Source: http://www.engadget.com/2013/04/26/dell-outfits-xps-10-with-lte-asks-100-for-the-privilege/
The FCC told us that an LTE ready version of the Dell XPS 10 was coming, but there's nothing like official confirmation: it's here, and it runs on AT&T. Dell officially announced the variant's availability on its community blog, identifying the radio the feds uncovered as a Qualcomm Gobi modem, a natural fit for the tablet's 1.5 GHz Snapdragon S4 CPU. The LTE option is only available for the device's 64GB configuration, and adds $100 to the tablet's total purchase price. Nobody said getting LTE on your Windows RT slab was cheap.
Via: CNET
Source: Dell