Enhancing Service Delivery Within the IMS Architecture

By Greg Pisano

Two small acronyms have been making a big impact on the communications industry of late: SIP (Session Initiation Protocol) and IMS (IP Multimedia Subsystem). They are taking center stage in the industry — and for good reason. We have seen the future of carrier-enhanced services, and it is based on SIP. But, what’s all the fuss about?Carriers need to embrace the IMS reference architecture. It’s all about meeting subscriber demand for new, advanced multimedia services, and generating increased revenue.

IMS: A Blueprint for Increased Revenue in Carrier-Enhanced Services

In next-generation fixed and mobile networks, SIP is a critical building block for new applications and service delivery, and IMS provides a framework for SIP-based services.
Thanks to SIP’s flexibility, IMS allows for converged and blended services such as e-mail, voice/video messaging, conferencing and music. Service providers can add content from separate application servers to any access medium over wireline, cable, or mobile networks — it doesn’t matter. These applications are network agnostic, but tailored to the requirements of subscriber endpoint devices such as cell phones, PDAs and desktop access methods.

As IMS gains even more credibility as a single environment for application development, new developers will be motivated to get into the business. Networks will continue to evolve and existing developers will build new SIP-based applications more quickly with much less risk than before. Most exciting of all, new, high-margin applications will be developed, including some killer apps we haven’t even thought of yet.

If service providers continue to use proprietary “siloed” technologies, they will never profit from IMS’s increased efficiency. Because IMS uses standards-based technology, providers can develop services quickly and share resources across many different applications. For example, with the scalable IMS model, they can share media server resources, user profile data, and service policies all across multiple applications.

In the IMS Session Layer, they can create a single, comprehensive profile for each user that includes a user’s presence information, call forwarding options, and preferences for voice mail and messaging delivery. IMS also empowers streamlined billing by centralizing all authentication, authorization, and accounting, with metering provisions for pre-paid applications. The Session Charging Function (SCF) and Event Collection Function (ECF) make this possible.

SIP and IMS: A Flexible Pair

“Pure” IMS is a granular IP-based architecture, where network elements are distributed into various functions. So, to adhere perfectly to the IMS model, providers would need new equipment. That may be an option for the top-tier carriers, but what about carriers that need to leverage the long-term value in their existing equipment and minimize operating expenditures? Fortunately, IMS is also designed to overlay existing TDM networks, with enough flexibility to accommodate equipment that does not perfectly match the model. Right now, service providers can implement a SIP-based, IMS-like architecture using IMS-compliant equipment. For example, providers can add a SIP-based application server and media server, while still using their existing media gateways for TDM connectivity.

Carriers are embracing IMS, and not just because it allows them to offer more services. As price competition heats up, they need to wring every bit of efficiency from their operations by migrating all voice services from TDM to VoIP. IMS provides the way. Users are demanding that next-generation services be blended together and “always on,” and IMS fits the bill. For carriers who adopt IMS, that means lower customer churn — a key to survival in the midst of fierce competition.

History, Challenges, and the Future

Originated by 3GPP/3GPP2 and adopted by other standards organizations as a framework for IP Multimedia applications and services, IMS is a very viable solution. But, it’s not without its challenges. H.323 and MGCP
will need to interwork with SIP for the foreseeable future, and IP address management will have to become much more secure and reliable. But, the benefits far outweigh the challenges. Users are demanding that next-generation services be blended together and “always on.”

The IMS architecture is already beginning to evolve and improve with the help of other industry organizations such as the IMS Forum, which is focused on accelerating the adoption of IMS. To speed up the process, the IMS Forum is creating a community for discussion and resolution of real world implementation and interoperability. True convergence and ubiquitous content delivery are finally becoming possible.

IMS in Action: “Sponsored Call” and Gaming Applications

IMS has inspired a wave of new applications and services. One such application is the “sponsored call” service. A European application developer recently created a new-generation telecommunication service whereby 3G subscribers agree to view a video commercial on a mobile handset from a sponsor. In return, the subscribers receive a discount on their phone charges. Based upon the IMS architecture, this application took only four weeks to create — from start to trial!

This is one example of how new applications, designed for IMS, benefit all parties involved — sponsors, subscribers, and service providers. Sponsors get a new targeted multimedia channel for advertising, promotions, campaigns, and surveys. Subscribers save money and receive useful promotions. Most importantly, carriers get increased air time and new revenue streams from the sponsors.

Pre-Paid Multiplayer Gaming

Another example of an IMS-inspired application is a multiplayer pre-paid mobile gaming service. Cell phone subscribers can play a pre-paid multi-player arcade game with rich multimedia capabilities, including player presence (availability) information and conferencing. Multi-player gaming is a very demanding application and that leverages the powerful capabilities of the IMS architecture. It also shows how operators can take steps today to migrate toward IMS infrastructure. When they do, they can swiftly develop and deploy innovative pre-paid services that will attract and retain subscribers, enhance brand value, and drive revenue growth.
Carriers need to maintain the momentum they have achieved with wireline and wireless calling services by leveraging the burgeoning demand for lucrative next-generation services. To do that, they should implement IMS quickly and seamlessly.

Carriers who adopt the IMS architecture or IMS-compliant components are in the midst of unprecedented opportunity — the future couldn’t be brighter.

Greg Pisano is the Market Development Director for Carrier Enhanced Services at Cantata Technology (news - alert). For more information, please visit the company online at www.cantata.com.

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