services

What sort of services is a subscriber allowed to access?


Subscriber AuthenticationWhat information is needed to authenticate the subscriber?

Ki Algorithms, Triplets


Types of subscriber information


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Type of info What info Where

Identity y IMSI

y TMSI

y IP address

y SIM, HLR, VLR,SGSN, GGSN

y VLR, SGSN

y MS, SGSN, GGSN

Location y VLR-address

y Location Area

y Serving SGSN

y Routing Area

y HLR

y SGSN, VLR

y HLR, VLR

y SGSN

Services y Basic services,supplementary services,circuit switched bearerservices, GPRS serviceinformation

y Basic services,supplementary services,CS bearer services

y GPRS service information

y HLR

y VLR

y SGSN

Authenticationdata

y Ki, algorithms

y Triplets

y SIM, AC

y VLR, SGSN

Types of subscriber information


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SGSN-1

BSC-1

RA-1 RA-3

SGSN-2

BSC-2

RA-2

LA-1 LA-3

Routing area


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GPRS has three MM states:

IDLE state: used when MS is not attached to network

READY state: when mobile is ready to transmit data or has just finishedtransmitting/receiving

STANDBY state: MS is attached to the network but has no data to send

When the MS is in each of the 3 states, different information is held inHLRVLRSGSN

What are the Mobility Management states?


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RA-1

VLR-1

HLR

SGSN-1BSC

IMSI 244...

VLRSGSN

IMSILAISGSN ?

IMSI ?

RA ?Cell ?

LA-1

Not possible to use GPRS

Mobile is either:

switched off

out of GPRScoverage

or only attached toCircuit-Switchedenvironment

PACKET DATA TRANSMISSION

IS NOT POSSIBLE IN STANDBYMODE!

MS Idle


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RA-1

VLR-1

HLR

SGSN-1BSC

IMSI 244...VLR VLR-1

SGSN SGSN-1IMSI 244...LAI LA-1SGSN SGSN-1

IMSI 244...

RAI RA-1CellCell cellcell--11

LA-1

Location known down to CELL level

Valid Mobility Management for theuser

Activation/deactivation of PDP

context is possible =POSSIBLE TO SEND AND RECEIVEDATA

Discontinuous reception (DRX) ispossible (only use the radioresources when needed)

AREADY timer supervises this state

MS Ready


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RA-1

VLR-1

HLR

SGSN-1BSC

IMSI 244...

VLR VLR-1SGSN SGSN-1

IMSI 244...LAI LA-1SGSN SGSN-1

IMSI 244...

RAI RA-1CellCell ??????????

LA-1

Attached (location known by SGSN downto Routing Area level)

There is a valid MM context for MS inSGSN and MS

If Mobile Station sends data -> READYmode

Mobile Station can receive paging forCircuit Switched calls and SMS

MS reachable timer: starts tickingwhen the MS moves to standby state.

PACKET DATA TRANSMISSION IS NOT

POSSIBLE IN STANDBY MODE!

MS Standby


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GPRS Attach

PDU transmission

GPRS Detach GPRS Attach

PDU reception

GPRS Detachor

Cancel Location

M M State M odel of M S M M S tate M odel of SGSN

IDLE

READY

STANDBY

IDLE

READY

STANDBY

STANDBY timer expiryor

Cancel Location

READY timer expiryorForce to STANDBY

READY timer expiryorForce to STANDBYor

Abnormal RLC condition

STANDBY timerexpiry

GPRS Mobility Management Mobile States


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Class Service MM State

A Circuit switched(AND) Packet

switched

GSM (AND)

GPRS

B Circuit switched

(OR) Packetswitched

GSM ( AND)GPRS

C Circuit switched(OR) Packet

switched

GSM ( OR) GPRS

MOBILE SERVICE CLASSES


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Multislot Type default

Rx tx sum Tta Ttb Tra Trb

1 1 1 2 3 2 4 2 1

2 2 1 3 3 2 3 1 1

3 2 2 3 3 2 3 1 1

4 3 1 4 3 1 3 1 1

5 2 2 4 3 1 3 1 1

6 3 2 4 3 1 3 1 1

7 3 3 4 3 1 3 1 1

8 4 1 5 3 1 2 1 1

9 3 2 5 3 1 2 1 1

10 4 2 5 3 1 2 1 1

11 4 3 5 3 1 2 1 1

12 4 4 5 2 1 2 1 113 3 3 NA NA a) 3 a) 2

14 4 4 NA NA a) 3 a) 2

15 5 5 NA NA a) 3 a) 2

16 6 6 NA NA a) 2 a) 2

17 7 7 NA NA a) 1 0 2

18 8 8 NA NA 0 0 0 2

19 6 2 NA 3 b) 2 c) 1

20 6 3 NA 3 b) 2 c) 1

21 6 4 NA 3 b) 2 c) 1

22 6 4 NA 2 b) 2 c) 1

23 6 6 NA 2 b) 2 c) 1

24 8 2 NA 3 b) 2 c) 1

25 8 3 NA 3 b) 2 c) 1

26 8 4 NA 3 b) 2 c) 1

27 8 4 NA 2 b) 2 c) 1

Minimum number of slotsMaximum number of slots

Mobile Multislot Classes


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aging Coordination-ConceptWith Paging coordination , if MS is in packet transfer mode then MS gets

circuit switched calls through SGSN depending on network mode and class of

mobile


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GPRS Attach: MS request to connect to GPRS network.

Successful GPRS Attach results in MS moving to READY state GPRS Detach: To terminate connections to GPRS network.

What needs to be done during a GPRS Attach? (Relate to GSM Attach)

Network Request Subscriber Identity

Authenticate Subscriber

Check IMEIAllocate MS Identifier

What are GPRSAttach and Detach?


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BSC SGSN HLR/EIRMS

1. REQUEST GPRS ATTACH (= UPDATE ROUTINGAREA)

2b. SEND SUBSCRIBER ID = IMSI = MCC + MNC +MSIN

2a. REQUEST SUBSCRIBER ID

3c.AUTHENTICATION

3d. AUTHENTICATIONRESPONSE

4a. REQUEST IMEI

4b. SEND IMEI

5a. UPDATE LOCATION

5c. ACKNOWLEDGEMENT

3a. REQUEST AUTHENTICATIONINFORMATION

3b. SEND AUTHENTICATION INFO

4c. CHECK IMEI

4d. CHECK IMEIACKNOWLEDGEMENT

5b. PROVIDE SUBSCRIBER INFORMATION

6a. SEND P-TMSI (32-bit number)

6b. P-TMSI ACKNOWLEDGEMENT

GPRSAttach- first time


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BSC SGSN HLR/EIRMS

1. REQUEST GPRS ATTACH (= UPDATE ROUTINGAREA)

2b. SEND SUBSCRIBER ID = IMSI = MCC + MNC +MSIN

2a. REQUEST SUBSCRIBER ID

3c.AUTHENTICATION

3d. AUTHENTICATIONRESPONSE

4a. REQUEST IMEI

4b. SEND IMEI

5a. UPDATE LOCATION

5c. ACKNOWLEDGEMENT

3a. REQUEST AUTHENTICATIONINFORMATION

3b. SEND AUTHENTICATION INFO

4c. CHECK IMEI

4d. CHECK IMEIACKNOWLEDGEMENT

5b. PROVIDE SUBSCRIBER INFORMATION

6a. SEND P-TMSI (32-bit number)

6b. P-TMSI ACKNOWLEDGEMENT

GPRSAttach- first time


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P-TMSI = Packet Temporary Mobile Subscriber Identity

SGSN allocates P-TMSI.

A new P-TMSI is allocated for each GPRS attach

P-TMSI is an alias for the GPRS MS just like the TMSI.

P-TMSI is only valid in a Routing Area (RA)

TLLI (Temporary Logical Link Identity) is derived from P-TMSI.The TLLI is used as an identifier for the connection between the

MS and the SGSN.

The TLLI is used as the MSs address for transmission betweenSGSN and MS.

Only SGSN and MS know relationship between TLLI and IMSI.

P-TMSI and TLLI


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After GPRS Attach, SGSN starts tracking location of the MS.

The MS can send and receive SMS, but no other data. To transfer other data it first has to activate a PDP context.

When the subscriber wants to end a connection to the GPRS network, theGPRS Detach is used.

GPRS Detach changes the state of MS to Idle and mobility managementcontext in SGSN (and in the MS) is removed.

MS normally initiates GPRS Detach, but it can also be initiated by thenetwork if mobile reachable timer expires.

What happens after a GPRS attach?


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How do we cope with a situation where the MS receives packet data whilemoving from one cell to another?

How do we cope with a situation where the MS moves from a routing area toanother in STANDBY state?

These problems are solved with location management.

Questions


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Subset of mobility management procedures

Used to handle the hanging of a cell or a routing area.

What types of location management procedures are needed?

1. Movement between cells

Cell Update

2. Movement between RA

Routing Area Update

3. Movement between LA

Location Area Update

4. Checking if MS is still active

Periodic Routing Area Update is used for checking thata MS that has not done any RA updates for someperiod of time is still reachable.

What is Location Management?


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Also called cell reselection.

Cell Update occurs when MS changes cell within RA in READY mode.Compared to handover in GSM

Initiated by MS

SGSN-1

BSC-1

RA-1

Old cellNew cell

What happens to Data Communications?

Cell update halts possible reception orsending of data.

If MS or SGSN send data during cellupdate, the data most likely will be

buffered in SGSN or

lost and has to be resent.

What is Cell Update?


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When the MS changes cells between the different routing areas, it

performs a Routing Area Update.

There are two types of routing area updates:

Intra-SGSN Routing Area Update

If new RA is managed by same SGSN, an Intra-SGSN

Routing Area Update is performed. The old SGSNforwards user packets to the new SGSN.

Inter-SGSN Routing Area Update

One SGSN can manage many routing areas. If the newrouting area is managed by a different SGSN, an Inter-SGSN Routing Area Update is performed.

What is Routing Area Update?


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Moving between two Routing Areas managed by same SGSN

MS is moving and listening to the information broadcasted by the cells.

MS decides to select a new cell that is in another routing area but sameSGSN.

SGSN-1

BSC-1

RA-1

Old cell New cell

RA-2

Intra-SGSN RoutingArea Update


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New RA

BSC SGSN HLR/EIRMS

1. REQUEST ROUTING AREA UPDATE

2b. AUTHENTICATION RESPONSE

2a. AUTHENTICATION

3. CHECK IF ALLOWED, ROUTING AREA UPDATEACCEPT

4. ACKNOWLEDGEMENT

HLR is notengaged here - it

is enough if itknows the SGSNaddress - and in

this case, the SGSN

does notchange!

Intra-SGSN RoutingArea Update


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If an MS stays a long time at the same place, the network has to receive anindication that the MS is still reachable.

This is the reason why the periodic routing area updates are made.

All MSs attached to the GPRS will perform a periodic Routing Area Update.

What is a Periodic Routing Area Update?


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Do you foresee any problems due to coexistence of GSM andGPRS?

Coexistence of GSM and GPRS network produces someoverhead traffic because both systems independently handlemobility management.

How can this problem be solved?

Network could make more efficient use of its resources byusing introducing an optional Gs interface between SGSN and

MSC.

What saving are obtained using the optional Gs interface?

Combined GPRS/IMSI Attach and Detach

Combined RA/LA update

Circuit switched services paging via GPRS network

Non-GPRS alertsIdentification procedure

MM-information procedure

SGSN and MSC/VLR interaction


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Do you foresee any problems due to coexistence of GSM andGPRS?

Coexistence of GSM and GPRS network produces someoverhead traffic because both systems independently handlemobility management.

How can this problem be solved?

Network could make more efficient use of its resources byusing introducing an optional Gs interface between SGSN and

MSC.

What saving are obtained using the optional Gs interface?

Combined GPRS/IMSI Attach and Detach

Combined RA/LA update

Circuit switched services paging via GPRS network

Non-GPRS alertsIdentification procedure

MM-information procedure

SGSN and MSC/VLR interaction


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Procedures that handle the GPRS MS connection to the external

data networks are called Session Management (SM). What types of SM Procedures exist?

PDP Context Activation

PDP Context Deactivation

PDP Context Modification: modifying a PDP context

What kinds of IP addresses can be used during a SM?

Static IP Address (permanent MS IP address)

Dynamic IP Address allocated by GGSN, DHCP or RADIUSserver

HPLMN Dynamic IP Address

VPLMN Dynamic IP Address

What is Session Management?


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Receive request from subscriber

Check MS subscription data (static/dynamic, APN, etc.) Authenticate the subscriber

Check if IP address has to be allocated and by whom

Convert APN name to GGSN IP Address using DNS

Contact GGSN and check if it is prepared to accept MS

Await GGSN confirmation

Get ready for charging!!!

What steps during PDP ContextActivation?


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DNSMS SGSN

1. REQUEST PDP CONTEXT ACTIVATION

2b. AUTHENTICATION AND IMEI CHECKING

GGSN

3. GET GGSN IP ADDRESS FROM DNS (APN IDENTIFIES THE GGSN)

3a. CREATE PDP CONTEXT REQUEST (STATIC IP ADDRESS ENCLOSED - IF USED)

4. ACTIVATE PDP CONTEXT ACCEPT

HLR

GGSN SELECTS ACCESS POINT TO BE USED ANDALLOCATES AN IP ADDRESS FOR USER IF NEEDED

3b. CREATE PDP CONTEXT RESPONSE (INCL IPADDRESS, TUNNEL ID INFORMATION, CHARGING ID)

(5. SGSN READY TO ROUTE TRAFFIC BETWEEN MS ANDGGSN)

Session Management - PDP ContextActivation


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Step:1

BTS BSC

SGSN

GGSN

Intranet

GPRSCore

Network

DNS

Internet

APN=

"Intranet.Ltd.com"

1.

AccessPoint


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Step: 2

B S BS

S S

S

RSe

et

S

t et

te et

1

2

A et


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Step: 3

S S

S S

S

RSe

et

S

t et

te et

t et Lt


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Step: 4

S S

S S

S

So e

et o k

nt anet

nte net

1.

2.


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PDP Type

PDP Address

IMSINSAPI

APN

SGSN Address

Charging ID

...

PDP Type (i.e. IP or X25)

PDP Address (IP address)NSAPI (Connection id)

APN (Default gateway)

...

PDP Type

PDPAddress

APNGGSNAddress

Charging ID

IMSI (User id)

NSAPI

(IMSI+NSAPI=TID)

...

Mobile Station SGSNGGSN

What information activated PDP Context?


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GGSN

InternetEdge

Router Service

GPRSBackbone

DNS

Operator's ISP Network

AP1

GGSN

AP2

NAT

VAS

BTS BSC

SGSN

GGSN has no active role in user authentication

Subscriber IP address static or GGSN allocated from operator's ISP Operator ISP gives Internet access and Value Added Services

(e-mail, web, etc.)

What is transparent access to Internet?


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GGSN

Intranet

Service

GPRSBackbone

VPN

Infra servers- RADIUS(SecurID)

- DNS

InternetEdge

Router

VPN

DNS

BTS BSC

SGSN

Service

GGSN provides user authentication towards RADIUS server

Subscriber IP address allocated from intranet address space Connection to the intranet router via a dedicated link or a VPN

What is non-transparent access?


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BTS BSC

SGSN

GGSN

Router

Service

GPRSBackbone

A

P

Intranet Internet

Infra servers- RADIUS- DNS

Connection from GGSN to intranetrouter is built using dedicated linee.g. Serial link.

Dynamic IP address allocated by a DHCP orRADIUS server in the customer'sIntranet or by an ISP

Access to public Internet via the company's intranet

Non-transparent access to intranet


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SMS can delivered by two routes

GSM: via MSCGPRS: via SGSN

Which route is more efficient?

The SMS delivery via the SGSN is more radio resource efficient thandelivery via the MSC/VLR.

Who selects the preferred path?

The preferred delivery path is selected by SMS-GMSC operator.

How is SMS delivered in GSM/GPRS network?


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MSC

G-MSC

SGSN

HLR

SMSC

1)

2)

3a)

3b)

4a)

4b)

a) MSC addressb) SGSN address

1. SMSC forwards the SM to an SMS-GMSC , which examines the destination MS address.

2. GMSC request info from HLR, which returns MS's current SGSN &| MSC number. 3a. If the result contains an MSC number, the SMS-GMSC forwards the SM to the MSC.

3b. The MSC then transfers the SM to the MS.

4a. If the result contains an SGSN number, the SMS-GMSC forwards the SM to the SGSN.

4b. The SGSN then transfers the SM to the MS.

SMS data transfer


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SGSN

EmbassyIntranet

SingaporeGPRS

Backbone

HOMEOperatorGPRS

BG

BG

.GPRSDNS

Inter-PLMNGPRS

Backbone

DNS

GGSN

GSMOPERATOR, Finland

Visited Operator, Singapore

DNSHOME

Roaming example

H d Vi i d d H N k i ?


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SGSN

HOMEOperatorGPRS

BG

BG

.GPRSDNS

Inter-PLMNGPRS

Backbone

DNS

GGSN

Visited Operator

DNSHOME

EmbassyIntranet

SingaporeGPRSBackbone

How does Visited and Home Network interact?

C t t A ti ti f R i U (1)


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SGSN

EmbassyIntranet

SingaporeGPRS

Backbone

HOMEOperatorGPRS

BG

BG

.GPRSDNS

Inter-PLMNGPRS

Backbone

DNS

GGSN



DNSHOME

2

1

3

(1) MS decides to use home APN. embassy.fi.gsmoperator.fi.gprs

(2) The MS sends PDP context activation request to the SGSN with APN.

(2b) Singapore operators SGSN checks with HLR if APN requested ispermissible.

(3) SGSN sends DNS query to local DNS in Singapore operators network.

ContextActivation for a Roaming User (1)



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SGSN

EmbassyIntranet

SingaporeGPRSBackbone

HOMEOperatorGPRS

BG

BG

.GPRSDNS

Inter-PLMNGPRS

Backbone

DNS

GGSN



DNSHOME

4

5

(4) Singapore DNS does not know the IP address, so it forwards the same query it receivedfrom the SGSN to the .gprs level DNS.

(5) .gprs level DNS replies with list of home operator DNS servers.




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SGSN

EmbassyIntranet

SingaporeGPRS

Backbone

HOMEOperatorGPRS

BG

BG

.GPRSDNS

Inter-PLMNGPRS

Backbone

DNS

GGSN



DNSHOME

6

7

(6) Singapore DNS forwards query to Finnish DNS.

(7) GSMOPERATOR DNS replies with the IP address of the GGSN.




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SGSN

EmbassyIntranet

SingaporeGPRS

Backbone

HOMEOperatorGPRS

BG

BG

.GPRSDNS

Inter-PLMNGPRS

Backbone

DNS

GGSN



DNSHOME

8

9

(8) Singapore DNS gives GGSN address to the Singapore SGSN.

(9) SGSN sends homeGGSN a request to create PDP context with the APN.


D t fl i i


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SGSN

EmbassyIntranet

Singapore

GPRSBackbone

HOMEOperatorGPRS

BG

BG

Inter-PLMNBackbone

GGSN



PDP context is active and SGSN sends notification of this to the MS.

Diplomat can now download e-mail from embassy e-mail server in the embassy intranet.

Data flow in a roaming case

I thi th l i b d ?


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APN in home network is not the only option. While attached to the visited network the subscriber could also use

APN provided by the visited network.

The types of access points allowed in HLR are the following:

User is allowed to use visited network Access Point

User can select home or visited Access Point, or

User needs to use the Access Points in home network

Connection between the two operators GPRS networks can beeither

through a public data network (PDN) network, such as theInternet

or through a private inter-PLMN network.

Is this the only way roaming can be done?

Visited or Home GGSN


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Visited GGSN APN advantages

FasterCheaper?

Home GGSN

Home operator offers some (value added or other) service that can beonly used via some specific access point.

User could be accessing a company intranet that could for securityreasons only be accessed via the home operator access point.

Intranets do not allow opening of TCP-ports in the company firewallfrom outside the intranet. In that case, for example downloading e-mails from a company server via the Internet is not possible.

Visited orHome GGSN

Roaming Static IP address


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SGSN

HOMEOperatorGPRS

BG

BG

Inter-PLMNGPRS

Backbone

GGSN

Visited Operator

Access Point

Always:192.100.107.10

GGSN

Visited-PLMNGPRS

Backbone

Internet/Intranet

If user has static IP address: will always use home network GGSN

APN.

Roaming, Static IP address

Roaming Dynamic IP address (Home network)


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SGSN

HOMEOperatorGPRS

BG

BG

Inter-PLMNGPRS

Backbone

GGSN

Visited Operator

Access Point

IP address changesGGSN

Visited-PLMNGPRS

Backbone

Internet/Intranet

If home network GGSN allocates dynamic IP address, then MS would request

visited network to activate a context with home network APN. Data would flow as in static case.

Roaming, Dynamic IP address (Home network)

Roaming: Dynamic IP address (Visited network)


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SGSN

HOMEOperatorGPRS

BG

BG

Inter-PLMN

GPRSBackbone

GGSN

Visited Operator

Access Point

x.x.x.xGGSN

Visited-PLMNGPRS

Backbone

Internet

The user would not have to specify any access point and the

visited network default access point would be used.

The visited network would allocate a dynamic address to the user.

Roaming: Dynamic IP address (Visited network)

Security related to GPRS


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Authentication:- SGSN can store max. 10 authentication triplets- Performed between MS and SGSN

Ciphering- Kc ciphering key (from authentication triplet)- A5/GPRS algorithm (in ME and SGSN), standardised by ETSI

P-TMSI- Used to avoid the broadcast of IMSI- 32 bits, operator specific

IMEI checking- Validation of GPRS ME- Performed between MS and EIR, via SGSN

Plus IP-related security aspects- Private IP Addresses in GPRS BB network- User authentication, VPN (ciphered links over the Internet), private IPconnections between operators, etc.- Firewalls - screening of packets

Security related to GPRS

Charging of GPRS services


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SGSN

OperatorIP backbone

GGSNBorder Gateway

Inter operatorIP network Internet

Billing SystemCharging gateway

Nokia GPRS Charging Gateway:

* receives CDRs generated bySGSN and GGSN

* consolidates and merges CDRsto a suitable format for BS

GTP'

GTP'

Charging of GPRS services

GGSN charging functions


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CG

Internet

GGSN

OperatorIP backbone

SGSN

G-CDRs

GGSN CDR (PDP context data): G-

CDR

Start collection:

- PDP context activation

Stop collection:- PDP context deactivation

Collected information e.g.

- Traffic volumes

uplink/downlink

- QoS negotiated

- Duration

- SGSN & GGSN address- Access Point Name

GGSN charging functions

SGSN charging functions


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SGSN CDR (PDP context data): S-CDR

Start collection:

- PDP context activation Stop collection:

- PDP context deactivation

Collected information e.g.

- Traffic volumes uplink/downlink

- QoS requested/negotiated

- Duration

- SGSN & GGSN address

- Access Point Name

Mobility Management CDR: M-CDR

Start collection:

- GPRS activation / Incoming SGSN RA

update Stop collection:

- GPRS deactivation / Outgoing SGSN RA

update

Collected information

- Location changes

CG

S-CDRsM-CDRsSMS-CDRs

Internet

GGSN

OperatorIP backbone

SGSN

Also S-SMO-CDRand S-SMT-CDR

generation!

SGSN charging functions

CG functionality


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CDR collection from GSNs (CG receives the CDRs with GTP')

Intermediate storage for CDRs CDR validation

CDR consolidation

CDR formatting

Adaptation to different CCB System interfaces

To reduce the CDR processing load of the CCB System

CG functionality

Legal Interception Gateway


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SGSN

GGSN

LIG LEA

InternetX.25

Normal Data transfer

Intercepted data transfer

Gn

National interface

Legal Interception Gateway

Ch4-GPRS Traffic Management

Documents

Transcript of Ch4-GPRS Traffic Management