T-Mobile USA said late Monday it has hired Ericsson and Nokia Siemens to expand its HSPA+ service and construct its new LTE network.

The infrastructure vendors supplied equipment for T-Mobile’s existing network along with Nortel, now part of Ericsson.

For T-Mobile’s new network, the two companies will roll out equipment compatible with LTE-Advanced Release 10 at 37,000 cell sites as part of the $4 billion project.

“With these partners on board and the AT&T AWS spectrum secured, we’re on track to enhance our 4G experience this year and deliver nationwide LTE in 2013," T-Mobile CTO Neville Ray said.

T-Mobile said it expects to be the first North American operator to deploy what it called "antenna integrated radios," designed to speed up construction of the network and address site loading.

Flush with a $3 billion breakup fee from the doomed AT&T merger, T-Mobile announced its infrastructure vendors less than three months after it decided to deploy LTE. Its LTE service is scheduled to go live in 2013 and uses AT&T AWS spectrum handed over to T-Mobile as part of the breakup fee.

Clearwire unveiled its TD-LTE plans last fall but has yet to announce suppliers for its network. It has said it is working to negotiate vendor financing.

AT&T’s AWS licenses, transferred to T-Mobile just last week, give it up to 20 MHz of spectrum for its LTE network in three-quarters of its top 25 markets. Most of its remaining markets will run on 10 MHz of spectrum.

T-Mobile is in the process of re-farming some of its 1900 MHz PCS spectrum for continued expansions of its HSPA+ service. The operator said it will launch HSPA+ in a "large number" of additional markets by the end of this year.

"Rolling out 4G HSPA+ services in the 1900 MHz band will also provide customers with the ability to use a broader range of devices, including the iPhone, on T-Mobile’s 4G network," it said.

Trials of its network modernization project indicated a 33 percent increase in HSPA+ data speeds and improved in-building coverage, the operator said. Its HSPA+ network currently covers more than 220 million people.

T-Mobile yesterday lit up its HSPA+ service in Hattiesburg, Miss., and Madison, Wis., and turned on its dual-carrier HSPA+ network in Fayetteville and Little Rock, Ark.; Lake Charles, La.; and Springfield, Mo.

Nokia Siemens will upgrade T-Mobile's GSM and HSPA+ core and radio access infrastructure in "key markets" and provide LTE equipment. T-Mobile will use Nokia Siemens’ evolved packet core platform, including its Flexi network server and network gateway and its Flexi multi-radio 10 base station.

In addition to the equipment, T-Mobile will use Nokia Siemens’ NetAct network management system, self-organizing network technology and a separate multi-vendor performance manager. Other services provided by Nokia Siemens include network planning, optimization and implementation.

Ericsson will install radio, tower and switch room equipment. It also will provide a number of services, including installation, commissioning, integration, migration and systems integration. T-Mobile plans to use Ericsson's antenna integrated radio, or AIR, which combines the antenna and radio into a single unit.