introduction. 1.1 why the internet protocol multimedia subsystem 1.2 where did it come from?
TRANSCRIPT
INTRODUCTION
1.1 Why the Internet Protocol Multimedia Subsystem
1.2 Where did it come from?
1.1 WHY THE INTERNET PROTOCOL MULTIMEDIA SUBSYSTEM New communication paradigm
networking Internet Protocol (IP)-based mobile devices
terminals large, high-precision displays built in cameras and a lot of resources for
applications always-on-always-connected application
devices
applications no longer isolated entities exchanging
information more exciting applications are peer-to-peer
entities, which facilitate sharing browsing whiteboard game experience two-way radio session (i.e., push to talk)
Figure 1.1 shows the key ingredient to a peer-to-peer connection between the new IP-enabled mobile devices
IMS a global system used to enable applications in
mobile devices to establish peer-to-peer connections
True integration of voice and data services increases productivity and overall effectiveness
The development of innovative applications integrating voice, data and multimedia will create demands for new services presence multimedia chat conferencing push to talk
Figure 1.2 shows a consolidated network where the IMS introduces
multimedia session control in the packet-switched domain
at the same time brings circuit-switched functionality in the packet-switched domain
Traditional mobile communication system has been divided in three parts terminals radio access network (RAN) core network
With IMS-based system "radio access network" should be replaced by
"access network" an IMS system can be deployed over non-RANs
as well
1.2 WHERE DID IT COME FROM?
1.2.4 3GPP Release 5 and Release 6
1.2.4 3GPP RELEASE 5 AND RELEASE 6 Release 5 introduced IMS as part of 3GPP
standards IMS is a standardized access-independent IP-
based architecture interworks with existing voice and data networks
for both fixed network users (e.g., PSTN, ISDN, Internet) mobile users (e.g., GSM, CDMA)
is able to establish peer-to-peer IP communications with all types of clients with the requisite quality of services
functionalities session management complete service delivery
e.g., registration, security, charging, bearer control, roaming
The functional content of 3GPP Release 5 was frozen in March 2002
Release 6 is completed in 2004 Table 1.1 shows the most important features
of Release 5 and the items postponed to Release 6
AKA : Authentication and Key Agreement
3GPP has defined a finite architecture for SIP-based IP multimedia service a functionality of logical elements a description of how elements are connected selected protocols and procedures
Optimization for the mobile communication environment has been designed in the form of user authentication and authorization based on
mobile identities definite rules at the user network interface for
compressing SIP messages security and policy control mechanisms that
allow radio loss and recovery detection
IMS development is distributed to multiple working groups in 3GPP
The working method has three different stages stage 1
a service description from a service user and operator point of view are evaluated
stage 2 problems are broken down into functional
elements and the interactions between the elements are identified
stage 3 all the protocols and procedures are defined in
detail Figure 1.3 shows
the most important working groups and responsibility areas that are involved in the development of IMS