T-Mobile's TV telephony news has been released since 2017 and a new FCC set-top box eventually implies an imminent launch. We saw from Variety, the archive contains a PDF user manual that calls the device "T-Mobile Mini" and has some photos of the streaming box. The deposit was made by Kaonmedia, the company that set up decoders for Layer3 TV, a small cable TV company acquired by T-Mobile earlier this year.
The back of the device displays HDMI input and output ports to allow connection for additional devices such as streaming boxes and game consoles. There is also an Ethernet port and a USB port for software upgrades, but there is no coaxial port, which suggests it will be a box only on the internet. The device will feature Wi-Fi 802.11ac and Bluetooth LE, probably for the remote to be transferred.
We do not know too much about what T-Mobile plans for its TV service but the company has announced during its recent earnings that it is still on track to launch the product by the end of this year.