Camarillo G., García-Martín M.-A. The 3G IP Multimedia Subsystem (IMS): Merging the Internet and the Cellular Worlds

3rd ed. - John Wiley & Sons Ltd, 2008. - 655 pp.When 3GPP started standardizing the IMS a few years ago, most analysts expected the number of IMS deployments to grow dramatically as soon the initial IMS specifications were ready (3GPP Release 5 was functionally frozen in the first half of 2002 and completed shortly after that). While those predictions have proven to be too aggressive owing to a number of upheavals hitting the ICT (Information and Communications Technologies) sector, we are now seeing more and more commercial IMS-based service offerings in the market. At the time of writing (May 2008), there are over 30 commercial IMS networks running live traffic, adding up to over 10 million IMS users around the world; the IMS is being deployed globally.
The most common applications running on IMS commercial deployments are IP telephony in fixed and mobile networks, IP centrex, messaging (including text, pictures, and videos), Push-to-talk, video sharing, and presence. However, there is much ongoing work on additional IMS applications. In particular, applications involving machine-to-machine communications (e.g., in sensor networks) are getting much attention. At present, most of the already deployed IMS networks run a specific service instead of using the IMS as the service delivery platform, as the IMS was once envisioned. We expect the market to evolve towards multi-service IMS networks in the following years.
When it comes to current standardization activities in the IMS area, the most relevant activities have to do with multi-access networks. Current IMS networks provide service to endpoints that use several different types of fixed and mobile access technologies, such as WCDMA, WLAN, ADSL and PacketCable. In order to have all these different accesses seemlessly integrated in the IMS architecture, there is still some work to be done to coordinate the specifications coming from 3GPP, 3GPP2, TISPAN, and PacketCable. In the past, there have been a few overlaps between specifications from different organizations. The idea is to minimize those overlaps by clarifying which parts of the architecture each organization should be working on. Additional standardization work includes simplifications of the IMS architecture and the development of new extensions to implement new services or provide new functionality.
The third edition of this book includes a great deal of new material. We have added new chapters discussing emergency calls, service configuration (XCAP and OMA XDM 2.0), conferencing, and Voice Call Continuity (VCC). We have updated the description of the PCC (Policy and Charging Control) architecture to 3GPP Release 7, OMA Presence 2.0, and PoC (Push-to-talk over Cellular) to OMA PoC 2.0. We have added detailed flow descriptions to each multimedia telephony service (or PSTN/ISDN simulation services). We have included discussions on GRUUs (Globally Routable User agent URIs) and their use in the IMS.
We have described new NAT traversal techniques such as ICE (Interactive Connectivity Establishment), protocols such as STUN and TURN, and how they apply to the IMS. We have introduced new service and application identification concepts such as ICSI (IMS Communication Services Identification) and IARI (IMS Application Reference Identifier). We have included a description of combinational services. The Security in the IMS chapter has been updated with HTTP Digest Access Authentication and TLS, Early IMS Security Solution, NASS-IMS bundled authentication, and TLS for Network Security. The Instant Messaging on the Internet chapter now discusses the ‘isComposing’ feature, MESSAGE URI-list services, chat rooms, and file transfer operations with SIP and SDP.Introduction to the IMS
IMS Vision: Where Do We Want to Go?
The Internet
The Cellular World
Why do we need the IMS?
Relation between IMS and non-IMS Services
The History of the IMS Standardization
Relations between IMS-related Standardization Bodies
Internet Engineering Task Force
Third Generation Partnership Project
Third Generation Partnership Project 2
IETF-3GPP/3GPP2 Collaboration
Open Mobile Alliance
General Principles of the IMS Architecture
From Circuit-switched to Packet-switched
IMS Requirements
Overview of Protocols used in the IMS
Overview of IMS Architecture
Identification in the IMS Identities
SIM, USIM, and ISIM in 3GPP
Next Generation Networks (NGN)
The Signaling Plane in the IMS
Session Control on the Internet
SIP Functionality
SIP Entities
Message Format
The Start Line in SIP Responses: the Status Line
The Start Line in SIP Requests: the Request Line
Header Fields
Message Body
SIP Transactions
Message Flow for Session Establishment
SIP Dialogs
Extending SIP
Caller Preferences and User Agent Capabilities
Reliability of Provisional Responses
Preconditions
Event Notification
Content Indirection
The REFER Method
Globally Routable User Agent URIs (GRUU)
NAT Traversal
Session Control in the IMS
Prerequisites for Operation in the IMS
IPv4 and IPv6 in the IMS
IP Connectivity Access Network
P-CSCF Discovery
IMS-level Registration
Subscription to the reg Event State
Basic Session Setup
Application Servers: Providing Services to Users
Changes due to Next Generation Networks (NGN)
Interworking
Basic Sessions Not Requiring Resource Reservation
Globally Routable User Agent URIs (GRUU) in IMS
IMS Communication Service Identifier (ICSI)
IMS Application Reference Identifier (IARI)
NAT Traversal in the IMS
AAA on the Internet
Authentication, Authorization, and Accounting
AAA Framework on the Internet
The Diameter Protocol
AAA in the IMS
Authentication and Authorization in the IMS
The Cx and Dx Interfaces Interface (RTR, RTA)
The Sh Interface Interface (SNR, SNA)
Accounting
Policy and Charging Control in the IMS
PCC Architecture
Charging Architecture
Offline Charging Architecture
Online Charging Architecture
Quality of Service on the Internet
Integrated Services
Differentiated Services
Quality of Service in the IMS
Policy Control and QoS
Instructions to Perform Resource Reservations
Reservations by the Terminals
QoS in the Network
Security on the Internet
HTTP Digest Access Authentication
Certificates
TLS
S/MIME
Authenticated Identity Body
IPsec
Privacy
Encrypting Media Streams
Security in the IMS
Access Security
UICC Contains an ISIM
Network Security
Emergency Calls on the InternetLocation Acquisition
Identifying Emergency Calls
Locating the Closest PSAP
Issuing the Emergency Call
Emergency Calls in the IMS
Architecture for Supporting Emergency Calls in IMS
Establishing an Emergency Call in IMS
IMS Registration for Emergency Calls
Call Back from the PSAP to a User
Anonymous Calls
Emergency Calls in Fixed Broadband Accesses
The Media Plane in the IMS
Media Encoding
Speech Encoding
Video Encoding
Text Encoding
Mandatory Codecs in the IMS
Media Transport
Reliable Media Transport
Unreliable Media Transport
Media Transport in the IMS
Building Services with the IMS
Service Configuration on the Internet
The XML Configuration Access Protocol (XCAP)
An Overview of XML
HTTP URIs that Identify XCAP Resources
XCAP Operations
Entity Tags and Conditional Operations
Subscriptions to Changes in XML Documents
XML Patch Operations
Service Configuration in the IMS
XDM architecture
Downloading an XML Document, Attribute, or Element
Directory Retrieval
Data Search with XDM
Subscribing to Changes in XML Documents
The Presence Service on the Internet
Overview of the Presence Service
The Presence Life Cycle
Presence Subscriptions and Notifications
Presence Publication
Presence Information Data Format (PIDF)
The Presence Data Model for SIP
Mapping the SIP Presence Data Model to the PIDF
Rich PIDF
CIPID
Timed Presence Extension to the PIDF
Presence Capabilities
Geographical Location in Presence
Watcher Information
Watcher Authorization: Presence Authorization Rules
URI-list Services and Resource Lists
Presence Optimizations
The Presence Service in the IMS
The Foundation of Services
Presence Architecture in the IMS
Presence Publication
Watcher Subscription
Watcher Information and Authorization of Watchers
Presence Optimizations
OMA Extensions to PIDF
Instant Messaging on the Internet
The im URI
Modes of Instant Messages
Pager-mode Instant Messaging
Session-based Instant Messaging
The “isComposing” Indication
Messaging Multiple Parties
File Transfer
The Instant Messaging Service in the IMS
Pager-mode Instant Messaging in the IMS
Pager-mode Instant Messaging to Multiple Recipients
Session-based Instant Messaging in the IMS
File Transfer
Conferencing on the Internet
Conferencing Standardization at the IETF
The SIPPING Conferencing Framework
The XCON Conferencing Framework
The Binary Floor Control Protocol (BFCP)
Conferencing in the IMS
The IMS Conferencing Service
Relation with the Work in TISPAN and OMA
Push-to-talk over Cellular
PoC Standardization
IETF Work Relevant to PoC
Architecture
Registration
PoC Server Roles
PoC Session Types
Adding Users to a PoC Session
Group Advertisements
Session Establishment Types
Answer Modes
Right-to-send-media Indication Types
Participant Information
Barring and Instant Personal Alerts
Full Duplex Call Follow On
The User Plane
Simultaneous PoC Sessions
Charging in PoC
Multimedia Telephony Services: PSTN/ISDN Simulation Services
Providing Audible Announcements
Communication Diversion (CDIV) and Communication Forwarding
Communication Diversion Notification (CDIVN)
Conference (CONF)
Message Waiting Indication (MWI)
Originating Identification Presentation/Restriction (OIP, OIR)
Terminating Identification Presentation/Restriction (TIP, TIR)
Anonymous Communication Rejection (ACR) and Communication Barring (CB)
Advice of Charge (AoC)
Completion of Communications to Busy Subscriber (CCBS) and Completion of Communications on No Reply (CCNR)
Malicious Communication Identification (MCID)
Communication Hold (HOLD)
Explicit Communication Transfer (ECT)
User Settings in PSTN/ISDN Simulation Services
Voice Call Continuity
Overview of Voice Call Continuity
VCC Architecture
Registration
Call Origination and Anchoring
Call Termination and Anchoring
Domain Transfer