Fixed/mobile convergence is becoming less of a pipe dream every day. But whose pipe dream is it anyway? Network service providers typically drive change and develop new services when they see the business case for a new revenue source or a significant cost savings. FMC, also known as seamless mobility, may not do either, so what is pulling the industry in that direction?

Grant Lenahan, vice president of IMS service delivery solutions for Telcordia, thinks it’s the customer. “We believe seamless mobility is a whole emerging lifestyle that is far broader than anything that is being addressed in the industry today,” he said.

FMC allows, ideally, users to access any application or service, from any device while attached to any access network, no matter where they are.

The inexorable shift into that lifestyle will be too strong for the service providers to resist. It will be a matter of demand. Lenahan said service providers are asking the usual questions about the business case and the incremental revenue.

“But we believe those are the wrong questions,” he said. “The reality is we have ruthless competition driving this convergence.” So, he said, they should instead ask how seamless mobility affects market share, drives usage gains or stems the losses.

So it becomes a game of giving customers what they want--this new mobile lifestyle--or getting left behind. Lenahan said subscribers do value low prices, but they value convenience and coverage more. “And they will pay for it,” he said.

But FMC, or seamless mobility, is still a capability that’s time has not yet fully arrived. But the limited deployments, such as those for unlicensed mobile access (UMA) networks, are truly the first mass market solutions that work on the concept of services being decoupled from the underlying network.

UMA only goes so far by providing existing services from the TDM world via wireless local area network technology. Lenahan said 3GPP technology, particularly in Release 7--which is expected to be complete this year and is where Telcordia is putting most of its seamless mobility efforts--will support all session initiated protocol-enabled voice-over-IP and will work across both GSM and CDMA networks.

He said the 3GPP standards are moving faster than any international standard he has seen. As the standards move forward, they will have to strike a balance between what the customer wants and what is feasible and economical for the network to provide.

Jim Alfieri, principal solution architect of IMS service delivery solutions for Telcordia, said the critical aspect to seamless mobility is one of business rules and that network selection, roaming and hand-overs are largely business decisions, not technical ones. There are a lot of technical solutions for addressing when a device should move from one network to another, but Alfieri said it gets to the heart and core of the operators business and what types of roaming and sharing arrangements it has in place.

“Signal strength, network congestion and quality will always have a role to play in whether a device needs to or wants to handover,” Alfieri said. “But the choice for a particular network at a particular time for a given service is really a business decision that needs to be under control of the operator in real time.”

The caveat? “Beyond the network criteria, you have to include subscriber and group preferences as well,” he said.

Although work in the standards bodies and in device development efforts tries to address this balance, Lenahan said the industry should take one thing at a time and concentrate on voice services for now.

“The vision is any service anywhere on any network, but the current reality is: Let’s get voice call continuity plus some exciting but separate work on converged messaging deployed in the near term, then differentiate ourselves, fight for market share and start converging these technologies,” Lenahan said.

Another company focused on FMC, but looking well beyond voice, is Mountain View, Calif.-based Stoke. It’s is a start-up that has raised about $30 million and has used some of it to develop a session management-type product for FMC that among other things facilitates hand-overs between networks.

The company agrees that operators must maintain control over that process. “Most people studying this space are saying, ‘Let the handset determine when you move between networks,’ but the carriers are pretty clearly looking for a carrier-controlled process,” said Keith Higgins, vice president of marketing for Stoke.