The telecoms industry has taken the first step in allowing mobile phone users to roam between cellular and wireless networks.
A new industry group, the Unlicensed Mobile Access (UMA) group, has been formed but, say experts, it has some way to go before realistic specs can be produced.
The group includes major operators and network suppliers and promises to let users make mobile calls over Wi-Fi networks in homes and hotspots. Unfortunately, it has not said how it will do that yet.
"This is a standardised wish-list for operators," said industry expert Dean Bubley of Disruptive Analysis, after ploughing through the 240 pages of specifications at the UMA site. "It doesn't come up with that many answers."
The issue of roaming between cell phones and other networks has become a hot one, as products are emerging that might do the job, but operators have yet to put roaming together properly, even for data.
UMA hopes to put together specifications for service providers to offer roaming services. These would hand over calls between cellular networks and networks using unlicensed bandwidth - in the shape of Wi-Fi and Bluetooth, as well as ultra-wide band (UWB) and WiMax in future.
The group's members include, among others, Alcatel, AT&T, BT, Nokia, Siemens and T-Mobile.
"There are some great lines in the spec," said Bubley, pointing out one section where the specification says that connections through a public hotspot "may" require firewall configuration.
The specification also says using Wi-Fi "should not impact on battery life", without specifying how to achieve that, he said.
The group is not limited to Wi-Fi, but wants to work with other unlicensed technologies, such as Bluetooth or - in future - WiMax or even UWB.
Bundling in calls across free spectrum is a good idea for operators, especially if it fills in gaps in their coverage.
"A high factor in churn for mobile operators is the fact that people's mobiles don't work at home," said Bubley.
A guaranteed cheap home connection through Wi-Fi could make mobile plans more attractive, and fixed-line providers could use UMA services to add mobile services through virtual operator deals.
The specs seem to be aimed mainly at proposed services for domestic or small services, such as BT's Bluephone.
The enterprise, meanwhile, is being targeted by a standards effort from Motorola, Avaya and Proxim, called Seamless Converged Communications Across Networks (SCCAN), which is being promoted by the IEEE Standards and Technology Organisation. SCCAN aims to support dual-mode handsets that can link to wireless PBXs in offices and to cellular services.
"UMA is about extending the cellular experience into Wi-Fi and Bluetooth," said Bubley. "SCCAN is about extending the PBX experience out into wireless domain."
Peter Judge writes for Techworld