The HTC One S, X and V

The Mobile World Congress, an annual gadgetfest held in Barcelona, has kicked off and come with a few major product announcements.

On Sunday, HTC announced a new line of phones collectively known as the HTC One series: the HTC One X, HTC One S and the HTC One V.

All are running Google’s latest Android operating system, Ice Cream Sandwich. The phones also all come with integrated access to the cloud-based locker service, Dropbox. HTC One owners will have 25 GB of free space on Dropbox for two years.

The HTC One X has a 1.5 GHz dual-core processor, a 4.7-inch screen and an 8 MP camera and will run on 4G LTE networks. It also has benefited from HTC’s partnership with Beats, and will have “enhanced sound,” according to a press release from HTC.

AT&T announced Sunday that it will carry the phone in the “coming months,” the carrier’s first phone with Beats Audio. AT&T has not yet named a release date or price.

The HTC One S is slightly smaller than the One X at 4.3 inches but is also packed with features. In addition to Beats Audio, the phone also has an 8MP camera and dual-core processor. The phone will be available this spring from T-Mobile, HTC’s release said.

Finally, the HTC One V rounds out the line. This phone is being marketed as the “essential smartphone,” and has less-impressive specs than its siblings. The phone has a 3.7-inch display 5 MP rear-camera and no front-facing camera.

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