SAN FRANCISCO -- CTIA Wireless -- Cingular Wireless LLC is pushing ahead with fixed/mobile convergence (FMC) plans, Unstrung has learned, and it could become the first GSM-based carrier to offer integrated services across cellular, fixed-line, and WLAN networks in the U.S.

Cingular is looking at first adding fixed/mobile convergence services with unlicensed mobile access (UMA) technology, but eventually it plans to tie all of its networks together using IMS techology when it upgrades its wireless data networks to broadband speeds, sources say.

UMA allows subscribers to move between cellular and WiFi networks outdoors, and a fixed line indoors, with just one phone.

The long-term plans include rolling out a High-Speed Downlink Packet Access (HSPDA) upgrade to its network. Cingular has said that it expects to implement the high-speed 3G upgrade across most of its network in the U.S. by the end of 2006.

Overall, Cingular is planning a unified network architecture that can support a range of IP-based services for both packet- and circuit-switched networks, and employ a range of different wireless and fixed access mechanisms. This involves a major software upgrade at the network core and requires better performance across the entire cellular access network before it can be fully implemented. This is why many analysts and industry figures don't believe that full IMS implementations will be in place before 2007 or 2008.

Cingular's plan is to have a mobile phone with a UMA client and a SIP (session initiation protocol) client on board. The UMA would handle the moves between the cellular network and public access hotspots. When the user gets home, the UMA client hands off to the SIP client, which enables voice over the wired network. The phone acts like a cordless unit with a wireless LAN connection between the handset and a base unit that is plugged into the PSTN.

Such a service could allow Cingular and its fixed line parents -- BellSouth Corp. (NYSE: BLS) and SBC Communications Inc. (NYSE: SBC) -- to offer some fairly sophisicated fixed/mobile bundling options to potential subscribers. (See BellSouth Trials Convergence.)

Astute readers will note that Cingular's FMC strategy is very similar to the "Fusion" project -- formerly known as "BluePhone" -- being developed by BT Group plc (NYSE: BT; London: BTA) on the other side of the pond. (See BT Unveils FMC Service.)

Indeed, as Roger Entner, VP of wireless telecoms at research firm Ovum Ltd. notes, Cingular has joined the BluePhone consortium, a group of vendors formed in May 2004 to develop the technology for BT Fusion. The body is lead by Alcatel (NYSE: ALA ; Paris: CGEP:PA) and includes Ericsson AB (Nasdaq: ERICY), Lucent Technologies Inc. (NYSE: LU ), and Motorola Inc. (NYSE: MOT ).

"I think they joined too late to influence much of the decision-making process," Entner notes.

But Cingular's membership of the group reinforces the notion that the carrier will use UMA as the basis for its initial FMC strategy, since this is the path BT and the consortium have already laid out.

UMA was initially devleoped by startup Kineto Wireless Inc. but has garnered fairly widespread industry support from infrastruture vendors and handset makers -- including Alcatel, Motorola, and Nokia Corp. (NYSE: NOK ) -- over the last year. (See Kineto Phones It In andUMA Gains Ground.).

"They’re moving fast on this now," says one source working with the company, adding that Cingular wants to edge out T-Mobile USA, which has been looking at a similar strategy but has hasn't moved too far forward with it yet.

But Cingular's major rival in the U.S. cellular scene, Sprint Nextel Corp. (NYSE: S ), still claims it will be first with a fully integrated FMC system in the U.S. (See Convergence Is Coming to CTIA.)

"We've had IMS underway for some time and hold the lead in North American implementation," a Sprint spokesman says.

— Dan Jones, Site Editor, Unstrung