IP Multimedia Subsystem (IMS) deployments may be notoriously slow to hit the launch pad, but that hasn’t slowed the IMS Forum’s unfailing advocacy of the industry’s end-target technology architecture.

The Forum’s latest move: the announcement today that it would combine with the NGN Forum to broaden its scope and support the deployment of next-generation networks and services – whether they be purely IMS-based or not. The combined group’s name: simply, the IMS/NGN Forum.

The two groups have always had largely complementary goals. And both network approaches, IMS and NGN, share a full IP infrastructure as a core feature. As for differences, in a nutshell: While IMS is focused largely on interoperability between existing networks and new converged networks and services via published 3GPP IMS guidelines and specs, NGN supports a similar portfolio of services – also over an IP infrastructure -- not limited in network approach to IMS standards but rather focused largely on leveraging the SIP network protocol.

In the real world, IMS and NGN standards and approaches have been converging for some time.

“Two thoughts have emerged,” said Michael Khalilian, who will retain the titles of chairman and president of the newly combined IMS/NGN Forum. “There are some very aggressive tier-one service providers globally working to bundle quad- and triple-play services. IMS is the architecture for those plays. But saying that, IMS may not be the only architecture for some service providers. NGN [approaches] are helping those operators to offer revenue generating services today as well as getting them where they need to be to deploy and utilize an IMS architecture [in the future].”

The merger of the two groups is at least in part driven by the relatively slow uptake of pure IMS networks and the need for service providers and vendors to find stepping-stone approaches, analysts said.

“IMS is embroiled in the classic chicken-and-egg scenario,” said Joe McGarvey, analyst with Current Analysis. “Operators recognize the capex and opex value of the technology once it is adopted but are reluctant to adopt it before they are assured it will produce immediate revenue. It’s a major source of frustration for equipment makers as well, as they have invested millions [and in some cases] billions in the architecture without any real return on investment to this point.”