The Federal Communications Commission has approved what could be the first phone in the U.S. market compatible with a Long Term Evolution network for high-speed, 4G data. But there are more questions than answers about the handset and when it will reach consumers.

About all that is known so far is that the Samsung SCH-r900 will be offered by MetroPCS, use the standard CDMA voice network as a backup when 4G is unavailable, be Wi-Fi and Bluetooth capable, and be able to browse the Internet and download music. It will operate at the spectrum of 1700/1900 megahertz.

When South Korea-based Samsung announced the phone at the CTIA Wireless show in March, it said "Samsung Mobile's commercial LTE network products leverage years of 4G orthogonal frequency division multiple access (OFDMA) commercial network experience and have flexible bandwidth support of 1.4 to 20 MHz standards."

Details Are Secret

Neither Samsung nor MetroPCS has revealed which operating system will power the SCH-r900, how much memory it will have, or what kind of processor, keyboard and camera it will use.

"It's all being shrouded in secrecy," said IDC Research wireless analyst Ramon Llamas, who has tried in vain to get more details about the phone. "They've been tight-lipped about this. I've tried numerous ways to get some read on it, but we still don't know if it's a feature phone or a smartphone, or where the coverage will be. Since it's not coming out until December, why tip your hand now?"

One of the biggest questions, Llamas said, is how MetroPCS -- known for flat-rate voice-calling plans -- will handle data-hungry 4G users. "This is a totally different ball of wax," said Llamas. "How do you price a phone that is all data?"

Richardson, Tex.,-based MetroPCS, formerly General Wireless, is the fifth largest cellular carrier in the United States...