IMS: a new spin on convergence: wireless and wireline carriers seek the "eBay" of flexible, responsive user experience

Telecommunications Americas, March, 2005 by Sean Buckley

For all its reliability, the TDM network lacks flexibility to create and deliver services quickly. Carriers had to create rigid silos per service: one each for voice, data, video and special offerings. But with the advent of the IMS (IP multimedia subsystem) network architecture, a new approach to enabling convergence is emerging that lets wireless and wireline carriers use a common IP foundation to deliver a host of multimedia and traditional services across any access channel.

Born out of the mobile world, IMS is an IP multimedia and telephony core network system comprising session control, connection control and applications services at a central point that provides converged voice and data services over a wireless or wireline network.

The IMS infrastructure holds promise for cellular and wireline worlds. For cellular operators such as Cingular, which are in the midst of migrating towards UMTS/HSDPA (high speed data packet access), the IMS architecture provides a common point from which to grow services. "I look at IMS in a simplistic way in that I call it 'eBay'," said Terry Durand, Cingular's executive director of engineering product realization, data services. "eBay has been successful at connecting its suppliers and content partners to its customers. [You can] look at IMS as kind of being an eBay central point where we have a standard way of connecting our partners to our customers, getting those rich multimedia services, being able to bill for them and having strong authentication and QoS."

Although the concept is still in its early stages, IMS is gaining continued momentum with wireline carriers, including MCI and BT, which have lacked a wireless component. Industry groups such as the MSF (Multiservice Switching Forum), ETSI (European Telecommunications Standards Institute and ATIS (Alliance for Telecommunications Industry Solutions) have adopted IMS as a foundational starting point for their next-generation infrastructure. This has inspired a trend that's catching the attention of carriers without wireless assets, including most notably MCI, Qwest and BT. They seek to adopt a mobile relationship by becoming MVNOs (mobile virtual network operators).

While in the pre-IMS world every service was relegated to a specific node and domain, the real value of the IMS infrastructure is the advent of reusable elements. "One of the things we need to avoid in becoming a best-in-class systems integrator, is creating silos in the IP world as everyone created in the PSTN world," said Bob Laird, MCI's IT chief architect. "The component-based architecture is one of the key concepts of IMS. "That and the ability to take advanced broadband services such as video on demand, video classrooms, video-conferencing, and mix and match them to create better, fast, cheaper products, is one of the keys to our IP vision."

Wireless/Wireline Integration

The world is becoming increasingly more mobile as consumers and business users want access to their applications from almost anywhere. The challenge is how to best link two disparate worlds. One popular approach with IMS is wireless/wireline convergence, a concept that enables users to have one number not just for a common bill, but a one-number identity that can span both wireless and wireline connections.

While a cover-the-waterfront approach to wireless/wireline convergence is lacking, the most common element will be the adoption of a common transport network and packet core. Albeit still a nascent market, major OEMs and their carrier customers are beginning to act on the IMS and wireless/wireline opportunity. For the super carriers such as Sprint, which owns both wireless and wireline assets, it will be necessary to integrate network core transport and session control layers. Wireless players should look to move toward an IP-based core network, while traditional wireline carriers such as BellSouth, BT, SBC and MCI will need to match their session control plans to those of their wireless partners.

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Late last year Sprint, in addition to announcing a new commitment to EVDO (evolution for data only) wireless data services, awarded a contract to Lucent for its Accelerate IMS product platform. While Sprint is mum about its IMS and wireless/wireline integration plans, others such as BellCanada, British Telecom and Cingular have been more vocal. Cingular's Fast Forward and Bell Canada's Simply ONE, for example, provide the device that enables cellular calls to be delivered to a home phone and also provides a common voice mail. Not to be outdone by its competitors, British Telecom, via its MVNO partnership with Vodafone, will launch an integrated wireless/wireline service called Bluephone this spring.

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No matter what path a carrier chooses, Larry Hettick, vice president of wireline services at Current Analysis, argues that there will need to be much coordination between the wireline carrier and the wireless carrier to make wireless/wireline integration successful. "When it comes to discussing next-gen networks, wireless and wireline service providers speak two different languages," he said. "Yet their different views are well-founded, because each has a different focus on their customers, service mix and short-term network traffic characteristics. Two different languages and, more importantly, two different objectives must be overcome if service providers ever expect to deliver converged fixed/mobile services."