This is something to keep an eye on, as it could be a very important interim step in seeing IMS advance as the next generation service provider architecture.

In studying the various documents on A-IMS, the reason for this new architecture is that when IMS standards were implemented they didn’t work in practice as well as they did in theory. In the ever-changing world of telecom it is not surprising that shortly after IMS becoming the ever-popular holy grail of telecom, it turns out that a group of individuals have come up with a newer flavor of this universally accepted architecture. It turns out that, when implementing IMS in the real world, companies came up against a number of hurdles that needed to be overcome. While overcoming these obstacles it seemed to make sense to term the new advances being made as A-IMS which stands for Advances to IMS.

For example, when a subscriber transitions from a CDMA-1x network to an EV-DO Rev A. network, the transition was not necessarily seamless. Since subscribers aren’t generally aware of what network they are using, it becomes necessary to ensure this challenge is solved.

One of the goals of A-IMS, in fact, is to ensure that services can be provided in a network agnostic fashion. The task force who are putting A-IMS forward will soon have concept documents and will be approaching the IETF, 3GPP, 3GPP2, CableLabs and other standards bodies. The group is careful to point out that IMS is all well and good, and that they are just fine-tuning the architectural principles a bit.

I am impressed also by the humility in which they seem to be proposing A-IMS. It seems the group is eager to put egos aside and work with existing vendors to make A-IMS a reality. Here are some of the architectural principles of the A-IMS standard:

Transitioning services across SIP and non-SIP endpoints through a Policy Manager, which allows a service provider to manage both types of network resources.

Comprehensive security, allowing all components of the network (down to the device level) to be aware of security and to respond to anomalies as needed.

Dual Anchoring, which allows two IP addresses to be associated with a mobile device so that certain applications that are latency sensitive can use the visited IP address if needed.

Three-Layer Peering: When connecting to roaming partners, peering occurs at three layers: security peering, used for access authentication, IP peering, used for transport of bearer traffic, and policy peering, used for controlMichael Khalilian is the Chairman of the IMS Forum. Here’s what he had to say about A-IMS:

“IMS is the way of answering to the consumer demands and expectations for new applications and service offerings with multimedia content and mobility. All Service Providers are expected to use IMS network optimization, service creations, creative product and marketing offerings sooner or later, and later means loss of opportunities and revenue. We at the IMS Forum launched the Service Provider and Integrator Board with upcoming events to provide a Forum for vendors and Service Providers to interact and become more informed about Technology and Deployment Strategies and to work closely on product marketing for IMS architectures and applications. In addition, the IMS Forum is launching Applications Interoperability and PlugFest as part of the IMS Forum initiatives.” For more info, see www.IMSForum.org.

Brian Partridge, senior analyst at Yankee Group, told TMCnet’s Robert Liu that the most newsworthy part of the A-IMS announcement is “the conspicuous absence of GSM.”

Here are some of his further comments.

“While Verizon and its partners have promoted this as access-agnostic, the ability to successfully drive this through the standards bodies is going to hinge on getting the GSM parties on board.”

“It’s hard to buy into the access-agnostic view given the fact that there’s only a CDMA player and they’re working on a CDMA network.”

“I don’t have any issue with the challenges they’ve brought to the table. My view is more around the industry challenges in going about it the way they have.” of bearer services. Policy server peering involves the usage of a policy server in both the home and visited networks. Usage of two allows for the home provider policies to apply even while roaming, yet allows them to be tempered by visited network policies on usage of the network.

For some commentary regarding this new initiative, check out the sidebar on the following page. I am getting ready now to look over some of the exciting things happening at TMC’s IMS EXPO this October 11–13, 2006 at the San Diego Convention Center. This is the world’s first IMS Expo and if you are interested in IP Multimedia Subsystem (News - Alert) solutions, you will definitely want to be there. Check out www.imsexpo.com for details. I hope to see you at the show.

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