After a year of hype, we all know about Wi-Fi to cell roaming. The principle is that one handset will operate on the cellular network and local hotspots, saving money by using cheap Wi-Fi (or Bluetooth) connections. Everyone wants to roam voice traffic between cellular and Wi-Fi services, but no-one is sure how it will be done (technically) or how it should be done (what kind of services customers want).

On the vendors' side, the problem is that mobile operators, fixed operators and intruders like cable want different things.

Wireline operators want to stop customers, particularly young people, from substituting fixed lines with mobile phones, according to Angel Dobardziev, senior analyst with Ovum. Mobile substitution has already reached 27 percent in Finland, he said.

Mobile operators have less of an incentive to push convergence, said Dobardziev: "Mobile operators would have to invest in their networks and tie up management resources. The result could be that they cannibalise their mobile voice service by allowing calls from the home zone to be made at cheap fixed-line rates."

Not everyone agrees. Many users change their mobile phone because they don't have good enough coverage at home, points out Dean Bubley of Disruptive Analysis. Using some sort of local wireless to connect to the fixed phone network would eliminate this problem, as well as offering cheaper calls in the home.

In the end, it seems everyone wants it, but not on the same terms. And the same goes for users.

Business versus consumer - yet again
On the users' side, there is a big difference between

  • domestic services, where one access point will serve a few handsets which are also used outside the house, and
  • enterprise services, where there are many access points making an office WLAN, and many phones are routed through an office PBX

And here is the strange thing. The operators are making a lot of noise in their effort to deal with the former group, without much definite in products, while vendors are working hard on the latter without any obvious interest from service providers. The operator-led consumer efforts get the limelight, while the enterprise efforts tend to fade from view.

This is strange, since, at least some analysts see the enterprise as a good source of revenue: "Many mobile operators are looking at ways to break into the enterprise market to offset consumer churn," said Emma McClune, wireless analyst with Current Analysis. "Fixed-mobile convergence could be one of many doors to the enterprise market."

The last month has seen the arrival of the UMA group whose specifications are intended for operators dealing with consumers, and the SCCAN group launched by Avaya, Proxim and Montorola, dealing with enterprise Wi-Fi-to-cell roaming.

The simplest way to see the two groups was put by Dean Bubley of Disruptive Analysis: "UMA is about extending the cellular experience into Wi-Fi and Bluetooth. SCCAN is about extending the PBX experience out into the wireless domain."

Early days yet
They are both at their early stages. While UMA has a lot of specifications online, they are more a list of preferences for how such a service should be delivered. Since some providers, including BT with its Bluephone proposal, are some way towards providing such services, UMA could be seen as a means to unify something that is due to happen.

Meanwhile, SCCAN (Seamless Converged Communications Across Networks), has emerged from a co-operation between Motorola, Proxim and Avaya announced back in 2003, to produce dual-mode handsets that link through Wi-Fi networks to IP PBXs in the office, and to the cellular network outside. The vendors have set up the SCCAN Forum, currently a private forum run by the IEEE's Industry Standards and Technology Organization. So far, no operators have signed up to deliver SCCAN-based services, although, and no-one has publicly joined the SCCAN Forum.

Whatever happened to FMCA?
As if these two groups were not enough, it's worth mentioning that BT started yet another group in July, the Fixed Mobile Convergence Alliance, which is also looking for standards in roaming.

"The group seems to be about fixed line providers adjusting to mobility," says Bubley, and its activities are not very visible. The group still lacks any web presence two months after its launch, and has been criticised by Gartner Group because its members, BT, NTT Docomo, Korea Telecom, Swisscom, Rogers Wireless and Brazil Telecom, were not broad enough.

"Fixed-mobile convergence is clearly on the roadmap of operators that want to create additional revenue streams from new value-added services," said Steve Andrews, chief of BT's mobility and convergence unit, in July, before the FMCA launch.

He indicated that FMCA would look first at the Bluetooth systems envisaged in BT's Bluephone, because this is more feasible in the short term. "We don't expect to see high-end, well-priced handsets with Wi-Fi capability for another 18 months to two years," said Andrews.

However, when the price of Wi-Fi enabled phones comes down, they will dominate the market. "Our development work will have a heavy focus on Wi-Fi," Andrews said.

Firm ideas to emerge?
The disparate standards work is an obvious indication of a lack of focus in fixed-mobile convergence. A lot of it is technically possible (though most of our arguments against Voice on Wi-Fi still apply) but we don't expect real sensible products for some time yet, even for the consumer.

"Don't put this on your Christmas list," says Bubley.

John Blau of IDG News Service contributed to this feature