IMS: The Road to Camelot?

by Rick Mace   

In the telecommunications industry, IMS (Internet Protocol Multimedia Subsystem) can be consideredWhile there are many variations of the tale of Camelot, the basis of the story is the same. Camelot is the most famous castle in the medieval legends of King Arthur, and where, according to the legend, he reigned over the golden age of Britain with the greatest and most chivalrous warriors in Europe, the Knights of the Round Table. Camelot was the Utopia, the starting point of the Quest for the Holy Grail, and it came to symbolize the center of the Arthurian world. our 21st century road to Camelot. It represents a change in the way carriers do business and provides great potential for the future. It is a blueprint for how carriers can architect their networks to deliver multimedia applications that are access and device independent. It also represents a fundamental and disruptive shift in the way networks will be built and managed over a very long period of time.

However, with every legend comes an element of the unknown. In the days of Camelot, King Arthur had Merlin to predict the future and protect the kingdom. Unfortunately, we have no Merlin, and no one can predict when IMS will be deployed, how successful it will be, or how far it can truly take us into the future.

IMS is an Evolution
Because we can’t see into the future, the path to IMS will be a long and sometimes difficult road for operators and vendors alike. What we do know is that given the tremendous investments in fixed and mobile legacy networks, the move to an IMS-based architecture will be more of an evolution than a revolution.

In reality, we are just beginning the quest. Consider just a few of the issues that operators will need to address during the transition to the IMS future:

• Completing an IMS services business case
• Integrating new services with legacy services
• Disassociating functions such as billing from the switching/access layer
• Creating new services independent of switches and service control points (SCPs) at the application/services layer
• Addressing the fixed mobile convergence (FMC) dynamic
• Anticipating the impact of future disruptive breakthroughs

In addition, carriers will continue to face pressure to compete for subscribers by simultaneously offering new multimedia services, reducing operational costs, leveraging existing investments, increasing revenues and remaining attractive to investors while sustaining their business models. The pressure will only grow as disruptive competitors, such as cable operators, voice over IP (VoIP) service providers and mobile virtual network operators (MVNOs) add voice services to their offerings.

Building the IMS Transition Path
Although the reality of full IMS deployment is many years away, most carriers today are developing their IMS architectures and selecting the vendors that will see them through the transition. As they begin their quest to the all-IP future, it is important to understand several realities about IMS, including the following:

• IMS is not the same as VoIP
• IMS is not an evolution of the switching fabric
• IMS will make hardware a commodity; and
• IMS is primarily a software-centric approach to multimedia services networking.

In many ways, the focus on IMS is misleading. Instead, carriers should be concentrating on the transition path to get them there, by defining the role of the network control layer in a way that an ever-increasing number and types of revenue-generating applications can be added in a vendor-independent environment. The focus of IMS investment should be on enabling the creation and deployment of these applications.

The challenge that carriers face is to leverage their investments in existing network resources as they add on new session initiation protocol (SIP)-based IMS elements. They also must ensure that they can deliver existing and future services, seamlessly, and across disparate networks.

A well-designed IMS architecture needs to address subscribers on both the legacy and next-generation sides of the network, anticipating and harmonizing services seamlessly across the legacy-next generation border. This will increase revenue opportunities by making next-gen services available on the legacy side and intelligent network (IN) services available in IMS environments.

IMS will not succeed if it is an “all-or-nothing” proposition that requires carriers to throw out their existing network equipment. For operators to select an IMS-based solution in today’s cut-throat market, it must improve economics.

By inter-working IMS services with existing services, devices and networks, operators immediately create this economic value. Selecting IMS service infrastructure elements that seamlessly co-exist and inter-work with circuit-switched networks makes economic sense and is critical to the success of IMS. See Figure 1.

Signaling at the Core of IMS
Many carriers are surprised to learn that IMS does not mean the end of signaling. In fact, the reality is quite the opposite. IMS networks are, by definition, services intense. IMS will actually require 30 times more signaling volume than the plain old telephone service (POTS). See Figure 2.

A gradual migration to IMS at the signaling layer is the most practical, technically feasible and cost-effective approach for both migrating to IMS and managing a hybrid Signaling System 7 (SS7)-SIP signaling network for years to come.

Transitional technologies such as SIGTRAN provide a “stepping-stone” function from the SS7-based TDM (time division multiplexing) and 2G wireless networks to IP and, eventually, the SIP-based IMS network. This allows carriers to address the financial, technological and network issues that come with migrating to IP-based signaling prior to IMS deployment. It also provides operators with a reusable, standards-based framework which enables them to more quickly and cost-effectively develop and deliver new, multimedia services to subscribers.

Future Promise of IMS
Lewis Carroll once said, “If you don’t know where you are going, any road will get you there.” Despite the uncertainty around IMS, it is still the road to the future. IMS will allow carriers to provide more content, volume, connections, sessions, transactions, revenue and profit than ever before. Most importantly, it will enable the introduction of new capabilities and revenue-generating services to market.

Like the road to Camelot, IMS is the path to great potential and great promise. We still have many challenges to conquer, but IMS is poised to guide carriers to a bright and prosperous future.

Rick Mace is executive vice president of global group operations at Tekelec  (News - Alert) (www.tekelec.com), where he is responsible for strategy development and planning for the company.