Is IMS (IP Multimedia Subsystem) a Revolutionary Architecture?

The last decade has been under the siege of a dual revolution : the mobile telephony revolution which knocked down the barriers of user localization, and the Internet revolution whose model liberated us from the constraints of distance and connection time. A new revolution, just as spectacular, is now in the works: the convergence of the Internet and mobile telephony , and the convergence of these two worlds with that of fixed telephony. In this emerging and ubiquitous global environment, people will be communicating with each other in a fluid and transparent way, mixing voice and data, no matter what type of terminal they use: smartphone, PC, fixed videophones. They’ll communicate on the move, and with a combination of devices.

Today’s operators view IMS (IP Multimedia Subsystem ) as the foundation in building networks to accommodate this third convergence revolution. What is this new architecture all about? What exactly does it allow you do? How will it be implemented? According to what timetable? Why is it so critical to operators’ development? What impact will it have on their business model, and on services rating and billing? Three specialists, Frédéric Fleurat, Technical Director, Lucent Technologies France, Isabelle Roussin, VP Marketing and Solutions, Highdeal, and David McNierney, Strategic Marketing Director at Highdeal, share their views with us, views that frequently converge…

Frédéric Fleurat, Technical Director Lucent Technologies France

Isabelle Roussin, VP Marketing & Solutions, Highdeal

David McNierney, Strategic Marketing Director Highdeal Inc.

TR: What exactly is IMS ?

Isabelle Roussin: It’s an IP based architecture designed by the 3GPP consortium (Third Generation Partnership Project) , which teams up operators and solution providers. IMS is based on the idea that communication networks will gradually become “all-IP.” The new infrastructure allows you to benefit from increased bandwidth speed (from 9.6 Mb per second in 2G, to 384 Mb with the advent of 3G, and up to 4 Gb a second in 3G+ for video services transport) by deploying multimedia services such as : real-time video, multimedia gaming and other applications.

David McNierney: Before IMS, operators were obliged to redesign all the components of a solution when a new service, MMS for example, was introduced: this meant a complete overhaul of network interfaces, applications, session management to incorporate new elements such as heavy data storage, GPRS connections, MMS email addresses, the different pre-paid and post-paid rating system interfaces, etc. The task implied a huge investment, with an indeterminate ROI that depended on the success of the service tested. It was vital to develop a standard back-office platform, a common generic trunk that would enable operators to integrate new applications without having to rebuild their entire systems from scratch. The point was to just be able to develop the application itself. IMS is a standardized technology that enables you to rationalize the development process.

TR: What does IMS offer operators in practical terms?

David McNierney: The financial gain is tremendous if you consider that the development of a new infrastructure represents about 60% of the total cost for each new application launched. With IMS, you make a one-time investment and recuperate it on all the applications developed.

Frédéric Fleurat: Operators can now choose between vertical applications developed in proprietary systems that cost less per unit in the short term, but whose interoperability is limited, and applications developed in open systems . The latter require a more substantial initial investment but can stimulate and accelerate the number of applications launched, and at a far lower cost.

Isabelle Roussin: For operators, IMS is a key factor for success. Faced with colossal UMTS licence acquisition costs, they are being forced to find ways to massively increase their ARPU (Average Revenue Per User). This means developing numerous new services under the best possible conditions and intensifying their usage. IMS is an ideal solution to the challenge: it gives operators a greater leeway in testing new applications, the opportunity to develop more of them, and to launch them more rapidly.

Frédéric Fleurat: In addition, applications developed in open systems will enable operators to better serve their customers. Customers will no longer be segmented by telephone numbers, but will be regrouped and integrated in an “Active Phone Book” (a dynamic directory) containing enriched user profiles. By adding new elements such as presence, for instance, it will be feasible to direct their calls and sessions more effectively. An example: if you want to contact me after 6 pm, you will be able to do so by whatever channel I opt for: by MMS on my cell phone, instant messaging on my PC, the voicebox or email on my smartphone, on my fixed personal line, or on the other line reserved for professional calls…

TR: Does IMS only concern mobile operators?

David McNierney: No, all the traditional operators such as France Telecom, British Telecom and Telecom Italia are now positioning themselves as integrated operators: voice, mobile, Internet, and embracing IMS in order to migrate from a voice-based to a session-based model.

TR: Could you explain what a session is ?

Frédéric Fleurat: A simple call has a beginning and an end, while a session implies a communication continuum during which all sorts of events can take place, and be linked or combined. This includes messages: voice, images, video, texts…as well as to the (number of) correspondents, both ingoing and outgoing, during the course of the session. All this is independent from the access mode: integrated operators have to operate not only on the level of network convergence, but also on usage on all types of terminals, whether it’s a PC, a mobile or a fixed device.

TR: What types of specific usages do you have in mind?

David McNierney: There are many of them, from unified mail messaging to VoIP, without forgetting push-to-talk which, by the way, is one of the first (ou, leading) IMS applications.

TR: Isn’t usage convergence going to require a lot of new end-user equipment?

Frédéric Fleurat: On the contrary, the real challenge for operators will be to maintain their customers’ loyalty on the basis of the equipment they already have, without making it more complex. All the intelligence should be in the network and not in an over-sophisticated terminal that customers can’t afford to buy or don’t know how to use. Simplicity is the keyword for getting these new applications to market and getting them accepted. Obviously, equipment manufacturers may have a different point of view.

TR: When do you expect the migration to IMS to take effect ?

Frédéric Fleurat: The main US operators predict a gradual conversion to IMS that probably will be completed by 2008. They’ve already launched pilots. Europe is also on the roadmap. Asia is forging ahead even faster, as operators in that area of the world don’t have to contend with traditional systems.

TR: What role will Highdeal play in the IMS revolution?

David McNierney: As we’ve seen, IMS is going to stimulate and accelerate the growth of new applications. There will be more services available and more combinations between the various fixed, mobile, and Internet platforms. There will also be a more diversified content mixing voice, images, video, as well as more players in the value chain. All this will require a simulation, pricing and billing system capable of integrating numerous rating criteria, a system that’s flexible, interoperable and, obviously, compatible with IMS architecture. Our software package meets all these requirements and is the only one (on the market today) capable of connecting to the system.