I've been searching the web for an answer to my question, but haven't been succesful. I'm hoping better informed folks here can provide some insight. In theory, if over the air broadcasters were to start using MPEG-4 compression, up to how many channels could they broadcast in 1080p/60fps? I know some folks aren't fans of multicasting, but I've been enjoyed it emmensely since my family made the switch to digital. I'd like to know more about possible advances.