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Leveraging IMS to Deliver Triple Play

By Akshay Goel

October 2006, Volume 9/ Number 10


In an increasingly crowded communications market, service providers are looking to the next generation of enhanced services to boost revenue and help attract and retain subscribers. Recently, many service providers have begun marketing bundled services in which a variety of products (e.g., VoIP, TV, and high-speed Internet) are offered side-by-side with discounted pricing and the convenience of one bill. But to grow and gain market share, service providers now need to differentiate themselves by offering blended services, where all aspects of the triple play (voice, video, and data) work together to provide a seamless, feature-rich, and personalized service experience.

As the IP Multimedia Subsystem (News - Alert) (IMS) architectural framework continues to evolve, one of the increasingly important functions to emerge is the Service Capability Interaction Manager (SCIM). The SCIM is the predominant point of orchestration for real-time multimedia applications. Wireless and wireline operators alike are quickly realizing that the SCIM is a critical component in their service management and delivery strategies. By providing dynamic service brokering among multiple application servers, the SCIM will play a key role in delivering blended triple play (and ultimately quadruple play) service packages (Figure 1).

Cross Domain Service Delivery

To accelerate introduction of value-added services, operators will require a flexible service delivery infrastructure able to rapidly integrate best of breed services as they become available without having to wait for the incumbent vendors to develop them. These new services may be IMS services, Web Services, or Content Services (such as IPTV (News - Alert), broadband, or mobile content) that may need to interact to provide a rich end user experience as part of the triple/quad play service bundle. This requires an open infrastructure, where loosely coupled, multi-domain services can be stitched together in any desired manner to form a composite service targeting niche subscriber profiles or demographics. This can be achieved with a converged Service Delivery Platform (SDP) that is flexible enough to package cross-domain services and define how they will interact.

Subscriber-Centric Service Model

A key step toward achieving greater subscriber loyalty and preventing churn is the development of a subscriber-centric model that delivers a personalized service experience. Leveraging the trusted business relationship with the subscriber, the service provider can mine critical information such as: profile, past purchasing history, locality, demographics, business, or personal needs. Service providers must learn how to exploit this intimacy to market services that premium customers perceive to be worth the price.

Subscriber Personalization

How is a subscriber-centric service model realized? By providing subscribers increased control over their unique service profile, including determining who can reach them, when they want to be reached, and the device(s) they want to be reached on. The service experience should be capable of changing automatically based on the personalization and the subscriber�s dynamic context reflecting in the profile. Some basic examples of personalization include:

� Allow subscribers, via self-care portal integration with universal address books, to create a single view of white lists and black lists for who can reach them and when, along with personalized screening override options (i.e., PIN).

� Use presence, availability, and calendar information to dynamically control the best method of reaching the subscriber � fixed line, mobile, video phone, SMS, voice mail, e-mail, etc.

� Configure optional services such as parental control for pre-screening of video on demand content via the parent�s mobile phone before authorizing the purchase of the content.

� Create account sub-profiles, such as a family plan with restrictions on teen calls being made during the school hours.

IMS Subscriber Service Profile

Fortunately, the IMS standards provide the foundation for implementing the types of personalized services described earlier through the IMS Subscriber Service Profile (IMS Profile). The IMS profile is created by the underlying SDP, based on the services purchased and provisioned into the Home Subscriber Server (HSS) during the provisioning process. The profile reflects the specific set of services the subscriber can use and contains the subscriber�s personalization data to be made available through the IMS architecture.

IMS profiles consist of multiple parts to be used by different elements in the IMS architecture. Parts of the IMS Profile are meant to be static in nature (i.e., they do not change very often) are generally used for executing basic session and service control capabilities by the Serving Call-Service Control Function (S-CSCF).

Subscribers� dynamic data is obtained from various sources such as self care portals, group list management tools, PIM, location based servers, service availability, calendar, and presence servers. This personalization data, the relationships among these pieces of data, and how they will be used in the IMS network, is all embedded in the IMS profile (i.e., Transparent Repository Data). Of particular note in this context is that the IMS SCIM is able to derive the subscriber�s personalization context embedded in the dynamic attributes of the IMS profile, and then utilize this dynamic data to create a premium service experience based on highly individualized service orchestration.

Service Orchestration

Business-driven imperatives, like service velocity, service agility, and personalization, can now be addressed by an IMS-compliant architecture for service orchestration that is hospitable to best-in-class solutions without vendor lock-in. As a guiding principle, service orchestration should be agnostic and enable multiple services that have been created independently (and potentially on different technologies) to work together seamlessly. Despite confusion about the concept, service orchestration can be defined at three �levels� in the context of the IMS architecture. It is critical that all three be implemented in any IMS architecture to support the fully desired service set:

1. Service Invocation: The method by which the core IMS infrastructure determines which application server should be invoked to handle services in the IMS Profile.

2. Service Execution: Most of the IMS Application Server technologies have some type of limited service orchestration to enable composite service execution in technologies such as: Parlay, Parlay(X), Java SIP servlets, JAIN SLEE, and SS7 SCPs.

3. Web Services: In most recent IMS designs, Web services interfaces are being added �to the top� of the IMS architecture to allow applications to either execute Web service transactions or for Web Services to initiate IMS sessions. Web Services have their own service orchestration technology that is independent of IMS Service Invocation or the IMS Defined Service Execution technologies.

Personalized Service Invocation via an External SCIM

IMS standards define the SCIM as a specialized type of SIP application server specifically designed to make more intelligent, subscriber-specific interaction management decisions between various application servers. This includes the ability to evaluate dynamic subscriber-specific service data to determine which services in the IMS Profile should be executed or not executed. The SCIM is �subscriber-aware,� and as a result is able to manage value-added NGN services based on complex service profiles.

By deploying the SCIM as an independent external component, service providers can expand the range of available cross-domain service combinations. The unique value-add of deploying an external SCIM is that it can be transparently inserted between the S-CSCF and the application servers. From the perspective of the S-CSCF, the SCIM will be just as easily integrated as any other application server. From the application server perspective, the SCIM will appear to behave just like an S-CSCF. An additional benefit of this approach is that where the IMS Subscriber Profiles that do not require the use of the SCIM function, the S-CSCF can still be communicating directly to the application servers, thereby reducing an unnecessary element in the signaling path.

The SCIM leverages the IMS profile, SIP message data and the information gathered from the subscriber�s service, network and personalization data to dynamically orchestrate services across multiple application domains. These can be executed on the basis of a complex set of Conditional Service Invocation rules derived from the SIP messaging (header and data attributes), service priority, service interaction (conflict), error handling rules, and subscriber�s personalized profile.

Cross Domain Service Orchestration

As mentioned earlier, Web Services orchestration is independent of IMS protocols, requiring a brokering function for tapping into internet-based application services. The SCIM interfaces with the Web Services layer by means of a SIP-to-Web Services gateway. The merger of real time communication services with the near-real time Internet services enables converged multimedia services by invoking Web and content services from the IMS domain and vice-versa.

The SCIM is best suited for service orchestration as it is aware of the real time needs of the communication network in responding to the network events in a timely manner while it is waiting for responses form the Web Services layer. The SCIM also prevents invoking applications and services that have been turned off or not available based on the subscriber�s dynamic context, thereby preventing unnecessary network delays in session setup.


With the deployment of broadband networks and convergence architectures such as IMS, service providers can expand their triple play product portfolios to include a virtually unlimited array of applications and services. When deployed properly, the SCIM provides a scalable, highly flexible IMS component that enables service providers to tap these new revenue sources, create differentiated triple play service bundles, enhance customer retention and speed time-to-market. IT

Akshay Goel is director of business development with Leapstone Systems, Inc. For more information, please visit the company online at

If you are interested in purchasing reprints of this article (in either print or PDF format), please visit Reprint Management Services online at or contact a representative via e-mail at [email protected] or by phone at 800-290-5460.


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