U.S. telecom operator T-Mobile is set to double the speed of its 4G network to the extent of 42 Mbps as part of its preparation to introduce an array of new devices on its network.

The carrier, which is being acquired by AT&T, said its customers in Las Vegas, New York and Orlando, Fla., will be the first in the country to experience the increased 4G speed. It will soon speed up the network similarly in New York’s Long Island as well as northern New Jersey.

By mid-year, T-Mobile (News - Alert) expects 140 million Americans in 25 markets to have access to increased 4G speeds.

“We’re doubling our maximum speed in more than two dozen markets, starting with three important cities today,” said Neville Ray (News - Alert), chief technology officer, T-Mobile USA.

At this week’s CTIA, the carrier also unveiled plans to introduce this year 25 new devices –– smartphones, tablets and mobile broadband products –– that run on its 4G Network.

The devices will allow customers to video chat, surf the Web, download and stream high-definition (HD) and 3D video, and use their favorite applications.

  “In fact, data traffic on T-Mobile’s network is quadrupled year-over-year. With smartphone data plans starting at just $10 a month — and a growing line-up of innovative 4G smartphones and tablets — we are meeting the demand for mobile data, and making it easier than ever for customers to step up to 4G,” said Cole Brodman, chief marketing officer, T-Mobile USA.

T-Mobile this week introduced the G2x with Google (News - Alert). The latest 4G smartphone, G2x is powered by dual-core processor, and has preloaded video games.

 Manufactured by LG, the G2x is powered by Android (News - Alert) 2.2 and comes equipped with an 8-megapixel rear-facing camera with LED flash and a front-facing camera paired with video chat powered by Qik.