Just curious because I don’t see people talk about it a lot.
Bandwidth is cheaper from the tower since the signal is the “same” for each client and it can then be distributed over a wide area. You send the “DRM” (Just a fancy encryption key) over the network since it’s relatively small and likely unique to each device (probably fingerprinting the device ids to the content invisibily in case of piracy).
Multicast is a thing, though it doesn’t seem to be widespread. That would make a lot more sense than this weird DRM broadcast system.
Multicast still requires more expensive less widespread bandwidth than sending out analog signals ota & shooting off a few packets of encryption information every now and then. US infrastructure has rapidly improved over the past few years, but we’re still a farcry from anything robust and reliable enough to serve the people benefiting from this type of content.