We've already seen pictures (and video) of the water-defiant Samsung Galaxy S 4 Active, so despite its unannounced status, it's difficult to refute its existence. Fortunately, we're starting to get even more evidence that its launch is rapidly approaching, as an AT&T-compliant version of the rugged device -- the SGH-I537 to be exact -- has made its way through the federal approval process. As you may already know, this is by no means any guarantee that it will be picked up by the mammoth GSM operator, but its inclusion of the same four LTE bands found in most current AT&T smartphones (2, 4, 5 and 17, if you're curious) is a pretty positive indicator. We're still in the woods as to the exact specs, but we're bracing ourselves for a midrange handset that doesn't sport quite the same oomph as its original namesake; that said, it appears to at least be a slick-looking rugged device, which is a rarity these days.