Fixed-mobile convergence: the dress rehearsal is over, it's time for the real thing! Equipped with a sturdy IP backbone, providers mature into the world of multi-service

America's Network, June 1, 2004 by John C. Tanner

"IMS was designed by the 3GPP, but it was also designed to be applied to other systems besides 3G, such as WiMax and Wi-Fi, and it can also be applied to fixed-line networks," says Liot of Alcatel. "It allows for a business model for delivering multimedia services, and it is based on SIP, which allows services to be converged into a single-user experience."

Liot adds that IMS is modeled as an overlay layer, allowing new services on top of the existing network without having to redo everything. "This is important because you want to be able to offer converged fixed-mobile services without changing the existing network functions too much."

IMS also allows operators to move up the value chain by allowing intelligent content delivery that in turn enables service and subscriber awareness, says Meijering.

"Service awareness means that you know which service is used by which subscriber--for example, VoIP or push-to-talk--where it's originating from and how it's being delivered."

One key benefit of this from a convergence standpoint, says Meijering, is that it gives wireless packet data the same "find and connect" ability as traditional voice.

"With regular voice services, you dial a number and the system finds the line or the handset assigned to that number and connects you," he explains. "You can't do that with GPRS. However, this is specified in the IMS standard, which uses SIP as the basis to connect for VoIP and push-to-talk. This also allows you to access the same service via wireless LAN."

Philip Marshall, wireless and mobile technologies analyst with Yankee Group, says that carriers will implement IMS platforms over the next 18 months, "largely for specific applications such as call forwarding--taking advantage of the subscriber's presence and availability profile--higher bandwidth capabilities using fixed network resources such as DSL and cable, increased monetization of instant messaging services across both mobile and fixed network environments, and converged billing."

Meanwhile, 1x EV-DO will purportedly be the first technology to bring FMC to the access link of the mobile network.

IN FOR THE LONG HAUL

All of this may go a long way in explaining where FMC went wrong and why everyone's suddenly so excited about it now. But then, we've been here before. A document submitted at a 1999 ITU conference had this to say about FMC: "Pie in the sky? Not any more. While [FMC] was a buzzword at TELECOM 95, real-life applications were by and large conspicuous by their absence. But in the last 18 months or so, that situation has changed dramatically."

And it had. And the same is true today. Yet for all the technological advances made in the past five years, challenges remain.

"Dominant operators in either the fixed or mobile markets face regulatory impediments in terms of sharing information between the fixed and mobile divisions, accounting separation and conditions under which they will be allowed to bundle or bill FMC services," says Dobardziev of Ovum. "The regulation of FMC services is not always clear cut."