The resulting article is an excellent primer on IMS, why IMS is needed and where it fits from a social and technical perspective.
"One of the big problems is that there are two sets of history coming at the marketplace," said Brown. "On the PC side everything is new and there aren't a lot of user expectations for new product concepts. The other dynamic is that we've had voice and phone communications for over 100 years and there are social, end user, governmental and regulatory expectations." Brown said combining devices and services is one challenge, but converging two very different attitudes toward delivering products may be an even bigger challenge. That's where groups like 3GPP and TISPAN come in, trying to build a bridge between people and attitudes, as well as networking environments.
The modular standards embodied in IMS enables easy interoperability of products and services from both the circuit and packet-switched worlds. For more, please read IMS: a Standard for Standards Bodies.