1

1

Chapter 7GPRS

GPRS System Overview

2

2

GPRS GPRS

3

3

GPRSGPRSGPRS

4

4

GPRS

GSM

GSM

1999 GPRS 3GPP http://www.3gpp.org

GPRS GSM , packet-switched.

end-to-end packet-switched.GPRS 1994 ETSI/SMGthe European Telecommunications Standards Institute / Special Mobile Group.GPRS 1997 SMG#25 (25SMG), , 1999 .

GPRS , GSM , IS-136. , GPRS IS-136 . GPRS core network 3G .GPRS circuit-switching : data burst , asymmetric (up/down ), GSM circuit-switching , data transfer rate , call setup access time , data data .

5

5

Section 7.1Section 7.1GPRS Introduction to GPRS

6

6

GPRS (1/2)

GPRS GSM

8 Channel Coding

SchemesCS1CS2CS3CS49.05kbps171.2 kbps

GPRS BS, . packet, logic radio channel, packet .

GPRS , channel , , .

timeslot packet , carrier 8 timeslots MS.

2003, 5 timeslots data, 3 downlinks 2 uplinks)

, timeslot, MS . capacity on demand , . channel, uplink downlink , Web, file transfer asymmetric flow . Channel coding schemes, CS1, CS2, CS3, CS4, 9kbps 150 kbps . coding , , coding. fast reservation , 0.5 1 sec . user GPRS 1 sec , resource access data. GPRS GPRS attached, always on line. data burst , .

GPRS GSM . packet data . GPRS SMS Circuit-switched .

SMS GPRS channel .

7

7

GPRS (2/2)

fast reservation 0.5 1 GSM

8

8

Section 7.1.1Section 7.1.1GPRS GPRS Architecture

9

9

GPRS

GSM BSSMSC/VLR HLR Serving GPRS Support NodeSGSNGateway GPRS Support NodeGGSN SGSN GSM MSCGPRS

GGSN GGSN

10

10

7-1 GPRS GSM

GSM

BSS

HLR

MSC/VLR GMSC/VLR

SGSN GGSN

GPRS

PSTN

PDN

PDU

Circuit-switched service (CS) domain

Packet-switched service (PS) domain

11

11

GPRS (1/2)

BSS Um BSS SGSN Gb GPRS SGSN GGSN Gn SGSN GGSN GPRS SGSN GGSN Gp

12

12

GPRS (2/2)

GGSN Gi MSC/VLR GPRS BSS GSM A SGSN Gs HLRGr Gc SGSN GGSN Gr Gc GSM MAP

13

13

SGSN (Ericsson)

SGSN solutionLucents solution supports 40,000 attached users and 4,000 simultaneous active GPRS data sessions.Nortels Passport 8380G and Symmetrys UWS-GMS support 50,000 attached users and 20,000 simultaneous active GPRS data sessions.Alcatels SGSN supports 52,000-96,000 attached users.

GGSN solution GGSN .Alcatel GGSN Cisco 7200 .Nokia GGSN Nokia IP routing . GGSN 5000 48000 , 25000 48000 attached GPRS .

SGSN, Ericsson . SGSN 25,000 PDP, 10,000 packet/sec. GGSN 35,000 PDP, 15,000 packet/sec. SGSN 100,000 PDP, 40,000 packet/sec. GGSN 150,000 PDP, 60,000 packet/sec. SGSN GGSN CGSN.

14

14

7-2 GPRS

BSS

Um

SGSN

Gb

GGSN

Gn

Gi

GPRS GGSN

Gp

SGSN

Gn

MSC/VLR HLR

D

A

Gs GcGr

CGF Billing System

Ga

Ga

SMS-GMSC/SMS-IWMSC

Gd

E C

Signaling Interface

Signaling and Data Transfer Interface

15

15

GPRS protocol stack transmission plane

signaling plane GPRS

GPRS, OSI 7-layer , interface layered structure. protocol stack : protocol structure transmission plane.

, ,.transmission plane protocol structure signaling plane.

user location update, PDP activate/deactivate, paging user. GPRS, OSI 7-layer , interface layered structure. protocol stack :

16

16

Section 7.1.2Section 7.1.2GPRS GPRS Transmission Plane

17

17

7-3 GPRS

, , , TCP , X.25 IP GPRS .Note: GGSN, SGSN IP

IP IP , GPRS .

GPRS , GPRS , .

IP , GPRS IP static IP, GPRS dynamic host configuration protocol DHCP IP dynamic IPIP virtual IP.

IP GPRS IP , GSN .

GPRS IP , OSI layer 1 L1layer 2 L2, .

18

18

MSCRLCLLC

Medium Access ControlLayerMAC LLC frame

Radio Link ControlLayerRLC

Logic Link Control LayerLLC SGSNGPRS

19

19

SNDCP

SubNetworkDependence Convergence ProtocolSNDCP GPRS

Segmentation and

ReassemblySAR-- N-PDU SN-PDU LLC LLC SNDCPLLC N-PDU

TCP/IP V.42bis

20

20

NS

Network ServiceNSBSS SGSN Frame Relay BSS SGSN (Virtual ConnectionNS-VC) NS BSSGP

BSSGP PDU

21

21

BSSGP

Base Station Subsystem GPRS Protocoldownlink SGSN BSS RLC/MAC

MS radio access capabilityQoS profile PDU PDU lifetime

uplinkBSS SGSN RLC/MAC

PDU PDU BSS BVC SGSN PDU BSS PDU BSS SGSN PDU SGSN BSS SGSN BSSGP

22

22

GTP (1/2)

GPRS GPRS Tunneling ProtocolGTP GPRS GSN GGSN PDU GTP GTP PDUtunnel SGSN

GSN -- Tunnel IDTID

GSN path

23

23

GTP (1/2)

GGSN IP TID IP TID TID GGSN SGSNSGSN GTP PDU PDU

24

24

Section 7.1.3Section 7.1.3GPRS GPRS Signaling Plane

25

25

7-4 GPRS

GPRS Signaling Plane MS SGSN , GMM/SM layer GPRS session .SGSN GGSN Gn interface Transmission Plane UDP .GGSN HLR Gc interface MAP GSM MAP GPRS .SGSN MSC/VLR Gs interface extended BSSAP, TCAP.

26

26

GMM / SM (1/2)

PS domain

Mobility Management Session Management

Mobility Management GPRS GPRS Mobility Management

GMM Mobility Management contextMM context AttachDetachRouting Area UpdateSecurity

GPRS (mobility management, MM) MM (session management, SM) ( attach) ( detach) ( routing area update) (security)SGSN

(SGSN) MM context MS , MS GPRS , . , MS .

IP address, , MS GPRS

(SGSN,GGSN) PDP context PDP Context Activation IP address PDP Context Deactivation Modification. SGSN GGSN

PDP context (QoS) QoS profile PS domain , package 3

27

27

GMM / SM (2/2)

Session Management Session ManagementSM

Packet Data Protocol contextPDP Context PDP Context ActivationDeactivationPDP Context

Modification Quality-of-service (QoS) profile

28

28

Gs / Gr / Gf BSSAP+

SGSN VLR/HLR/EIR Gs/Gr/Gf MAP GSM TCAPSCCP MTPBSSAP+ IMSI GPRS GSM MSC/VLR SGSN

GSM GPRS location areaVLR/HLR/SGSN

29

29

GTP

GPRS GSN GTP

GTP TCP UDP GTP UDP GTP path management tunnel management location management mobility management

30

30

Section 7.1.3Section 7.1.3GPRS GPRS Area Planning

31

31

GPRS

GPRS Routing AreaRARouting Area IdentityRAI RAI

GPRS RAI RAI RA

32

32

GPRS

Routing Area 1

Location Area 1 Location Area 2

Routing Area 2 Routing Area 3

33

33

CS PS

CS domain location areas (LAs) LA VLR

PS domain routing areas (RAs) RA LA RA SGSN MS SGSN

SGSN MS cell

RARA

RA

LA

MS CS domain PS domain location mobility management

MS CS domain (i.e., GSM MS ) IMSI-attached

LA MS , VLR

MS PS domain , GPRS-attached RA MS MS SGSN MS MS , SGSN cell MS

Why RA?MS network access, paging cells , paging cost ( registration cost ). MS , . page BTS , BTS

34

34

Section 7.1.4Section 7.1.4MM Context PDP Context

35

35

GPRS

GPRS

GPRS GPRS GPRS

GMM / SM

GMM/SM GPRS GPRS PDP Context Activation PDP Context Deactivation

36

36

(1/2)

GPRS MS GPRS-attach GPRSGPRS GPRS-detach GPRS always on

37

37

(2/2)

always on GPRSMobility ManagementMM

MS RA

38

38

(1/2)

GGSN logic address IPIP

GPRSPDPPacket Data Protocol addressPDP address

39

39

(2/2)

PDP radio priorityPDP contextPDP context PDP context activationPDP contextSGSN GGSN PDP context PDP context

40

40

7-6 MM state

Session

ReadyStandbyReady Standby Ready

PDP context Activation PDP context Deactivation

Session

ReadyStandbyReady Standby Ready

PDP context Activation PDP context Deactivation

41

41

MM Context

GPRS SGSN MM Context

MM stateidle statestandby stateready state

42

42

7-5

GPRS Attach GPRS Detach GPRS Attach

PDU transmission

Ready timer expiry

Force to StandBy

ImplicitDetach

CancelLocation

PDU reception

GPRS Detach

Cancel Location

Ready timer expiry

Force to StandBy

Abnormal RLC condition

SGSN

Detach

43

43

PLMN GPRS GPRS SGSN

PTM-MPoint to Multipoint -Multicast

PTM-GPoint to Multipoint Group Call

SGSN

/attach

44

44

(1/2)

SGSN RA cell GPRS SGSN PTM-M PTM-G

45

45

(2/2)

SGSN MM Context GPRS SGSN RLC SGSN MM Context

SGSN HLR Cancel LocationSGSNMM ContextPDP Context

46

46

(1/2)

GPRS SGSN MM Context GPRS

RA PTM-M/PTM-G GSM SGSN PTM-G detach

47

47

(2/2)

mobile reachable timer SGSN SGSN

GGSN PDP Context SGSN MM Context PDP Context

48

48

PDP Context (1/2)

GPRS PDP Context GPRS SGSN GGSN PDP Context

GPRS GPRS PDP Context

MM Context

49

49

PDP Context (2/2)

GPRS PDP PDP address IPv4IPv6X.25 PDP GPRS

PDP PDP state PDP

PDP INACTIVE ACTIVE

IP IP GPRS PDP Packet Data Protocol addressGPRS PDP

50

50

GPRS (2/8)

51

51

7-7 PDP

52

52

PDP MS PDP Context PDP

Context GGSN GGSN PDP ContextNetwork-Initiated PDP Context Activation PDP PDP ContextMS-Initiated PDP Context Activation PDP

53

53

PDP Context PDP SGSNGGSN MM Context SGSN SGSN BSS RASGSN

54

54

PDP Context

GPRS PDP Context PDP Context Deactivation ProcedurePDP

MM State PDP

MM State PDP

GPRS GPRS/ PDP Context PDP Context

55

55

PDP Context

APNAccess Point Name GGSN

QoS profile PDP ContextSGSN GGSN PDP ContextPDP PDP Type IPPPP IPv6QoS Requested

56

56

MM ContextPDP Context QoS Profile

MM ContextPDP Context

QoS Profile

PDP Context

QoS Profile

PDP Context

QoS Profile

MM Context PDP Context QoS Profile PDP Context maintain PDP Context ACTIVATE GPRS QoS Profile negotiated radio network resources

57

57

GPRS MS MM and PDP ContextsField SIM Description

IMSI International Mobile Subscriber Identity.

MM State Mobility management state, IDLE, STANDBY, or READY.

P-TMSI Packet Temporary Mobile Subscriber Identity.

P-TMSI Signature A signature used for identification checking purposes.

Routeing Area Current routeing area.

Cell Identity Current cell.

Kc Currently used ciphering key.

CKSN Ciphering key sequence number of Kc.

Ciphering algorithm Selected ciphering algorithm.

Classmark MS classmark.

DRX Parameters Discontinuous reception parameters.

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

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

PDP Type PDP type, e.g., X.25, PPP or IP.

PDP Address PDP address, e.g., an X.121 address.

PDP State Packet data protocol state, INACTIVE or ACTIVE.

Dynamic Address Allowed Specifies whether the MS is allowed to use a dynamic address.

NSAPI Network layer Service Access Point Identifier.

TI Transaction Identifier.

QoS Profile Requested The quality of service profile requested.

QoS Profile Negotiated The quality of service profile negotiated.

Radio Priority The RLC/MAC radio priority level for uplink user data transmission.

SIM card SIM .

IMSI (International mobile subscriber identity) VLR, HLR SGSN, GGSN .P-TMSI (Packet-TMSI, packet temporary mobile subscriber identity) GPRS GSM TMSI ID.RA (Routing Area): MS for GPRS MM.Ciphering key Kc, CKSN (ciphering key sequence number) Kc .P-TMSI Signature.

MM :MM state, Cell Identity, Ciphering algorithm.radio access classmark radio capabilities, multiple time slot capability, power class.SGSN classmark network-related capability, ciphering capability.

PDP context :PDP type, PDP address, PDP state.Dynamic-Address-Allowed MS dynamic address.Requested and negotiated QoS profile.

NSAPI (, )

58

58

Section 7.2Section 7.2GPRS GPRS Radio Interface

59

59

GPRS

GPRS GSM

GPRS

GPRS

60

60

Section 7.2.1Section 7.2.1GPRS GPRS Logic Channels

61

61

GPRS

GPRS Packet Data CHannelPDCHGPRS logic channel PDCH

traffic channelscontrol channels

62

62

7-8 GPRS

63

63

Traffic Channel

PDTCHPacket Data Traffic Channel PDTCH PDTCH

PDTCH PDTCH

64

64

Control Channels

Packet Broadcast Control

CHannelPBCCH GPRS

Packet Common Control CHannelPCCCH

Packet Dedicated Control CHannelPDCCH

65

65

PCCCH

PRACH PCCCH

PPCH GPRS

PAGCHGPRS

PNCH GPRS PTM-M PTM-M

PTM-MPNCH

66

66

PDCCH (1/2)

PACCHPacket Associated Control Channel acknowledge

PACCH PDTCH PDTCH

PACCH

67

67

PDCCH (2/2)

PTCCH Timing AdvanceTA BTS PTCCH/UPacket Timing advance Control

CHannel/UplinkPTCCH/U BTS BTS

PTCCH/DPacket Timing advance Control CHannel/Downlink

BTS TA MS

68

68

Section 7.2.2Section 7.2.2GPRS GPRS Radio Resource Management

69

69

(master-slave) capacity on demand PDCH master PCCCH PDCH slave (PDTCH) (PACCH)GPRS i.e.PDCH

70

70

Section 7.2.3Section 7.2.3GPRS GPRS Uplink Data Transfer and Paging

71

71

7-9 GPRS

packet channel request PRACH/RACH

GPRS PAGCH/AGCH

MS GPRS PRACH packet channel request, packet immediate assignment

, GPRS 11 bits 8 bits packet channel request, . PACCH packet resource requestpacket resource assignmentPDCH

PACCH PRACH

( phase 1) ( phase 2optional)

GPRS PDCH PRACH PAGCHMS GSM RACH AGCHPACCHMS .

72

72

MS (1/2)

one phase PRACH RACH Packet Channel RequestGPRS MS PDCH

73

73

MS (2/2)

Packet Uplink Assignment

RACH MS

MS PACCH Packet Resource Request GPRS

74

74

7-10 GPRS RA

PPCH

, .

PPCH packet paging request PRACH packet channel request PAGCH PACCH PPCHPRACHPAGCHPCHRACHAGCH

75

75

PPCHPRACH PAGCH PCHRACH AGCH

7-9 Packet Resource Request Packet Uplink Assignment

76

76

Section 7.3Section 7.3GPRS GPRS High Level Communication Procedure

77

77

GPRS

GPRS GPRS location update

procedure SGSN

GPRS GPRS GPRS attach and detach procedure

GPRS

GPRSGPRS PDP context procedure

GGSN

GPRS procedures GPRS interface, , . 4 GPRS message flow:

RA/LA Update: GPRS network MS , MS RA/LA location information.GPRS Attach: MS GPRS network GPRS Detach: MS GPRS network PDP context procedure: MS GPRS network , PDP context

procedure , entities interface ( top layer) , , , procedure .

78

78

Section 7.3.1Section 7.3.1GPRSGPRS GPRS Location Update

79

79

PS domain

MS RA SGSN RA SGSNRAIntra-SGSN Routing Area

Update SGSN SGSN

SGSNRAInter-SGSN Routing Area Update 2 SGSNGGSNHLR

Periodically Routing Area Update MS RA

MS location update :Intra-SGSN Routing Area Update

MS SGSN cells , SGSN location . MS Routing Area Update Request SGSN.SGSN Authentication. SGSN RAND MS, MS SRES SGSN, SGSN .SGSN P-TMSI MS.MS Routing Area Update Complete, location update.

Inter-SGSN Routing Area Update MS 2 SGSN, GGSN, HLR, , MS location .

MS routing area updateMS network, .Ex: 45

80

80

7-11 SGSN (1/2)

81

81

7-11 SGSN (2/2)

82

82

SGSN (1/7)

1. Routing Area Update Request new SGSN old RAIRouting Area Identity

SGSN P-TMSI Update TypeRA/LA Update

2. old RAInew SGSN old SGSN New SGSN SGSN Context Request new SGSN IP GTP P-TMSI

83

83

SGSN (2/7)

3. Old SGSN P-TMSI new SGSNSGSN Context Response

PDP contextMM context IMSIPDP Context GTP PDU APNGGSN MM Context Authentication

Triplets

PDU new SGSN

4. old SGSN HLR

84

84

SGSN (3/7)

5. new SGSN old SGSN SGSN Context Acknowledge PDP Context SGSN 6. Old SGSN new SGSN 7. New SGSN Update PDP Context Request GGSN GGSN SGSN GGSN PDP Context

85

85

SGSN (4/7)

8. GGSN Update PDP Context Response new SGSN GGSN new SGSN 9. New SGSN Update Location HLR HLR new SGSN 10. HLR MAP Cancel Location old SGSNold SGSN PDP Context SGSN Cancel Location ACK HLR

86

86

SGSN (5/7)

11. HLR Insert Subscriber Data SGSN SGSN Routing AreaRA SGSN MM Context Insert Subscriber Data ACK HLR 12. HLR Update Location ACK SGSN

87

87

SGSN (6/7)

13New SGSN Location Update Request new VLR new SGSN 14 VLR GSM HLR VLR old VLR 15New VLR TMSI Location Update Accept new SGSN TMSI new SGSN

88

88

SGSN (7/7)

16SGSN PDP Context MM Context Routing Area Update Accept TMSI 17 Routing Area Update Complete new SGSN N-PDU N-PDU 18New SGSN TMSI Reallocation Complete VLR TMSI

89

89

Section 7.3.2Section 7.3.2GPRSGPRSProcedures of GPRS Attach and Detach

90

90

7-12 GPRS

(old-PTMSI, old SGSN) (old-PTMSI)

(old-PTMSI)

(new P-TMSI)

Um Gb Gn

GPRS signaling plane. GPRS attached MS SGSN GMM layer . MS attach . MS old SGSN , detach. MS new SGSN, , GPRS Attach .Step 1.1. MS GMM layer Attach Request SGSN.Step 1.2. New SGSN GTP Mobility Management Identification_Request(old P-TMSI) old SGSN, MS IMSI.

Case 1: Old SGSN P-TMSI MS IMSI, Identification_Response(IMSI) new SGSN. new SGSN MS (authentication) (ciphering) security procedures.Case 2: , old SGSN MS , error new SGSN. New SGSN Air interface MS IMSI. MS attach, MS new SGSN, new SGSN RA (and possibly the LA) update.

Step 1.3. New SGSN radio priority, New SGSN GMM layer Attach Accept(P-TMSI, VLR TMSI, P-TMSI Signature, Radio Priority SMS) MS.

MS new P-TMSI, MS an acknowledge VLR.

91

91

GPRS (1/2)

SGSN 1. Attach Request SGSN IMSI P-TMSI 2. New SGSN P-TMSI new SGSN Identification Request old SGSN IMSI 3. Old SGSN Identification Response IMSI SGSN

GPRS attach IMSI attachedGPRS AttachGPRS attachIMSI attach

SGSN SGSN 3 SGSN SGSN IMSI

92

92

GPRS (2/2)

4. MM Context 5. RA LA UpdateNew SGSN Update Location Request HLR 6. New SGSN Attach Accept SGSN P-TMSI

7. new SGSN Attach Complete

5 GPRS SGSN SGSNRA LA Update

93

93

MS-Initiated Detach GPRS GPRS detach

Network-Initiated Detach GPRS GPRS detach

HLRHLR-Initiated Detach GPRS HLR SGSN

GPRS detach HLR (HLR-initiated), SGSN (SGSN-initiated) MS (MS-initiated). MS Idle state.

SGSN-initiated detach IP network , GGSN fail/reset, PDP context lost. HLR-initiated detach prepaid service money .

GPRS detach, : IMSI detach: GSM network GPRS detach: GPRS network Combined GPRS/IMSI detach: GSM GPRS network

MS Combined GPRS/IMSI detach, . HLR MS , . SGSN HLR , Steps 2.1 2.6 , . MS SGSN , Steps 2.2 Step 2.5 Detach Accept : Detach Request (MSSGSN) Detach Accept(SGSMMS).

94

94

7-13 GPRS

Um Gb Gn Gr D

Gr: in GSM MAP

in GMM layer in GTP layer

Gs: in BSSAPT layer

in GMM layer

HLR detach:Step 2.1. HLR GSM MAP, Gr , MAP_CANCEL_LOCATION(IMSI, Cancellation Type) SGSN, .Step 2.2. SGSN GMM Detach Request MS. detach type parameter MS attach. detach type parameter :

(1) SGSN-initiated detach, the SGSN MS attach.(2) MS-initiated detach, MS detach type GPRS-detach, IMSI-detach, GPRS IMSI detach.

Step 2.3. SGSN GGSN GTP tunnel management Delete_PDP_Context_Request(TID) Response(TID) MS GGSN PDP context.Step 2.4. MS GPRS/IMSI-attached, SGSN BSSAP+ Gs GPRS_Detach_Indication(IMSI) VLR. VLR MS SGSN , paging, location update , GPRS network .

VLR flag, GPRS paging. SGSN VLR, VLR GPRS .

Step 2.5. MS GMM Detach Accept GPRS network.Step 2.6. MS Step 2.5 detach, SGSN GSM MAP Gr MAP_CANCEL_LOCATION_ack HLR, HLR MM and PDP contexts.

95

95

GPRS (2/2)

HLR GPRS 1. HLRCancel Location SGSN

2. SGSN GPRS Detach Request 3.4. SGSN Delete PDP Context Request GGSN PDP contextGGSNDelete PDP Context Response

96

96

GPRS (2/2)

5. SGSN GPRS Detach Indication VLRSGSN 6. SGSNGPRSDetach Accept 7. SGSN MM context PDP contextCancel Location AckHLR

97

97

Section 7.3.3Section 7.3.3GPRSGPRS PDP Context Procedures

98

98

PDP Context

PDP Context Activation MS-Initiated Network-Initiated

GGSN PDP PDU GGSN PDP PDP Context PDP ContextGGSN PDP Context

PDP Context ModificationPDP Context Deactivation SGSN-initiated MS-initiated GGSN-initiated

: MS, SGSN, GGSN PDP context. PDP context procedure . PDP Context .

PDP Context Activation PDP Context activation, MS PSDN/PDN . SGSN MS GGSN , .PDP Context Activation MS, network party (GGSN ).

PDP Context Modification PDP Context , PDP Context update message flow.

PDP Context DeactivationPDP Context Deactivation SGSN, MS, GGSN .

SGSN GGSN Gn interface GTP tunnel management request/response pair.SGNS MS Um /Gb interfaces GMM request/accept pair.

99

99

7-14 GPRS PDP context

in GMM(APN, QoS...) Gn:in GTP layer

(IP address...)

(IP address, negotiated QoS...)

MS network , PDP context activation .Step 1.1. MS GMM Activate PDP Context Request (NSAPI, TI, PDP Type, PDP Address, Access Point Name, QoS Requested, PDP Configuration Options) SGSN

MS static dynamic PDP addresses. MS , QoS. SGSN QoS ., SGSN MS security functions.

Step 1.2. SGSN GTP tunnel management Gn Create_PDP_Context_Request GGSN.

SGSN GGSN MS PDP context, PDP contexts tunnel/logical link.GGSN external network IP address MS.GGSN SGSN Create_PDP_Context_Response , SGSN activates the PDP context MS GGSN .

Step 1.3. SGSN PDP context GGSN address dynamic PDP address. SGSN negotiated QoS radio priority, GMM layer Activate PDP Context Accept MS.

100

100

GPRS PDP Context (1/3)

1. Activate PDP Context Request SGSN PDP type, PDP address, APN, QoS profile 2. SGSN GGSN

101

101

GPRS PDP Context (2/3)

3. GGSN SGSN GGSN GGSN

GGSN PDP Context IP GGSN IP

GGSN SGSN Create PDP Context Response IP GGSN

102

102

GPRS PDP Context (3/3)

4. SGSN GGSN IP PDP Context SGSN Activate PDP Context Accept PDP Context

Deactivate PDP Context APN

103

103

PDP Context

GGSN SGSN PDP context PDP context GPRS negotiated QoSradio priorityPDP Traffic Flow TemplateTFT 7-15 SGSN PDP context SGSN-Initiated PDP Context Modification Procedure

104

104

7-15 SGSN PDP Context

BSS SGSN GGSN

1. Update PDP Context Request

3. Modify PDP Context Request

2. Update PDP Context Response

4. Modify PDP Context Response

SGSN PDP Context , GGSN MS .Step 1 (GTP tunnel management on Gn interface).

SGSN GGSN Update_PDP_Context_Request Response.

Step 2 (GMM/Um and Gb interfaces).SGSN MS Modify PDP Context Request Accept MS PDP context. MS SGSN QoS, MS (deactivate) PDP context.

105

105

7-16 PDP Context

MS PDP context deactivation , deactivation .

Step 1. MS Deactivate PDP Context Request (TI: Transaction Identifier) SGSN deactivate PDP context.

MS SGSN Security functions . (optional, )

Step 2, 3. SGSN Gn interface GTP Delete PDP Context Request (TID: Tunnel Identifier) GGSN. GGSN PDP context Delete PDP Context Response (TID) SGSN. MS PDP address, GGSN PDP address PDP context activation MSs .Step 4. SGSN Deactivate PDP Context Accept (TI)message MS, PDP context deactivation.

106

106

Section 7.3.4Section 7.3.4GPRSGPRS Billing

GPRS , PDP context activated , . ,. GPRS . GGSN, SGSN , CDR. GPRS .Billing .

107

107

GPRS (1/2)

GPRS SGSN

GGSN

SGSN GGSN Call Detailed RecordCDRCharging Gateway FunctionCGF SGSN GGSN Billing SystemBS

GSM MSCGPRS SGSN GGSN .SGSN MS radio resource usage.GGSN MS network usage.

GPRS network external network . MS GPRS network , GPRS network dynamic address to an MS, home GPRS network.

108

108

GPRS (2/2)

CDR CDR CDR SGSN CDRInter-SGSN

Routing Area Update

GPRS GSN CDR

(activate) PDP context , CDR. PDP context S-CDRs G-CDRs. GSN, GSNs CDRs.CDR :

End-of-Call Accounting Schedule: Time-of-Day Accounting Schedule: Inter-SGSN Routing Area Update: SGSN RA

109

109

7-17 GPRS

GPRS

110

110

GPRS

SGSN GGSN

BSC

BTS

MS 1

Service Application

MSC

PLMN

MSC CGF

GPRS Billing Mediation

Billing System

Billing records

Backbone network

CGF: Charging Gateway Function

CDR: Charging Data Record

Charging gateway Function (CGF), SGSNs/GGSNs CDR .Charging gateway function (CFG) charging data record (CDR) .CDR GPRS Billing Mediation (), billing record, Billing system, .

111

111

SGSN

SGSN PDP GPRS

SGSN : Location information MS home network visited network, cell location . Mobile origination, mobile termination , QoS profile, .SMS MS PDP context .MS GPRS . MS, GPRS activity (e.g., MM context).

Note: SGSN SNDCP level . IP. , .

112

112

GGSN

GGSN SGSN PDP

GGSN :Destination source addresses ( address GPRS operator ).MS external data network (). QoS profile, .MS PDP address .

Note: GGSN GTP level , IP , GPRS .

113

113

(1/2)

GPRSCDRS-CDRG-CDRM-CDRS-SMO-CDR S-SMT-CDRS-CDR SGSN IMSISGSNcharge identifierGGSNAPNAPNPDPPDPSGSN

G-CDR GGSN IMSIGGSNSGSNAPNPDPPDPGGSN

SGSN GGSN Call Detailed Records (CDR).Call Detailed Record (CDR)

S-CDR (SGSN PDP context generated-CDR): SGSN , MS .G-CDR (GGSN generated-CDR): GGSN , MS GGSN .M-CDR (Mobility Management generated-CDR): SGSN , MS .S-SMO-CDR (mobile origination) SGSNIMSISGSN E.164SGSN

S-SMT-CDR (mobile termination) SGSNSGSNS-SMO-CDRS-SMO-CDRSGSNSGSN

M-CDRSGSNIMSISGSNRALA

114

114

(2/2)

M-CDR SGSN IMSISGSN

RALA S-SMO-CDR SGSN IMSISGSN E.164SGSN

S-SMT-CDR SGSN SGSN S-SMO-CDRSGSNSGSN

S-CDR (SGSN PDP context generated-CDR) :Mobile Originating (MO) data volume: Mobile Terminating (MT) data volume: Location Information: SMS MO: SGSN Mobile originated SMS recordSMS MT: SGSN Mobile terminated SMS recordAssociated QoS: QoS Record Duration: record SGSN

G-CDR (GGSN generated-CDR) : QoS Record Duration: record GGSN

GGSNPDP ContextSGSN. GGSNSGSN/GGSNCDR, PDP Context GGSNGGSNCGFBSGGSN

115

115

GPRS

: GSMGPRS PDP context

GSM GPRS CDR GPRSCGFSGSNs/GGSNs

(packet-switched) circuit-switched , :1., .2. GSM GPRS CDR .

116

116

Section 7.4Section 7.4Summary

117

117

Summary

GPRS3Gbursty and bulkyradio resource on demandalways onvolume-dependent charging3GB3Gbeyond 3G

118

118

Homework

1 (1)-1(10),1,3,5,7,9

119

119

APN (Access Point Name)

Access Point Name is a label according to DNS naming conventions describing the access point to the external packet data network. An APN is the logic way to name a GPRS service.Domain Name Service (DNS) server translates APN to GGSNs IP address.

GPRS (GGSN, SGNS ) addressing , operator , (domain nameIP address) , APN GPRS , MS . , APN , GPRS service, name GPRS GGSNAPN Label DNS GPRS APN, .

Internet domain name a page on a specific server, APN service, , , GGSN. GGSN , ex: one GGSN for emone, one GGSN for WAP. ( 5 GGSN for WAP, load balancing, DNS GGSN lists ). Internet , DNS domain name IP address, GPRS network DNS server, APN GGSN IP address.

HLR MS APN, HLR MS APN.HLR APN* default APN, user APN.

120

120

Access a GPRS Service with an APN

Mobile user activates a service.MS sends request to SGSN (including APN).SGSN check whether the service has be authorized for this user.SGSN acquires the IP address of this specific GGSN (for the APN) from DNS server.A tunnel is created between SGSN and GGSN.

GPRS service : service, MS request SGSN.SGSN HLR , service user.SGSN local GPRS DNS server APN GGSN IP address. DNS a list of GGSNs IP addresses. local DNS APN IP address:Case 1: user home network, request .Case 2: user foreign network, SGSN MS home network DNS . GGSN IP address, SGSN GGSN tunnel by GTP. GGSN IP MS, MS.

121

121

IP Address Allocation

Fixed Addressing IP address is stored in HLR. It is sent to MS when MS wants to send data.

Dynamic Addressing GGSN gets an IP address. GGSN assigns an address to MS.

MS external network PDP context, MS IP address. GPRS MS IP address :Fixed addressing:

MS IP address, IP address HLR . MS PDP context APN, HLR IP address SGSN, MS. MS network IP address. fixed IP address, ID. fixed IP address IP , ICANN .

Dynamic addressing: MS PDP context , GGSN IP address MS. PDP context, GGSN IP address.IP address. IP address,

122

122

Mechanism to Get IP Address

From a local address pool on the GGSNVia DHCPVia RADIUS from an external RADIUS serverFrom the customer network via an L2TP tunnel from the GGSN

GGSN IP address: From a local address pool on the GGSN

PSTN dialup server. GGSN IP address pool, MS IP, GGSN pool IP MS., APN address pool. APN IP address space, private network IP range. operator IP, .

Via DHCPDHCP server operator (GPRS internally) customer network. So, DHCH server GGSN . DHCP server GGSN LAN .GGSN DHCP server () IP address. DHCP server fixed IP address, MS IP address.

Via RADIUS form an external RADIUS server RADIUS server customer network.GGSN RADIUS server user terminal, fixed IP address.

From the customer network via an L2TP tunnel from the GGSNL2TP layer 2 tunneling protocol. IP user traffic IP network . PSTN dial-up to a Remote Access Server. GPRS , L2TP GGSN customer network router . customers router , IP address. User network . customer security, (operator) . GGSN customers network RADIUS server IP.