IMS: IP Multi-media Subsystem

IP Multi-media Subsystem (IMS) is a cost-effective technology architecture that allows operators to expand their current operations and leverage their investments in Internet Protocol (IP) technologies. IMS was created by wireless operators and vendors in order to enable rapid, reliable introduction of IP and SIP services into their existing and new networks. IMS is designed to provide operators with the means to satisfy the growing demand for diverse and rich communications services that provide direct revenue streams to service providers. Specifically, IMS defines a SIP-based (Session Initiation Protocol) session and service control platform that enables delivery of multimedia applications across different access networks, such as cellular, wireline and cable.

IMS is defined by the Third Generation Partnership Project (3GPP) as the new application enabler for IP-based multimedia services. UMTS/HSPA is evolving toward a future wireless all-IP network, including access network capabilities that enable a multitude of new, mobile multimedia applications. UMTS/HSPA networks will provide the increased bandwidth necessary for a user to access services while on the move. IMS provides an architecture that facilitates the creation and deployment of complex multimedia applications, and provides service transparency and integration between networks and services. An IMS-based multimedia service ecosystem is able to take maximum advantage of UMTS/HSPA network technology and its ability to supply high-speed data access; coupled with other key value-added characteristics such as an ‘always on’ connection, unprecedented quality of service, security and regulatory support. Together, UMTS/HSPA and IMS will drive mobile data growth and user adoption.

IMS enables multi-vendor networks. It clearly defines a standard architecture and interfaces that not only separate the transport, session, and application layers, but also accommodates mobility, component reuse, and roaming. IMS core architecture and specifications have been adopted as key components in other IP-based next-generation network standards bodies, namely ETSI (European Telecommunications Standards Institute), TISPAN (Telecoms & Internet converged Services & Protocols for Advanced Networks), ATIS NGN (The Alliance for Telecommunications Industry Solutions Next Generation Network Focus Group), and CableLabs’ PacketCable specifications.

Additional Information

IMS Q&A

AT&T Launches Groundbreaking Wireless Video Share Service (June 19, 2007)

Common IMS to be centered in the 3GPP Services Specification Group (June 18, 2007)

IMS: Application Enabler and UMTS/HSPA Growth Catalyst (White Paper July 2006)

IMS: Overview and Applications (White Paper July 2004)