Together, the tablets give AT&T some Windows 8 fighting power as well as bring customers "the convenience of a tablet with productivity of a PC," the company said in a press release.
The deal for both tablets is exclusive, at least for the 2012 holiday shopping season, AT&T continued.
Pricing wasn't revealed and neither was an exact release date for either tab, but AT&T assured both would be available at AT&T retail stores and online "in time for the holidays."
Six of one, half dozen of the other
TechRadar got its hands on both these tabs at IFA 2012, giving us a hearty look at what these slates have in store.
The 11.6-inch Ativ comes with a detachable keyboard-docking system that allows for easy clamshell notebook to tablet conversion.
Its Intel Clover Trail 1.5GHz dual core processor and 64GB of internal storage are nothing to scoff at, though at 9.9 millimeters thick, it's not as thin as the Vivo Tab RT's older brother, the Vivo Tab and its 8.7 millimeter width.
On the other hand, the Windows 8 RT Vivo will be compatible with AT&T's 4G LTE network.
The Vivo's got 32GB of storage and Nvidia's quad-core Tegra 3 TE processor with a screen resolution of 1366 x 768, a spec that we found makes Windows 8 look great.
The 10.1-inch multi-touch Super IPS display slate comes with Microsoft Office Home and Student 2013 RT Preview Edition.
According to Chris Penrose, senior vice president, AT&T Emerging Devices, customers can connect the tabs to 4G LTE for as low as $10 a month on one of the carrier's Mobile Share plans.
One hint of a release is that Windows 8 is set to debut Oct. 26, so AT&T could plan to launch these products on or soon after that day.
TechRadar will update this story with more details as they emerge, so stay tuned for all the AT&T goodness.
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Michelle was previously a news editor at TechRadar, leading consumer tech news and reviews. Michelle is now a Content Strategist at Facebook. A versatile, highly effective content writer and skilled editor with a keen eye for detail, Michelle is a collaborative problem solver and covered everything from smartwatches and microprocessors to VR and self-driving cars.