Since 2016, I've been working on a way to transmit digital TV in the 900 MHz Part 15 band. The main focus is on reliability, because ATSC fails miserably in that department. The second focus is on unlicensed operation, because broadcasting is a near-monopoly.
The format officially consists of a 1 Mbit data stream containing VP9 video at about 900 kbits and Opus audio at 48 kbits. Opus is extremely resilient and can withstand high loss, similar to analog TV's sound. It also sounds amazing at that bitrate. Other services, such as audio or data, could be conveyed as well.
My proposed standard is called UTSC. The acronym means nothing, officially. It is designed to be expansible like WAV, meaning that new features can be added without breaking compatibility with the first receivers. My current research suggests that I can fit 32 channels in the band in any given area.
The standard can accommodate any video codec, resolution, and frame rate in theory, but VP9 960x540 @ 30.000 fps is suggested.
I finalized the standard today and I'm documenting it here as proof that I devised this first. If someone else claims to have been first, you can verify with the Wayback Machine that no site before this date carried this info.
The encoder and air interface are proprietary and will not be released yet. However, I'm planning to release the packet format for public review. I'm submitting it privately to Foxx, Corrosive, and wordsun for a pre-review.