00- GPRS Fundamental Introduction

1GPRS Fundamental Introduction

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2 GPRS GPRS Network architectureNetwork architecture Mobility managementMobility management Radio resource ManagementRadio resource Management Location managementLocation management Session managementSession management

OutlineOutline


3GPRS Network StructureGPRS Network Structure

FR

EIREIRHLRHLRSMS-GMSCSMS-IWMSCSMS-GMSCSMS-IWMSC

MSC/VLRMSC/VLR

BSSBSS

UTRANUTRAN

SGSNSGSN

SGSNSGSN

GGSNGGSN

BGBG

CGCG

TETEInternet

SS7

ATM

DDN

ISDN

Ethernet.etc

GPRSBackbone

Gs Gd Gr Gf Gc

Gb

Iu

Um

Um

Gp

Gi

Gn

Gn

ATM Ga

Abbreviation of General Packet Radio Service

SCPSCP GMLCGMLC

Ge Lg


4 GPRS GPRS Network architectureNetwork architecture Mobility managementMobility management Radio resource ManagementRadio resource Management Location managementLocation management Session managementSession management

OutlineOutline


5GMMGPRS Mobility ManagementGMMGPRS Mobility Management

Function of the Mobility Management sublayer to keep track of the current location of an MS within the

PLMN or within another PLMN

GMM specific procedures Attach procedure RAU and periodic RAU Detach Service request (UMTS only)

GMM common procedures P-TMSI reallocation procedure Authentication procedure Identification procedure


62G Network States2G Network States

PDU transmission

Implicit Detachor

Cancel Location

GPRS Attach

READY timer expiryorForce to STANDBY

GPRS Detach GPRS Attach

PDU reception

GPRS Detachor

Cancel Location

MM State Model of MS MM State Model of SGSN

IDLE

READY

STANDBY

IDLE

READY

STANDBY

READY timer expiryorForce to STANDBYorAbnormal RLC condition


73G Network states3G Network states

PMM-DETACHED

PS Attach

PS SignallingConnection Release

PS SignallingConnection Establish

PS Detach

PMM-CONNECTEDPMM-IDLE

Detach,PS Attach Reject,RAU Reject

PMM-DETACHED

PS Detach

PMM-CONNECTED

Serving RNCrelocation

3G-SGSN MM StatesMS MM States

SM-ACTIVE orINACTIVE




Detach,PS Attach Reject,RAU RejectPS Attach

PS SignallingConnection Establish

PS SignallingConnection Release

PMM-IDLE


8Timers of Mobility ManagementTimers of Mobility Management Periodic RA Update Timer

Monitors the periodic routing area update procedure in the MS Upon expiry of the timer, the MS shall start a periodic routing area

update procedure. The length of the timer shall set in SGSN; The value of the timer shall

send to MS an attach procedure or routing update procedure

Mobile Reachable Timer Upon the expiry of this timer, the MS is detached This is reset and started when the state returns to STANDBY or

PMM-IDLE. The timer shall be slightly longer than the periodic RA update timer

used by an MS The length of the timer shall set in SGSN

Purge Timer Allows the SGSN to inform the HLR that it has deleted the MM and

PDP contexts of a detached MS. The purge timer is set longer than the mobile reachable timer


9Attach ProcedureAttach Procedure


10

Attach Procedure Attach Procedure


11

Attach ProcedureAttach Procedure

Results after any attach procedure SGSN get subscriber data from HLR HLR recorded the MSs serving SGSN number SGSN and MS create MM context for the MS

MS can request Session Management services


12

MS-initiated Detach ProcedureMS-initiated Detach Procedure

2. Delete PDP Context Response

1. Detach Request

2. Delete PDP Context Request

3. Detach Accept

MS BSS/UTRAN GGSN SGSN

4. PS Signalling Connection Release


13

Detach ProcedureDetach Procedure

The detach procedure can be initiated by SGSN or MS,HLR

Explicitly detach and implicitly detach Explicit detach: The network or the MS explicitly requests detach. Implicit detach: No message exchange between SGSN and MS.

The mobile reachable timer expires or radio error causes disconnection of the logical link.

After detach procedure The SGSN shall not service the detached MS, unless reattach.


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Purge MSPurge MS

The Purge function allows an SGSN to inform the HLR that it has deleted the MM and PDP contexts of a detached MS

After the MS detach, SGSN may have two choice to handle MM/PDP context

Delete immediately, or Delete after a long time (Purge timer expires). The value of this time is set in

SGSN

1. Purge MS

2. Purge MS Ack

SGSN HLR


15

Authentication Procedure(2G)Authentication Procedure(2G)

1. Send Authentication Info

2. Authentication and Ciphering Request 1. Send Authentication Info Ack

2. Authentication and Ciphering Response

MS BSS/UTRAN HLRSGSN

IMSI

(RAND, CKSN, Ciphering Algorithm)

SRES

Purpose to ensure that the user is authorised to use the particular network

services selection of the ciphering algorithm Each triplet contains RAND, SRES and Kc.

(Authentication Triplets)


16

Authentication Procedure(3G)Authentication Procedure(3G)

1. Send Authentication Info

2. Authentication and Ciphering Request 1. Send Authentication Info Ack

2. Authentication and Ciphering Response

MS BSS/UTRAN HLRSGSN

IMSI

RAND, AUTN,KSI

XRES

Purpose to ensure that the user is authorised to use the particular network

services selection of the ciphering algorithm Each quintuplet contains RAND, XRES, AUTN, CK, and IK.

(quintuplet)


17

Identity Check ProcedureIdentity Check Procedure

Purpose Get IMSI from MS Validate IMEI

1. Identity Response 2. Check IMEI

1. Identity Request

2. Check IMEI Ack

MS BSS/UTRAN EIRSGSN


18

P TMSI ReallocationP TMSI Reallocation

2. P-TMSI Reallocation Complete

1. P-TMSI Reallocation Command

MS BSS/UTRAN SGSN

The SGSN may reallocate the P-TMSI at any time.

The reallocation procedure can be included in the Attach or Routeing Area Update procedures.


19

GPRS GPRS Network architectureNetwork architecture Mobility managementMobility management Radio resource ManagementRadio resource Management Location managementLocation management Session managementSession management

OutlineOutline


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Paging for GPRSPaging for GPRS

5. Any LLC Frame

4. Any LLC Frame

3. GPRS Paging Request

2. Paging Request

1. PDP PDU

MS BSS SGSN

STANDBY

READY

(IMSI, P-TMSI, Area, Channel Needed, QoS, DRX Parameters)

(Receive Ready or Information frame)


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Paging initiated by the CNPaging initiated by the CN

4. Service Request4. Service Request

3. Paging Type12. Paging

MS RNS MSC/VLR

3G-SGSN1. PDP PDU or

Downlink signalingPMM IDLE

PMM CONNECTED

PS Paging Without RRC Connection for CS

(PCH paging)(IMSI, P-TMSI, Area, CN Domain Indicator, DRX parameters)


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Paging initiated by the CNPaging initiated by the CN

4. Service Request

4. Service Request

3. Paging Type22. Paging

MS RNS MSC/VLR

3G-SGSN

Connection Established

1. PDP PDU orDownlink signalling

PS Paging With RRC Connection for CS

(RRC paging)(IMSI, P-TMSI, Area, CN Domain Indicator, DRX parameters)

PMM IDLE

PMM CONNECTED


23

Paging SummaryPaging Summary

MM state in SGSN,MS :IDLE mode A Paging message is received by SGSN

Change MM state in SGSN

A Paging message is received by MS P-TMSI is used to identify the MS If P-TMSI is invalid or MS not respond ,then use IMSI Change MM state in MS to PMM-Connected or Ready


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OutlineOutline


25

Layered Location Management ModeLayered Location Management Mode

The Location Management function provides:

a mechanism for the network to know the RA for MSs in STANDBY, PMM-IDLE, READY, and PMM-CONNECTED states

a mechanism for the 2G-SGSN to know the cell identity for MSs in READY state

a mechanism for the UTRAN to know the URA identity or cell identity for MSs in PMM-CONNECTED state

a mechanism for the UMTS network to know the address of the serving RNC handling an MS in PMM-CONNECTED state


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SGSN

HLR

BSS

MS

SGSN number

ready state: cell number

Standby state : RAI

2G


27


SGSN

HLR

RNC

MS

SGSN number

PMM-connect state :RNCID,RAI

PMM-idle :RAI

3G


28

Network ArchitectureNetwork Architecture

Handover procedure Move the radio link to the other

NodeB

Route area update procedure SGSN can manage the MS

location information via RAU procedure in RAI level

Relocation procedure Move the Iu interface to the

other RNC

old SGSN

RNC2RNC1

MS

GGSN

Iu

new SGSN

RNC4 RNC3

IU

HLR/AUC

Gn/Gp Gn/Gp

PDN

Gi

Gr GrIUIu

Gn

RA1 RA2 RA3

RA4 RA5

RA6 RA7 RA9

RA9 RA10

Iur


29

RAU ProcedureRAU Procedure

MS

RAI 2 RAI 4

SGSN SGSN

RAI 1 RAI 3

cell

Intra SGSN-Rau

Inter SGSN -Rau

Gn


30

Inter-SGSN Route Area Update Procedure(3G)Inter-SGSN Route Area Update Procedure(3G)


31


CONSTRUCT MM CONTEXT

ESTABLISH MM CONTEXT


32



33



34

Route Area Update summaryRoute Area Update summary

RAU update MS Entered a new Route Area Periodic RAU ( after periodic timer expires)

Inter-SGSN RAU The new SGSN Find the old SGSN from the old RAI Old SGSN stop downlink signaling, transfer MM context and

PDP context to new SGSN tunnelling N-PDU to the new SGSN Update PDP context and subscriber data


35

Service Request ProcedureService Request Procedure

Service request procedure Establish Iu signaling connection for the MS

MS initiated For the active PDP context request procedure For the data

Network initiated Paging response


36

Service Request ProcedureService Request Procedure

MS initialed service request procedure

SGSNMS

2. Service Request

3. Security Functions

RNC1. RRC Connection Request

8. Uplink PDU

1. RRC Connection Setup

4. Radio Access Bearer AssignmentRequest

6. Radio Access Bearer AssignmentResponse

5. Radio Bearer Setup

6. Radio Bearer SetupComplete

HLR GGSN

7. SGSN-Initiated PDP Context Modification

4. Service Accept

(SERVICE TYPE)


37


OutlineOutline


38

PDP ContextPDP Context

What is the PDP context?

The PDP context is Packet Data protocol Context PDP context contains all the information needed to transfer

user data between MS and GGSN. The context defines parameters such as Routing, QoS

(Quality of Service), Charging ID etc.


39

Functional PDP State ModelFunctional PDP State Model

PDP state inactivecannot transmit data activecan transmit data

Deactivate PDP Contextor

MM state change to IDLEor PMM-DETACHED

Activate PDPContext

INACTIVE

ACTIVE


40

PDP contextPDP context

XXSpecifies whether the MS is allowed to use the APN in the domain of the HPLMN only, or additionally the APN in the domain of the VPLMN.

VPLMN Address Allowed

XXThe IP address of the GGSN currently used.GGSN Address in Use

XTunnel Endpoint Identifier for the Iu interface.TEID for Iu

XXTunnel Endpoint Identifier for the Gn and Gp interfaces.

TEID for Gn/GpXXTransaction Identifier.TIXXNetwork layer Service Access Point Identifier.NSAPIXXThe APN currently used.APN in UseXXThe APN received from the HLR.APN SubscribedXXPDP address, e.g., an IP address.PDP AddressXXPDP type, e.g., PPP or IP.PDP TypeXXPacket data protocol state, INACTIVE or ACTIVE.PDP State

XXIndex of the PDP context.PDP Context Identifier

Each MM context contains zero or more of the following PDP contexts: Gb Iu


41


XXGTP-U sequence number of the next downlink N-PDU to be sent to the MS.

GTP-SND

XSNDCP sequence number of the next uplink N-PDU expected from the MS.

Receive N-PDU Number

XSNDCP sequence number of the next downlink N-PDU to be sent to the MS.

Send N-PDU Number

XThe aggregate BSS quality of service profile negotiated for the packet flow that this PDP context belongs to.

Aggregate BSS QoS Profile Negotiated

XPacket flow identifier.Packet Flow Id

XThe RLC/MAC radio priority level for uplink user data transmission.

Radio Priority

XXThe quality of service profile negotiated.QoS Profile Negotiated

XXThe quality of service profile requested.QoS Profile Requested

XXThe quality of service profile subscribed.QoS Profile Subscribed


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XThe IP address of the RNC currently used.RNC Address in Use

XXThe charging characteristics of this PDP context, e.g., normal, prepaid, flat-rate, and/or hot billing.

PDP Context Charging Characteristics

XXCharging identifier, identifies charging records generated by SGSN and GGSN.

Charging Id

XSequence number of the next uplink in-sequence PDCP-PDU expected from the MS.

PDCP-SNU

XSequence number of the next downlink in-sequence PDCP-PDU to be sent to the MS.

PDCP-SND

XXGTP-U sequence number of the next uplink N-PDU to be sent to the GGSN.

GTP-SNU


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Subscriber Data in HLRSubscriber Data in HLR

Domain Description

IMSI International M obile Subscriber Identity MSISDN Mobile Subscriber ISDN Number SGSN Number NO.7 number of the SGSN SGSN Address IP address of the SGSN SM S Parameters MS Purged for GPRS M NRG GGSN-lis t GGSN lis t including IP address and the NO.7 coding of the

GGSN PDP Contex t Identifier PDP Type IP or X.25 PDP Address The us er ip address Qos Profile Subscribed VPLM N Address Allowed Access Point Name


44

PDP and MM ContextPDP and MM Context

HLR

SGSNBSC

or RNC

MS GGSNGnGb

or IU

Uu

PDP context #2

.

.

PDP context #1

MM context

PDP context #2

.

.

PDP context #1

MM context

PDP context #2

.

.

.

PDP context #1


45

APN structureAPN structure

www.huawei.com.mnc.mcc.gprs

APNNetwork ID

APNOperator ID

Operator ID : fixed extension

Network ID shall not end with .gprs


46

How to find GGSN?How to find GGSN?

DNS

BTS

SGSN

MS

DNS

BSC

GGSN (B)BackboneBackboneDNS

ISP BISP B

ISP AISP A

Corp.Network

Corp.Network

GGSN (A)

APNAPN--NINI

APNAPN--NINIAPNAPN--OIOIIP IP addraddr

APNAPN--NINI

TS 23.060 ANNEX A


47

General APNGeneral APN

SGSN

MS

SGSN

MS

internet

GGSN GGSN

Beijing province

Roaming

Example APN:CMNET

GuangDong province


48

Regional APN (for VPNs)Regional APN (for VPNs)

SGSN

MS

SGSN

MS

GGSN GGSN

Roaming

Example APN:test.xy

VPN tunnel

Province 2Province 1


49

PDP Context ProcedurePDP Context Procedure

PDP context activation procedure To establish a PDP context between the MS and the SGSN,

the GGSN The first PDP context for a given PDP address and APN

Secondary PDP context active procedure (Traffic Flow Template (TFT) )-distinguish

PDP context modification change the QoS negotiated, the Radio priority level, or the

TFT PDP deactivation procedure


50

PDP Active Procedure(2G)PDP Active Procedure(2G)

l2Gl-GGSN

l 9. Activate PDP Context Accept

l 4. Create PDP Context Response

l 4. Create PDP Context Request

l 1. Activate PDP Context Request

l2Gl-SGSNlBSS

l 2. Security Functions

lMS

l 7. BSS Packet Flow Context Procedures

lC1

lC2


51

PDP Active Procedure(3G)PDP Active Procedure(3G)

(PDP Type, PDP Address, Access Point Name, QoS Requested, PDP Configuration Options)

Charging ID allocation

l3Gl-GGSN

l7. Activate PDP Context Accept

l3. Create PDP Context Response

l2. Create PDP Context Request

1. Activate PDP Context Request

l3Gl-SGSNlUTRANlMS

4. lRadio Access Bearer Setup

lC1

lC2

6. Update PDP Context Response

5. Update PDP Context Request


52

Handle in MSHandle in MS

MS start Provide QoS parameter Provide a APN-NI Provide a static IP or null

Receive ACCEPT from SGSN If the QoS not accept by MS, then starts deactive procedure.


53

Handle in SGSNHandle in SGSN

Check subscriber data APN selection

According to TS 23.060 default APN,APN provide from MS and the APN subscribed in HLR APN-NI.APN-OI

Interrogate DNS Hostfile/Cache/DNS server

QoS negotiation QoS provided from MS, default QoS ,QoS subscribed in HLR

Send message create PDP context request to GGSN Send message active PDP context accept to MS

Dynamic IP address QoS

RAB assignment


54

Handle in RNCHandle in RNC

RAB assignment

RNC

SGSNMS GGSN

RAB assignment (Final negotiated Qos)

Allocate Iu interface resource Allocate radio resource


55

Handle in GGSNHandle in GGSN

Check the APN provided by SGSN QoS negotiation Allocate a dynamic IP to the MS Allocate a charging ID for the PDP context Return a CREATE PDP CONTEXT ACCEPT message to

SGSN Dynamic IP QoS Charging ID Other information

Update PDP context


56

Network-initiated PDP Active ProcedureNetwork-initiated PDP Active Procedure

MS SGSN GGSN

3. PDU Notification Request

HLR

1. PDP PDU

2. Send Routeing Info for GPRS

2. Send Routeing Info for GPRS Ack

4. Request PDP Context Activation

5. PDP Context Activation procedure

3. PDU Notification Response


57

Network-initiated PDP Active ProcedureNetwork-initiated PDP Active Procedure

MS must have static IP address GGSN finds the routing of the MS via IMSI HLR returns the SGSN address of Gn interface SGSN pages the MS

Cause is Request PDP context active

MS initialize the active procedure via service request procedure


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00- GPRS Fundamental Introduction

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