IMS enables wireless convergence, Part 1

This week, we’d like to turn our attention to how the evolution in wireless networks and services is contributing to eventual wireline and wireless convergence.

How wireless phones fit into the rest of the world is becoming increasingly important because, according to the International Telecommunication Union (ITU), the number of global wireless phone subscribers exceeded the number of wireline subscribers in 2002. This year, worldwide projections are for about 1.2 billion wireline subscribers and almost 1.5 billion wireless subscribers – with wireline compound annual growth estimated at 2% and wireless growth at 9%.

The Third Generation Partnership Project (3GPP) has introduced an architectural framework called IP Multimedia Subsystem, or IMS, which should facilitate this convergence through specifications for bringing a wide range of IP-based services to wireless networks.

3GPP develops technical specifications for IMT-2000, the ITU framework for third-generation standards. The group represents a global effort among six of the world’s major standards bodies from Japan, China, Europe, the U.S. and Korea.

Release 5 of the IMS specification focuses on third-generation mobile telecommunications systems; Release 6 will add a specification for fixed-wireless and wireline networks.

IMS relies on Session Initiation Protocol (SIP) to establish and maintain call control. Our readers may recall that SIP is becoming the signaling protocol of choice for VoIP, and that SIP brings with it the advantage of presence to multimedia, concurrent sessions.

Next time, we’ll focus on applications and user benefits.