It was 1 way or 2 way radio back in the day, now wiki says it’s 1 way video stream with 2 way voice.
From wiki... “ Each student typically spends one hour per day receiving group or individual lessons from the teacher, and the rest of the day working through the assigned materials with a parent, older sibling or a hired home-stay tutor.”
These children might develop an amazing self-sufficiency or some advanced self-organization skills (if they manage to deal with it well). I often wonder how I myself would have turned out, if I had been taught this way or similarly.