IMS & SOA — Driving the Future of Telecommunications

By Mike McHugh

The IP Multimedia Subsystem (News - Alert) (IMS) framework is supposed to take over the world and solve the challenges of sAs has been discussed in several previous articles in this magazine, service providers are facing new sets of challenges. Chief among these is the imperative to offer new compelling, revenue-generating services that capture subscribers’ loyalty — and do so in a cost-effective manner. Service providers’ networks are converging and they must figure out how to integrate these new compelling services, which will consist of traditional voice services, Web services offerings and real-time, person-to-person multimedia services, in a meaningful way across multiple network types.ervice providers. It offers a framework structure which operators can leverage to deliver new, compelling, revenue-generating multimedia services. It will provide a service creation framework that will allow a very large ecosystem of non-telco-savvy application developers to rapidly create applications and deploy them to various types of IP and telecom networks serving millions of subscribers. It will allow companies to make their workers more productive, give central control of telephony and allow communications to be based on contacting a person, not an army of disparate devices and phone numbers. It allows for the unification of wireless, wireline and wide variety of communication and collaboration services like never before.

A common service delivery platform (SDP) architecture gives services providers the ability to deliver next-generation multimedia services across multiple network access technologies, all the while providing an evolutionary approach that enables the service provider to migrate from today’s existing legacy networks to the IMS networks of tomorrow. Agnostic to network type, a common SDP bridges the networks of today and tomorrow by evolving the underlying network model to a service-oriented architecture (SOA). This SOA model decouples underlying network resources from service development and delivery. Services are then allowed to evolve independently of each other. This simplifies service creation, composition and delivery and should in turn enable the service provider development community to innovate rapidly — mostly because the developer is not required to understand the underlying network technology on which the service is built. This move to an SDP built on SOA principles is a very big first step toward IMS.

SDP enables re-usability of network resources such as group list management, location, presence and more. With SOA-based composition and orchestration technologies, these service building blocks can be leveraged by third party developers and the service provider to build new service capabilities. This innovation demonstrates what is likely to be one of the first steps in the evolution towards IMS with an SDP built on SOA principles. The focus will be on the integration of communication into business processes.

One example of such a case is when Web services are exposed to users of IMS. This model allows Web services (say, within an IT domain) to use an IMS network to locate and interact with other Web services that are also exposed as users of the IMS network. Use cases of this model include the User Agent Configuration, or the use of SIP ( Session Initiation Protocol (News - Alert)) and XCAP (XML Configuration Access Protocol) for presence and group list management. In this latter case, SIP can be used to establish and manage access to XCAP-based Web services. It’s entirely possible for other types of services to be exposed in a similar fashion, and is of particular interest where services are likely to be mobile. A user device, for example, that exposes and consumes Web services is easily handled in this way and offers the benefit of separation of the control messages from the payload, allowing optimization of access network usage. It is also reasonable to expose content services in this way, such as mobile location services, data services or other services. In this way the IMS is simply used as a request broker between processes.

It is foreseeable in the long term that owners and operators of both enterprise and commercial networks will be required to support increasingly integrated information communications system infrastructure. Within this integrated communications system infrastructure, Web service implementations support SIP, which is used to locate service interfaces and manage sessions between providers and consumers. Orchestration and composition of service interactions is handled at the level of the SIP intermediaries, supplemented by a UDDI (Universal Description, Discovery, and Integration) infrastructure for publication and discovery of services described by UDDI and WSDL (Web Services Description Language). A UDDI registry complements the mobility features provided by the IMS architecture. Note that Web services is but one paradigm applicable to the proper application of SOA principles to the SDP.

There’s little doubt that the future of IMS is bright. IMS provides a superior infrastructure that enables the delivery of next-generation multimedia services through flexible responses to market trends. However, successful carriers will first need to implement a common SDP built on SOA principles. The IMS really represents the standardization of an SOA designed for real-time, large scale, secure and reliable application usages. The principles of the IMS are drawn from the experience and operational requirements of the telecommunications industry and draw on the most successful technologies and strategies that have propelled the Internet to its place at the heart of modern global information systems.

Mike McHugh is vice president and general manager, BEA WebLogic Communications Platform, at BEA Systems (news - alert). For more information, please visit the company online at www.bea.com.