Sprint Nextel plans to use a single core infrastructure for all its networks, including the WiMax wireless broadband system coming later this year, and to capture information that will help third parties customize services.

A common optical backbone, IP network, cell-site infrastructure, and IMS (Internet Protocol Multimedia Subsystem) will serve all of the carrier's networks, said Ben Vos, vice president of core technologies at Sprint, in a speech at the VON.x conference Tuesday in San Jose, Calif. The carrier will also give third-party software developers and content owners access to that infrastructure through common APIs.

All this is necessary to deliver a consistent experience to subscribers using multiple devices, Vos said.

"You need to have a unified service architecture at the heart of the network that is agnostic of those underlying technologies at the edge," Vos said.

For consumers, it means they should have a consistent type of experience when they access Sprint's services from a mobile phone, a PDA, and a laptop computer, for example.

In building this single architecture, the ailing Sprint is taking on yet another ambitious project on top of its nationwide WiMax rollout. Many service providers are working on building overarching service platforms using IMS and SIP (Session Initiation Protocol), but those technologies are still in their infancy and there are numerous legacy systems already in place. Sprint has three separate networks, counting CDMA (Code-Division Multiple Access), the iDEN cellular network from Nextel and WiMax. Meanwhile, the third-place U.S. mobile operator has suffered numerous subscriber complaints about its customer service and billing, according to news reports.

Along with the common service infrastructure and APIs, Sprint wants to make information about subscribers available to developers so they can offer customized services to individual subscribers, Vos said. For example, service developers could access a customer's location or presence status to present valuable real-time information, he told reporters after the speech. These types of information could also be used to provide detailed billing for third-party content providers on a Sprint bill. Ultimately, information about the people driving along a particular stretch of highway could be used to control what's displayed on a digital billboard, Vos said.

Vos also gave some information about the emerging WiMax service, called Xohm, though the company is holding back in a few areas until it releases financial results for the first quarter of the year.

The soft launch of Xohm in Chicago and the Baltimore-Washington, D.C., area is under way, and the wide-area wireless network is still on track for a commercial launch in the second quarter, he said. But Sprint is holding off until the first-quarter report to say how much it will invest and how widely the network will be rolled out this year. It had said last year the service would reach 100 million U.S. residents by the end of 2008.

Despite its continuing high hopes for a wide range of devices, and partner Intel's disclosure Tuesday that more than a third of the portable devices coming in the second quarter on its Atom Centrino platform will include WiMax, Sprint is focusing first on modems for laptops and for home broadband, Vos said. It also is concentrating on non-real-time applications, and on nomadic use -- using the service in one place, then moving to another and starting up again -- rather than true mobile use in a car or train. For example, mobile VoIP on WiMax requires more work on call handoffs, he said.