According to numerous recent reports, Sony has at least one high-end phone and a top-notch tab prepped for February introductions, both of which may have received FCC’s blessing with US-friendly 4G LTE support.

xperia tablet z xperia z Mystery Sony phone/tablet pair swings by FCC with US LTE support, signs point at Sirius and Castor

What comes after the Xperia Z1? A full-on Z2 upgrade, or a minor rehash, to be dubbed Z1 Plus, Z1 Ultra or something along those lines? No one knows for sure. What’s certain is the “Sirius”, aka D6503, is officially FCC approved and thus looming large on the horizon.

The federal agency’s certification docs label the handheld as the Sony PM-0740-BV, which is confusing as hell, but there’s little doubt we’re dealing with this Sirius thing. Interestingly, it carries LTE speeds on a number of different bands, including 2, 4, 13 and 17.

As such, activating it on T-Mobile, AT&T and Verizon and taking advantage of the trio’s full range of connectivity goodness should be easy as pie. Mind you however, that doesn’t necessarily mean all three carriers (or any one of them) shall sell the Sirius directly, with subsidies and value plans. It merely means, once it’s out, you can score it, say, in Japan, bring it to the States and party like it’s 2014 connectivity-wise.

Sony D6503 2 Mystery Sony phone/tablet pair swings by FCC with US LTE support, signs point at Sirius and Castor

The FCC reveals little else on the D6503: Wi-Fi b/g/n/a/ac, Bluetooth 4.0, GSM and W-CDMA support. Thankfully, there are other sources to fill in the blanks, so expect the 5.2-inch giant with a Full HD display, quad-core MSM8974-AB Snapdragon 800 chip, 3 GB RAM, Android 4.4 KitKat and 20.7 MP camera.

Meanwhile, a second FCC approval seems to confirm the existence of an Xperia Tablet Z follow-up, known on the inside as the “Castor” or TM-0043-BV. Like the Sirius, the probable 10-incher hauls LTE on a heap of frequencies, plus Wi-Fi and Bluetooth 4.0.

A backing from any of America’s big four wireless service providers is even less likely for the Castor, expected out on NTT DoCoMo and KDDI in Japan sometime in Q2. So no earlier than April. Specs? Android 4.4 KitKat and quad-core S800 SoC is all we have at the moment.

Sources: Phone Arena, Ameblo (1), (2), FCC (1), (2)