Simulcast
Simulcast (a portmanteau of "simultaneous broadcast") is the broadcasting of programs or events across more than one resolution, bitrate or medium, or more than one service on the same medium, at exactly the same time (that is, simultaneously). For example, BBC Radio 4 is simulcast on both FM and DAB. Likewise, the BBC's Prom concerts were formerly simulcast on both BBC Radio 3 and BBC Television.