IMS Triple Play



The IP Multimedia Subsystem (IMS) is a framework basically specified for third generation (3G) mobile networks, for providing Internet Protocol (IP) telecommunication services. The IMS standard defines a generic architecture for offering Voice over IP (VoIP) and multimedia services. It is first specified by the Third Generation Partnership Project (3GPP/3GPP2) and now being embraced by other standards bodies including ETSI/TISPAN. The standard supports multiple access types–including GSM, WCDMA, CDMA2000, wireline broadband access and WLAN.

The Session Initiation Protocol (SIP)  is used as a signalling protocol in the IMS environment. It is defined in RFC 3261 [8] which have functionalities on registration, session establishment, session management and participant invocation (including creating, modifying, and terminating sessions with one or more participants). SIP signalling is the primary method for user registration and session control in the IMS architecture. The Call Session Control Function (CSCF) is the core signalling server in the IMS networks architecture. It acts as both a SIP Registrar and a SIP proxy server.

The “Triple Play” refers to the ability to provide integrated services including data (traditional Web and e-mail), voice-over-IP (VoIP) and high-definition video over the digital network. Now, the term is in the process of being replaced by IMS, which refers to “IP multimedia subsystem,” a much more comprehensive concept that includes both fixed cable and mobile networks that will hopefully be able to adapt to and accommodate services we haven’t even thought of yet.

For users, IMS-based services enable person-to-person and person-to-content communications in a variety of modes – including voice, text, pictures and video, or any combination of these – in a highly personalized and controlled way. For operators, IMS takes the concept of layered architecture one step further by defining a horizontal architecture, where service enablers and common functions can be reused for multiple applications. The horizontal architecture in IMS also specifies interoperability and roaming, and provides bearer control, charging and security. What is more, it is well integrated with existing voice and data networks, while adopting many of the key benefits of the IT domain.

This makes IMS a key enabler for fixed-mobile convergence. For these reasons, IMS will become preferred solution for fixed and mobile operators’ multimedia business. The integration of different media opens up new possibilities for far richer services than those available today and for which users will probably be willing to pay IMS is concerned with the creation and deployment of multimedia telecommunication services over any IP network. Importantly, this includes person-to-person real time services (such as voice) over Packet Switched (PS) networks, removing the need for a Circuit Switched (CS) domain. However, emulation of mobile CS services is not the primary goal of IMS, although their replacement by IMS services is unavoidable in the long run. Furthermore, it will be necessary for IMS to interwork with external CS networks, such as the Public Switched Telephone Network (PSTN) and Public Land Mobile Network (PLMN), even if there is no longer a circuit switched core network domain.

Several projects have been carried out in this area. Some of them were done by the students, as did by M. Thaha Ayub, Oktaviana Damayanti, and Davina Olivia.