[1] https://www.mikrocontroller.net/topic/232846
[2] https://apollo.open-resource.org/mission:log:2014:08:08:darc...
I once worked for a radio station that made 90% of its revenue from carrying data feeds on subcarriers, and not from main music programs.
Because of the geographic location and size of the signal, it was a vital link between two major cities before planting fiber optic lines became cheap.
Just stream me the weather, traffic, text msgs & some news stories that a TTS can read out to me.
Won’t work well for streaming a video but for most of us generally on wifi except out-of-doors, I can live with it.
SiriusXM is half way there. It supplies weather and traffic as a data service.
I knew about traffic from way back when the service was new, and found out Sirius Marine Weather a few years ago, but recently rented a car that also had Sirius-delivered weather and traffic alerts.
It was very useful as I was deeply off the grid (no radio stations at all during the day and AM skywave only at night), and the car alerted me to nearby lightning and thunderstorms that I couldn't see because of the terrain.
All gone now, it's all 4G.
A few hours drive north of me is Mormond Hill, formerly the site of one part of the North Atlantic Radio System[2]. This used tropospheric scattering and huge dish aerials to communicate radar data down to RAF Fylingdales. There's not much up there now. There were various BT microwave links for offshore oil installations and assorted UHF and VHF links up, but the masts are pretty bare now.
[1] https://en.wikipedia.org/wiki/Meteor_burst_communications
[2] https://en.wikipedia.org/wiki/North_Atlantic_Radio_System
See Minitel from France and Telidon from Canada as other examples of data systems riding on analogue TV and/or POTS telephone systems.