Chapter 2: Wireless IP Network Architectures: Jyh-Cheng Chen and Tao Zhang

Chapter 2: Wireless IP Network Architectures
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.
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 users 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.
Outline
2.1 3GPP Packet Data Networks 2.2 3GPP2 Packet Data Networks 2.3 MWIF All-IP Mobile Networks
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
2.1.1 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)

Core Network (CN)

GSM/EDGE RAN (GERAN) UMTS Terrestrial RAN (UTRAN) Broadband Radio Access Networks (BRANs) Circuit-Switched (CS) Domain Packet-Switched (PS) Domain IP Multimedia Subsystem (IMS) Information Servers
Fig. 2.1 3GPP conceptual network architecture (Release 5)

PSTN and Circuit-Switched Wireless Network External IP Networks
IP Multimedia Subsystem (IMS)
GMSC Circuit Switched Domain Information Servers Shared by PS and CS Domain (HSS, EIR, AuC)
GGSN
Packet Switched Domain
MSC + VLR
SGSN Core Network
GSM RAN (i.e., Base Station Subsystems) Radio Access Networks
UTRAN (UMTS Terrestrial Radio Access Network)
GERAN and UTRAN

GERAN
Base Station Subsystem (BSS)

Base Transceiver Station (BTS) Base Station Controller (BSC)
UTRAN
Radio Network Subsystem (RNS)

Node B Radio Network Controller (RNC)
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2.1.1.1 Mobile Devices, Subscribers, and Their Identifiers

Mobile Station (MS): in GSM User Equipment (UE): in UMTS
Mobile Equipment (ME)

Terminal Equipment (TE) Mobile Termination (MT)
Terminal Adapter (TA)
UMTS Subscriber Identity Module (USIM)
Fig. 2.2 Functional architecture of an user equipment (UE)

UE ME USIM
TE MT TA
Identifiers
International Mobile Station Equipment Identity (IMEI): identify MT
manufacturer, country, type
International Mobile Subscriber Identity (IMSI): globally unique and permanently assigned for each subscriber
stored on USIM
10
Fig. 2.3 Structure of International Mobile Subscriber Identity (IMSI)
No more than 15 digits
3 digits
2 3 digits
Mobile Country Code (MCC)
Mobile Network Code (MNC)
Mobile Subscriber Identification Number (MSIN)
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Identifiers (Cont.)
Temporary Mobile Subscriber Identity (TMSI)
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 single or multiple may acquire an IP address only when necessary
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IP address

2.1.1.2 Circuit-Switched Domain in Core Network

Mobile-services Switching Center (MSC) Gateway MSC (GMSC) Visitor Location Register (VLR) Home Subscriber Server (HSS), Equipment Identity Register (EIR), and Authentication Center (AuC)
13
Switching vs. Call Control

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
14
2.1.1.3 Packet-Switched Domain in the Core Network

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
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Serving GPRS Support Node (SGSN)

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 mobiles 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
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Identifiers of SGSN and GGSN

IP address
may be private IP address used primarily with non-IP protocols, e.g., MAP or other SS7-based protocols
SGSN Number and GGSN Number
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2.1.1.4 IP Multimedia Subsystem

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
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2.1.1.5 Information Servers

Shared by CS and PS domains Home Subscriber Server (HSS)

Authentication Center (AuC)

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 information to authenticate each user and to encrypt the communication accessed by the HSS maintain IMEIs of the subscribers
Equipment Identity Register (EIR)
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2.1.2 Protocol Reference Model

RAN Internal Interfaces RAN-to-CN Interfaces CS CN Internal Interfaces
many interfaces use MAP protocol
PS CN Internal Interfaces
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To PSTN
To external IP networks Gi IMS
To external To GGSN in IP networks Other networks
Fig. 2.4
CS-MGW Nb G VLR B E MSC Server Mc CS-MGW Nb A NC CS-MGW
Mc
GMSC Server Nc D
Go C HSS (HLR) F Gc H AuC GGSN
Gi
Gp
Gn Gr Gf SGSN Iu-PS
VLR B MSC Server Mc
EIR Gs
Gb Core Network Iu-CS UTRAN Abis Traffic interface Signaling interface GSM BSS BTS Um MT Radio Access Networks MT BTS Iu-CS Iur BSC RNC Iub Node B Cell Cell Uu Node B Cell Cell RNC
A IuCS
22
RAN Internal Interfaces

GERAN

Abis Um Iub Iur: logical signaling interface Uu

23
UTRAN

RAN-to-CN Interfaces
GERAN

UTRAN

A or Iu-CS: CS CN domain Gb or Iu-PS: PS CN domain Iu-CS: CS CN domain Iu-PS: PS CN domain A/Gb mode Iu mode
24
One and only one mode

Fig. 2.5 Protocol reference model for 3GPP PS domain

MSC + VLR Gs D HSS/HLR Gr Gc External Packet Network Gi
Node B Mobile Uu UTRAN Iub
RNC IuPS
SGSN Gn PS CN
GGSN
Gp
GGSN PS CN in different PLMN
25
2.1.3 Packet Data Protocols, Bearers, and Connections for Packet Services
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
26
Fig. 2.6 3GPP bearers (connections) for supporting packet-switched services

Mobile RNC
3GPP Bearer
SGSN
GGSN
Radio Access Bearer (RAB)
CN Bearer
Radio Bearer
Iu Bearer Lower Layer Bearers
Lower Layer Bearers
Lower Layer Bearers
Iu
Gn
27
Separation of Bearers
The (Traffic) Radio Bearers, Iu (Traffic) Bearers, Radio Access Bearers, and CN Bearers are managed by different protocols and procedures.
allows different protocols and procedures to be used; evolve with less dependency on each other facilitates mobility management
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Fig. 2.7 Signaling and traffic connections between mobile and SGSN
RRC Connection RANAP Connection
Mobile
Signaling Radio Bearer
Mobile-SGSN Signaling Connection
RNC
Iu Signaling Bearer
SGSN
Traffic Radio Bearer
Radio Access Bearer (RAB)
Iu Traffic Bearer
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Connections
Radio Resource Control (RRC) connection

Signaling Radio Bearer Traffic Radio Bearer
Radio Access Network Application Part (RANAP) connection

Iu Signaling Bearers Iu Traffic Bearers

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2.1.4 Packet Data Protocol (PDP) Context

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

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
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PDP States
ACTIVE state

INACTIVE state
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 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.
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Fig. 2.8 3GPP PDP context state transitions

PDP Context Modification
PDP Context ACTIVE
PDP Context Deactivation or Mobility Management state changes to PMM-IDLE or PMM-DETACHED
PDP Context Activation
PDP Context INACTIVE
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State Transition
PDP Context Activation PDP Context Modification
modify the PDP Address or the attributes of the QoS profile Release 5 only allows the GGSN-initiated PDP Context Modification
PDP Context Deactivation

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2.1.5 Steps for a Mobile to Access 3GPP Packet-Switched Services

GPRS Attach PDP Context Activation and RAB Establishment Register with the IMS
35
HSS
GPRS Attach
SGSN
Fig. 1.9 Three-phased access to 3GPP packet-switched network and services
Mobile (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 4. Activate PDP Context Accept SGSN GGSN
(b) Phase 2: Activate PDP Context and establish Radio Access Bearer.
SGSN Registration with IMS Mobile
GGSN IMS
(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.
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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 mobiles 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.
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PDP Context Activation and RAB Establishment

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.
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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
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2.1.6 User Packet Routing and Transport

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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Packet Routing
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.
GPRS Tunneling Protocol (GTP): routing and mobility management
Host-specific routes are used to forward user packets between a mobile and a GGSN.
maintain an individual routing entry as part of a PDP context for every mobile terminal that has an active PDP context
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IP Network
Fig. 2.10
Gn
Gi
Gi
GGSN
GGSN
Gn GTP Tunnel GTP Tunnel
SGSN
SGSN
Iu GTP Tunnel
Iu GTP Tunnel
RNC
RNC
Radio Bearer
User packets
Radio Bearer
Source Mobile
Destination Mobile
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Mapping between Identifiers

Packets addressed to the PDP address are delivered by the lower protocol to the IP layer through the Service Access Point.

Tunnel Endpoint Identifier (TEID)
identified by a Network-layer Service Access Point Identifier (NSAPI) a unique NAPSI is used for each IP address exchanged during tunnel setup process
Radio Access Bearer Identifier (RAB ID) Radio Bearer Identifier (RB ID)
43
PDP Context PDP Address IP Address IMSI P-TMSI NSAPI NSAPI
PDP Context PDP Address IMSI P-TMSI NSAPI
RAB ID
RAB ID Radio Access Bearer (RAB)
RAB ID
TEID GTP Tunnel
TEID
RB ID Radio Bearer (RB)
RB ID
TEID Iu Bearer
TEID
Mobile
RNC Mapping X Y
SGSN
GGSN
44
2.1.7 Configuring PDP Addresses on Mobile Stations

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
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Dynamic PDP Address from an External IP Network

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 mobiles PDP context. The mobiles serving GGSN in the visited network will have to learn the PDP address assigned to the mobile.
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2.1.8 GPRS Attach Procedure

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
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MS Attach Request
New SGSN
Old SGSN
EIR
GGSN
HLR
Identification Request Identification Response Identity Request Identity Response
Fig. 2.12
Authentication and Authorization
Authentication and Authorization
IMEI Verification
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 Attach Complete Copyright 2004 by John Wiley & Sons, Inc. All rights reserved.
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Attach Request
Identifiers of the mobile: P-TMSI or its IMSI, but not both P-TMSI Signature:

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)
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
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2.1.9 PDP Context Activation and Modification

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.)

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
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2.1.9.1 Mobile-Initiated PDP Context Activation and Modification

Activate PDP Context Request
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
52
Fig. 2.13 3GPP mobile-initiated PDP context activation
1. Activate PDP Context Request
RNC
SGSN
2. Create PDP Context Request 3. Create PDP Context Response
GGSN
4. Establish or Modify Radio Access Bearers 5. Invoke Trace Mobile 8. Activate PDP Context Accept 6. Update PDP Context Request 7. Update PDP Context Response
53
Access Point Name (APN)

Select a service (or a GGSN) in the PS domain or a contact point in an external packet network Contain two main parts

Same name syntax as the Internet Domain Name Domain Name System (DNS) can be used to translate an APN to an IP address
APN Network Identifier APN Operator Identifier: identify the PLMN (optional)
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Create PDP Context Request

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 mobiles 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
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Create PDP Context Response

TEID: to identify the GGSN side of the GTP tunnel PDP Address:

QoS Negotiated: QoS profile agreed by the GGSN PDP Configuration Options: relayed by intermediate nodes transparently to the mobile
a PDP address assigned by the GGSN 0.0.0.0 if the mobile asks to acquire from an external network
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2.1.9.2 Network-Requested PDP Context Activation

GGSN must have static information about the PDP address
For example, the GGSN needs to know the mobiles 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
57
Fig. 2.14 3GPP networkrequested PDP context activation

HSS/HLR
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 7. Mobile-Initiated PDP Context Activation Mobile GGSN
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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
59
Fig. 2.15 3GPP GGSN-initiated PDP context modification

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
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Update PDP Context Request

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
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2.1.10 Radio Access Bearer Assignment

RAB Assignment: assignment, modification and release of RAB In R5, can only be initiated by the network
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
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initiated by the SGSN upon triggered by other network entities in the CN or the RAN
Fig. 1.16 3GPP Radio Access Bearer Assignment
1. RAB Assignment Request 2. Establish, modify, and release Radio Bearers Mobile
RNC
3. RAB Assignment Responses
SGSN
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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
64
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
65
Fig. 1.17 3GPP Gn and Gp interface protocol stacks
GTP-U UDP IP Layer 2 Layer 1 SGSN
GTP-U UDP IP Layer 2 Layer 1 GGSN (a) Gn and Gp Interface User Plane.
GTP-C UDP IP Layer 2 Layer 1 SGSN
GTP-C UDP IP Layer 2 Layer 1 GGSN
(b) Gn and Gp Interface Control Plane.
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GPRS Tunneling Protocol (GTP)

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
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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
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GTP Header Format

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
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Fig. 2.18 GPRS Tunneling Protocol (GTP) header format

8 7 Version 6 5 PT 4 (*) 3 E 2 S 1 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)
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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
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Fig. 2.19 3GPP Iu-PS interface protocol stacks
GTP-U UDP IP Layer 2 Layer 1 RNC (a) Iu-PS User Plane.
GTP-U UDP IP Layer 2 Layer 1 SGSN
RANAP SCCP Signaling Bearer AAL 5 ATM RNC (b) Iu-PS Control Plane.
RANAP SCCP Signaling Bearer AAL 5 ATM SGSN
RANAP: Radio Access Network Application Part SCCP: Signaling Connection Control Part
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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
73
Fig. 2.20 3GPP Gi interface protocol stack
IP Layer 2 Layer 1 GGSN Gi
IP Layer 2 Layer 1 External IP Network
74
Fig. 2.21 3GPP control-plane protocol stack between SGSN (or GGSN) and HLR
MAP TCAP SCCP Signaling Bearer

Gr or Gc SGSN or GGSN
MAP TCAP SCCP Signaling Bearer

HLR
TCAP: Transaction Capabilities Application Part
75
Fig. 2.22 3GPP control-plane protocol stack between GGSN and HLR based on GTP
MAP GTP-C UDP IP Layer 2 Layer 1

Gn
MAP TCAP SCCP MTP 3 MTP 2 Layer 1

Gc
GTP-C TCAP UDP IP Layer 2 Layer 1 SCCP MTP 3 MTP 2 Layer 1
GGSN
GSN serving as Protocol Converter
HLR
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Fig. 2.23 3GPP control-plane protocol stack between SGSN and MSC/VLR
BSSAP+ SCCP Signaling Bearer

Gs SGSN
BSSAP+ SCCP Signaling Bearer

MSC
BSSAP+: Base Station System Application Part+
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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) Robust Header Compression (ROHC)
Mapping higher-layer data into the underlying radio interface protocols Maintaining data transmission orders for upper layer protocols that have such requirement
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Fig. 2.24 3GPP user-plane protocol stack between mobile and GGSN
Applications
PDP (e.g., IP, PPP)
PDP (e.g., IP, PPP)
PDCP
PDCP
GTP-U
GTP-U
GTP-U
GTP-U
UDP RLC MAC Layer 1 Uu MS UTRAN RLC IP MAC Layer 1 Layer 2 Layer 1 Iu-Ps
UDP IP Layer 2 Layer 1
UDP IP Layer 2 Layer 1 Gn SGSN
UDP IP Layer 2 Layer 1 GGSN
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Radio Link Control (RLC)

Provides logical link control over the radio interfaces A mobile can have multiple RLC connections Support

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
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Fig. 2.25 3GPP control-plane protocol stack between mobile and SGSN
GMM
SM
SMS
GMM
SM
SMS
RRC RLC MAC
RRC RLC MAC
RANAP SCCP Signaling Bearer AAL 5
RANAP SCCP Signaling Bearer AAL 5 ATM Iu-PS SGSN
Layer 1 Uu MS
Layer 1 ATM RNS
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GMM, SM, and SMS

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
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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
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Fig. 2.26 Access another IP network through 3GPP PS domain
User Traffic
RNC Mobile
SGSN
GGSN Gi
Router
External IP Network
RAN
3GPP PS Domain
84
Transparent Access vs. Nontransparent Access

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.
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2.1.12 Accessing IP Networks through PS Domain

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
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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
87
Fig. 2.27 Protocol stacks for transparent to IP networks through 3GPP PS CN
Higher-Layer IP Protocols (e.g., MIP, IPsec) UDP/TCP IP IP IP Layer 2 3GPP Packet Domain Bearer Layer 1 Gi Mobile Terminal GGSN
Higher-Layer IP Protocols (e.g., MIP, IPsec) UDP/TCP IP Layer 2 Layer 1 External IP Network
88
2.1.12.2 Non-Transparent Access Using Mobile IP

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
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Fig. 2.28 Protocol stacks for non-transparent access to IP networks through PS CN domain
MIPv4 UDP IP
MIPv4 Foreign Agent UDP IP UDP IP Layer 2 3GPP Packet Domain Bearer Layer 1 Gi
MIPv4 UDP IP Layer 2 Layer 1 External IP Network
Mobile Terminal
GGSN
90
Fig. 2.29
Mobile SGSN Activate PDP Context Request (PDP Address = 0.0.0.0 APN=MIPv4FA)
GGSN With Mobile IP FA
Mobile IP HA
Create PDP Context Request (PDP Address = 0.0.0.0 APN=MIPv4FA) Create PDP Context Response (PDP Address = 0.0.0.0)
Activate PDP Context Accept (PDP Address = 0.0.0.0)
Mobile IP Agent Advertisement
Mobile IP Registration Request (CoA = FA CoA = Address of GGSN)
Mobile IP Registration Request (CoA = FA CoA = Address of GGSN) Mobile IP Registration Reply Extract mobiles home address And enter it to PDP Context
Mobile IP Registration Reply
GGSN-initiated PDP Context Modification Copyright 2004 by John Wiley & Sons, Inc. All rights reserved.
91
2.1.12.3 Acquiring IP Address Dynamically Using DHCP from an External Network

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 mobiles PDP contexts on the SGSN and the GGSN need to be updated to include the mobiles IP address.
92
Fig. 2.30 3GPP protocol stacks for supporting IP address assignment by external network using DHCP
DHCP Client Process UDP IP Lower Layers Mobile Station
DHCP Relay Agent UDP IP UDP IP
DHCP Server Process UDP IP Lower Layers External IP Network
Lower Layers Lower Layers GGSN
93
Fig. 2.31
Mobile SGSN Activate PDP Context Request (PDP Address = 0.0.0.0)
GGSN with DHCP Relay Agent
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)
Activate PDP Context Accept (PDP Address = 0.0.0.0)
DHCPDISCOVER
DHCPDISCOVER DHCPOFFER DHCPREQUEST DHCPACK Extract IP Address Assigned to Mobile DHCPACK
DHCPOFFER DHCPREQUEST
GGSN-initiated PDP Context Modification
94
2.1.12.4 Dial-up Access Using PPP

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
95
Fig. 2.32 Protocol stacks for dialup through 3GPP packet domain to an IP network
PPP
PPP
Protocols for tunneling over IP network (e.g., L2TP) UDP IP
Protocols for tunneling over IP network (e.g., L2TP) UDP IP Lower Layers LNS in External IP Network
Lower Layers Mobile
Lower Layers
Lower Layers
GGSN (LAC)
96
Fig. 2.33 Signaling flows for dialup through 3GPP packet domain to an IP network
Visited Network External IP Network
1. Activate PDP Context Request (PDP Address = 0.0.0.0)
2. Create PDP Context Request (PDD Address = 0.0.0.0) 3. Create PDP Context Response (PDP Address = 0.0.0.0)
4. Activate PDP Context Accept (PDP Address = 0.0.0.0)
SGSN
GGSN
6. L2TP Negotiation
LNS
Mobile
5. Establish PPP and Configure IP over PPP
97
2.2 3GPP2 PACKET DATA NETWORKS

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
98
2.2.1 3GPP2 Network Architecture

Core network

circuit-switched domain packet-switched domain
Radio Networks (RNs): based on circuitswitched technologies and is used for both circuit-switched and packetswitched services
99
Radio Networks (RNs)

cdma2000 base station

System ID (SID): identify a system Network ID (NID): identify a network pair (SID, NID) (SID, NID): uniquely identify a network within a system Base Station Controller (BSC) Base Transceiver System (BTS)
Base Station (BS)

100
Fig. 2.34 3GPP2 conceptual network architecture

Circuit Switched Core Network Servers (e.g., SCP, VMS, MC, PDE, NPDB, SN) Ai Radio Network MSC C A HLR VLR B Pi
PSTN
BTS
BSC Aquinter
Packet Switched Core Network
AAA Server Pi
HA Pi Pi IP Network
Aquater PCF PDSN
101
2.2.1.1 Circuit-Switched Core Network

Switching and call control components
Mobile Switching Center (MSC) Home Location Registrar (HLR) Visitor Location Registrar (VLR) Equipment Identity Registrar (EIR) Service Control Point (SCP) Voice Message System (VMS) Message Center (MC) Position Determining Entity (PDE) Number Portability Database (NPDB) Service Node (SN)
Information Servers

Service control servers

102
2.2.2 3GPP2 Packet Data Network Architecture

2.2.2.1 Functional Architecture 2.2.2.2 Reference Network Architecture
103
2.2.2.1 Functional Architecture

Packet Data Serving Node (PDSN) Packet Control Function (PCF) Radio Resource Control (RRC) Mobile Station (MS) Home Agent (HA) Authentication, Authorization, Accounting (AAA)
104
Fig. 2.35 3GPP2 packet data network functional architecture
RRC
PCF
PDSN
HA
MS
AAA
105
Packet Data Serving Node (PDSN)

Route IP packets between the 3GPP2 network and any external IP networks Route IP packets between mobile terminals inside the same operators 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
106
Packet Control Function (PCF)

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
107
Radio Resource Control (RRC)

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)
108
Mobile Station (MS)

User Identity Module (UIM): removable or integrated into ME Mobile Equipment (ME)

Terminal Equipment (TE) Mobile Terminal (MT) Terminal Adapter (TA)
109
Fig. 2.36 Functional architecture of a mobile station (MS)

MS ME
TE MT TA
UIM
110
2.2.2.2 Reference Network Architecture

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 (v4 or v6)
Mobile IP Access
111
Fig. 2.37 3GPP2 packet data network reference physical architecture Home Access
Visited Access Provider Network 1 MSC/ VLR Provider Network
SS7 Network
HLR
Visited AAA
Home AAA Home IP Network
IP Network
AAA Broker AAA Network
A10/A11 RN Mobile Terminal PDSN HA
P-P Interface
Visited Access Provider Network 2
Home IP Network, Private Network, or Home Access Provider Network
PDSN Copyright 2004 by John Wiley & Sons, Inc. All rights reserved.
112
IPv6
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
113
Relation with CS Network

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
114
2.2.3 Protocol Reference Model

A Reference Point Ater Reference Point Aquinter Reference Point Aquarter Reference Point P-P Interface (optional)
PDSN-to-PDSN Interface is used support fast handoff between PDSNs

115
Fig. 2.38 3GPP2 protocol reference model

MSC
Call Control And Mobility Management
Circuit Switch
PDSN
A1 (Signaling)
A2 (User Traffic)
A5 (User Traffic) A Reference Point
P-P Interface
A3 (User Traffic) BSC2 A3 (Signaling) A7 (Signaling) BSC1
A8 (User Traffic) A9 (Signaling) PCF
A10 (User Traffic) A11 (Signaling) PDSN
Ater Reference Point
Aquinter Reference Point Traffic interface Signaling interface
Aquater Reference Point (R-P interface)
116
A 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
117
Ater Reference Point

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
118
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
119
Aquarter Reference Point (R-P Interface)

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
120
2.2.4 Access to 3GPP2 Packet Data Network

Step 1: Gain access to PDSN
Step 1-A: Gain access to the Radio Network. Step 1-B: Setting up resources between the BSC and the PDSN.
May not need to set up A8 connection
Step 1-C: Establish PPP connection between mobile and PDSN.
Step 2: MIPv4 registration

121
MS
BSC Origination ACK
MSC
PCF
PDSN
Foreign AAA Server
Home AAA Server
Mobile IP Home Agent
CM Service Request Assignment Request
Step 1
Establish Traffic radio channel A9-Setup-A8 A9-Connect-A8 Assignment Complete Establish PPP connection Mobile IP Agent Advertisement Mobile IP Registration Request Establish A10
Fig. 2.39 3GPP2 Packet Service Activation (using Mobile IP)
Authorization Request Authorization Response
Authorization Request Authorization Response
Step 2
Mobile IP Registration Request Mobile IP Registration Request Reply Mobile IP Registration Request Reply Accounting Request Accounting Response
User packets over PPP
122
2.2.5 User Packet Routing and Transport

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)
123
IP Network
Fig. 2.40
A10/A11
IP
IP
PDSN 1
PDSN 2
A10/A11 GRE Tunnel GRE Tunnel
PCF 1
PCF 2
A8/A9 GRE Tunnel PPP connections
A8/A9 GRE Tunnel
BSC 1
BSC 2
Radio Bearer
User packets
Radio Bearer
Source Mobile Copyright 2004 by John Wiley & Sons, Inc. All rights reserved.
Destination Mobile
124
2.2.6 Protocol Stacks for Packet Data Services

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 Stacks over A9 and A11 Stacks over A8 and A10 Stacks over P-P Stacks Between Mobile
125
2.2.6.1 Protocol Stacks over A9 and A11 Interfaces

Main messages of A9

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
126
2.2.6.1 Protocol Stacks over A9 and A11 Interfaces (Cont.)

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 Request A11 Registration Reply A11 Registration Update A11 Registration Acknowledge
Soft state: PCF periodically sends A11 Registration Request to refresh A10 connection
127
Fig. 2.41 3GPP2 protocol stacks for the A9 and A11 interfaces
A9 Signaling TCP/UDP IP Link Layer Physical Layer

BSC
A9 Signaling TCP/UDP IP Link Layer Physical Layer A9 PCF
A11 Signaling UDP IP Link Layer Physical Layer A11
A11 Signaling UDP IP Link Layer Physical Layer

PDSN
128
2.2.6.2 Protocol Stacks over A8 and A10 Interfaces

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

PCF Session Identifier (PCF SID) PDSN Session Identifier (PDSN SID)
129
Fig. 2.42 3GPP2 protocol stacks for the A8 and A10 interfaces
GRE IP Link Layer Physical Layer

BSC
GRE IP Link Layer Physical Layer A8 PCF
GRE IP Link Layer Physical Layer A10
GRE IP Link Layer Physical Layer

PDSN
130
Fig. 2.43 Generic Routing Encapsulation (GRE) protocol header

0 1 2 3 4 5 6 7 8 90 1 2 3 4 5 Recur Flags Ver 6 7 8 9 0 1 2 3 4 5 6 7 8 0 1 2 Protocol Type Offset (optional) Key (optional) Sequence Number (optional) Routing (optional) C R K S s Checksum (optional)
(a) GRE header format.
0 1
4 5 6 7 8 90 1 2 3 4 5 Recur Flags Ver Key
6 7 8 9 0 1 2 3 4 5 6 7 8 0 1 2 Protocol Type
C R K S s
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
2.2.6.3 Protocol Stacks over P-P Interface

The P-P interface is an optional interface used to support fast inter-PDSN handoff (see 4.4.4) Two individual interfaces
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
132
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 Registration Request A11 Registration Reply A11 Registration Update A11 Registration Acknowledge
133
Fig. 2.44 Protocol stacks for the P-P interface

P-P Signaling UDP IP, IPsec Link Layer Physical Layer Target PDSN (a) Control-plane protocol stack P-P Signaling UDP IP, IPsec Link Layer Physical Layer Serving PDSN
GRE IP, IPsec Link Layer Physical Layer Target PDSN (b) User-plane protocol stack
GRE IP, IPsec Link Layer Physical Layer Serving PDSN
134
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
With P-P interface Signaling between a mobile and its serving PDSN

Set up PPP MIPv4 registration

135
Fig. 2.45 3GPP2 protocol stacks for user data between mobile terminal and PDSN (without P-P interface)
IP PPP GRE LAC LAC IP Link Physical Link Link IP Link IP Link GRE GRE
IP PPP GRE
IP
IP
Link IP Link Physical Physical
Link
Physical Physical A8
Physical Physical
Physical
A10 (R-P) PCF Serving PDSN CH
Mobile
BSC
136
Fig. 2.46 Protocol stacks for end-to-end user traffic transport when P-P interface is used
IP PPP GRE LAC LAC IP Link Physical Link Link IP Link IP Link IP Link IP Link IP Link Physical Physical P-P Target PDSN Serving PDSN CH Physical GRE GRE GRE GRE IP PPP GRE Link Link IP IP
Physical Physical
Physical Physical
A10 (R-P) PCF
Mobile
BSC
137
Fig. 2.47 3GPP2 protocol stacks for signaling between mobile terminal and PDSN
MIPv4 Client UDP IP PPP GRE LAC LAC IP MAC Physical MAC Link IP Link IP Link IP Link Physical A10 PCF Serving PDSN Physical GRE GRE MIPv4 Foreign Agent UDP IP PPP GRE Link Layer UDP IP
Physical Physical
Mobile
BSC
138
2.3 MWIF ALL-IP MOBILE NETWORKS

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.
139
2.3.1 Network Architectures

Core Network

All-IP using standard IETF protocols Independent of access-specific technologies used in different Access Networks
Access Networks
140
Layered Functional Architecture

Transport Layer (in both Access Network and Core Network) Control Layer Service Layer Application Layer The security and the OAM&P (Operation, Administration, Maintenance and Provisioning) functions may span across multiple functional layers.
141
Fig. 2.48
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. Transport Layer Core Network Access Network Access Gateway Router
Security Functions
OAM&P
Router Router
IP Gateways
Media Gateways
Signaling Gateway
Mobile Terminals
External IP Networks
PSTN and Circuit-Switched Wireless Networks
142
Operations, Administration, Maintenance & Provisioning

Configuration Management Fault Management Security Management Performance Management Billing Management
S63 S11 S41 Service Discovery Server S41 S40 S39
S64
S66
S65
S67 Third Party Application
Core Network Functional Entities S16
Application Functional Entities Core Network Application S13
Directory Services Resource Profile S41 S26 Directory Server Location Global Policy Server Name Repository Server S25 S24 S33 S59
S14
Fig. 2.49
S38
Geographic Location Manager
S58 S15 AAA Functional Entities
Home Mobility Manager S36 Home IP Address Manager Communication Session Manager S18 Session Proxy S41 S35 S34 Mobile Attendant Access Transport Gateway B01 B03
CN Interworking Functions
S48 S50 S51 S49
Authorisation Server S56 S41
Authentication Server S55 S41
Accounting Server S57 S60 S61 S62
S54
S19 S41
S20 Session S29 Anchor S32 S28 S52 Multimedia Resource Controller S47 S27 S31 Multimedia Resource IP Function Gateway B09 B02 S53 Resource Manager S30 S21 S22 Router B07 Media Gateway Controller S43 S44 Signalling Gateway S12
S17
S23
S42
B10
Access Gateway IP Address Manager
B04
Media Gateway
Transport Gateway FEs B05 B05 Internet B05 Intranet B06 S46 S45 MAP Network
PSTN
Access Network S37 Terminal B08 S68 User Identity Module Collective
Enterprise Network
Key
Network Reference Point Functional (Signalling) Entity Snn Bnn
Reference Point (User Data Bearer)
Network
A reference point to a collective goes to every network functional entity within the collective
143
2.3.2 Access to MWIF Networks

Access Network Registration
Basic Registration for Core Network
Specific to each access network
SIP Registration

Enable a mobile to gain access to the core network and to send and receive IP packets over the core network Enable a user to use SIP to initiate and receive multimedia communications An integral part of session and service management
144
Serving Network
Home Network Home Mobility Authentication Policy Server Repository Manager Home IP Address Manager
Terminal
Mobile Attendant
Authentication Policy Policy Server Repository Server
Profile Server
Access Network Registration Step 1 Obtain IP Address and Mobile Attendant Address Request Terminal Registration Request Authentication Policy Request Policy Response Request Authentication Step 2 Policy Request Policy Response
Fig. 2.50 MWIF basic registration procedure

Response Response Terminal Authentication Registration Step 3 Response Authentication
Request Terminal Registration Response Terminal Registration Profile Request Profile Response
Address Request Address Response
QoS Procedure Copyright 2004 by John Wiley & Sons, Inc. All rights reserved.
145
2.3.3 Session Management

2.3.3.1 Functional Entities, Protocol Reference Points and Stacks 2.3.3.2 Mobile-Initiated Call Setup
146
DIAMETER AAA Server Global Name server S25 Communication Session Manager S19 Communication Communication Session Session Manager Manager Session S20 Anchor S41 S29 S21 S27 S28 Media Resource Controller IP Gateway Resource Directory S24 S22 Media Gateway Controller Authentication Authorization Accounting
S49
S49
Core Network
S20
Session Anchor
S18
S18
Service Discovery Server S41
Session Proxy
Session Proxy S17 Access Gateway
Fig. 2.51
Radio Access Network Visited Network Home Network
147
Serving Network Access Transport Gateway SIP INVITE
Home Network
Terminal
Session Proxy
IP Gateway SIP INVITE
CSM
Authentication Server
Authorization Server
Profile Server
Policy Repository
Request Authentication Response Authentication
Fig. 2.52 MWIF mobile-originated call setup procedure

183 Call Processing PRACK 200 OK ACK User Data ACK User Data 200 OK
Request Authorization
Request Profile Response Profile Request Policy
Response Authorization SIP INVITE sent to destination
Response Policy
183 Call Processing from destination
183 Call Processing PRACK
PRACK 200 OK
ACK User Data
148

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Chapter 2: Wireless IP Network Architectures

Jyh-Cheng Chen and Tao Zhang

2.1 3GPP Packet Data Networks

2.1.1 Network Architecture

Core Network (CN)

Fig. 2.1 3GPP conceptual network architecture (Release 5)

IP Multimedia Subsystem (IMS)

Packet Switched Domain

SGSN Core Network

GSM RAN (i.e., Base Station Subsystems) Radio Access Networks

UTRAN (UMTS Terrestrial Radio Access Network)

GERAN and UTRAN

Base Station Subsystem (BSS)

Radio Network Subsystem (RNS)

2.1.1.1 Mobile Devices, Subscribers, and Their Identifiers

Mobile Equipment (ME)

Terminal Adapter (TA)

UMTS Subscriber Identity Module (USIM)

Fig. 2.2 Functional architecture of an user equipment (UE)

manufacturer, country, type

Fig. 2.3 Structure of International Mobile Subscriber Identity (IMSI)

No more than 15 digits

Mobile Country Code (MCC)

Mobile Network Code (MNC)

Mobile Subscriber Identification Number (MSIN)

2.1.1.2 Circuit-Switched Domain in Core Network

Switching vs. Call Control

2.1.1.3 Packet-Switched Domain in the Core Network

Serving GPRS Support Node (SGSN)

Gateway GPRS Support Node (GGSN)

Identifiers of SGSN and GGSN

SGSN Number and GGSN Number

2.1.1.4 IP Multimedia Subsystem

2.1.1.5 Information Servers

Authentication Center (AuC)

Equipment Identity Register (EIR)

2.1.2 Protocol Reference Model

many interfaces use MAP protocol

To external IP networks Gi IMS

To external To GGSN in IP networks Other networks

Go C HSS (HLR) F Gc H AuC GGSN

VLR B MSC Server Mc

RAN Internal Interfaces

Abis Um Iub Iur: logical signaling interface Uu

One and only one mode

Fig. 2.5 Protocol reference model for 3GPP PS domain

Node B Mobile Uu UTRAN Iub

GGSN PS CN in different PLMN

Fig. 2.6 3GPP bearers (connections) for supporting packet-switched services

Radio Access Bearer (RAB)

Iu Bearer Lower Layer Bearers

Lower Layer Bearers

Lower Layer Bearers

Signaling Radio Bearer

Mobile-SGSN Signaling Connection

Traffic Radio Bearer

Radio Access Bearer (RAB)

Signaling Radio Bearer Traffic Radio Bearer

Radio Access Network Application Part (RANAP) connection