Huawei Gprs Umts Ps Fundamental

GPRS&UMTS PS Fundamental www.huawei.com

Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.

Foreword l

GPRS&UM GPRS&UMTS TS PS fundamen fundamental tal is the basic part of the whole system and the later products learning. This slide will help us to understand the GPRS system networking and some important procedure.


Page2

References l

3GPP protocol 23060

l

3GPP protocol 29060

l

3GPP protocol 24008


Page3

Objectives l

Upon completion of this course, you will be able to: p

Describe the GPRS networking structure

p

Describe the GPRS mobility management procedure

p

Describe the GPRS session management procedure


Page4

Contents 1. GPRS&UMTS Network Structure 2. Mobility Management 3. Radio Resource Management 4. Session Management


Page5

GPRS&UMTS Network Structure l

What is GPRS? p

l

What is the function of GPRS? p

l

l

General Packet Radio Service

In order to provide the data service out the scope of the fixed network

GPRS network classification p

GSM GPRS

p

UMTS GPRS

GPRS network background p

GSM GPRS network reuse the existed GSM network

p

UMTS GPRS network just change the RAN side


Page6

GPRS&UMTS Network Structure MSC/VLR MSC/VLR

SMS-GMSC SMS-GMSC SMS-IWMSC SMS-IWMSC

SCP SCP

GMLC GMLC

HLR HLR

EIR EIR

SS7 Gs

FR/IP

BSS BSS Um

Gd

Ge

ATM DDN

Gn

Gr

Gf

Gn

SGSN SGSN

Gb

Lg

ISDN

Gc

GGSN GGSN

GPRS Backbone

Ga

Ethernet.etc

UTRAN UTRAN Um

ATM/IP

SGSN SGSN

CG CG

Ga

Iu BG BG Gp Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.

Page7

PDN Gi

TE TE


Some Abbreviation p

GPRS: General Packet Radio Service

p

BSS: Base Station Subsystem

p

UTRAN: UMTS Terrestrial Radio Access Network

p

SGSN: Service GPRS Support Node

p

GGSN: Gateway GPRS Support Node

p

CG: Charging Gateway

p

BG: Border Gateway

p

PDN: Packet Data Network


Page8


Abbreviations: p

MSC/VLR: Mobile Switch Center/Visitor Location Register

p

SMS-GMSC: Gateway MSC For Short Message Service

p

SMS-IWMSC: Short Message Service Interworking MSC

p

SCP: Service Control Point

p

GMLC: Gateway Mobile Location Center

p

HLR: Home Location Register

p

EIR: Equipment Identity Register


Page9

Functions of SGSN l

Important Entity Function: SGSN p

Mobility management n

p

Session management n

p

SM function manages the PDP context of MS.

Routing and transfer n

p

The MM functions are used to keep track of the current location of an MS within the PLMN or within another PLMN.

SGSN performs routing and forwarding of service data between MS and GGSN.

Charging n

SGSN can generate, store, convert and send CDRs.

p

Lawful Interception

p

NTP


Page10

Functions of GGSN l

Important Entity Function : GGSN p

Session management n

p

SM function manages the PDP context of MS.

Routing and transfer n

GGSN performs routing and forwarding of service data between MS and internet.

p

Charging n

GGSN can generate, store, convert and send CDRs.

p

Dynamic IP allocation

p

Service management n

Manage APN


Page11

Functions of CG l

Important Entity Function: CG p

Real-time collection of GPRS CDRs

p

Temporary storage and buffering of GPRS CDRs

p

Pre-processing of GPRS CDRs

p

Sending GPRS CDRs to the billing center


Page12

Functions of DNS SGSN l

GGSN(A)

Important Entity ISP A A

Function: DNS GPRS GPRS backbone backbone

ISP ISP B

BSS DNS

MS

Internet/ Intranet

GGSN(B)

p

Resolve the APN to a GGSN IP in the PDP active procedure

p

Resolve the RAI to a SGSN IP in the inter-SGSN RAU procedure

p

Resolve the RNCID to a SGSN IP in the relocation procedure (UMTS)


Page13

Functions of HLR l

Important Entity Function: HLR p

Saving and updating GPRS subscriber subscription data

p

User authentication

p

Providing location information and processing needed in mobility management and routing, for example n

Saving and updating user service SGSN number and address

n

GPRS user location deletion indication

n

Whether MS is reachable


Page14

Functions of BG l

BG：the border gateway between two PLMN, It provides, apart from the security function, the routing function between SGSNs and GGSNs in different GPRS/UMTS networks.

l

BG supports the following necessary protocols for inter-networking of the different operators;

l

p

Security protocol：recommend to use IPSEC and firewall;

p

Routing protocol ： recommend to use BGP

Base on common router; Gp GSN PLMN A

R R

BG


BG

R R

GSN PLMN B

Page15

Functions of AAA server l

AAA Server is used to perform authentication, authorization and accounting functions.

l

In Non-transparent access mode, the GGSN will communicate with remote AAA Server to check the validity of MS/UE by using RAIDUS (Remote Authentication Dial In User Service) protocol.


Page16

SMS- GMSC and SMS- IWMSC l

SMS-GMSC and SMS-IWMSC: are the part of SMSC, and used to handle the MAP protocol.

l

The Short message can be sent via CS domain or PS domain.

l

The operator can decide to use CS or PS to send the short message to MS. SMS

MS

Gd

SGSN


SMS-IWMSC SMS-GMSC Page17

User Terminal: MS (2G) l

A GSM/GPRS Mobile Station can operate in one of three modes of operation: p

Class A: n

p

Class B: n

p

operates GPRS and other GSM services simultaneously

monitors control channels for GSM GPRS and other GSM services simultaneously, but can only operate one set of services at one time

Class C: n

exclusively operates GPRS services


Page18

User Terminal: UE (3G) l

A UMTS user equipment can operate in one of three modes of operation: p

PS/CS mode: n

p

PS mode: n

p

operates PS and CS services simultaneously

exclusively operates PS services

CS mode: n

exclusively operates CS services

In order to read more easily, 2G MS and 3G UE are all named as MS in this document.


Page19

Summary l

GPRS network provides data service to the mobile subscribers.

l

GPRS network is composed of SGSN, GGSN and CG. BG and DNS provide special function during the data service.


Page20

Objectives l

GPRS&UMTS Network Structure

l

Mobility Management

l

Radio Resource Management

l

Session Management


Page21

Contents 2. Mobility Management 2.1 Basic concepts 2.2 Attach and Detach 2.3 Security Function 2.4 Location Management 2.5 Service Request (UMTS only)


Page22

GMM (GPRS Mobility Management) l

Function of the Mobility Management p

keep track of the current location of an MS within the PLMN or within another PLMN

p

Subscription data management

p

MS states management


Page23

GMM (GPRS Mobility Management) l

GMM main procedures p

l

Attach procedure

p

RAU and periodic procedure

p

Detach procedure

GMM other procedures p

p

P-TMSI reallocation procedure Authentication procedure

p

Identification procedure

p

Subscriber management procedure


Page24

GMM States IDLE

IDLE

GPRS Attach

GPRS Detach

READY

READY timer expiry or Force to STANDBY

GPRS Detach or Cancel Location

GPRS Attach

Implicit Detach or Cancel Location

PDU transmission

READY

READY timer expiry or Force to STANDBY or Abnormal RLC condition

PDU reception

STANDBY

STANDBY

MM State Model of MS

MM State Model of SGSN


Page25

PMM (Packet Mobility Management) l

The function of PMM is similar to GMM.

l

PMM other procedures P-TMSI reallocation

p

Authentication

p

l

PMM main procedures Attach

p

RAU and periodic RAU

p

Detach

Identification

p

Subscriber management

p

p

p

Service request SRNS relocation

p


Page26

PMM States PMMDETACHED

PS D etach

PMM-IDLE SM-ACTIVE or INACTIVE

PS Attach PS Signalling Connection Release

PS Signalling Connection Establish

PMMDETACHED

Detach, PS Attach Reject, RAU Reject

PMMCONNECTED SM-ACTIVE or INACTIVE

PS Detach

PMM-IDLE

PS Attach PS Signalling Connection Release

Detach, PS Attach Reject, RAU Reject

PMMCONNECTED

SM-ACTIVE or SM-ACTIVE or PS Signalling INACTIVE INACTIVE Connection Establish

Serving RNC relocation

MS M M States


3G-SGSN MM States

Page27

Mobility Management Timer Functions l

READY Timer Function (GSM only) p

The READY timer controls the time an MS remains in READY state in the MS and the SGSN. When the READY timer expires, the MS and SGSN MM contexts shall return to STANDBY state.

l

Periodic RA Update Timer Function p

Upon expiry of the periodic RA update timer, the MS shall start a periodic routeing area update procedure.

l

Mobile Reachable Timer Function p

p

If the mobile reachable timer expires, the SGSN shall clear PPF. After expiry of the mobile reachable timer the SGSN may perform an implicit detach.


Page28



Page29

Attach Procedure l

Function p

An MS/UE shall perform a GPRS Attach to the SGSN in order to obtain access to the GPRS services.

p

If the MS/UE is connected via a GSM radio, it shall perform a GSM GPRS Attach procedure.

p

If the MS/UE is connected via a UMTS radio access network, it shall perform a UMTS GPRS Attach procedure


Page30

Attach Procedure (IMSI or PTMSI+RAI)

(PTMSI) (IMSI)

(Identity Type = IMSI) (IMSI)


Page31

Attach Procedure


Page32

Attach Procedure l

l

Results after any attach procedure: p

SGSN get subscriber data from HLR

p

HLR recorded the MS ’s serving SGSN number

p

SGSN and MS create MM context for the MS

MS can request Session Management services


Page33

MM Context Field

Description

A/Gb mode

Iu mode

IMSI

IMSI is the main reference key.

X

X

MM State

Mobility management state, IDLE, STANDBY, READY, PMM-DETACHED, PMM-IDLE, or PMM-CONNECTED.

X

X

P-TMSI

Packet Temporary Mobile Subscriber Identity.

X

X

P-TMSI Signature

A signature used for identification checking purposes.

X

X

IMEI

International Mobile Equipment Identity

X

X

MSISDN

The basic MSISDN of the MS.

X

X

Routeing Area

Current routeing area.

X

X

Cell Identity

Current cell in READY state, last known cell in STANDBY or IDLE state.

X

Cell Identity Age

Time elapsed since the last LLC PDU was received from the MS at the SGSN.

X

Service Area Code

Last known SAC when initial UE message was received or Location Reporting procedure was executed.

X

Service Area Code Age

Time elapsed since the last SAC was received at the 3G-SGSN.

X

VLR Number

The VLR number of the MSC/VLR currently serving this MS.

X

X

New SGSN Address

The IP address of the new SGSN where buffered and not sent N-PDUs should be forwarded to.

X

X

Authentication Vectors

Authentication and ciphering parameters (authentication triplets or quintets).

X

X

Kc

Currently used A/Gb mode ciphering key.

X

2)

CKSN

Ciphering key sequence number of Kc.

X

2)

Ciphering algorithm

Selected ciphering algorithm (GEA).

X

X

CK

Currently used Iu mode ciphering key.

1)

X


Page34

MM Context IK

Currently used Iu mode integrity key.

1)

X

KSI

Key Set Identifier.

1)

X

MS Radio Access Capability

MS radio access capabilities.

X

MS Network Capability

MS network capabilities.

X

X

DRX Parameters

Discontinuous reception parameters.

X

X

Radio Priority SMS

The RLC/MAC radio priority level for uplink SMS transmission.

X

MNRG

Indicates whether activity from the MS shall be reported to the HLR.

X

X

NGAF

Indicates whether activity from the MS shall be reported to the MSC/VLR.

X

X

PPF

Indicates whether paging for PS and CS services can be initiated.

X

X

Subscribed Charging

The charging characteristics for the MS, e.g. normal, prepaid, flat-rate, and/or

X

X

Characteristics

hot billing subscription.

SMS Parameters

SMS-related parameters, e.g. operator-determined barring.

X

X

Recovery

Indicates if HLR or VLR is performing database recovery.

X

X

GPRS-CSI

Optional GPRS CAMEL subscription information, see 3GPP TS 23.016

X

X

ODB for PS parameters

Indicates that the status of the operator determined barring for packet oriented

X

X

services. l

l

The information marked with a "1)" may be maintained if authentication is performed by the UMTS authentication procedure. The information marked with a "2)" may b e maintained if authentication is performed by t he GSM authentication procedure.


Page35

Detach Procedure l

Function p

The GPRS Detach procedure allows an MS to inform the network that it does not want to access the SGSN-based services any longer

p

The GPRS Detach procedure allows the network to inform an MS that it does not have access to the SGSN-based services any more

l

The following three entity can initiate the detach procedure p

MS

p

SGSN

p

HLR


Page36

Detach Procedure l

l

Results after any Detach procedure: p

The SGSN shall not service the detached MS, unless reattach

p

The MS is in idle or PMM-DETACHED state

The MS is detached either explicitly or implicitly: p

Explicit detach: The network or the MS explicitly requests detach

p

Implicit detach: The network detaches the MS, without notifying the MS, a configuration-dependent time after the mobile reachable timer expired, or after an irrecoverable radio error causes disconnection of the logical link.


Page37

Detach Types l

l

The different types of detach are: p

IMSI detach;

p

GPRS detach;

p

combined GPRS / IMSI detach (MS-initiated only).

The MS can make an IMSI detach in one of two ways depending on whether it is GPRS-attached or not: p

A GPRS-attached MS sends a Detach Request message to the SGSN, indicating an IMSI detach. This can be made in combination with GPRS detach.

p

An MS that is not GPRS-attached makes the IMSI detach as already defined in A/Gb mode or UMTS.


Page38

Detach Procedure (MS Initiated) MS

BSS/UTRAN

SGSN

GGSN

MSC/VLR

1. Detach Request 2. Delete PDP Context Request 2. Delete PDP Context Response C1 3. IMSI Detach Indication 4. GPRS Detach Indication 5. Detach Accept

C2

6. PS Signalling Connection Release


Page39

Detach Type IE of Detach Request Type of detach (octet 1)

8

7 6 5 Detach type IEI

4

3

2

Power Type of off detach

Power off (octet 1) In the MS to network direction: Bit

1

In the MS to network direction: Bits 3 2 1 0 0 1

GPRS detach

0 1 0

IMSI detach

0 1 1

Combined GPRS/IMSI detach

All other values are interpreted as Combined GPRS/IMSI detach by this version of the protocol. In the network to MS direction:

4

Bits

0

normal detach

1

power switched off

In the network to MS direction the Power off bit shall be spare and set to zero.

3 2 1 0 0 1

re-attach required

0 1 0

re-attach not required

0 1 1

IMSI detach (after VLR failure)

All other values are interpreted as reattach not required by this version of the protocol.


Page40

Detach Procedure (SGSN Initiated) MS

BSS/UTRAN

1. Detach Request

SGSN

GGSN

MSC/VLR

2. Delete PDP Context Request 2. Delete PDP Context Response C1

4. Detach Accept

3. GPRS Detach Indication C2



Page41

Detach Procedure (HLR Initiated) MS

BSS/UTRAN

2. Detach Request

SGSN

GGSN

HLR

1. Cancel Location 3. Delete PDP Context Request 3. Delete PDP Context Response C1

5. Detach Accept

4. GPRS Detach Indication C2 6. Cancel Location Ack



Page42

MSC/VLR

Purge Function l

Function p

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

l

After the MS detach from the network: p

p

l

The SGSN may delete the MM/PDP context immediately the SGSN may keep the MM/PDP context for some time of the detached MS

Purge Timer Function p

Allows the SGSN to inform the HLR that it has deleted the MM and PDP contexts of a detached MS.

p

The purge timer is set longer than the mobile reachable timer


Page43

Purge Function SGSN

HLR

1. Purge MS 2. Purge MS Ack


Page44



Page45

Authentication Function l

Function p

Permit the network to check whether the identity provided by the mobile station is acceptable or not;

p

Provide parameters enabling the mobile station to calculate a new ciphering key ; （UMTS and GSM ）

p

Provide parameters enabling the mobile station to calculate a new UMTS integrity key; （UMTS only）

p

Permit the mobile station to authenticate the network. （UMTS only）


Page46

Authentication Function l

Authentication types: p

p

GSM Authentication n

Using triplet: RAND, SRES, Kc

n

Using GPRS Encryption Algorithm (GEA)

UMTS Authentication n

Using quintet: RAND, XRES, AUTN, CK, IK – –

n

l

AUTN: for UE authenticate network IK: for data integrity function

Using UMTS Encryption Algorithm (UEA)

These procedures are used independent of the GSM or U TRAN RANs, i.e. each procedure may be executed in A/Gb mode or in Iu mode.


Page47

Authentication Function MS

BSS/UTRAN

SGSN

HLR/Auc

1a. Send Authentication Info 1b . Send Authentication Info ack 2a. Authentication and Ciphering Request 2b. Authentication and Ciphering Response


Page48

Authentication Function(3G) MS

VLR/SG SN

HE/HLR

Au the ntic ati on da ta req ue st

Generate authentication vectors AV(1..n)

Distribution of authentication vectors from HE to SN

Au th en tic at ion da ta res pon se AV(1..n)

Store authentication vectors

Select authentication vector AV(i) User authentication request RAND(i) || AUTN(i)

Verify AUTN(i) Compute RES(i) User authentication response RES(i)

Authentication and key establishment

Compare RES(i) and XRES(i)

C om pute CK (i) and IK (i)

Select CK (i) and IK (i)


Page49

Scope and Start of Ciphering l

In A/Gb mode, the scope of ciphering is from the ciphering function in the SGSN to the ciphering function in the MS.

l

In Iu mode, the scope of ciphering is from the ciphering function in the UTRAN to the ciphering function in the MS. MS

BSS/UTRAN

SGSN Scope of GSM GPRS ciphering Scope of UMTS ciphering

l

In A/Gb mode, the MS starts ciphering after sending the Authentication and Ciphering Response message.

l

In Iu mode, the start of ciphering is controlled by the security mode procedure after authentication procedure.


Page50

Identity Check MS

BSS/UTRAN

SGSN

EIR

1. Identity Request 1. Identity Response 2. Check IMEI 2. Check IMEI Ack

l

Function p

Get IMSI from MS

p

Check the IMEI


Page51

P- TMSI Reallocation l

Function p

The SGSN may reallocate the P -TMSI at any time

p

The reallocation procedure can be performed by the P -TMSI Reallocation procedure

p

The P-TMSI can be included in the Attach or Routeing Area Update procedures.

MS

BSS/UTRAN

SGSN

1. P-TMSI Reallocation Command 2. P-TMSI Reallocation Complete


Page52



Page53

Location Management l

Function

p

A mechanisms for cell and PLMN selection;

p

A mechanism for the network to know the Routeing Area for MSs in STANDBY, PMM-IDLE, READY, and PMM -CONNECTED states;

p

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


Page54

Layered Location Management Mode (2G)

•HLR

•SGSN

•SGSN number

•BSS •ready •MS

state: cell number

•Standby


state: RAI

Page55

Layered Location Management Mode (3G)

•HLR

•SGSN

•SGSN

number

•RNC •PMM-connect •MS

•PMM-idle:


state: RNCID,RAI,SAI

RAI

Page56

Network Architecture l

Routeing area update procedure p

PD N

SGSN can manage the MS

Gi

GGSN

location information via RAU procedure in RAI level l

old SGSN

Gr

only) Move the Iu interface to the

IU

HLR/AUC

Iur RNC1

RA4 RA1

Move the radio link to the other

RA2

RA5

RA9

RA3

RA6

BTS/NodeB MS


IU

RNC3

RNC4

RNC2

Handover procedure p

Gr

Iu

Iu

other RNC l

new SGSN

Gn

Relocation procedure (UMTS

p

Gn/Gp

Gn/Gp

Page57

RA7

RA9

RA10

Routeing Area Update Procedure l

l

RAU procedure will happen in the following two case: p

MS entered a new Route Area

p

Periodic RAU ( after periodic timer expires)

In the viewpoint of SGSN: p

intra-SGSN RAU

p

Inter-SGSN RAU


Page58

Routeing Area Update Procedure Gn SGSN

RAI 1

SGSN

RAI 2

RAI 4

RAI 3

cell

Inter SGSN -RAU

MS

Intra SGSN-RAU


Page59

Inter-SGSN RAU Procedure (2G)


Page60



Page61



Page62



Page63



Page64

Service Request Procedure l

The Service Request procedure is used by a 3G -MS in PMM -IDLE state to request the establishment of a secure connection to a 3G-SGSN.

l

The MS in PMM -IDLE state initiates this procedure in order to send uplink signalling messages (e.g. Activate PDP Context Request), user data, or as paging response, or after the MS has regained radio coverage.

l

This procedure is also used by an MS in PMM -CONNECTED state to request resource reservation for active PDP contexts.


Page65

MS Initiated MS

SGSN

RNC

HLR

1. RRC Connection Request 1. RRC Connection Setup 2. Service Request 3. Security Functions 4. Service Accept

4. Radio Access Bearer Assignment Request 5. Radio Bearer Setup 6. Radio Bearer Setup Complete 6. Radio Access Bearer Assignment Response 7. SGSN-Initiated PDP Context Modification

8. Uplink PDU


Page66

GGSN

Network Initiated MS

RNC

SGSN

HLR

GGSN

1. Downlink PDU 2. Paging 2. Paging 3. RRC Connection Request 3. RRC Connection Setup

4. Service Request 5. Security Functions

6. Radio Bearer Setup

6. Radio Bearer Setup Complete

6. Radio Access Bearer Ass ignment Request

6. Radio Access Bearer Ass ignment Response

7. SGSN-Initiated PDP Context Modification Procedure 8. Downlink PDU


Page67

Service Type IE of Service Request Msg. l

l

MS initiated p

Service type= signalling.

p

Service type= data.

Network initiated p

Service type= paging response


Page68

Summary l

Attach, location management, security function and detach procedures are the main procedures in PS core network.

l

SRNS relocation procedure and Service request procedure are newly added in UMTS PS core network.


Page69



Page70

Paging Summary l

l

The MM state in SGSN and MS before paging: p

PMM-IDLE

p

STANDBY mode

Change MM state in MS to PMM-Connected or Ready after successful paging.

l

Identification of MS in Paging message: p

P-TMSI is used to identify the MS

p

If P-TMSI is invalid or MS not respond ,then use IMSI


Page71

Paging for GPRS (2G) l

Function p

An MS in STANDBY state is paged by the SGSN before a downlink transfer to that MS

p

p

Paging move the MS state from STANDBY to READY. Any uplink data from MS is a valid response to paging


Page72

Paging for GPRS (2G) MS

BSS

SGSN 1. PDP PDU

STANDBY

2. Paging Request

3. GPRS Paging Request

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

4. Any LLC Frame (Receive Ready or Information frame)

5. Any LLC Frame

READY


Page73

Paging Initiated by CN (3G) l

PS Paging Initiated by 3G-SGSN without RRC Connection for CS p

p

A CN node requests paging only for MSs in PMM -IDLE state The RNS controls whether the MS has an established RRC connection or not

p

MS has no RRC connection

p

Paging Type 1 is transferred on the Paging channel


Page74

Paging Initiated by CN (3G) PS Paging Initiated by 3G -SGSN without RRC Connection for CS

l

MS

RNS

MSC/VLR

3G-SGSN 1. PDP PDU or Downlink signaling

PMM IDLE

3. Paging Type1

(PCH paging)

2. Paging

4. Service Request

-

4. Service Request PMM CONNECTED


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

Page75

Paging Initiated by CN (3G) l

PS Paging Initiated by 3G-SGSN with RRC Connection for CS p

p

A CN node requests paging only for MSs in PMM -IDLE state The RNS controls whether the MS has an established RRC connection or not

p

In this case, MS has an established RRC connection for CS service

p

Paging Type 2 is base on the establish RRC connection


Page76

Paging Initiated by CN (3G) PS Paging Initiated by 3G -SGSN with RRC Connection for CS

l

MS

RNS

MSC/VLR

Connection Established

3G-SGSN 1. PDP PDU or Downlink signalling

PMM IDLE

3. Paging Type2

(RRC paging)

2. Paging

4. Service Request

-

4. Service Request PMM CONNECTED


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

Page77

CS Paging (GSM only) l

When an MS is both IMSI and GPRS-attached in a network that operates in mode I, the MSC/VLR executes paging for circuit-switched services via the SGSN. If the MS is in STANDBY state, it is paged in the routeing area and in the null routeing area (see clause "Routeing Area Identity

“

of TS23060). If the MS is in

READY state, it is paged in the cell. The SGSN converts the MSC paging message into an SGSN paging message. MS

BSS

SGSN

MSC/VLR

1. Page 2. Paging Request 3. Paging Request 4. SABM (Paging Response) 5. SCCP Connection Request (Paging Response)


Page78

CS Paging (UMTS only) l

When an MS is both IMSI- and GPRS-attached in a network that operates in mode I, the MSC/VLR executes paging for circuit-switched services via the SGSN.

l

In the MSC, a paging timer supervises the paging procedure. MS

RNS

3G-SGSN

MSC/VLR

1. Page 2. Paging 3. Paging Request 4. RRC Initial Direct Transfer (Paging Response) 5. RANAP Initial UE (Paging Response)


Page79

Summary l

In UMTS, Paging type 1 for UE without RRC connection with RNC, Paging type 2 for UE with RRC connection with RNC.

l

CS paging can be executed via PS.


Page80



Page81

Contents 4. Session Management 4.1 Basic concepts

4.2 PDP Context Activation Procedure

4.3 PDP Context Modification Procedure

4.4 PDP Context Deactivation Procedure


Page82

Session Management l

Function p

Establish and monitor a packet tunnel from MS to GGSN, and allocate system resource for the packet service.

l

Important Procedure p

PDP Context Activation

p

PDP Context Modification

p

PDP Context Deactivation


Page83

PDP Context l

PDP Context: Packet Data Protocol context

p

PDP context contains all the information needed to transfer user data between MS and GGSN.

p

The context includes parameters parameters such as RA, QoS (Quality of Service), Service), Charging Charging ID etc.

p

PDP context exists in MS, SGSN, GGSN.


Page84

PDP Context Each MM context contains zero or more of the following PDP contexts: Field

Description

A/Gb mode

Iu mode

PDP Context Identifier

Index of the PDP context.

X

X

PDP State

Packet data protocol state, INACTIVE or ACTIVE.

X

X

PDP Type

PDP type, e.g. PPP or IP.

X

X

PDP Address

PDP address, e.g. an IP address.

X

X

APN Subscribed

The APN received from the HLR.

X

X

APN in Use

The APN currently used. This APN shall be composed of the APNNetwork APNNetwork Identifier and and the APN Operator Identifier.

X

X

NSAPI

Network layer Service Access Point Identifier.

X

X

TI

Transaction Identifier.

X

X

TEID for Gn/Gp Gn/Gp

Tunnel Endpoint Identifier Identifier for the Gn and Gp interfaces.

X

X

TEID TEID for Iu

Tunnel Endpoint Endpoint Identifier for the Iu interface.

GGSN Address in Use

The IP address of the GGSN currently used.

VPLMN Address Allowed QoS Profile Profile Subscribed Subscribed

Specifies whether the MS is allowed to use the APN in the domain of the HPLMN only, or additionally the APN in the domain domain of the VPLMN. The quality of service profile subscribed.


Page85

X X

X

X

X

X

X

PDP Context QoS Profile Profile Requested Requested QoS Profile Profile Negotiated Negotiated Radio Priority

The quality of service profile requested. The quality of service profile negotiated. The RLC/MAC radio priority level for uplink user data transmission. Packet Flow Id Packet flow identifier. Aggregate BSS QoS The aggregate BSS quality of service profile negotiated Profile Negotiated for the packet flow that this PDP context belongs to. Send N-PDU Number SNDCP sequence number of the next d ownlink N-PDU to be sent to the MS. Receive N-PDU Number SNDCP sequence number of the next uplink N -PDU expected from the MS. GTP-SND GTP-U sequence number of the next d ownlink N-PDU to be sent to the MS. GTP-SNU GTP-U sequence number of the next uplink N -PDU to be sent to the GGSN. PDCP-SND Sequence number of the next downlink in-sequence PDCP-PDU to be sent to the MS. PDCP-SNU Sequence number of the next uplink in-sequence PDCP-PDU expected from the MS. Charging Id Charging identifier, identifies charging r ecords generated by SGSN and GGSN. PDP Context Charging The charging characteristics of this PDP context, e.g. Characteristics normal, prepaid, flat-rate, and/or hot billing. RNC Address in Use The IP address of the RNC currently used. Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.

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X X X

X X

X X X X X

X

X

X X X

X

X

X

X X

MM Context and PDP Context HLR

MS

BSC Uu

SGSN Gb/ Iu

GGSN Gn

or RNC MM context

MM context

PDP context #1 .

PDP context #1

. PDP context #n

PDP context #1 .

.

.

.

.

PDP context #n


PDP context #n

Page87

PDP State INACTIVE

l

PDP state p

p

inactive：cannot transmit data active：can transmit data

Activate PDP Context

Deactivate PDP Context or MM state change to IDLE or PMM-DETACHED

ACTIVE


Page88

PDP Type and PDP Address l

l

PDP Type p

IPV4

p

IPV6

p

PPP

PDP Address p

Static IP n

n

p

Public IP Allocate by the operator

Dynamic IP n

n

Private IP Allocate by GGSN, DHCP or Radius


Page89

QoS l

QoS: quality of service p

It is a group of parameters that can define the network ability, such as the bit rate for downlink or uplink data transmission and the reliability class and so on

p

It is end to end concept


Page90

APN l

APN structure: APN-NI+APN-OI

huawei.com.cn.mnc.mcc.gprs

APN Network ID

APN Operator ID

•Operator

ID : fixed extension, must end with “.gprs”

• Network

ID shall not end with “.gprs”


Page91

APN IP1

GGSN1

APN1

APN1 APN2

MS

APN

SGSN

GGSN2

APN2

APN3

APN

GGSN IP GGSN3 APN3

DNS

APN1=GGSN1 IP1 APN2=GGSN2 IP2 APN3=GGSN3 IP3


Page92

APN •internet

l

General APN

•GuangDong

GGSN

GGSN

SGSN

SGSN

province

APN:CMNET MS

MS Roaming


Page93

APN l

Local APN

VPN tunnel

GGSN

GGSN

Province 1

Province 2

SGSN

SGSN

APN:test.xy MS

MS Roaming


Page94

APN BTS /NodeB

BSC /RNC

ISP ISP A A GGSN (A)

ISP ISP B B

MS

•APNAPN-NI/ •Or APNAPN-NI+APNNI+APN-OI

SGSN DNS

GGSN (B)

Backbone Backbone

•APNAPN-NI

DNS DNS

•APNAPN-NI+APNNI+APN-OI


GGSN IP address Page95

Corp. Corp. Network Network






Page96

Activation Procedure l

PDP context activation procedure p

To establish a PDP context between the MS and the SGSN, the GGSN

l

Activation procedure types: p

PDP context activation procedure

p

Secondary PDP Context Activation Procedure

p

Network-Requested PDP Context Activation Procedure


Page97

PDP Context Activation Procedure (2G) MS

BSS

2G-SGSN

2G-GGSN

1. Activate PDP Context Request

2. Security Functions

3. Create PDP Context Request 3. Create PDP Context Response 4. BSS Packet Flow Context Procedures

5. Activate PDP Context Accept


Page98

PDP Context Activation Procedure (3G) MS

UTRAN

3G-SGSN

3G-GGSN

1. Activate PDP Context Request (PDP Type, PDP Address, Access Point Name, QoS Requested) 2. Create PDP Context Request 3. Create PDP Context Response 4. Radio Access Bearer Setup （Qos ）

Charging ID allocation IP address 5. Update PDP Context Request 6. Update PDP Context Response

7. Activate PDP Context Accept


Page99

Handling in MS l

l

MS start and send “ Active PDP context request” to SGSN p

Provide QoS parameter

p

Provide a APN-NI

p

Provide a static IP or null

Receive ACCEPT from SGSN p

If the QoS not accept by MS, then starts delete PDP context procedure.


Page100

Handling in SGSN l l

Check subscriber data APN selection p p p

l

Interrogate DNS p

l

l l

Hostfile/Cache/DNS server

QoS negotiation p

l

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

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

Send message “Create PDP context request ” to GGSN RAB assignment (UMTS only) Send message “ Active PDP context accept” to MS p p

Dynamic IP address QoS


Page101

Handling in GGSN l

Check the APN provided by SGSN

l

QoS negotiation

l

Allocate a dynamic IP to the MS

l

Allocate a charging ID for the PDP context

l

l

Return a CREATE PDP CONTEXT ACCEPT message to SGSN p

Dynamic IP

p

QoS

p

Charging ID

p

Other information

Update PDP context


Page102

Handling in RNC l

RAB assignment MS

SGSN

RAB assignment (Final negotiated Qos)

RNC

Allocate radio resource

GGSN

Allocate Iu interface resource


Page103

Network-Requested PDP Context Activation Procedure MS

SGSN

HLR

GGSN 1. PDP PDU

2. Send Routeing Info for GPRS 2. Send Routeing Info for GPRS Ack 3. PDU Notification Request 3. PDU Notification Response 4. Request PDP Context Activation 5. PDP Context Activation procedure


Page104






Page105

Modification Procedures l

Modification procedures modify parameters that were negotiated during an activation procedure for one or several PDP contexts.

l

An MS, a GGSN, an SGSN, or an RNC can request a modification procedure.

l

The following parameters can be modified: p

QoS Negotiated;

p

Radio Priority;

p

Packet Flow Id;

p

PDP Address (in case of the GGSN-initiated modification procedure);

p

TFT (in case of MS-initiated modification procedure).


Page106

SGSN-Initiated Modification Procedure MS

UTRAN

SGSN

GGSN

1. Update PDP Co ntext Request 2. Update PDP Context Response 3. Modify PDP Context Request 4. Modify PDP Context Accept C1 5. Radio Access Bearer Modification 6. Invoke Trace


Page107

GGSN-Initiated Modification Procedure MS

UTRAN

SGSN

GGSN

1. Update PDP Context Request 2. M odify PDP Context Request 3. Modify PDP Context Accept 4. Radio Access Bearer Modification 5. Update PDP Cont ext Response C1


Page108

MS-Initiated Modification Procedure MS

UTRAN

SGSN

GGSN

1. Modify PDP Context Re quest 2. Update PDP Context Request 3. Update PDP Context Response 4. Radio Access Bearer Modification 5. Modify PDP Context Accept C1


Page109

RNC-initiated RAB Modification Procedure l

RNC modify RAB may cause SGSN modify PDP context. MS

RNC

SGSN

1. RAB M odify Req uest

2. SGSN initiated PDP Context Modification Procedure


Page110

GGSN






Page111

MS Initiated Deactivation Procedure l

For GPRS MS

2G-SGSN

2G-GGSN

1. Deactivate PDP Context Request C1 2. S ecurity Functions 3. Delete PDP Context Request 3. Delete PDP Context Response 4. Deactivate PDP Context Accept


Page112

MS Initiated Deactivation Procedure l

For UMTS MS

UTRAN

3G-SGSN

3G-GGSN

1. Deactivate PDP Context Request C1 3. Delete PDP Context Request 3. Delete PDP Context Response 4. Deactivate PDP Context Accept 5. Radio Access Bearer Release


Page113

SGSN-initiated SGSN-initiate d Deactivat Deactivation ion Procedure MS

UTRAN

SGSN

GGSN

C1 1. Delete PDP Context Request 1. D elete elete P DP Context Response 2. Deactivate PDP Context Request 2. Deactivate Deactivate P DP Conte Con text xt A ccept ccept 3. Radio Access Bearer Release


Page114

GGSN-initiated Deactivation Procedure

MS

UTRAN

SGSN

GGSN

1. Delete PDP Context Request C1 2. Deactivate PDP Context Request 2. Deactivate PDP Context Accept 3. Delete PDP Context Response 4. Radio Access Bearer Release


Page115

Summary l

The session management function includes the flowing functions: p

PDP context activation function;

p

PDP context modification function;

p

PDP context deactivation function;


Page116

Huawei Gprs Umts Ps Fundamental

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