NeoGaf user ekim has made a compilation of information about recent Federal Communications Commission (FCC) filings.
The FCC is an independent agency that regulates interstate communications by radio, television, wire, satellite, and cable in the U.S. The agency works towards six goals in the areas of broadband, competition, the spectrum, the media, public safety and homeland security, and modernizing itself. In other words, the FCC must approve every device that includes any wireless data transmission technology that is to be be sold in the U.S.
Microsoft is currently testing a wireless chip for FCC approval. The wireless chip is rumoured to be part of an updated console, currently known as the "Host".
The external photos and user manual will not be available until June 25, 2016- which, coincidentally, is just after E3 2016.
ekim also found that the chip was tested on two separate consoles with different availability dates. One FCC model number references the Xbox One, but the second model did not.
Given the expiry date on the private photos, it could be inferred that one or both of these consoles will be revealed at E3 2016. It is likely that one console is a revised Xbox One, and the other is whatever Microsoft is planning neXt. (Get it? Like the rumoured Xbox neXt?)