2.1.9 PDP Context Activation and Modification. 2.1.10 Radio Access Bearer ..... (b
) Phase 2: Activate PDP Context and establish Radio Access Bearer. (c) Phase 3:
Registers with ...... Interface A1: carry signaling traffic between the Call Control ...
Chapter 2: Wireless IP Network Architectures
This material is protected under all Copyright Laws as they currently exist. ©2004 Jyh-Cheng Chen and Tao Zhang, and John Wiley & Sons, Inc. All rights reserved. Notwithstanding user’s ability to use and modify the PowerPoint Slides, it is understood that the original version of these slides, as well as any and all modifications thereof, and all corresponding copyrights, shall at all times remain the property of Jyh-Cheng Chen and Tao Zhang, and John Wiley & Sons, Inc.
Jyh-Cheng Chen and Tao Zhang
IP-Based Next-Generation Wireless Networks Published by John Wiley & Sons, Inc. January 2004
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Outline
2.1 3GPP Packet Data Networks 2.1.1 Network Architecture 2.1.2 Protocol Reference Model 2.1.3 Packet Data Protocols, Bearers, and Connections for Packet Services 2.1.4 Packet Data Protocol (PDP) Context 2.1.5 Steps for a Mobile to Access 3GPP Packet-Switched Services 2.1.6 User Packet Routing and Transport 2.1.7 Configuring PDP Addresses on Mobile Stations 2.1.8 GPRS Attach Procedure 2.1.9 PDP Context Activation and Modification 2.1.10 Radio Access Bearer Assignment 2.1.11 Packet-Switched Domain Protocol Stacks 2.1.12 Accessing IP Networks through PS Domain
2.1 3GPP Packet Data Networks 2.2 3GPP2 Packet Data Networks 2.3 MWIF All-IP Mobile Networks
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
2
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
3
4
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Fig. 2.1 3GPP conceptual network architecture (Release 5) PSTN and Circuit-Switched Wireless Network
2.1.1 Network Architecture Public Land Mobile Network (PLMN): a public network administrated by a single network operator for providing land mobile services Radio Access Networks (RANs)
GSM/EDGE RAN (GERAN) UMTS Terrestrial RAN (UTRAN) Broadband Radio Access Networks (BRANs)
External IP Networks
IP Multimedia Subsystem (IMS)
GMSC Circuit Switched Domain
MSC + VLR
GGSN Information Servers Shared by PS and CS Domain (HSS, EIR, AuC)
SGSN Core Network
Core Network (CN)
Circuit-Switched (CS) Domain Packet-Switched (PS) Domain IP Multimedia Subsystem (IMS) Information Servers
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Packet Switched Domain
GSM RAN (i.e., Base Station Subsystems)
UTRAN (UMTS Terrestrial Radio Access Network) Radio Access Networks
5
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
6
1
2.1.1.1 Mobile Devices, Subscribers, and Their Identifiers
GERAN and UTRAN GERAN
Mobile Station (MS): in GSM User Equipment (UE): in UMTS
Base Station Subsystem (BSS) Base Transceiver Station (BTS)
Base Station Controller (BSC)
Terminal Equipment (TE)
UTRAN
Mobile Equipment (ME) Mobile Termination (MT)
Radio Network Subsystem (RNS)
Node B
Terminal Adapter (TA)
UMTS Subscriber Identity Module (USIM)
Radio Network Controller (RNC)
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
7
Fig. 2.2 Functional architecture of an user equipment (UE)
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
8
Identifiers International Mobile Station Equipment Identity (IMEI): identify MT
UE ME
International Mobile Subscriber Identity (IMSI): globally unique and permanently assigned for each subscriber
MT
USIM TE
TA
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
manufacturer, country, type
9
Fig. 2.3 Structure of International Mobile Subscriber Identity (IMSI)
stored on USIM
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
10
Identifiers (Cont.) Temporary Mobile Subscriber Identity (TMSI)
No more than 15 digits
3 digits
2 – 3 digits
4-octet number assigned to a mobile temporarily by a MSC/VLR or by a SGSN P-TMSI mapping between TMSI and IMSI: only known by mobile and network
IP address Mobile Country Code (MCC)
Mobile Network Code (MNC)
Mobile Subscriber Identification Number (MSIN)
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
11
single or multiple may acquire an IP address only when necessary
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
12
2
2.1.1.2 Circuit-Switched Domain in Core Network
Switching vs. Call Control
Mobile-services Switching Center (MSC) Gateway MSC (GMSC) Visitor Location Register (VLR) Home Subscriber Server (HSS), Equipment Identity Register (EIR), and Authentication Center (AuC)
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
13
2.1.1.3 Packet-Switched Domain in the Core Network
14
Access control Location management: track the locations of mobiles; may report the location information to the HLR Route management: maintain and relay user traffic between the mobile and the GGSN Paging: initiating paging to idle mobiles Interface with service control platforms: contact point with CAMEL (Customized Applications for Mobile Enhanced Logic)
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Gateway GPRS Support Node (GGSN) Packet routing and forwarding center: all user packets to and from a mobile in a PLMN will be sent first to a GGSN (refer to as the mobile’s serving GGSN) Route and mobility management: maintain a route to the SGSN that is currently serving a mobile and uses the route to exchange the user traffic with the SGSN
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Serving GPRS Support Node (SGSN)
Network access control: registration, authentication and authorization, admission control, message filtering, usage data collection Packet routing and transport: route user packets toward their destinations Mobility management: tracking the locations of mobile terminals, initiating paging, maintaining up-to-date routes Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
MSC Server: call control and mobility management CS Media Gateway (CS-MGW): circuit switching, media conversion, payload processing (e.g., echo canceller, codec), payload transport
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Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
16
Identifiers of SGSN and GGSN IP address
may be private IP address
SGSN Number and GGSN Number
used primarily with non-IP protocols, e.g., MAP or other SS7-based protocols
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
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3
2.1.1.5 Information Servers
2.1.1.4 IP Multimedia Subsystem
Shared by CS and PS domains Home Subscriber Server (HSS)
Release 5 introduced the IP Multimedia Subsystem (IMS) Support real-time voice and multimedia IP services Use the Session Initiation Protocol (SIP) for signaling and session control for all real-time multimedia services Will be discussed in Chapter 3
Authentication Center (AuC)
maintain information to authenticate each user and to encrypt the communication accessed by the HSS
Equipment Identity Register (EIR)
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
master logical database maintain user subscription information to control network services Home Location Registrar (HLR): main component of HSS which maintains users’ identities, locations, and service subscription information
maintain IMEIs of the subscribers
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To external IP networks
To PSTN
Fig. 2.4
2.1.2 Protocol Reference Model
Gi
C
Nc
Gc HSS (HLR)
H
EIR
Gf
AuC Gn Gr
F
VLR
VLR B
E
GGSN
D
G B
Gs
SGSN
MSC Server Mc
NC
Iu-PS Gb
CS-MGW
Core Network
CS-MGW
many interfaces use MAP protocol
Nb A
PS CN Internal Interfaces
A IuCS
Iu-CS
Iu-CS Iur UTRAN
BSC
RNC
Abis Traffic interface Signaling interface
GSM BSS
BTS
BTS
RAN Internal Interfaces
Uu
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Abis Um
22
A or Iu-CS: CS CN domain Gb or Iu-PS: PS CN domain
UTRAN
Iub Iur: logical signaling interface Uu
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
MT
GERAN
UTRAN
Node B Cell Cell
RAN-to-CN Interfaces
GERAN
Node B Cell Cell
Um Radio Access Networks
21
RNC
Iub
MT
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Gp
Gi
Go
GMSC Server
Nb
MSC Server Mc
To external To GGSN in IP networks Other networks
IMS Mc CS-MGW
RAN Internal Interfaces RAN-to-CN Interfaces CS CN Internal Interfaces
20
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Iu-CS: CS CN domain Iu-PS: PS CN domain
One and only one mode
23
A/Gb mode Iu mode
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
24
4
Fig. 2.5 Protocol reference model for 3GPP PS domain D
MSC + VLR
Mobile
RNC
Uu
Gr
SGSN
Iub
IuPS
UTRAN
Packet Data Protocol (PDP): used to exchange user packets over a 3GPP PS CN domain Packet Data Unit (PDU): user packet transported inside a 3GPP network over traffic bearer Traffic bearer: a set of network resources and data transport functions used to deliver user traffic between two network entities
HSS/HLR
Gs
Node B
2.1.3 Packet Data Protocols, Bearers, and Connections for Packet Services
Gc External Packet Network
GGSN Gn
Gi
PS CN Gp
GGSN PS CN in different PLMN
25
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Fig. 2.6 3GPP bearers (connections) for supporting packet-switched services Mobile
RNC
SGSN
Radio Bearer
Lower Layer Bearers
The (Traffic) Radio Bearers, Iu (Traffic) Bearers, Radio Access Bearers, and CN Bearers are managed by different protocols and procedures.
GGSN
CN Bearer
Iu Bearer
Lower Layer Bearers
Lower Layer Bearers
Iu
27
Fig. 2.7 Signaling and traffic connections between mobile and SGSN
Mobile
Signaling Radio Bearer
Mobile-SGSN Signaling Connection
Iu Signaling Bearer
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
28
Connections Radio Resource Control (RRC) connection
RANAP Connection
RNC
allows different protocols and procedures to be used; evolve with less dependency on each other facilitates mobility management
Gn
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
RRC Connection
26
Separation of Bearers
3GPP Bearer
Radio Access Bearer (RAB)
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
SGSN
Signaling Radio Bearer Traffic Radio Bearer
Radio Access Network Application Part (RANAP) connection Traffic Radio Bearer
Radio Access Bearer (RAB)
Iu Traffic Bearer
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
29
Iu Signaling Bearers Iu Traffic Bearers Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
30
5
2.1.4 Packet Data Protocol (PDP) Context
PDP States
A set of information that the network uses to determine how to forward user packets destined to and originated from a particular PDP address Contain the following main information
ACTIVE state
INACTIVE state
PDP Address Routing Information: identifiers of tunnels and Access Point Name (APN) Quality of Service (QoS) Profiles: QoS Profile Subscribed, QoS Profile Requested, QoS Profile Negotiated
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
31
Fig. 2.8 3GPP PDP context state transitions
32
State Transition PDP Context Activation PDP Context Modification
PDP Context ACTIVE
PDP Context Activation
modify the PDP Address or the attributes of the QoS profile Release 5 only allows the GGSN-initiated PDP Context Modification
PDP Context Deactivation
PDP Context INACTIVE
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
may contain a valid PDP address, but will not contain valid routing and mapping information needed to determine how to process PDP packets no user data can be transferred changing location of a mobile user will not cause an update for the PDP context If a GGSN has user packets to send to a mobile, the GGSN may use Network-requested PDP Context Activation procedure to change the PDP context of the destination mobile into ACTIVE state. The GGSN may also discard packets destined to a mobile if the corresponding PDP context is in INACTIVE state.
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
PDP Context Modification
PDP Context Deactivation or Mobility Management state changes to PMM-IDLE or PMM-DETACHED
contains update-to-date information for forwarding PDP packets between the mobile and the GGSN RABs may be established only when there are user packets
33
34
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
2.1.5 Steps for a Mobile to Access 3GPP Packet-Switched Services
HSS
GPRS Attach
SGSN
Fig. 1.9 Three-phased access to 3GPP packet-switched network and services
Mobile
GPRS Attach PDP Context Activation and RAB Establishment Register with the IMS
(a) Phase 1: Mobile registers with PS CN via GPRS Attach
1. Activate PDP Context Request 2. PDP Context Activation 3. Establish Radio Access Bearer Mobile
SGSN
GGSN
4. Activate PDP Context Accept
(b) Phase 2: Activate PDP Context and establish Radio Access Bearer.
SGSN
GGSN
Registration with IMS
IMS
Mobile
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
35
(c) Phase 3: Registers with the IMS (only if the mobile wishes to use services provided by IMS). Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
36
6
PDP Context Activation and RAB Establishment
GPRS Attach A mobile registers with SGSN. A mobile provides its identity and service requirements to the SGSN and will be authenticated and authorized by the SGSN. Establish a Mobility Management Context on the mobile, in the RAN, and on the SGSN. This allows the RAN and the SGSN to track the mobile’s location. Establish a signaling connection between the mobile and the SGSN. The mobile and the SGSN use this signaling connection to exchange signaling and control messages needed to perform the GPRS Attach procedure. Allow the mobile to access some services provided by the SGSN. Such services include sending and receiving SMS messages and being paged by the SGSN. Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
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Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
2.1.6 User Packet Routing and Transport
Register with the IMS When a mobile wishes to use the IPbased real-time voice or multimedia services provided by the IMS, the mobile needs to perform registration with the IMS. SIP registration procedure is used for a user to register with the IMS. Will be described in detail in Chapter 3 Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
A mobile can request the network to establish and activate a PDP Context for its PDP address after the mobile has performed GPRS Attach successfully. A successful PDP context activation will trigger the PS CN domain to establish the CN Bearer and the RAB. A mobile will be able to send and receive user packets over the PS CN domain.
Inside the PS CN domain, IP is the main protocol for transporting user packets between network nods. IP is used for routing between GGSNs. Routing of user packets between SGSN and GGSN is based on GPRS-specific protocols and procedures.
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40
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
IP Network
Fig. 2.10
Packet Routing
GGSN
Gn
Gn GTP Tunnel
GPRS Tunneling Protocol (GTP): routing and mobility management
SGSN
SGSN
Iu GTP Tunnel
GTP Tunnel
maintain an individual routing entry as part of a PDP context for every mobile terminal that has an active PDP context
RNC
RNC
User packets
Radio Bearer
Source Mobile Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
GTP Tunnel
Iu
Host-specific routes are used to forward user packets between a mobile and a GGSN.
Gi
GGSN
GGSN acts as a central point for routing of all user packets. User packets are tunneled between RNC and SGSN, between SGSN and GGSN, and between two SGSNs.
Gi
41
Radio Bearer
Destination Mobile
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
42
7
Mapping between Identifiers
IP Address
Packets addressed to the PDP address are delivered by the lower protocol to the IP layer through the Service Access Point.
PDP Context
PDP Address
PDP Address
IMSI
IMSI
P-TMSI
P-TMSI
……
……
NSAPI
NSAPI
RAB ID
identified by a Network-layer Service Access Point Identifier (NSAPI) a unique NAPSI is used for each IP address
RAB ID
RAB ID
NSAPI
TEID
Radio Access Bearer (RAB)
Tunnel Endpoint Identifier (TEID)
PDP Context
RB ID
exchanged during tunnel setup process
RB ID
TEID
TEID
Radio Bearer (RB)
Radio Access Bearer Identifier (RAB ID) Radio Bearer Identifier (RB ID)
Mobile
TEID GTP Tunnel
Iu Bearer
RNC
SGSN
GGSN
Mapping X Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
43
2.1.7 Configuring PDP Addresses on Mobile Stations
44
Dynamic PDP Address from an External IP Network
Use a static PDP address assigned by the visited 3GPP network Use a static PDP address assigned by an external IP network Acquire a PDP address dynamically from the visited 3GPP network Acquire a PDP address dynamically from an external IP network Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Y
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
The visited PS domain first activates a PDP context without a PDP address for the mobile. The visited PS CN will not forward other user packets to or from the mobile before a valid PDP address is added to the mobile’s PDP context. The mobile’s serving GGSN in the visited network will have to learn the PDP address assigned to the mobile.
45
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
MS
New SGSN
Old SGSN
EIR
GGSN
46
HLR
Attach Request
2.1.8 GPRS Attach Procedure
Identification Request
Fig. 2.12
Identification Response Identity Request Identity Response
GPRS Attach procedure to attach to the PS domain IMSI Attach procedure to attach to the CS domain May combine GPRS Attach procedure and IMSI Attach procedure to attach to the PS and the CS domain simultaneously
Authentication and Authorization
IMEI Verification
Authentication and Authorization
IMEI verification Update Location Cancel Location Cancel Location ACK Delete PDP Context Request Delete PDP Context Response Insert Subscriber Data Insert Subscriber Data ACK Update Location ACK
Attach Accept
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
47
Attach Complete Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
48
8
2.1.9 PDP Context Activation and Modification
Attach Request Identifiers of the mobile: P-TMSI or its IMSI, but not both P-TMSI Signature:
3-octet number assigned to the mobile by the SGSN that assigned the P-TMSI used by the SGSNs to authenticate a P-TMSI can also be used by the mobile to authenticate the network node that is assigning the P-TMSI
Attach Type: indicate whether the Attach Request is for GPRS Attach only, GPRS Attach while already IMSI attached, or combined GPRS/IMSI Attach Location information: Routing Area Identity (RAI) (will be discussed in more detail in Chapter 4) Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
PDP Address allocation: The network allocates an PDP address to the mobile if needed. CN Bearer Establishment: The network creates and activates the PDP context on GGSN and SGSN and establishes all the necessary bearers between SGSN and GGSN for transporting user and signaling traffic for the activated PDP context. RAB Assignment: The network establishes the Radio Access Bearers to carry user traffic.
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2.1.9 PDP Context Activation and Modification (Cont.)
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
2.1.9.1 Mobile-Initiated PDP Context Activation and Modification Activate PDP Context Request
2.1.9.1 Mobile-Initiated PDP Context Activation and Modification 2.1.9.2 Network-Requested PDP Context Activation 2.1.9.3 PDP Context Modification
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
51
Fig. 2.13 3GPP mobile-initiated PDP context activation
1. Activate PDP Context Request
RNC
SGSN
2. Create PDP Context Request
GGSN
8. Activate PDP Context Accept
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
6. Update PDP Context Request
APN Network Identifier APN Operator Identifier: identify the PLMN (optional)
Same name syntax as the Internet Domain Name Domain Name System (DNS) can be used to translate an APN to an IP address
7. Update PDP Context Response
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
52
Select a service (or a GGSN) in the PS domain or a contact point in an external packet network Contain two main parts
4. Establish or Modify Radio Access Bearers
Mobile
PDP Address: either 0.0.0.0 or specified by the mobile Network-layer Service Access Point Identifier (NSAPI) PDP Type Access Point Name (APN) QoS Requested PDP Configuration Options: optional PDP parameters directly with GGSN
Access Point Name (APN)
3. Create PDP Context Response
5. Invoke Trace
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53
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
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9
Create PDP Context Request
Create PDP Context Response TEID: to identify the GGSN side of the GTP tunnel PDP Address:
NSAPI: copied from Activate PDP Context Request PDP Type: copied from Activate PDP Context Request PDP Address: from the Activate PDP Context Request message APN: selected by SGSN QoS negotiated: QoS profile the SGSN agrees to support Tunnel Endpoint Identifier (TEID): created by SGSN based on mobile’s IMSI and on the NSAPI in the Activate PDP Context Request Selection Mode: whether the APN was subscribed by mobile or selected by SGSN Charging Characteristics: what kind of charging the PDP context is liable for PDP Configuration Options: copied from the Activate PDP Context Request
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
a PDP address assigned by the GGSN 0.0.0.0 if the mobile asks to acquire from an external network
QoS Negotiated: QoS profile agreed by the GGSN PDP Configuration Options: relayed by intermediate nodes transparently to the mobile
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Fig. 2.14 3GPP networkrequested PDP context activation
2.1.9.2 Network-Requested PDP Context Activation GGSN must have static information about the PDP address
HSS/HLR
For example, the GGSN needs to know the mobile’s IMSI in order to query the HLR
A Request PDP Context Activation message to the mobile to instruct the mobile to start the Mobile-initiated PDP Context Activation procedure described in Figure 2.13 Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
3. Send Routing Info for GPRS ACK
2. Send Routing Info for GPRS 1. User packets
4. PDU Notification Request 5. PDU Notification Response 6. Request PDP Context Activation SGSN
GGSN
7. Mobile-Initiated PDP Context Activation Mobile
57
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
58
Fig. 2.15 3GPP GGSN-initiated PDP context modification
2.1.9.3 PDP Context Modification Active PDP context can be modified PDP address: only a GGSN can initiate the process to modify the PDP address in an active PDP context QoS profiles: can be initiated by the mobile, GGSN, SGSN, or the RAN
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
56
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
59
RNC
2. Modify PDP Context Request
SGSN
1. Update PDP Context Request
GGSN
3. Modify PDP Context Accept
4. RAB Assignment Procedure (to modify existing RABs) Mobile
5. Update PDP Context Response
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
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10
2.1.10 Radio Access Bearer Assignment
Update PDP Context Request
RAB Assignment: assignment, modification and release of RAB In R5, can only be initiated by the network
TEID: identify the SGSN end of the GTP tunnel NSAPI: identify the PDP context to be modified PDP Address: a new PDP address if the GGSN wishes to modify the PDP Address (optional) QoS Requested: new QoS profile suggested by the GGSN
Radio Resource Control (RRC) protocol will be used to establish, maintain, and release the Radio Bearers SGSN negotiates with the RAN about the QoS profile for the mobile
61
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Fig. 1.16 3GPP Radio Access Bearer Assignment
RNC
3. RAB Assignment Responses
2.1.11 Packet-Switched Domain Protocol Stacks 2.1.11.1 Gn and Gp interfaces and the GPRS Tunneling Protocol 2.1.11.2 The Iu-PS Interface 2.1.11.3 Gi, Gr, Gc, and Gs Interfaces 2.1.11.4 Mobile-to-GGSN Protocol Stacks
SGSN
Mobile
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
63
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
64
Fig. 1.17 3GPP Gn and Gp interface protocol stacks
2.1.11.1 Gn and Gp interfaces and the GPRS Tunneling Protocol Gn: between SGSN and GGSN as well as SGSNs in the same PLMN Gp: between an SGSN and a GGSN in a different PLMN GPRS Tunneling Protocol (GTP) is used for both user plane and control plane
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
62
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
1. RAB Assignment Request 2. Establish, modify, and release Radio Bearers
initiated by the SGSN upon triggered by other network entities in the CN or the RAN
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GTP-U
GTP-U
GTP-C
GTP-C
UDP
UDP
UDP
UDP
IP
IP
IP
IP
Layer 2
Layer 2
Layer 2
Layer 2
Layer 1
Layer 1
Layer 1
SGSN
GGSN
Layer 1 SGSN
GGSN (a) Gn and Gp Interface User Plane.
(b) Gn and Gp Interface Control Plane.
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
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11
GPRS Tunneling Protocol (GTP)
GTP Messages Tunnel Management: activate, modify and remove PDP Contexts and their associated GTP tunnels Location Management: used by a GGSN to retrieve location information from the HLR Mobility Management: used between SGSNs to transfer mobility related information Path Management: used by a node to determine if a peer node is alive and to inform the peer node of what GTP header extensions it can support
GTP-C: manage (create, modify, and release) GTP-U tunnels, manage PDP contexts, location management, and mobility management
multiple PDP contexts with the same PDP address will share a common GTP-C tunnel
GTP-U: establish and manage GTP tunnels used to tunnel user packets
one GTP-U tunnel between SGSN and GGSN will be established for every active PDP context
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
67
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
68
Fig. 2.18 GPRS Tunneling Protocol (GTP) header format
GTP Header Format
8
7
6
Version
Version: 1 for the current version PT (Protocol Type): for 3GPP CN or GPRS/GSM E (Extension header Flag): indicates whether the Next Extension Header is present S (Sequence Number flag): indicates if the Sequence Number field is present PN (N-PDU Number Flag): indicates whether the N-PDU Number field is present Message Type: indicates the type of the GTP message N-PDU Number: used in inter-SGSN Routing Area Update procedure and some inter-system handoff procedures for coordinating data transmission between a mobile terminal and a SGSN
5
4
3
2
1
PT
(*)
E
S
PN
Message Type Length (1st octet) Length (2nd octet) Tunnel Endpoint Identifier (1st octet) Tunnel Endpoint Identifier (2nd octet) Tunnel Endpoint Identifier (3rdoctet) Tunnel Endpoint Identifier (4th octet) Sequence Number (optional) (1st octet) Sequence Number (optional) (2nd octet) N-PDU Number (optional) Next Extension Header Type (optional)
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
69
70
Fig. 2.19 3GPP Iu-PS interface protocol stacks
2.1.11.2 The Iu-PS Interface Tunnel Management: establishing, maintaining and releasing the GTP tunnels between a RNC and a SGSN Radio Access Bearer Management: establishing, maintaining and releasing Radio Access Bearers (RABs) Radio Resource Management: Radio Resource Admission Control by RNC Mobility Management: handoff between RNC; paging; positioning services
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
71
GTP-U
GTP-U
UDP
UDP
IP
IP
Layer 2
Layer 2
Layer 1
Layer 1
RNC
(a) Iu-PS User Plane.
SGSN
RANAP
RANAP
SCCP
SCCP
Signaling Bearer
Signaling Bearer
AAL 5
AAL 5
ATM RNC
ATM (b) Iu-PS Control Plane.
SGSN
RANAP: Radio Access Network Application Part SCCP: Signaling Connection Control Part
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
72
12
Fig. 2.20 3GPP Gi interface protocol stack
2.1.11.3 Gi, Gr, Gc, and Gs Interfaces Gi: used by GGSN to connect to any external IP network Gr: between SGSN and HLR Gc: between GGSN and HLR Gs: between SGSN and MSC/VLR
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
MAP
MAP TCAP
IP Layer 2
Layer 1
Layer 1 Gi
GGSN
73
Fig. 2.21 3GPP control-plane protocol stack between SGSN (or GGSN) and HLR
TCAP
IP Layer 2
External IP Network
74
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Fig. 2.22 3GPP control-plane protocol stack between GGSN and HLR based on GTP
GTP-C
MAP
MAP
TCAP
TCAP
GTP-C
SCCP
SCCP
UDP
UDP
SCCP
SCCP
Signaling Bearer
Signaling Bearer
IP
IP
MTP 3
MTP 3
Layer 2
Gr or Gc SGSN or GGSN
Layer 1
HLR
TCAP: Transaction Capabilities Application Part
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Layer 2
MTP 2
Layer 1
Layer 1
Gn
GGSN
75
Fig. 2.23 3GPP control-plane protocol stack between SGSN and MSC/VLR
MTP 2 Layer 1 Gc
GSN serving as Protocol Converter
HLR
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
76
2.1.11.4 Mobile-to-GGSN Protocol Stacks Packet Data Convergence Protocol (PDCP)
Header compression for higher-layer data streams IP Header Compression (IPHC)
BSSAP+
BSSAP+
SCCP
SCCP
Signaling Bearer
Robust Header Compression (ROHC)
Signaling Bearer Gs
SGSN
MSC
BSSAP+: Base Station System Application Part+
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
77
Mapping higher-layer data into the underlying radio interface protocols Maintaining data transmission orders for upper layer protocols that have such requirement
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
78
13
Fig. 2.24 3GPP user-plane protocol stack between mobile and GGSN
Radio Link Control (RLC) Provides logical link control over the radio interfaces A mobile can have multiple RLC connections Support
Applications
PDP (e.g., IP, PPP)
PDP (e.g., IP, PPP)
PDCP
PDCP
RLC
RLC
GTP-U
GTP-U
GTP-U
GTP-U
UDP
UDP
UDP
UDP
IP
IP
IP
IP
MAC
Layer 2
Layer 2
Layer 2
Layer 2
Layer 1
Layer 1
Layer 1
Layer 1
MAC Layer 1
Iu-Ps
Uu MS
Layer 1 Gn
UTRAN
SGSN
GGSN
79
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Fig. 2.25 3GPP control-plane protocol stack between mobile and SGSN
GMM
SM
SMS
GMM
SM
RRC
RRC
RANAP
RLC
RLC
SCCP
SCCP
MAC
MAC
Signaling Bearer
Signaling Bearer
GPRS Mobility Management (GMM): support mobility management functions including GPRS Attach and Detach operations, security, and routing area update procedure. Session Management (SM): support PDP context activation, modification, and deactivation SMS (Short Message Service): support short messages
SMS
AAL 5
ATM MS
GMM, SM, and SMS
Layer 1 Uu
ATM Iu-PS
RNS
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
SGSN
81
82
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Fig. 2.26 Access another IP network through 3GPP PS domain
2.1.12 Accessing IP Networks through PS Domain User registration (e.g., authentication and authorization) with the external IP network Dynamic assignment of IP addresses to the mobile by the external IP network Encryption of user data transported between the mobile and the external IP network Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
80
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
RANAP
AAL 5 Layer 1
Broadcast information related to the RAN and the CN to the mobiles Establish, maintain, and release RRC connections Establish, maintain, and release Radio Bearers Paging Radio power control Control of radio measurement and reporting Control of the on and off of ciphering between the mobile and the RAN
83
User Traffic
RNC
SGSN
Router
GGSN
External IP Network
Gi Mobile
RAN
3GPP PS Domain
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
84
14
Transparent Access vs. Nontransparent Access
2.1.12 Accessing IP Networks through PS Domain
Transparent Access: The GGSN does not participate in any interaction between the mobile and the external IP network except transporting user packets. Non-transparent Access: The GGSN participates in at least one of the interactions between the mobile and the external IP network described above.
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
2.1.12.1 Transparent Access 2.1.12.2 Non-Transparent Access Using Mobile IP 2.1.12.3 Acquiring IP Address Dynamically Using DHCP from an External Network 2.1.12.4 Dial-up Access Using PPP
85
86
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Fig. 2.27 Protocol stacks for transparent to IP networks through 3GPP PS CN
2.1.12.1 Transparent Access Gain access to a GGSN in the local PS CN Acquire an IP address from the local PS domain to use as its PDP address in local PS CN domain Register with the external IP network
Higher-Layer IP Protocols (e.g., MIP, IPsec)
Higher-Layer IP Protocols (e.g., MIP, IPsec)
UDP/TCP
UDP/TCP
IP
IP
IP
IP
Layer 2
Layer 2
3GPP Packet Domain Bearer Layer 1
Layer 1 Gi
Mobile Terminal
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
87
2.1.12.2 Non-Transparent Access Using Mobile IP
GGSN
External IP Network
88
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Fig. 2.28 Protocol stacks for non-transparent access to IP networks through PS CN domain
GGSN also serves as a MIPv4 FA Mobile uses the IP address of the GGSN as its FA CoA HA may be inside an external IP network
MIPv4
MIPv4 Foreign Agent
MIPv4
UDP
UDP
UDP
IP
IP
IP
UDP IP
Layer 2
Layer 2
3GPP Packet Domain Bearer Layer 1
Layer 1 Gi
Mobile Terminal
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
89
GGSN
External IP Network
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
90
15
Fig. 2.29 Mobile
GGSN With Mobile IP FA
SGSN
Activate PDP Context Request (PDP Address = 0.0.0.0 APN=MIPv4FA)
Activate PDP Context Accept (PDP Address = 0.0.0.0)
Mobile IP HA
Create PDP Context Request (PDP Address = 0.0.0.0 APN=MIPv4FA)
Before an IP address is assigned to the mobile by the external IP network, the PS CN domain should be able to relay DHCP messages between the mobile and external DHCP server. When an IP address is assigned to the mobile by the external IP network, the mobile’s PDP contexts on the SGSN and the GGSN need to be updated to include the mobile’s IP address.
Create PDP Context Response (PDP Address = 0.0.0.0)
Mobile IP Agent Advertisement
Mobile IP Registration Request (CoA = FA CoA = Address of GGSN)
2.1.12.3 Acquiring IP Address Dynamically Using DHCP from an External Network
Mobile IP Registration Request (CoA = FA CoA = Address of GGSN) Mobile IP Registration Reply Extract mobile’s home address And enter it to PDP Context
Mobile IP Registration Reply
GGSN-initiated PDP Context Modification
91
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Fig. 2.30 3GPP protocol stacks for supporting IP address assignment by external network using DHCP
Fig. 2.31 Mobile
DHCP Relay Agent
Activate PDP Context Request (PDP Address = 0.0.0.0)
UDP
UDP
UDP
IP
IP
IP
IP
Lower Layers Mobile Station
Lower Layers Lower Layers GGSN
DHCP Server in External IP Network
Create PDP Context Request (PDP Address = 0.0.0.0) Create PDP Context Response (PDP Address = 0.0.0.0)
DHCPDISCOVER
DHCP Server Process
UDP
GGSN with DHCP Relay Agent
SGSN
Activate PDP Context Accept (PDP Address = 0.0.0.0)
DHCP Client Process
92
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
DHCPDISCOVER
DHCPOFFER
DHCPOFFER
DHCPREQUEST
DHCPREQUEST
Lower Layers
DHCPACK
External IP Network
Extract IP Address Assigned to Mobile DHCPACK
GGSN-initiated PDP Context Modification
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
93
2.1.12.4 Dial-up Access Using PPP
Fig. 2.32 Protocol stacks for dialup through 3GPP packet domain to an IP network
Dialup refers to the process of establishing a link-layer connection to an IP network PPP connection is a natural choice for implementing the portion of a dialup connection over the PS domain L2TP may be used to extend the PPP connection from GGSN to external IP network
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
94
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
95
PPP
Lower Layers Mobile
PPP
Lower Layers
Protocols for tunneling over IP network (e.g., L2TP)
Protocols for tunneling over IP network (e.g., L2TP)
UDP
UDP
IP
IP
Lower Layers
Lower Layers
GGSN (LAC)
LNS in External IP Network
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
96
16
Fig. 2.33 Signaling flows for dialup through 3GPP packet domain to an IP network Visited Network
1. Activate PDP Context Request (PDP Address = 0.0.0.0)
4. Activate PDP Context Accept (PDP Address = 0.0.0.0)
Mobile
External IP Network
2. Create PDP Context Request (PDD Address = 0.0.0.0)
SGSN
3. Create PDP Context Response (PDP Address = 0.0.0.0)
GGSN
6. L2TP Negotiation
LNS
5. Establish PPP and Configure IP over PPP
2.2.1 3GPP2 Network Architecture
98
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Radio Networks (RNs) cdma2000 base station
Core network
2.2.1 3GPP2 Network Architecture 2.2.2 3GPP2 Packet Data Network Architecture 2.2.3 Protocol Reference Model 2.2.4 Access to 3GPP2 Packet Data Network 2.2.5 User Packet Routing and Transport 2.2.6 Protocol Stacks for Packet Data Services
97
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
2.2 3GPP2 PACKET DATA NETWORKS
circuit-switched domain packet-switched domain
Radio Networks (RNs): based on circuitswitched technologies and is used for both circuit-switched and packetswitched services
Base Station (BS)
99
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Fig. 2.34 3GPP2 conceptual network architecture Circuit Switched Core Network Servers (e.g., SCP, VMS, MC, PDE, NPDB, SN)
PSTN
MSC C
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
100
2.2.1.1 Circuit-Switched Core Network
VLR
Mobile Switching Center (MSC)
Information Servers
Pi
B
A HLR
Base Station Controller (BSC) Base Transceiver System (BTS)
Switching and call control components Ai
Radio Network
System ID (SID): identify a system Network ID (NID): identify a network pair (SID, NID) (SID, NID): uniquely identify a network within a system
Home Location Registrar (HLR) Visitor Location Registrar (VLR) Equipment Identity Registrar (EIR)
Service control servers BTS
BSC
Packet Switched Core Network Aquinter
AAA Server Pi
HA Pi Pi
Aquater PCF
IP Network
PDSN
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
101
Service Control Point (SCP) Voice Message System (VMS) Message Center (MC) Position Determining Entity (PDE) Number Portability Database (NPDB) Service Node (SN) Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
102
17
2.2.2 3GPP2 Packet Data Network Architecture
2.2.2.1 Functional Architecture
2.2.2.1 Functional Architecture 2.2.2.2 Reference Network Architecture
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
103
Fig. 2.35 3GPP2 packet data network functional architecture
RRC
MS
PCF
PDSN
104
Route IP packets between the 3GPP2 network and any external IP networks Route IP packets between mobile terminals inside the same operator’s 3GPP2 network Act as an IP address server to assign IP address to mobiles Act as a PPP server for mobiles (i.e., establish, maintain and terminate PPP session to a mobile terminal) Provide mobility management functions (FA) Communicate with an AAA server to authenticate and/or authorize MS
AAA
105
Packet Control Function (PCF)
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
106
Radio Resource Control (RRC)
Establish, maintain, and terminate layer-2 connections to the PDSN Maintain reachability information for mobile terminals Relay IP packets between RN and PDSN Tracks status of radio resources Communicate with RRC function on the BSC to manage radio resources Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Packet Data Serving Node (PDSN)
HA
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Packet Data Serving Node (PDSN) Packet Control Function (PCF) Radio Resource Control (RRC) Mobile Station (MS) Home Agent (HA) Authentication, Authorization, Accounting (AAA)
107
Establish, maintain, and terminate radio connections to mobiles and management radio resources allocated to these connections Broadcast system information to mobiles Maintain status of mobile terminals (e.g., active, dormant) Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
108
18
Fig. 2.36 Functional architecture of a mobile station (MS)
Mobile Station (MS) User Identity Module (UIM): removable or integrated into ME Mobile Equipment (ME)
MS ME
Terminal Equipment (TE) Mobile Terminal (MT) Terminal Adapter (TA)
MT
TE
TA
UIM Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
109
2.2.2.2 Reference Network Architecture
Fig. 2.37 3GPP2 packet data network reference physical architecture Home Access Visited Access Provider Network 1
Provider Network MSC/ VLR
Simple IP Access
mobile is assigned an IP address dynamically by PDSN obtain a new IP address when MS moves to a new PDSN
Mobile IP Access
HLR
Home AAA Home IP Network
IP Network
AAA Broker AAA Network
A10/A11
Mobile Terminal
111
PDSN
P-P Interface
Visited Access Provider Network 2
IPv6
SS7 Network
Visited AAA
RN
Mobile IP (v4 or v6)
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
110
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
HA
Home IP Network, Private Network, or Home Access Provider Network
PDSN Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
112
Relation with CS Network
PDSN acts as an IPv6 access router PPP is established between MS and PDSN IPv6 over PPP PDSN sends Router Advertisement MS can use IPv6 stateless autoconfiguration to construct and configure a local IPv6 address Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Many critical capabilities in PS network rely on CS network
handoff, paging, connection setup
PS network does not directly interface with the CS network CS procedures are initiated by the BSC inside RN upon receiving data or requests from PCF 113
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
114
19
Fig. 2.38 3GPP2 protocol reference model
2.2.3 Protocol Reference Model
MSC
A Reference Point Ater Reference Point Aquinter Reference Point Aquarter Reference Point P-P Interface (optional)
Call Control And Mobility Management
A1 (Signaling)
A2 (User Traffic)
Circuit Switch
PDSN
A5 (User Traffic)
P-P Interface
A Reference Point A3 (User Traffic) BSC2
A3 (Signaling)
A8 (User Traffic) BSC1
A9 (Signaling)
A10 (User Traffic) PCF
A11 (Signaling)
PDSN
A7 (Signaling)
PDSN-to-PDSN Interface is used support fast handoff between PDSNs
Ater Reference Point
Aquinter Reference Point
Aquater Reference Point (R-P interface)
Traffic interface Signaling interface Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
115
A Reference Point
117
Interface A3: carry signaling and user traffic between SDU on a source BSC and a target BTS for supporting soft handoff
A3 signaling controls the allocation and use of A3 user traffic channels
Interface A7: carry other signaling information not carried by the A3 interface between a source and a target BS
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
118
Aquarter Reference Point (R-P Interface)
Aquinter Reference Point A8 interface: transport user data traffic A9 interface: signaling between a BSC and a PCF The A8 and A9 interfaces are also used to support mobility between BSCs under the same PCF
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
116
Ater Reference Point
Interface A1: carry signaling traffic between the Call Control and Mobility Management functions of the MSC and the Call Control function of the BSC Interface A2 and A5: carry different types of user traffic between the switch component of MSC and Selection and Distribution Unit (SDU) on BSC Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
119
A10 interface: provide a path for user traffic A11 interface: signaling between the PCF and the PDSN The A10 and A11 interfaces are also used to support mobility between PCFs under the same PDSN
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
120
20
2.2.4 Access to 3GPP2 Packet Data Network
MS
Step 1
Establish A10 A9-Connect-A8
Establish PPP connection Mobile IP Agent Advertisement Mobile IP Registration Request
Authorization Request
Authorization Request Authorization Response
Authorization Response
Mobile IP Registration Request
Step 2
Mobile IP Registration Request Reply Mobile IP Registration Request Reply
Accounting Request Accounting Response
User packets over PPP
121
2.2.5 User Packet Routing and Transport
122
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
IP Network
Fig. 2.40
IP
IP
PDSN 2
PDSN 1
A10/A11
Mobile maintains a PPP connection to its serving PDSN All user packets to and from the mobile will be sent to the serving PDSN first A8 and A10 connections are implemented as IP tunnels using Generic Routing Encapsulation (GRE)
A10/A11 GRE Tunnel
GRE Tunnel
PCF 2
PCF 1
A8/A9
A8/A9 GRE Tunnel
GRE Tunnel PPP connections
BSC 2
BSC 1
User packets
Radio Bearer
Source Mobile
123
2.2.6 Protocol Stacks for Packet Data Services
Radio Bearer
Destination Mobile
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
124
2.2.6.1 Protocol Stacks over A9 and A11 Interfaces
Stacks over A9 and A11
Main messages of A9
Stacks over A8 and A10
Stacks over P-P
Stacks Between Mobile
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Mobile IP Home Agent
Assignment Complete
Step 2: MIPv4 registration
2.2.6.1 Protocol Interfaces 2.2.6.2 Protocol Interfaces 2.2.6.3 Protocol Interface 2.2.6.4 Protocol and PDSN
Home AAA Server
Fig. 2.39 3GPP2 Packet Service Activation (using Mobile IP)
A9-Setup-A8
Step 1-C: Establish PPP connection between mobile and PDSN.
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Foreign AAA Server
PDSN
Establish Traffic radio channel
Step 1-A: Gain access to the Radio Network. Step 1-B: Setting up resources between the BSC and the PDSN.
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
PCF
CM Service Request
May not need to set up A8 connection
MSC
Assignment Request
Step 1: Gain access to PDSN
BSC Origination ACK
125
A9-Setup-A8 and A9-Connect-A8 A9-Release-A8 and A9-Release-A8 Complete A9-Disconnect-A8 A9-Update-A8 and A9-Update-A8 Ack A9-Air Link (AL) Connected and A9-Air Link (AL) Connected Ack A9-Air Link (AL) Disconnected and A9-Air Link (AL) Disconnected Ack
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
126
21
2.2.6.1 Protocol Stacks over A9 and A11 Interfaces (Cont.)
Fig. 2.41 3GPP2 protocol stacks for the A9 and A11 interfaces
A11 signaling protocol is modeled after the Mobile IPv4 protocol
PDSN acts as if it was a MIPv4 HA PCF acts as if it was a MIPv4 FA
Main messages of A11
A11 Registration A11 Registration A11 Registration A11 Registration
A9 Signaling
Request Reply Update Acknowledge
C R K S s
Recur
Flags
Offset (optional)
Physical Layer
Physical Layer
Physical Layer A11
PCF
PDSN
128
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
GRE
GRE
GRE
IP
IP
IP
IP
Link Layer
Link Layer
Link Layer
Link Layer
Physical Layer
Physical Layer
A8
PCF
GRE
Physical Layer A10
PDSN
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
130
The P-P interface is an optional interface used to support fast inter-PDSN handoff (see 4.4.4) Two individual interfaces
Routing (optional)
(a) GRE header format.
Flags
Link Layer
2.2.6.3 Protocol Stacks over P-P Interface
Sequence Number (optional)
Recur
Link Layer
129
Key (optional)
C R K S s
UDP
Protocol Type
Checksum (optional)
0 1 2 3 4 5 6 7 8 90 1 2 3 4 5
Link Layer
BSC
6 7 8 9 0 1 2 3 4 5 6 7 8 0 1 2
Ver
IP
Link Layer
Physical Layer
Fig. 2.43 Generic Routing Encapsulation (GRE) protocol header 0 1 2 3 4 5 6 7 8 90 1 2 3 4 5
IP
A9
UDP
Fig. 2.42 3GPP2 protocol stacks for the A8 and A10 interfaces
PCF Session Identifier (PCF SID) PDSN Session Identifier (PDSN SID)
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
IP
127
GRE encapsulates a user packet by adding a GRE header to the user packet Sequence Number: ensure packet delivery order Key: identify the IP packets to and from each mobile terminal
A11 Signaling
IP
BSC
2.2.6.2 Protocol Stacks over A8 and A10 Interfaces
A11 Signaling
TCP/UDP
Physical Layer
Soft state: PCF periodically sends A11 Registration Request to refresh A10 connection
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
A9 Signaling
TCP/UDP
6 7 8 9 0 1 2 3 4 5 6 7 8 0 1 2
Ver
Protocol Type
Key
P-P Bearer Interface: P-P traffic connection to tunnel user packets between the PDSNs by GRE tunnel P-P Signaling Interface: signaling messages and procedures for managing the P-P traffic connections
Sequence Number (optional)
(b) Format of GRE header used for tunneling between PCF and PDSN or between BSC and PCF. Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
131
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
132
22
Fig. 2.44 Protocol stacks for the P-P interface
P-P Signaling
P-P Signaling
Modeled after the Mobile IPv4 protocol
Serving PDSN acts as if it was a MIPv4 HA Target PDSN acts as if it was a proxy/MIPv4 FA
Main messages of A11
A11 A11 A11 A11
P-P Signaling
UDP
UDP
IP, IPsec
IP, IPsec
Link Layer
Link Layer
Physical Layer
Physical Layer
Target PDSN
Serving PDSN (a) Control-plane protocol stack
Registration Request Registration Reply Registration Update Registration Acknowledge
GRE
GRE
IP, IPsec
IP, IPsec
Link Layer
Link Layer
Physical Layer
Physical Layer
Target PDSN
Serving PDSN (b) User-plane protocol stack
133
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Fig. 2.45 3GPP2 protocol stacks for user data between mobile terminal and PDSN (without P-P interface)
2.2.6.4 Protocol Stacks Between Mobile and PDSN Mobile is not in the process of fast inter-PDSN handoff (without P-P interface)
Link Access Control (LAC): establish, use, modify, remove of radio links
IP
IP
PPP
PPP
LAC
With P-P interface Signaling between a mobile and its serving PDSN
Link Physical
GRE
GRE
GRE
GRE
IP
IP
IP
IP
Link
Link
LAC
Link
Link
Physical Physical
Mobile
135
BSC
IP
IP
Link
Link
Link
Physical Physical A8
Set up PPP MIPv4 registration Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
134
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Physical Physical
PCF
Serving PDSN
CH
136
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Fig. 2.46 Protocol stacks for end-to-end user traffic transport when P-P interface is used
Fig. 2.47 3GPP2 protocol stacks for signaling between mobile terminal and PDSN MIPv4 Client
UDP
UDP IP
IP
IP PPP
IP
IP
GRE
PPP
PPP
LAC
LAC
Link
Link
Physical
GRE
GRE
GRE
Link IP
IP
IP
IP
IP
IP
Link
Link
Link
Link
Link
Link
Physical Physical
Physical Physical A8
Mobile
GRE
IP
MIPv4 Foreign Agent
UDP
PPP GRE
IP
Physical
A10 (R-P)
BSC
Physical Physical
A10 (R-P) PCF
Link
GRE LAC
IP
Physical Physical
Physical
P-P Target PDSN
MAC Physical
Serving PDSN
137
GRE
MAC
IP
Link
GRE
IP
Link
Physical Physical
CH
BSC
IP
Link
Link Layer
Link
Physical Physical A8
Mobile
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
GRE
LAC
Physical
Physical
A10 PCF
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Serving PDSN
138
23
2.3 MWIF ALL-IP MOBILE NETWORKS
2.3.1 Network Architectures
MWIF seeks to develop an end-to-end all-IP wireless network that will use IETF protocols to support all networking functions at the network-layer and higher layers, including naming and addressing, signaling, service control, routing, transport, mobility management, quality of service mechanisms, security, accounting, and network management. Unlike the 3GPP and 3GPP2 networks, the MWIF architecture will no longer rely on protocols or network entities in circuitswitched core networks.
Core Network
All-IP using standard IETF protocols Independent of access-specific technologies used in different Access Networks
Access Networks
139
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
Fig. 2.48
Layered Functional Architecture Transport Layer (in both Access Network and Core Network) Control Layer Service Layer Application Layer
Application Layer
3rd Party Applications
Service Layer Applications/Services, Directory Servers, Global Name Servers, Location Servers, Authorization Server, Policy Server Control Layer Mobility Management, Communication Session Management, Address Management, Resource Manager, Authentication, Accounting.
Security Functions
OAM&P
Transport Layer Core Network Access Network
The security and the OAM&P (Operation, Administration, Maintenance and Provisioning) functions may span across multiple functional layers.
Access Gateway
141
Router
Router
IP Gateways
Mobile Terminals Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
140
Router
Media Gateways
External IP Networks
Signaling Gateway
PSTN and Circuit-Switched Wireless Networks
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
142
O p e r a t io n s , A d m in ist r a tio n , M a in t e n a n c e & P r o v is io n in g C o n f ig u r a t io n M anagem ent
F a u lt M an agem en t
S63
S66
S65
S41
S41
L o c a tio n Server
S39
S38
R esource D ir e c t o r y
G lo b a l N am e Server
S40
S25
G e o g r a p h ic L o c a tio n M anager
T h ir d P a r ty A p p lic a tio n
C ore N etw ork A p p lic a t io n
S16
D ir e c t o r y S e r v ic e s S41 S26
S67
A p p lic a t io n F u n c t io n a l E n t itie s
S11 S e r v ic e D is c o v e r y Server
B illin g M anagem ent
P erfo rm a n ce M anagem ent
S e c u r it y M anagem ent
S64
C o r e N e tw o r k F u n c tio n a l E n t itie s
P r o file Server
S13
S33
S59
S58
S15
A u t h o r is a tio n Server S56
A u t h e n tic a t io n Server S55
S41
A c c o u n t in g Server
S18
S41 S29
S e s s io n A nchor S28
S53
S35 M o b ile A tte n d a n t
A ccess G atew ay
S47
A ccess T ra n sp o rt G atew ay
IP A ddress M anager
B 04
M u lt im e d ia R esource F u n c tio n
S30
R ou ter B 07
S31
B 10
S43
B 05
B 05
In te r n e t
B 05
B 06
In tr a n e t
S46
P STN
T e r m in a l
K ey
B 08 S68
S45 M A P N e tw o rk
E n te r p r is e N etw ork
A c c e ss N e tw o rk
U ser I d e n tit y M o d u le
C o lle c t iv e
Snn R e fe r e n c e P o in t ( S ig n a llin g )
N etw ork F u n c tio n a l E n tity
B nn R e fe r e n c e P o in t (U se r D a ta B e a re r)
Enable a mobile to gain access to the core network and to send and receive IP packets over the core network
SIP Registration
S ig n a llin g G atew ay
T r a n sp o r t G a te w a y F E s
C N I n te r w o r k in g F u n c tio n s
S37
S42
S44
M e d ia G a te w a y
IP G a te w a y
B 09
S12
M e d ia G atew ay C o n t r o lle r
S23
S27
B 02
B 01 B 03
S21 S22
R esource M anager S52
M u ltim e d ia R esource C o n t r o lle r
Specific to each access network
Basic Registration for Core Network
S54
S32 S41
S34
S61 S62
S20
S19
S e s s io n P roxy
S17
S57
S41 S60
C o m m u n ic a t io n S e s sio n M anager
S36
2.3.2 Access to MWIF Networks Access Network Registration
A A A F u n c tio n a l E n tit ie s S48 S50 S51 S49
H om e M o b ilit y M anager
H o m e IP A ddress M anager
Fig. 2.49
S14
P o lic y R e p o s ito r y S24
Enable a user to use SIP to initiate and receive multimedia communications An integral part of session and service management
N etw ork
A r e fe r e n c e p o in t to a c o lle c tiv e g o e s to e v e r y n e tw o rk f u n c tio n a l e n tity w ith in th e c o lle c tiv e
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
143
Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
144
24
Serving Network
Mobile Attendant
Terminal
Home Network
Authentication Policy Policy Server Repository Server
Home Mobility Authentication Policy Server Repository Manager
Home IP Address Manager
Profile Server
Access Network Registration Step 1
2.3.3 Session Management
Obtain IP Address and Mobile Attendant Address Request Terminal Registration
Request Authentication
2.3.3.1 Functional Entities, Protocol Reference Points and Stacks 2.3.3.2 Mobile-Initiated Call Setup
Policy Request Policy Response Policy Request
Request Authentication Step 2
Policy Response
Fig. 2.50 MWIF basic registration procedure
Request Terminal Registration Response Terminal Registration
Address Request Address Response
Profile Request Response Response Terminal Authentication Registration Step 3
Profile Response
Response Authentication
QoS Procedure
145
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Serving Network DIAMETER AAA Server
Authentication Authorization Accounting Terminal Global Name server
Resource Directory
S25
Core Network
S49
S49
Access Transport Gateway
Home Network
IP Gateway
Session Proxy
SIP INVITE
SIP INVITE
Session Anchor
S19
S20
S18
Communication Communication Session Session Manager Manager
S18
S21
Session S20 Anchor S41
Service Discovery Server S41
S29
Media Gateway Controller
S27 S28 Media Resource Controller
IP Gateway
Fig. 2.52 MWIF mobile-originated call setup procedure
S17
183 Call Processing
183 Call Processing
PRACK
Access Gateway
Fig. 2.51
PRACK
Authorization Server
Profile Server
Policy Repository
Request Authentication
Request Authorization
Request Profile Response Profile Request Policy
Response Authorization
Response Policy
ACK
Home Network User Data Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
147
183 Call Processing from destination
PRACK 200 OK
200 OK
200 OK Radio Access Network
Visited Network
Authentication Server
SIP INVITE sent to destination
Session Proxy
Session Proxy
CSM
Response Authentication
S24 S22
Communication Session Manager
146
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ACK User Data
ACK User Data
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