A new industry group has been formed to allow phones to roam between cellular and wireless networks. But, say experts, it has some way to go before realistic specs can be produced.
Created this week, the Unlicensed Mobile Access (UMA) group includes major operators and network vendors, and promises to let users make mobile calls over Wi-Fi networks in homes and hotspots. Unfortunately, it hasn't actually said how it will do that yet.
"This is a standardised wish list for operators," said Dean Bubley of Disruptive Analysis, after plowing through the 240 pages of specifications at the UMA site. "It doesn't come up with that many answers."
The issue of roaming between cellphones 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 which handover calls between cellular networks and networks using unlicensed bandwidth - in the shape of Wi-Fi and Bluetooth, as well as UWB and WiMax in future. Its members include Alcatel, AT&T, BT, Cingular, Ericsson, Kineto, Motorola, Nokia, Nortel, O2, Rogers, Siemens, Sony Ericsson, and T-Mobile USA.
"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. "That covers a world of pain for customer support," he commented. The specification also says using Wi-Fi "should not impact on battery life", without specifying how to achieve that, he said.
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 operators have early versions of this sort of thing, and it looks as if BT is trying to shoehorn Bluephone into this specification," said Bubley. "A variety of operators were going in different directions, but now they are getting together with cellular operators for a set of baselines."
The enterprise, meanwhile, is being targetted by a standards effort from Motorola, Avaya and Proxim, called SCCAN (Seamless Converged Communications Across Networks), which is being promoted by the IEEE Standards and Technology Organization. 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."For more on the cell-to-Wi-fi groups read our feature.
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