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

WHAT WENT WRONG?

So with all of the touted benefits of FMC, many of which have been repeated since the mid-90's, why has it taken so long to actually happen?

Reasons vary, but a common theme is technological maturity. In the core network, for example, the move to FMC has been held up largely by the QoS issues involved in IP backbones.

On the mobile side, packet traffic is a recent phenomenon that has only taken off in earnest in the past few years, says Bareld Meijering head of marketing at Nokia Networks.

"Back then, operators weren't really focused on data, and there was no reason to be with voice expanding 20% to 30% a year. When GPRS technology first became available, the richness of the service wasn't high because of the throughput limitations--20-30Kbps just wasn't in line with end-user expectations."

Another reason FMC has been held back is the comparative lack of emphasis on open standards.

Murphy of Nortel adds that the emergence of common standards both in wireless and wireline for multimedia (SIP) and presence management (CSCF), and the acceptance of cross platform operating systems such as Symbian, Java and Palm "make it now technically possible, and efficient, to start sharing not only the network infrastructure, but also the application and billing layers."

TERMINAL BLISS

Meanwhile, on the handset side, vendors are making significant advances in developing multi-mode terminals that support both cellular and Wi-Fi. NTT DoCoMo, for example, has introduced a dual-mode phone that supports both WLAN and its 3G FOMA service. The WLAN portion doesn't have to be a data-only proposition: voice over WLAN services already exist in Japan and are expected to see widespread use in both public and private WLAN networks.

Another advancement, says Meijering of Nokia, is highlighted in the emergence of handsets that are essentially IPenabled platforms onto which users can download applications.

"This is enabling convergence on the terminal side. It's not like before, where the applications on the phone were fixed and you couldn't change them or add new ones. And these new apps can make use of the find-and-connect capability of SIP."

Still, Dobardziev of Ovum cautions that converged dual-mode services aren't always a question of technology.

"I think it's a problem of understanding what you're offering versus what you're trying to substitute," he says. "If you look at BT's OnePhone GSM/DECT service in the late '90s, which was an FMC service, the phones were large and expensive, you had to manually switch between networks, there was no handover available, and they hadn't resolved the billing issues. They were sending two separate bills for what was supposed to be an integrated service. Overall, it was an expensive, inconvenient and impractical solution."

THE IMS FACTOR

However, one thing mobile networks have now that they didn't have then is IMS (IP multimedia subsystem), the architecture recently standardized by the 3GPP that gives operators a common service environment and incorporates IP, SIP, application servers, home subscriber servers and multimedia resource functions.